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Miller E, Lee HW, Abzhanov A, Evers SW. The topological organization of the turtle cranium is constrained and conserved over long evolutionary timescales. Anat Rec (Hoboken) 2024; 307:2713-2748. [PMID: 38102921 DOI: 10.1002/ar.25356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/30/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023]
Abstract
The cranium of turtles (Testudines) is characterized by the secondary reduction of temporal fenestrae and loss of cranial joints (i.e., characteristics of anapsid, akinetic skulls). Evolution and ontogeny of the turtle cranium are associated with shape changes. Cranial shape variation among Testudines can partially be explained by dietary and functional adaptations (neck retraction), but it is unclear if cranial topology shows similar ecomorphological signal, or if it is decoupled from shape evolution. We assess the topological arrangement of cranial bones (i.e., number, relative positioning, connections), using anatomical network analysis. Non-shelled stem turtles have similar cranial arrangements to archosauromorph outgroups. Shelled turtles (Testudinata) evolve a unique cranial organization that is associated with bone losses (e.g., supratemporal, lacrimal, ectopterygoid) and an increase in complexity (i.e., densely and highly interconnected skulls with low path lengths between bones), resulting from the closure of skull openings and establishment of unusual connections such as a parietal-pterygoid contact in the secondary braincase. Topological changes evolutionarily predate many shape changes. Topological variation and taxonomic morphospace discrimination among crown turtles are low, indicating that cranial topology may be constrained. Observed variation results from repeated losses of nonintegral bones (i.e., premaxilla, nasal, epipterygoid, quadratojugal), and changes in temporal emarginations and palate construction. We observe only minor ontogenetic changes. Topology is not influenced by diet and habitat, contrasting cranial shape. Our results indicate that turtles have a unique cranial topology among reptiles that is conserved after its initial establishment, and shows that cranial topology and shape have different evolutionary histories.
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Affiliation(s)
- Eve Miller
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Berkshire, UK
- Natural History Museum, London, UK
| | - Hiu Wai Lee
- Department of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Arkhat Abzhanov
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Berkshire, UK
- Natural History Museum, London, UK
| | - Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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2
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Werneburg I, Preuschoft H. Evolution of the temporal skull openings in land vertebrates: A hypothetical framework on the basis of biomechanics. Anat Rec (Hoboken) 2024; 307:1559-1593. [PMID: 38197580 DOI: 10.1002/ar.25371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 01/11/2024]
Abstract
The complex constructions of land vertebrate skulls have inspired a number of functional analyses. In the present study, we provide a basic view on skull biomechanics and offer a framework for more general observations using advanced modeling approaches in the future. We concentrate our discussion on the cranial openings in the temporal skull region and work out two major, feeding-related factors that largely influence the shape of the skull. We argue that (1) the place where the most forceful biting is conducted and (2) the handling of resisting food (sideward movements) constitute the formation and shaping of either one or two temporal arcades surrounding these openings. Diversity in temporal skull anatomy among amniotes can be explained by specific modulations of these factors with different amounts of acting forces which inevitably lead to deposition or reduction of bone material. For example, forceful anterior bite favors an infratemporal bar, whereas forceful posterior bite favors formation of an upper temporal arcade. Transverse forces (inertia and resistance of seized objects) as well as neck posture also influence the shaping of the temporal region. Considering their individual skull morphotypes, we finally provide hypotheses on the feeding adaptation in a variety of major tetrapod groups. We did not consider ligaments, internal bone structure, or cranial kinesis in our considerations. Involving those in quantitative tests of our hypotheses, such as finite element system synthesis, will provide a comprehensive picture on cranial mechanics and evolution in the future.
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Affiliation(s)
- Ingmar Werneburg
- Paläontologische Sammlung, Fachbereich Geowissenschaften, Eberhard Karls Universität, Tübingen, Germany
- Senckenberg Center for Human Evolution and Palaeoenvironment, Eberhard Karls Universität, Tübingen, Germany
| | - Holger Preuschoft
- Funktionelle Morphologie im Anatomischen Institut, Ruhr-Universität Bochum, Bochum, Germany
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3
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Evers SW, Al Iawati Z. Digital skull anatomy of the Oligocene North American tortoise Stylemys nebrascensis with taxonomic comments on the species and comparisons with extant testudinids of the Gopherus- Manouria clade. SWISS JOURNAL OF PALAEONTOLOGY 2024; 143:12. [PMID: 38455968 PMCID: PMC10914918 DOI: 10.1186/s13358-024-00311-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/12/2024] [Indexed: 03/09/2024]
Abstract
The anatomy of North American tortoises is poorly understood, despite a rich fossil record from the Eocene and younger strata. Stylemys nebrascensis is a particularly noteworthy turtle in this regard, as hundreds of specimens are known from Oligocene deposits, and as this species is one of the earliest fossil turtles to have been described in the scientific literature. Since its initial description based on a shell, many specimens with more complete material have been referred to Stylemys nebrascensis. Here, we review and confirm the referral of an important historic specimen to Stylemys nebrascensis, which includes shell, non-shell postcranial, and skull material. This allows us to document unique skull features of Stylemys nebrascensis (e.g., an unusual 'poststapedial canal' that connects the posterior skull surface with the cavum acustico-jugulare) and to refer another well-preserved skull to the species. Based on computed-tomography scanning of these two skulls, we provide a detailed description of the cranial and mandibular osteology of Stylemys nebrascensis. Stylemys nebrascensis has a combination of plesiomorphic skull characteristics (e.g., retention of a medial jugal process) and derived traits shared with extant gopher tortoises (e.g., median premaxillary ridge) that suggest it may be a stem-representative of the gopher tortoise lineage. This supports the hypothesis that extant and fossil tortoises from North America form a geographically restricted clade that split from Asian relatives during the Paleogene.
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Affiliation(s)
- Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Zahra Al Iawati
- GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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4
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Gray JA, Gignac PM, Stanley EL. The first full body diffusible iodine-based contrast-enhanced computed tomography dataset and teaching materials for a member of the Testudines. Anat Rec (Hoboken) 2024; 307:535-548. [PMID: 37409685 DOI: 10.1002/ar.25282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/08/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
Diffusible iodine-based contrast-enhanced Computed Tomography (diceCT) is now a widely used technique for imaging metazoan soft anatomy. Turtles present a particular challenge for anatomists; gross dissection is inherently destructive and irreversible, whereas their near complete shell of bony plates, covered with keratinous scutes, presents a barrier for iodine diffusion and significantly increases contrast-enhanced CT preparation time. Consequently, a complete dataset visualizing the internal soft anatomy of turtles at high resolution and in three dimensions has not yet been successfully achieved. Here we outline a novel method that augments traditional diceCT preparation with an iodine injection technique to acquire the first full body contrast-enhanced dataset for the Testudines. We show this approach to be an effective method of staining the soft tissues inside the shell. The resulting datasets were processed to produce anatomical 3D models that can be used in teaching and research. As diceCT becomes a widely employed method for nondestructively documenting the internal soft anatomy of alcohol preserved museum specimens, we hope that methods applicable to the more challenging of these, such as turtles, will contribute toward the growing stock of digital anatomy in online repositories.
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Affiliation(s)
- Jaimi A Gray
- Florida Museum of Natural History, Gainesville, Florida, USA
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Ingle DN, Perez E, Porter ME, Marshall CD. Feeding without teeth: the material properties of rhamphothecae from two species of durophagous sea turtles. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221424. [PMID: 37090964 PMCID: PMC10113817 DOI: 10.1098/rsos.221424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/27/2023] [Indexed: 05/03/2023]
Abstract
The feeding apparatus of sea turtles comprises cornified keratinous rhamphothecae overlaying a bony rostrum. Although keratin is less stiff than the enamel of toothed animals, certain species of sea turtles are capable of withstanding large forces when feeding on hard prey. We aimed to quantify the mineral density, water content and compressive mechanical properties of rhamphothecae from two durophagous species: loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) sea turtles. Since loggerheads theoretically produce the greater bite forces of these two species, we predicted that keratin from their rhamphothecae would have a greater mineral density and be stiffer, stronger and tougher compared with Kemp's ridley sea turtles. We found that total water weight of hydrated specimens (20%) was consistent between species. Rhamphotheca mineral density ranged between 0 and 0.069 g cm-3; loggerheads had significantly greater mineral density compared with Kemp's ridleys, for which several specimens had no mineral detected. Despite the greater mineral density in loggerheads, we found no significant difference in Young's modulus, yield strength or toughness between these species. In addition to mineral density, our findings suggest that other material components, such as sulfur, may be influencing the material properties of keratin from sea turtle rhamphothecae.
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Affiliation(s)
- Danielle N. Ingle
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
- Gulf Center for Sea Turtle Research, Texas A&M University, College Station, TX 77843, USA
| | - Eliza Perez
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
| | - Marianne E. Porter
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Christopher D. Marshall
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
- Gulf Center for Sea Turtle Research, Texas A&M University, College Station, TX 77843, USA
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USA
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Anatomical Description of Loggerhead Turtle ( Caretta caretta) and Green Iguana ( Iguana iguana) Skull by Three-Dimensional Computed Tomography Reconstruction and Maximum Intensity Projection Images. Animals (Basel) 2023; 13:ani13040621. [PMID: 36830407 PMCID: PMC9951731 DOI: 10.3390/ani13040621] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/30/2023] [Accepted: 02/04/2023] [Indexed: 02/12/2023] Open
Abstract
The growing interest in reptiles has posed a challenge to veterinary clinicians due to the lack of a standardized system to perform anatomical studies similar to those used for dogs and cats. In this paper, we have attempted to describe, employing computed tomography and subsequent three-dimensional reconstructions, the normal anatomical features that comprise the skulls of two species of reptiles: the loggerhead turtle (Caretta caretta) and the green iguana (Iguana iguana). Computed tomography (CT) and subsequent image processing allowed the identification of the bony structures that comprise the head of these species. As a result, and based on previous articles, we propose the most significant anatomical differences and similarities between these species.
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Tokita M, Sato H. Creating morphological diversity in reptilian temporal skull region: A review of potential developmental mechanisms. Evol Dev 2023; 25:15-31. [PMID: 36250751 DOI: 10.1111/ede.12419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 01/13/2023]
Abstract
Reptilian skull morphology is highly diverse and broadly categorized into three categories based on the number and position of the temporal fenestrations: anapsid, synapsid, and diapsid. According to recent phylogenetic analysis, temporal fenestrations evolved twice independently in amniotes, once in Synapsida and once in Diapsida. Although functional aspects underlying the evolution of tetrapod temporal fenestrations have been well investigated, few studies have investigated the developmental mechanisms responsible for differences in the pattern of temporal skull region. To determine what these mechanisms might be, we first examined how the five temporal bones develop by comparing embryonic cranial osteogenesis between representative extant reptilian species. The pattern of temporal skull region may depend on differences in temporal bone growth rate and growth direction during ontogeny. Next, we compared the histogenesis patterns and the expression of two key osteogenic genes, Runx2 and Msx2, in the temporal region of the representative reptilian embryos. Our comparative analyses suggest that the embryonic histological condition of the domain where temporal fenestrations would form predicts temporal skull morphology in adults and regulatory modifications of Runx2 and Msx2 expression in osteogenic mesenchymal precursor cells are likely involved in generating morphological diversity in the temporal skull region of reptiles.
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Affiliation(s)
- Masayoshi Tokita
- Department of Biology, Faculty of Science, Toho University, Funabashi, Chiba, Japan
| | - Hiromu Sato
- Department of Biology, Faculty of Science, Toho University, Funabashi, Chiba, Japan
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Rowe AJ, Rayfield EJ. The efficacy of computed tomography scanning versus surface scanning in 3D finite element analysis. PeerJ 2022; 10:e13760. [PMID: 36042861 PMCID: PMC9420411 DOI: 10.7717/peerj.13760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/29/2022] [Indexed: 01/17/2023] Open
Abstract
Finite element analysis (FEA) is a commonly used application in biomechanical studies of both extant and fossil taxa to assess stress and strain in solid structures such as bone. FEA can be performed on 3D structures that are generated using various methods, including computed tomography (CT) scans and surface scans. While previous palaeobiological studies have used both CT scanned models and surface scanned models, little research has evaluated to what degree FE results may vary when CT scans and surface scans of the same object are compared. Surface scans do not preserve the internal geometries of 3D structures, which are typically preserved in CT scans. Here, we created 3D models from CT scans and surface scans of the same specimens (crania and mandibles of a Nile crocodile, a green sea turtle, and a monitor lizard) and performed FEA under identical loading parameters. It was found that once surface scanned models are solidified, they output stress and strain distributions and model deformations comparable to their CT scanned counterparts, though differing by notable stress and strain magnitudes in some cases, depending on morphology of the specimen and the degree of reconstruction applied. Despite similarities in overall mechanical behaviour, surface scanned models can differ in exterior shape compared to CT scanned models due to inaccuracies that can occur during scanning and reconstruction, resulting in local differences in stress distribution. Solid-fill surface scanned models generally output lower stresses compared to CT scanned models due to their compact interiors, which must be accounted for in studies that use both types of scans.
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Affiliation(s)
- Andre J. Rowe
- School of Earth Sciences, University of Bristol, Bristol, United Kingdom
| | - Emily J. Rayfield
- School of Earth Sciences, University of Bristol, Bristol, United Kingdom
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9
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Horvath-Pereira BDO, Paulini F, Sotelo MO, Leardini EG, Tavares DC, Almeida GHDR, da Silva Júnior LN, Pinho LBM, Miglino MA, Araujo MS. Case report: An innovative non-invasive technique to manage shell injuries in C. carbonarius. Front Vet Sci 2022; 9:930419. [PMID: 35982919 PMCID: PMC9379249 DOI: 10.3389/fvets.2022.930419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/11/2022] [Indexed: 11/19/2022] Open
Abstract
Shell fractures are one of the most traumatic and recurrent injuries observed in chelonians during clinical practice. The most common causes of fractures are falling, being run over by automobiles, being burned, and wild animal bites. Epoxy, acrylic resin, polyester, fiber-grass blanket, and screw fixation are among the current techniques used to treat fractures. Regarding the difficulty of fracture repair in the carapace, this case report aimed to report a procedure that is effective, less time-consuming, accessible, affordable, and safe for shell fractures in C. carbonarius. During the physical examination, the animal showed two fractures, in the dorsal region of the carapace and right lateral side of the bridge, with subcutaneous tissue exposure and loss of a small piece of dorsocranial carapace. To treat these injuries, the animal was submitted to a resin application. The procedure consists of using ethyl-cyanoacrylate associated with sodium bicarbonate, which produces a more resistant resin that is bactericidal, non-toxic, and easy to apply in a low surgery time compared to the common methods used to fix shell fractures. The resin application was successfully done, and the animal was under care for a month after the fracture reduction. It was observed that the treatment was effective, presenting reduction of the fracture. A month after the procedure, the animal showed no intercurrence. Three years after the procedure, the animal still presents part of the material still fixed to the shell, normal growth, without interference in locomotor capacity. This resin proved to be an innovative and promising alternative way to treat fractures, suggesting the development of new non-invasive approaches for several tissues and different animal species.
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Affiliation(s)
| | - Fernanda Paulini
- Department of Physiological Sciences, Institute of Biological Sciences, University of Brasilia, Brasília, Brazil
| | | | | | | | | | | | - Letícia Beatriz Mazo Pinho
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Maria Angelica Miglino
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Michelle Silva Araujo
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
- School of Veterinary Medicine, UniEduk University Center, Indaiatuba, Brazil
- *Correspondence: Michelle Silva Araujo
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10
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Evers SW, Ponstein J, Jansen MA, Gray JA, Fröbisch J. A systematic compendium of turtle mandibular anatomy using digital dissections of soft tissue and osteology. Anat Rec (Hoboken) 2022; 306:1228-1303. [PMID: 35900121 DOI: 10.1002/ar.25037] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/11/2022]
Abstract
Turtles are a charismatic reptile group with a peculiar body plan, which most notably includes the shell. Anatomists have often focused descriptive efforts on the shell and other strongly derived body parts, such as the akinetic skull, or the cervical vertebrae. Other parts of turtle osteology, like the girdles, limbs, and mandibles, are documented with less rigor and detail. The mandible is the primary skeletal element involved in food acquisition and initial food processing of turtles, and its features are thus likely linked to feeding ecology. In addition, the mandible of turtles is composed of up to seven bones (sometimes fused to as little as three) and has thus anatomical complexity that may be insightful for systematic purposes and phylogenetic research. Despite apparent complexity and diversity to the mandible of turtles, this anatomical system has not been systematically studied, not even in search of characters that might improve phylogenetic resolution. Here, we describe the mandibular osteology for all major subclades of extant turtles with the help of digitally dissected 3D models derived from high-resolution computed tomography (μCT) scans of 70 extant species. We provide 31 fully segmented mandibles, as well as 3D models of the mandibular musculature, innervation, and arterial circulation of the cryptodire Dermatemys mawii. We synthesize observed variation into 51 morphological characters, which we optimize onto a molecular phylogeny. This analysis shows some mandibular characters to have high systematic value, whereas others are highly homoplastic and may underlie ecological influences or other factors invoking variation.
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Affiliation(s)
- Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Jasper Ponstein
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany.,Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Maren A Jansen
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany.,Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jaimi A Gray
- Division of Herpetology, Florida Museum of Natural History, University of Florida, Gainesville, Florida, USA
| | - Jörg Fröbisch
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany.,Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
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11
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Abel P, Pommery Y, Ford DP, Koyabu D, Werneburg I. Skull Sutures and Cranial Mechanics in the Permian Reptile Captorhinus aguti and the Evolution of the Temporal Region in Early Amniotes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.841784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While most early limbed vertebrates possessed a fully-roofed dermatocranium in their temporal skull region, temporal fenestrae and excavations evolved independently at least twice in the earliest amniotes, with several different variations in shape and position of the openings. Yet, the specific drivers behind this evolution have been only barely understood. It has been mostly explained by adaptations of the feeding apparatus as a response to new functional demands in the terrestrial realm, including a rearrangement of the jaw musculature as well as changes in strain distribution. Temporal fenestrae have been retained in most extant amniotes but have also been lost again, notably in turtles. However, even turtles do not represent an optimal analog for the condition in the ancestral amniote, highlighting the necessity to examine Paleozoic fossil material. Here, we describe in detail the sutures in the dermatocranium of the Permian reptile Captorhinus aguti (Amniota, Captorhinidae) to illustrate bone integrity in an early non-fenestrated amniote skull. We reconstruct the jaw adductor musculature and discuss its relation to intracranial articulations and bone flexibility within the temporal region. Lastly, we examine whether the reconstructed cranial mechanics in C. aguti could be treated as a model for the ancestor of fenestrated amniotes. We show that C. aguti likely exhibited a reduced loading in the areas at the intersection of jugal, squamosal, and postorbital, as well as at the contact between parietal and postorbital. We argue that these “weak” areas are prone for the development of temporal openings and may be treated as the possible precursors for infratemporal and supratemporal fenestrae in early amniotes. These findings provide a good basis for future studies on other non-fenestrated taxa close to the amniote base, for example diadectomorphs or other non-diapsid reptiles.
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12
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Hussein Yousif N. Comparative anatomical study to skeleton for same species of Turtles in Iraq. BIONATURA 2022. [DOI: 10.21931/rb/2022.07.02.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Bones were recorded in the skeleton of some species of Iraqi turtle Mauremys rivulata; the objectives of this study came in light of current conditions, environmental developments, talents and techniques of biological studies taking place in the country, need for an anatomy guide in river turtles of Iraqi species, to identify all kinds of similarities and differences with their preaching, this work or study has become written in response to those modern needs. It is designed to be one of the resources for those interested in biological studies, beginners or professionals, and veterinarians, distinguishing them from marine and global species. Turtles were dissected in the laboratories of the Research Center and Museum of Natural History / the University of Baghdad. The specimen was dissected by removing the abdominal cortex, muscles, and internal viscera and imaging the bone starting from the skull to the hind leg bones. This first study was in Iraq.
Keywords: Turtles (Mauremys rivulata), anatomy, skeleton, bone, Iraq
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13
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Chatterji RM, Hipsley CA, Sherratt E, Hutchinson MN, Jones MEH. Ontogenetic allometry underlies trophic diversity in sea turtles (Chelonioidea). Evol Ecol 2022. [DOI: 10.1007/s10682-022-10162-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractDespite only comprising seven species, extant sea turtles (Cheloniidae and Dermochelyidae) display great ecological diversity, with most species inhabiting a unique dietary niche as adults. This adult diversity is remarkable given that all species share the same dietary niche as juveniles. These ontogenetic shifts in diet, as well as a dramatic increase in body size, make sea turtles an excellent group to examine how morphological diversity arises by allometric processes and life habit specialisation. Using three-dimensional geometric morphometrics, we characterise ontogenetic allometry in the skulls of all seven species and evaluate variation in the context of phylogenetic history and diet. Among the sample, the olive ridley (Lepidochelys olivacea) has a seemingly average sea turtle skull shape and generalised diet, whereas the green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) show different extremes of snout shape associated with their modes of food gathering (grazing vs. grasping, respectively). Our ontogenetic findings corroborate previous suggestions that the skull of the leatherback (Dermochelys coriacea) is paedomorphic, having similar skull proportions to hatchlings of other sea turtle species and retaining a hatchling-like diet of relatively soft bodied organisms. The flatback sea turtle (Natator depressus) shows a similar but less extreme pattern. By contrast, the loggerhead sea turtle (Caretta caretta) shows a peramorphic signal associated with increased jaw muscle volumes that allow predation on hard shelled prey. The Kemp’s ridley (Lepidochelys kempii) has a peramorphic skull shape compared to its sister species the olive ridley, and a diet that includes harder prey items such as crabs. We suggest that diet may be a significant factor in driving skull shape differences among species. Although the small number of species limits statistical power, differences among skull shape, size, and diet are consistent with the hypothesis that shifts in allometric trajectory facilitated diversification in skull shape as observed in an increasing number of vertebrate groups.
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14
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Tokita M, Watanabe T, Sato H, Kondo S, Kitayama C. A comparative study of cranial osteogenesis in turtles: implications for the diversification of skull morphology. ZOOMORPHOLOGY 2021. [DOI: 10.1007/s00435-021-00544-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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15
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Werneburg I, Evers SW, Ferreira G. On the “cartilaginous rider” in the endocasts of turtle brain cavities. VERTEBRATE ZOOLOGY 2021. [DOI: 10.3897/vz.71.e66756] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Abstract
In recent years, paleoneurology became a very popular research field and hundreds of brain-endocasts were described. The interpretation of a dorsal protuberance of the brain-endocast puzzled researchers for a long time, the so-called (cartilaginous) rider. This is mainly because of technical limitations in the past and due to non-accessibility of comparative material. Using turtles as a case-study, we conducted a literature review and studied embryological data in addition to fossil and extant species’ endocasts. We assessed three hypotheses on the origin of the rider as relating to 1) the pineal gland, to 2) the blood vessel system, and to 3) skull roof elements. Based on our integrated anatomical observations, we refute the pineal gland hypothesis (1) and an exclusive blood vessel explanation (2). However, we show that, in most cases, the cartilaginous origin applies (3). The related cartilages, mainly the anterior process of the chondrocranial tectum synoticum, can persist until adulthood. Its diversity is interpreted in regard to the mechanical support for the temporal skull region, the shape of which has been shown to be in turn related to neck retraction and jaw mechanics. Finally, we highlight the value of embryological data to provide profound hypotheses for evolutionary research despite its low quantitative evaluability. We argue that it should be studied in conjunction with modern computer-aided data acquisition whenever possible.
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16
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Abel P, Werneburg I. Morphology of the temporal skull region in tetrapods: research history, functional explanations, and a new comprehensive classification scheme. Biol Rev Camb Philos Soc 2021; 96:2229-2257. [PMID: 34056833 DOI: 10.1111/brv.12751] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 12/21/2022]
Abstract
The morphology of the temporal region in the tetrapod skull traditionally has been a widely discussed feature of vertebrate anatomy. The evolution of different temporal openings in Amniota (mammals, birds, and reptiles), Lissamphibia (frogs, salamanders, and caecilians), and several extinct tetrapod groups has sparked debates on the phylogenetic, developmental, and functional background of this region in the tetrapod skull. This led most famously to the erection of different amniote taxa based on the number and position of temporal fenestrae in their skulls. However, most of these taxa are no longer recognised to represent natural groupings and the morphology of the temporal region is not necessarily an adequate trait for use in the reconstruction of amniote phylogenies. Yet, new fossil finds, most notably of parareptiles and stem-turtles, as well as modern embryological and biomechanical studies continue to provide new insights into the morphological diversity of the temporal region. Here, we introduce a novel comprehensive classification scheme for the various temporal morphotypes in all Tetrapoda that is independent of phylogeny and previous terminology and may facilitate morphological comparisons in future studies. We then review the history of research on the temporal region in the tetrapod skull. We document how, from the early 19th century with the first recognition of differences in the temporal region to the first proposals of phylogenetic relationships and their assessment over the centuries, the phylogenetic perspective on the temporal region has developed, and we highlight the controversies that still remain. We also compare the different functional and developmental drivers proposed for the observed morphological diversity and how the effects of internal and external factors on the structure of the tetrapod skull have been interpreted.
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Affiliation(s)
- Pascal Abel
- Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) at Eberhard Karls Universität, Sigwartstraße 10, Tübingen, 72076, Germany.,Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße 12, Tübingen, 72074, Germany
| | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) at Eberhard Karls Universität, Sigwartstraße 10, Tübingen, 72076, Germany.,Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße 12, Tübingen, 72074, Germany
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17
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Ingle DN, Meredith TL, Perrault JR, Wyneken J. Two heads are not always better than one: Craniofacial and axial bifurcation in cheloniid embryos and hatchlings (Chelonia mydas and Caretta caretta). J Morphol 2021; 282:1233-1244. [PMID: 33982303 DOI: 10.1002/jmor.21366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/05/2021] [Accepted: 05/09/2021] [Indexed: 11/08/2022]
Abstract
Morphological data on craniofacial and axial bifurcation in sea turtles is not well documented in the literature. Here, we use micro-computed tomography (μ-CT) imaging to describe the body, skull, and vertebral morphology in axially-bifurcated cheloniid sea turtle embryos and hatchlings (Chelonia mydas and Caretta caretta) from south Florida beaches. We describe three types of craniofacial and axial bifurcations: bifacial, bicephalic, and bicephalic with biaxial duplication ranging from facial bones to the sacrum. We predicted smaller body dimensions in bifacial and bicephalic embryos and hatchlings compared with their normal counterparts. In addition, we hypothesized that bicephalic individuals would have greater rostral deviation angles than bifacial animals, and that vertebral dimensions would vary between the control and anomalous embryos and hatchlings. Among hatchlings (developmental Stage 31), we found that maximum curved carapace length and curved carapace width were greatest in the control specimens when compared with the anomalous specimens. Overall, we found that rostral deviations were smaller in bifacial animals compared with their bicephalic counterparts. Right and left rostral deviations were symmetrical or nearly symmetrical in all bifacial and bicephalic specimens. Among C. caretta, we found that bicephalic animals had greater standardized vertebral measurements than their bifacial conspecifics. In bifacial animals, bifurcation extended to either the frontal or parietal skull bones, while duplication extended to C5 vertebrae and T8 vertebrae in bicephalic animals. This study provides an in-depth description of anatomical alterations associated with these abnormalities. Prognosis of these organisms is poor; however, understanding the prevalence of these malformations can allow for better assessments of population health, as numerous environmental factors are known to lead to these changes.
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Affiliation(s)
- Danielle N Ingle
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA.,Florida Atlantic University High School, Boca Raton, Florida, USA.,College of Education, Florida Atlantic University, Boca Raton, Florida, USA
| | - Tricia L Meredith
- Florida Atlantic University High School, Boca Raton, Florida, USA.,College of Education, Florida Atlantic University, Boca Raton, Florida, USA
| | | | - Jeanette Wyneken
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
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18
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Chatterji RM, Hutchinson MN, Jones MEH. Redescription of the skull of the Australian flatback sea turtle, Natator depressus, provides new morphological evidence for phylogenetic relationships among sea turtles (Chelonioidea). Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlaa071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
Chelonioidea (sea turtles) are a group where available morphological evidence for crown-group relationships are incongruent with those established using molecular data. However, morphological surveys of crown-group taxa tend to focus on a recurring subset of the extant species. The Australian flatback sea turtle, Natator depressus, is often excluded from comparisons and it is the most poorly known of the seven extant species of Chelonioidea. Previous descriptions of its skull morphology are limited and conflict. Here we describe three skulls of adult N. depressus and re-examine the phylogenetic relationships according to morphological character data. Using X-ray micro Computed Tomography we describe internal structures of the braincase and identify new phylogenetically informative characters not previously reported. Phylogenetic analysis using a Bayesian approach strongly supports a sister-group relationship between Chelonia mydas and N. depressus, a topology that was not supported by previous analyses of morphological data but one that matches the topology supported by analysis of molecular data. Our results highlight the general need to sample the morphological anatomy of crown-group taxa more thoroughly before concluding that morphological and molecular evidence are incongruous.
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Affiliation(s)
- Ray M Chatterji
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, SA, Australia
- South Australian Museum, Adelaide, Adelaide, South Australia, SA, Australia
| | - Mark N Hutchinson
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, SA, Australia
- South Australian Museum, Adelaide, Adelaide, South Australia, SA, Australia
| | - Marc E H Jones
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, SA, Australia
- South Australian Museum, Adelaide, Adelaide, South Australia, SA, Australia
- Earth Sciences, Natural History Museum, London, UK
- Cell and Developmental Biology, UCL, University College London, London, UK
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19
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Rollot Y, Evers SW, Joyce WG. A review of the carotid artery and facial nerve canal systems in extant turtles. PeerJ 2021; 8:e10475. [PMID: 33552706 PMCID: PMC7839387 DOI: 10.7717/peerj.10475] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/11/2020] [Indexed: 11/25/2022] Open
Abstract
The cranial circulation and innervation systems of turtles have been studied for more than two centuries and extensively used to understand turtle systematics. Although a significant number of studies related to these structures exists, a broader comprehension of variation across the tree has been hindered by poor sampling and a lack of synthetic studies that addressed both systems together. We here provide new insights regarding the carotid circulation and facial nerve innervation systems in a broad set of extant turtles using CT (computed tomography) scans, which allow us to trace the canals these structures form in bone and understand the interaction between both systems. We document that the palatine artery, including the lateral carotid canal, is absent in all pleurodires and carettochelyids and was likely reduced or lost several times independently within Testudinoidea. We also highlight osteological correlates for the location of the mandibular artery. We finally summarize variation regarding the placement of the mandibular artery, location of the geniculate ganglion, placement of the hyomandibular and vidian nerves, and situations where we recommend caution when assessing canals in fossils. A morphometric study confirms that the relative sizes of the carotid canals are correlated with one another. Our results have the potential for building new phylogenetic characters and investigating the circulation systems of fossil taxa, which are expected to shed light on the evolution of the circulation system of turtles and clarify some unresolved relationships between fossil turtle clades.
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Affiliation(s)
- Yann Rollot
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Walter G. Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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20
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Hampl M, Dumkova J, Kavkova M, Dosedelova H, Bryjova A, Zahradnicek O, Pyszko M, Macholan M, Zikmund T, Kaiser J, Buchtova M. Polarized Sonic Hedgehog Protein Localization and a Shift in the Expression of Region-Specific Molecules Is Associated With the Secondary Palate Development in the Veiled Chameleon. Front Cell Dev Biol 2020; 8:572. [PMID: 32850780 PMCID: PMC7399257 DOI: 10.3389/fcell.2020.00572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/15/2020] [Indexed: 12/27/2022] Open
Abstract
Secondary palate development is characterized by the formation of two palatal shelves on the maxillary prominences, which fuse in the midline in mammalian embryos. However, in reptilian species, such as turtles, crocodilians, and lizards, the palatal shelves of the secondary palate develop to a variable extent and morphology. While in most Squamates, the palate is widely open, crocodilians develop a fully closed secondary palate. Here, we analyzed developmental processes that underlie secondary palate formation in chameleons, where large palatal shelves extend horizontally toward the midline. The growth of the palatal shelves continued during post-hatching stages and closure of the secondary palate can be observed in several adult animals. The massive proliferation of a multilayered oral epithelium and mesenchymal cells in the dorsal part of the palatal shelves underlined the initiation of their horizontal outgrowth, and was decreased later in development. The polarized cellular localization of primary cilia and Sonic hedgehog protein was associated with horizontal growth of the palatal shelves. Moreover, the development of large palatal shelves, supported by the pterygoid and palatine bones, was coupled with the shift in Meox2, Msx1, and Pax9 gene expression along the rostro-caudal axis. In conclusion, our results revealed distinctive developmental processes that contribute to the expansion and closure of the secondary palate in chameleons and highlighted divergences in palate formation across amniote species.
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Affiliation(s)
- Marek Hampl
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czechia.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia
| | - Jana Dumkova
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Michaela Kavkova
- Laboratory of Computed Tomography, Central European Institute of Technology, Brno University of Technology, Brno, Czechia
| | - Hana Dosedelova
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czechia
| | - Anna Bryjova
- Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czechia
| | - Oldrich Zahradnicek
- Department of Developmental Biology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czechia.,Department of Radiation Dosimetry, Nuclear Physics Institute, Czech Academy of Sciences, Prague, Czechia
| | - Martin Pyszko
- Department of Anatomy, Histology, and Embryology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | - Milos Macholan
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czechia
| | - Tomas Zikmund
- Laboratory of Computed Tomography, Central European Institute of Technology, Brno University of Technology, Brno, Czechia
| | - Jozef Kaiser
- Laboratory of Computed Tomography, Central European Institute of Technology, Brno University of Technology, Brno, Czechia
| | - Marcela Buchtova
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czechia.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia
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21
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Morphology and intraspecific variation in the skull and mandible of the slider turtle Trachemys dorbigni (Testudines, Emydidae). ZOOMORPHOLOGY 2020. [DOI: 10.1007/s00435-020-00491-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Ferreira GS, Lautenschlager S, Evers SW, Pfaff C, Kriwet J, Raselli I, Werneburg I. Feeding biomechanics suggests progressive correlation of skull architecture and neck evolution in turtles. Sci Rep 2020; 10:5505. [PMID: 32218478 PMCID: PMC7099039 DOI: 10.1038/s41598-020-62179-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/09/2020] [Indexed: 02/07/2023] Open
Abstract
The origin of turtles is one of the most long-lasting debates in evolutionary research. During their evolution, a series of modifications changed their relatively kinetic and anapsid skull into an elongated akinetic structure with a unique pulley system redirecting jaw adductor musculature. These modifications were thought to be strongly correlated to functional adaptations, especially to bite performance. We conducted a series of Finite Element Analyses (FEAs) of several species, including that of the oldest fully shelled, Triassic stem-turtle Proganochelys, to evaluate the role of force distribution and to test existing hypotheses on the evolution of turtle skull architecture. We found no support for a relation between the akinetic nature of the skull or the trochlear mechanisms with increased bite forces. Yet, the FEAs show that those modifications changed the skull architecture into an optimized structure, more resistant to higher loads while allowing material reduction on specific regions. We propose that the skull of modern turtles is the result of a complex process of progressive correlation between their heads and highly flexible necks, initiated by the origin of the shell.
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Affiliation(s)
- Gabriel S Ferreira
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, 14040-901, Ribeirão Preto, Brazil. .,Fachbereich Geowissenschaften der Eberhard Karls Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany.
| | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT, Birmingham, United Kingdom
| | - Serjoscha W Evers
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK.,Department of Geosciences, University of Fribourg, Chemin du musée, 1700, Fribourg, Switzerland
| | - Cathrin Pfaff
- University of Vienna, Department of Palaeontology, Althanstraße 14, 1090, Vienna, Austria
| | - Jürgen Kriwet
- University of Vienna, Department of Palaeontology, Althanstraße 14, 1090, Vienna, Austria
| | - Irena Raselli
- Jurassica Museum, Route de Fontenais 21, 2900, Porrentruy, Switzerland.,Department of Geosciences, University of Fribourg, Chemin du musée, 1700, Fribourg, Switzerland
| | - Ingmar Werneburg
- Fachbereich Geowissenschaften der Eberhard Karls Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany. .,Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) an der Eberhard Karls Universität, Sigwartstraße 10, 72076, Tübingen, Germany.
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23
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Figgener C, Bernardo J, Plotkin PT. Beyond trophic morphology: stable isotopes reveal ubiquitous versatility in marine turtle trophic ecology. Biol Rev Camb Philos Soc 2019; 94:1947-1973. [PMID: 31338959 PMCID: PMC6899600 DOI: 10.1111/brv.12543] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/07/2019] [Accepted: 06/13/2019] [Indexed: 11/30/2022]
Abstract
The idea that interspecific variation in trophic morphology among closely related species effectively permits resource partitioning has driven research on ecological radiation since Darwin first described variation in beak morphology among Geospiza. Marine turtles comprise an ecological radiation in which interspecific differences in trophic morphology have similarly been implicated as a pathway to ecopartition the marine realm, in both extant and extinct species. Because marine turtles are charismatic flagship species of conservation concern, their trophic ecology has been studied intensively using stable isotope analyses to gain insights into habitat use and diet, principally to inform conservation management. This legion of studies provides an unparalleled opportunity to examine ecological partitioning across numerous hierarchical levels that heretofore has not been applied to any other ecological radiation. Our contribution aims to provide a quantitative analysis of interspecific variation and a comprehensive review of intraspecific variation in trophic ecology across different hierarchical levels marshalling insights about realised trophic ecology derived from stable isotopes. We reviewed 113 stable isotope studies, mostly involving single species, and conducted a meta-analysis of data from adults to elucidate differences in trophic ecology among species. Our study reveals a more intricate hierarchy of ecopartitioning by marine turtles than previously recognised based on trophic morphology and dietary analyses. We found strong statistical support for interspecific partitioning, as well as a continuum of intraspecific trophic sub-specialisation in most species across several hierarchical levels. This ubiquity of trophic specialisation across many hierarchical levels exposes a far more complex view of trophic ecology and resource-axis exploitation than suggested by species diversity alone. Not only do species segregate along many widely understood axes such as body size, macrohabitat, and trophic morphology but the general pattern revealed by isotopic studies is one of microhabitat segregation and variation in foraging behaviour within species, within populations, and among individuals. These findings are highly relevant to conservation management because they imply ecological non-exchangeability, which introduces a new dimension beyond that of genetic stocks which drives current conservation planning. Perhaps the most remarkable finding from our data synthesis is that four of six marine turtle species forage across several trophic levels. This pattern is unlike that seen in other large marine predators, which forage at a single trophic level according to stable isotopes. This finding affirms suggestions that marine turtles are robust sentinels of ocean health and likely stabilise marine food webs. This insight has broader significance for studies of marine food webs and trophic ecology of large marine predators. Beyond insights concerning marine turtle ecology and conservation, our findings also have broader implications for the study of ecological radiations. Particularly, the unrecognised complexity of ecopartitioning beyond that predicted by trophic morphology suggests that this dominant approach in adaptive radiation research likely underestimates the degree of resource overlap and that interspecific disparities in trophic morphology may often over-predict the degree of realised ecopartitioning. Hence, our findings suggest that stable isotopes can profitably be applied to study other ecological radiations and may reveal trophic variation beyond that reflected by trophic morphology.
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Affiliation(s)
- Christine Figgener
- Marine Biology Interdisciplinary ProgramTexas A&M University3258 TAMU, College StationTX77843U.S.A.
- Department of BiologyTexas A&M University3258 TAMU, College StationTX77843U.S.A.
- Department of OceanographyTexas A&M University3146 TAMU, College StationTX77843U.S.A.
| | - Joseph Bernardo
- Marine Biology Interdisciplinary ProgramTexas A&M University3258 TAMU, College StationTX77843U.S.A.
- Department of BiologyTexas A&M University3258 TAMU, College StationTX77843U.S.A.
- Program in Ecology and Evolutionary BiologyTexas A&M University2475 TAMU, College StationTX77843U.S.A.
| | - Pamela T. Plotkin
- Marine Biology Interdisciplinary ProgramTexas A&M University3258 TAMU, College StationTX77843U.S.A.
- Department of OceanographyTexas A&M University3146 TAMU, College StationTX77843U.S.A.
- Texas Sea Grant, Texas A&M University4115 TAMU, College StationTX77843U.S.A.
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24
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Harvey VL, LeFebvre MJ, deFrance SD, Toftgaard C, Drosou K, Kitchener AC, Buckley M. Preserved collagen reveals species identity in archaeological marine turtle bones from Caribbean and Florida sites. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191137. [PMID: 31824722 PMCID: PMC6837194 DOI: 10.1098/rsos.191137] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 10/04/2019] [Indexed: 05/03/2023]
Abstract
Advancements in molecular science are continually improving our knowledge of marine turtle biology and evolution. However, there are still considerable gaps in our understanding, such as past marine turtle distributions, which can benefit from advanced zooarchaeological analyses. Here, we apply collagen fingerprinting to 130 archaeological marine turtle bone samples up to approximately 2500 years old from the Caribbean and Florida's Gulf Coast for faunal identification, finding the vast majority of samples (88%) to contain preserved collagen despite deposition in the tropics. All samples can be identified to species-level with the exception of the Kemp's ridley (Lepidochelys kempii) and olive ridley (L. olivacea) turtles, which can be separated to genus level, having diverged from one another only approximately 5 Ma. Additionally, we identify a single homologous peptide that allows the separation of archaeological green turtle samples, Chelonia spp., into two distinct groups, which potentially signifies a difference in genetic stock. The majority of the archaeological samples are identified as green turtle (Chelonia spp.; 63%), with hawksbill (Eretmochelys imbricata; 17%) and ridley turtles (Lepidochelys spp.; 3%) making up smaller proportions of the assemblage. There were no molecular identifications of the loggerhead turtle (Caretta caretta) in the assemblage despite 9% of the samples being morphologically identified as such, highlighting the difficulties in relying on morphological identifications alone in archaeological remains. Finally, we present the first marine turtle molecular phylogeny using collagen (I) amino acid sequences and find our analyses match recent phylogenies based on nuclear and mitochondrial DNA. Our results highlight the advantage of using collagen fingerprinting to supplement morphological analyses of turtle bones and support the usefulness of this technique for assessing their past distributions across the Caribbean and Florida's Gulf Coast, especially in these tropical environments where DNA preservation may be poor.
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Affiliation(s)
- Virginia L. Harvey
- Manchester Institute of Biotechnology, School of Earth and Environmental Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - Michelle J. LeFebvre
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Susan D. deFrance
- Department of Anthropology, University of Florida, Gainesville, FL 32611, USA
| | - Casper Toftgaard
- The SAXO Institute, University of Copenhagen, Karen Blixens Plads 8, 2300 København S, Denmark
- National Museum of Denmark, Nationalmuseet, Ny Vestergade 10, Prinsens Palæ, DK-1471, København K, Denmark
| | - Konstantina Drosou
- KNH Centre for Biomedical Egyptology, School of Biological Sciences, 99 Oxford Road, Manchester, M13 9PG, UK
| | - Andrew C. Kitchener
- Department of Natural Sciences, National Museums Scotland, Chambers Street, Edinburgh EH1 1JF, UK
- The University of Edinburgh, Institute of Geography, School of Geosciences, Drummond Street, Edinburgh, EH8 9XP, UK
| | - Michael Buckley
- Manchester Institute of Biotechnology, School of Earth and Environmental Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
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25
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Evers SW, Neenan JM, Ferreira GS, Werneburg I, Barrett PM, Benson RBJ. Neurovascular anatomy of the protostegid turtle Rhinochelys pulchriceps and comparisons of membranous and endosseous labyrinth shape in an extant turtle. Zool J Linn Soc 2019. [DOI: 10.1093/zoolinnean/zlz063] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AbstractChelonioid turtles are the only surviving group of reptiles that secondarily evolved marine lifestyles during the Mesozoic Early chelonioid evolution is documented by fossils of their stem group, such as protostegids, which yield insights into the evolution of marine adaptation. Neuroanatomical features are commonly used to infer palaeoecology owing to the functional adaptation of the senses of an organism to its environment. We investigated the neuroanatomy and carotid circulation of the early Late Cretaceous protostegid Rhinochelys pulchriceps based on micro-computed tomography data. We show that the trigeminal foramen of turtles is not homologous to that of other reptiles. The endosseous labyrinth of R. pulchriceps has thick semicircular canals and a high aspect ratio. Comparisons among turtles and other reptiles show that the endosseous labyrinth aspect ratio is not a reliable predictor of the degree of aquatic adaptation, contradicting previous hypotheses. We provide the first models of neuroanatomical soft tissues of an extant turtle. Turtle brain morphology is not reflected by the brain cavity, and the endosseous labyrinth provides an incomplete reflection of membranous semicircular duct morphology. Membranous labyrinth geometry is conserved across gnathostomes, which allows approximate reconstruction of the total membranous labyrinth morphology from the endosseous labyrinth despite their poor reflection of duct morphology.
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Affiliation(s)
- Serjoscha W Evers
- Department of Earth Sciences, University of Oxford, Oxford, UK
- Department of Earth Sciences, Natural History Museum, London, UK
| | | | - Gabriel S Ferreira
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße, Tübingen, Germany
| | - Ingmar Werneburg
- Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße, Tübingen, Germany
- Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) an der Eberhard Karls Universität, Sigwartstraße, Tübingen, Germany
| | - Paul M Barrett
- Department of Earth Sciences, Natural History Museum, London, UK
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26
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Foth C, Evers SW, Joyce WG, Volpato VS, Benson RBJ. Comparative analysis of the shape and size of the middle ear cavity of turtles reveals no correlation with habitat ecology. J Anat 2019; 235:1078-1097. [PMID: 31373396 DOI: 10.1111/joa.13071] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2019] [Indexed: 02/06/2023] Open
Abstract
The middle ear of turtles differs from other reptiles in being separated into two distinct compartments. Several ideas have been proposed as to why the middle ear is compartmentalized in turtles, most suggesting a relationship with underwater hearing. Extant turtle species span fully marine to strictly terrestrial habitats, and ecomorphological hypotheses of turtle hearing predict that this should correlate with variation in the structure of the middle ear due to differences in the fluid properties of water and air. We investigate the shape and size of the air-filled middle ear cavity of 56 extant turtles using 3D data and phylogenetic comparative analysis to test for correlations between habitat preferences and the shape and size of the middle ear cavity. Only weak correlations are found between middle ear cavity size and ecology, with aquatic taxa having proportionally smaller cavity volumes. The middle ear cavity of turtles exhibits high shape diversity among species, but we found no relationship between this shape variation and ecology. Surprisingly, the estimated acoustic transformer ratio, a key functional parameter of impedance-matching ears in vertebrates, also shows no relation to habitat preferences (aquatic/terrestrial) in turtles. We suggest that middle ear cavity shape may be controlled by factors unrelated to hearing, such as the spatial demands of surrounding cranial structures. A review of the fossil record suggests that the modern turtle ear evolved during the Early to Middle Jurassic in stem turtles broadly adapted to freshwater and terrestrial settings. This, combined with our finding that evolutionary transitions between habitats caused only weak evolutionary changes in middle ear structure, suggests that tympanic hearing in turtles evolved as a compromise between subaerial and underwater hearing.
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Affiliation(s)
- Christian Foth
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland.,Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Walter G Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Virginie S Volpato
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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Jones MEH, Button DJ, Barrett PM, Porro LB. Digital dissection of the head of the rock dove ( Columba livia) using contrast-enhanced computed tomography. ZOOLOGICAL LETTERS 2019; 5:17. [PMID: 31205748 PMCID: PMC6558907 DOI: 10.1186/s40851-019-0129-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
The rock dove (or common pigeon), Columba livia, is an important model organism in biological studies, including research focusing on head muscle anatomy, feeding kinematics, and cranial kinesis. However, no integrated computer-based biomechanical model of the pigeon head has yet been attempted. As an initial step towards achieving this goal, we present the first three-dimensional digital dissection of the pigeon head based on a contrast-enhanced computed tomographic dataset achieved using iodine potassium iodide as a staining agent. Our datasets enable us to visualize the skeletal and muscular anatomy, brain and cranial nerves, and major sense organs of the pigeon, including very small and fragile features, as well as maintaining the three-dimensional topology of anatomical structures. This work updates and supplements earlier anatomical work on this widely used laboratory organism. We resolve several key points of disagreement arising from previous descriptions of pigeon anatomy, including the precise arrangement of the external adductor muscles and their relationship to the posterior adductor. Examination of the eye muscles highlights differences between avian taxa and shows that pigeon eye muscles are more similar to those of a tinamou than they are to those of a house sparrow. Furthermore, we present our three-dimensional data as publicly accessible files for further research and education purposes. Digital dissection permits exceptional visualisation and will be a valuable resource for further investigations into the head anatomy of other bird species, as well as efforts to reconstruct soft tissues in fossil archosaurs.
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Affiliation(s)
- Marc E. H. Jones
- Department of Earth Sciences, Natural History Museum, London, SW7 5BD UK
| | - David J. Button
- Department of Earth Sciences, Natural History Museum, London, SW7 5BD UK
| | - Paul M. Barrett
- Department of Earth Sciences, Natural History Museum, London, SW7 5BD UK
| | - Laura B. Porro
- Department of Cell and Developmental Biology, UCL, University College London, Gower Street, London, WC1E 6BT UK
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28
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Evers SW, Barrett PM, Benson RBJ. Anatomy of Rhinochelys pulchriceps (Protostegidae) and marine adaptation during the early evolution of chelonioids. PeerJ 2019; 7:e6811. [PMID: 31106054 PMCID: PMC6500378 DOI: 10.7717/peerj.6811] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/19/2019] [Indexed: 11/22/2022] Open
Abstract
Knowledge of the early evolution of sea turtles (Chelonioidea) has been limited by conflicting phylogenetic hypotheses resulting from sparse taxon sampling and a superficial understanding of the morphology of key taxa. This limits our understanding of evolutionary adaptation to marine life in turtles, and in amniotes more broadly. One problematic group are the protostegids, Early-Late Cretaceous marine turtles that have been hypothesised to be either stem-cryptodires, stem-chelonioids, or crown-chelonioids. Different phylogenetic hypotheses for protostegids suggest different answers to key questions, including (1) the number of transitions to marine life in turtles, (2) the age of the chelonioid crown-group, and (3) patterns of skeletal evolution during marine adaptation. We present a detailed anatomical study of one of the earliest protostegids, Rhinochelys pulchriceps from the early Late Cretaceous of Europe, using high-resolution μCT. We synonymise all previously named European species and document the variation seen among them. A phylogeny of turtles with increased chelonioid taxon sampling and revised postcranial characters is provided, recovering protostegids as stem-chelonioids. Our results imply a mid Early Cretaceous origin of total-group chelonioids and an early Late Cretaceous age for crown-chelonioids, which may inform molecular clock analyses in future. Specialisations of the chelonioid flipper evolved in a stepwise-fashion, with innovations clustered into pulses at the origin of total-group chelonioids, and subsequently among dermochelyids, crown-cheloniids, and gigantic protostegids from the Late Cretaceous.
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Affiliation(s)
- Serjoscha W. Evers
- Department of Earth Sciences, University of Oxford, Oxford, UK
- Department of Earth Sciences, Natural History Museum, London, UK
| | - Paul M. Barrett
- Department of Earth Sciences, Natural History Museum, London, UK
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Iwasaki SI, Erdoğan S, Asami T. Evolutionary Specialization of the Tongue in Vertebrates: Structure and Function. FEEDING IN VERTEBRATES 2019. [DOI: 10.1007/978-3-030-13739-7_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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30
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Evolution, Diversity, and Development of the Craniocervical System in Turtles with Special Reference to Jaw Musculature. HEADS, JAWS, AND MUSCLES 2019. [DOI: 10.1007/978-3-319-93560-7_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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31
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Urano Y, Tanoue K, Matsumoto R, Kawabe S, Ohashi T, Fujiwara SI. How does the curvature of the upper beak bone reflect the overlying rhinotheca morphology? J Morphol 2018; 279:636-647. [DOI: 10.1002/jmor.20799] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/19/2018] [Accepted: 01/27/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Yukine Urano
- Department of Earth and Planetary Sciences, Graduate School of Environmental Studies; Nagoya University; Nagoya Japan
| | - Kyo Tanoue
- Department of Earth System Science; Fukuoka University; Fukuoka Japan
| | | | | | - Tomoyuki Ohashi
- Kitakyushu Museum of Natural History and Human History; Kitakyushu Japan
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Kim MJ, Kim YY, Chao JR, Park HS, Chang J, Oh D, Lee JJ, Kang TC, Suh JG, Lee JH. Comparing the Organs and Vasculature of the Head and Neck in Five Murine Species. ACTA ACUST UNITED AC 2017; 31:861-871. [PMID: 28882952 DOI: 10.21873/invivo.11140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 07/19/2017] [Accepted: 07/26/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The purpose of the present study was to delineate the cervical and facial vascular and associated anatomy in five murine species, and compare them for optimal use in research studies focused on understanding the pathology and treatment of diseases in humans. MATERIALS AND METHODS The specific adult male animals examined were mice (C57BL/6J), rats (F344), mongolian gerbils (Merionesunguiculatus), hamsters (Syrian), and guinea pigs (Hartley). To stain the vasculature and organs, of the face and neck, each animal was systemically perfused using the vital stain, Trypan Blue. Following this step, the detailed anatomy of the head and neck could be easily visualized in all species. RESULTS Unique morphological characteristics were demonstrated by comparing the five species, including symmetry of the common carotid origin bilaterally in the Mongolian Gerbil, a large submandibular gland in the hamster and an enlarged buccal branch in the Guinea Pig. In reviewing the anatomical details, this staining technique proves superior for direct surgical visualization and identification. CONCLUSION The anatomical details provided through these five species atlas will help experimental researchers in the future to select the most appropriate animal model for specific laboratory studies aimed to improve our understanding and treatment of diseases in patients.
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Affiliation(s)
- Min Jae Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Yoo Yeon Kim
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Janet Ren Chao
- School of Medicine, George Washington University, Washington, DC, U.S.A
| | - Hae Sang Park
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Jiwon Chang
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Dawoon Oh
- Department of Anesthesiology and Pain Medicine, Dongtan Sacred Heart Hospital, Hallym University, Dongtan, Republic of Korea
| | - Jae Jun Lee
- Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea.,Department of Anesthesiology and Pain Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Tae Chun Kang
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jun-Gyo Suh
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea .,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
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Mariani TF, Romano PSR. Intra-specific variation and allometry of the skull of Late Cretaceous side-necked turtle Bauruemys elegans (Pleurodira, Podocnemididae) and how to deal with morphometric data in fossil vertebrates. PeerJ 2017; 5:e2890. [PMID: 28413719 PMCID: PMC5390767 DOI: 10.7717/peerj.2890] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 12/09/2016] [Indexed: 11/28/2022] Open
Abstract
Background Previous quantitative studies on Bauruemys elegans (Suárez, 1969) shell variation, as well as the taphonomic interpretation of its type locality, have suggested that all specimens collected in this locality may have belonged to the same population. We rely on this hypothesis in a morphometric study of the skull. Also, we tentatively assessed the eating preference habits differentiation that might be explained as due to ontogenetic changes. Methods We carried out an ANOVA testing 29 linear measurements from 21 skulls of B. elegans taken by using a caliper and through images, using the ImageJ software. First, a Principal Components Analysis (PCA) was performed with 27 measurements (excluding total length and width characters; =raw data) in order to visualize the scatter plots based on the form variance only. Then, a second PCA was carried out using ratios of length and width of each original measurement to assess shape variation among individuals. Finally, original measurements were log-transformed to describe allometries over ontogeny. Results No statistical differences were found between caliper and ImageJ measurements. The first three PCs of the PCA with raw data comprised 70.2% of the variance. PC1 was related to size variation and all others related to shape variation. Two specimens plotted outside the 95% ellipse in PC1∼PC2 axes. The first three PCs of the PCA with ratios comprised 64% of the variance. When considering PC1∼PC2, all specimens plotted inside the 95% ellipse. In allometric analysis, five measurements were positively allometric, 19 were negatively allometric and three represented enantiometric allometry. Many bones of the posterior and the lateral emarginations lengthen due to increasing size, while jugal and the quadratojugal decrease in width. Discussion ImageJ is useful in replacing caliper since there was no statistical differences. Yet iterative imputation is more appropriate to deal with missing data in PCA. Some specimens show small differences in form and shape. Form differences were interpreted as occuring due to ontogeny, whereas shape differences are related to feeding changes during growth. Moreover, all outlier specimens are crushed and/or distorted, thus the form/shape differences may be partially due to taphonomy. The allometric lengthening of the parietal, quadrate, squamosal, maxilla, associated with the narrowing of jugal and quadratojugal may be related to changes in feeding habit between different stages of development. This change in shape might represent a progressive skull stretching and enlargement of posterior and lateral emargination during ontogeny, and consequently, the increment of the feeding-apparatus musculature. Smaller individuals may have fed on softer diet, whereas larger ones probably have had a harder diet, as seen in some living species of Podocnemis. We conclude that the skull variation might be related to differences in feeding habits over ontogeny in B. elegans.
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Affiliation(s)
- Thiago F Mariani
- Deparatamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Current affiliation: Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Pedro S R Romano
- Deparatamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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Cadena E. The first South American sandownid turtle from the Lower Cretaceous of Colombia. PeerJ 2015; 3:e1431. [PMID: 26713227 PMCID: PMC4690369 DOI: 10.7717/peerj.1431] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/03/2015] [Indexed: 11/20/2022] Open
Abstract
Sandownids are a group of Early Cretaceous-Paleocene turtles that for several decades have been only known by cranial and very fragmentary postcranial elements. Here I report and describe the most complete sandownid turtle known so far, including articulated skull, lower jaw and postcranial elements, from the Early Cretaceous (upper Barremian-lower Aptian, >120 Ma), Paja Formation, Villa de Leyva town, Colombia. The new Colombian sandownid is defined here as Leyvachelys cipadi new genus, new species and because of its almost identical skull morphology with a previously reported turtle from the Glen Rose Formation, Texas, USA, both are grouped in a single and officially (ICNZ rules) defined taxon. Phylogenetic analysis including L. cipadi supports once again the monophyly of Sandownidae, as belonging to the large and recently redefined Pan-Chelonioidea clade. The morphology of L. cipadi indicates that sandownids were not open marine turtles, but instead littoral to shallow marine durophagous dwellers. Leyvachelys cipadi not only constitutes the first record of sandowinds in South America, but also the earliest global record for the group.
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Affiliation(s)
- Edwin Cadena
- Centro de Investigaciones Paleontológicas , Villa de Leyva , Colombia
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35
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Natchev N, Tzankov N, Werneburg I, Heiss E. Feeding behaviour in a 'basal' tortoise provides insights on the transitional feeding mode at the dawn of modern land turtle evolution. PeerJ 2015; 3:e1172. [PMID: 26339550 PMCID: PMC4558077 DOI: 10.7717/peerj.1172] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 07/20/2015] [Indexed: 11/20/2022] Open
Abstract
Almost all extant testudinids are highly associated with terrestrial habitats and the few tortoises with high affinity to aquatic environments are found within the genus Manouria. Manouria belongs to a clade which forms a sister taxon to all remaining tortoises and is suitable as a model for studying evolutionary transitions within modern turtles. We analysed the feeding behaviour of Manouria emys and due to its phylogenetic position, we hypothesise that the species might have retained some ancestral features associated with an aquatic lifestyle. We tested whether M. emys is able to feed both in aquatic and terrestrial environments. In fact, M. emys repetitively tried to reach submerged food items in water, but always failed to grasp them—no suction feeding mechanism was applied. When feeding on land, M. emys showed another peculiar behaviour; it grasped food items by its jaws—a behaviour typical for aquatic or semiaquatic turtles—and not by the tongue as generally accepted as the typical feeding mode in all tortoises studied so far. In M. emys, the hyolingual complex remained retracted during all food uptake sequences, but the food transport was entirely lingual based. The kinematical profiles significantly differed from those described for other tortoises and from those proposed from the general models on the function of the feeding systems in lower tetrapods. We conclude that the feeding behaviour of M. emys might reflect a remnant of the primordial condition expected in the aquatic ancestor of the tortoises.
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Affiliation(s)
- Nikolay Natchev
- Department of Integrative Zoology, Vienna University , Vienna , Austria ; Faculty of Natural Science, Shumen University , Shumen , Bulgaria
| | - Nikolay Tzankov
- Section Vertebrates, National Museum of Natural History, Bulgarian Academy of Sciences , Sofia , Bulgaria
| | - Ingmar Werneburg
- Museum für Naturkunde, Leibniz-Institut für Evolutions- & Biodiversitätsforschung an der Humboldt-Universität zu Berlin , Berlin , Germany ; Institut für Biologie, Humboldt-Universität zu Berlin , Berlin , Germany
| | - Egon Heiss
- Institute of Systematic Zoology and Evolutionary Biology, Friedrich-Schiller-University Jena , Jena , Germany
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Anquetin J, Püntener C, Billon-Bruyat JP. Portlandemys gracilis n. sp., a New Coastal Marine Turtle from the Late Jurassic of Porrentruy (Switzerland) and a Reconsideration of Plesiochelyid Cranial Anatomy. PLoS One 2015; 10:e0129193. [PMID: 26106888 PMCID: PMC4480851 DOI: 10.1371/journal.pone.0129193] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/05/2015] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Several groups of stem cryptodires became adapted to coastal marine environments as early as the Late Jurassic, 40 million years before the Pan-Chelonioidea. The Plesiochelyidae are a major component of this first radiation of crown-group turtles into marine habitats. They are abundant in many European localities, but their systematics is still greatly confused. Only three species are represented by cranial material: Plesiochelys etalloni, Plesiochelys planiceps, and Portlandemys mcdowelli. METHODOLOGY/PRINCIPAL FINDINGS In the present study, we describe a cranium and a mandible from the Kimmeridgian of Porrentruy (Switzerland), which we refer to a new species, Portlandemys gracilis n. sp. This new taxon differs from Portlandemys mcdowelli in several aspects of the cranium and mandible, notably in being generally more gracile, but the two species share a narrow skull, a more acute angle between the labial ridges on the mandible, and a unique configuration of the anterodorsal part of the basicranium. The cranial anatomy of plesiochelyid turtles is discussed in details based primarily on these new specimens and new cranial material of Plesiochelys etalloni from Solothurn, Switzerland. CONCLUSIONS/SIGNIFICANCE Several characters (e.g., the contribution of the parietal to the foramen nervi trigemini, the configuration of the dorsum sellae and sella turcica, the presence of an infolding ridge on the posterior surface of the quadrate) appear as potential candidates to help elucidate plesiochelyid relationships. Some of these characters are included in a previously published phylogenetic dataset and help to stabilize the relationships of plesiochelyid turtles and closely related taxa. For the first time, our results suggest that plesiochelyids, 'Thalassemys' moseri, and Solnhofia parsonsi (representing the Eurysternidae) form a clade at the base of Eucryptodira.
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Affiliation(s)
- Jérémy Anquetin
- Section d'archéologie et paléontologie, Office de la culture, République et Canton du Jura, 2900 Porrentruy, Switzerland
| | - Christian Püntener
- Section d'archéologie et paléontologie, Office de la culture, République et Canton du Jura, 2900 Porrentruy, Switzerland
| | - Jean-Paul Billon-Bruyat
- Section d'archéologie et paléontologie, Office de la culture, République et Canton du Jura, 2900 Porrentruy, Switzerland
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Fernando N, Hui SW, Tsang CC, Leung SY, Ngan AHY, Leung RWW, Groff JM, Lau SKP, Woo PCY. Fatal Fusarium solani species complex infections in elasmobranchs: the first case report for black spotted stingray (Taeniura melanopsila) and a literature review. Mycoses 2015; 58:422-31. [PMID: 26095191 DOI: 10.1111/myc.12342] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/24/2015] [Accepted: 05/15/2015] [Indexed: 11/28/2022]
Abstract
Fusarium species are environmental saprophytic fungi. Among the many Fusarium species, members of the Fusarium solani species complex (FSSC) are the most prevalent and virulent in causing human and animal infections. In this study, we describe the first case of fatal FSSC infection in a black spotted stingray and three concomitant infections in scalloped hammerhead sharks. In the stingray, cutaneous lesions were characterised by ulcers and haemorrhage of the ventral pectoral fin, or 'ray', especially around the head; while cutaneous lesions in the sharks were characterised by ulcers, haemorrhage, as well as white and purulent exudates at the cephalic canals of the cephalofoil and lateral line. Histological sections of the cutaneous lesions revealed slender (1-4 μm in diameter), branching, septate fungal hyphae. Internal transcribed spacer region and 28S nrDNA sequencing of the fungal isolates from the fish showed two isolates were F. keratoplasticum (FSSC 2) and the other two were FSSC 12. Environmental investigation revealed the FSSC strains isolated from water and biofilms in tanks that housed the elasmobranchs were also F. keratoplasticum and FSSC 12. Fusarium is associated with major infections in elasmobranchs and FSSC 12 is an emerging cause of infections in marine animals. DNA sequencing is so far the most reliable method for accurate identification of Fusarium species.
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Affiliation(s)
| | | | - Chi-Ching Tsang
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong
| | - Shui-Yee Leung
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong
| | - Antonio H Y Ngan
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong
| | | | - Joseph M Groff
- School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Susanna K P Lau
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.,Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.,Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong
| | - Patrick C Y Woo
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.,Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.,Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong
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Werneburg I, Hinz JK, Gumpenberger M, Volpato V, Natchev N, Joyce WG. Modeling neck mobility in fossil turtles. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 324:230-43. [DOI: 10.1002/jez.b.22557] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/18/2013] [Accepted: 12/23/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Ingmar Werneburg
- Fachbereich Geowissenschaften der Eberhard Karls Universität Tübingen; Tübingen Germany
- Museum für Naturkunde; Leibniz Institute for Research on Evolution and Biodiversity; Berlin Germany
- Paläontologisches Institut und Museum der Universität Zürich; Zürich Switzerland
| | - Juliane K. Hinz
- Fachbereich Geowissenschaften der Eberhard Karls Universität Tübingen; Tübingen Germany
| | | | - Virginie Volpato
- Paläoanthropologie und Messelforschung/Mammalogie; Senckenberg Gesellschaft für Naturforschung; Frankfurt am Main Germany
| | - Nikolay Natchev
- Department of Integrative Zoology; University of Vienna; Vienna Austria
- Faculty of Natural Science; Shumen University; Bulgaria, Shumen 9712, Univeristetska str. 115
| | - Walter G. Joyce
- Fachbereich Geowissenschaften der Eberhard Karls Universität Tübingen; Tübingen Germany
- Department of Geoscience; University of Fribourg; Fribourg Switzerland
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Johnston P. Homology of the Jaw Muscles in Lizards and Snakes-A Solution from a Comparative Gnathostome Approach. Anat Rec (Hoboken) 2014; 297:574-85. [DOI: 10.1002/ar.22857] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 05/27/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Peter Johnston
- Department of Anatomy with Radiology; University of Auckland; Private Bag 92019 Auckland New Zealand
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Tokita M, Chaeychomsri W, Siruntawineti J. Skeletal gene expression in the temporal region of the reptilian embryos: implications for the evolution of reptilian skull morphology. SPRINGERPLUS 2013; 2:336. [PMID: 24711977 PMCID: PMC3970585 DOI: 10.1186/2193-1801-2-336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 07/08/2013] [Indexed: 01/17/2023]
Abstract
Reptiles have achieved highly diverse morphological and physiological traits that allow them to exploit various ecological niches and resources. Morphology of the temporal region of the reptilian skull is highly diverse and historically it has been treated as an important character for classifying reptiles and has helped us understand the ecology and physiology of each species. However, the developmental mechanism that generates diversity of reptilian skull morphology is poorly understood. We reveal a potential developmental basis that generates morphological diversity in the temporal region of the reptilian skull by performing a comparative analysis of gene expression in the embryos of reptile species with different skull morphology. By investigating genes known to regulate early osteoblast development, we find dorsoventrally broadened unique expression of the early osteoblast marker, Runx2, in the temporal region of the head of turtle embryos that do not form temporal fenestrae. We also observe that Msx2 is also uniquely expressed in the mesenchymal cells distributed at the temporal region of the head of turtle embryos. Furthermore, through comparison of gene expression pattern in the embryos of turtle, crocodile, and snake species, we find a possible correlation between the spatial patterns of Runx2 and Msx2 expression in cranial mesenchymal cells and skull morphology of each reptilian lineage. Regulatory modifications of Runx2 and Msx2 expression in osteogenic mesenchymal precursor cells are likely involved in generating morphological diversity in the temporal region of the reptilian skull.
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Affiliation(s)
- Masayoshi Tokita
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tenno-dai 1-1-1, Tsukuba, Ibaraki, 305-8572 Japan ; Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138 USA
| | - Win Chaeychomsri
- Department of Zoology, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok, 10900 Thailand
| | - Jindawan Siruntawineti
- Department of Zoology, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok, 10900 Thailand
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Gröning F, Jones MEH, Curtis N, Herrel A, O'Higgins P, Evans SE, Fagan MJ. The importance of accurate muscle modelling for biomechanical analyses: a case study with a lizard skull. J R Soc Interface 2013; 10:20130216. [PMID: 23614944 PMCID: PMC3673157 DOI: 10.1098/rsif.2013.0216] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Computer-based simulation techniques such as multi-body dynamics analysis are becoming increasingly popular in the field of skull mechanics. Multi-body models can be used for studying the relationships between skull architecture, muscle morphology and feeding performance. However, to be confident in the modelling results, models need to be validated against experimental data, and the effects of uncertainties or inaccuracies in the chosen model attributes need to be assessed with sensitivity analyses. Here, we compare the bite forces predicted by a multi-body model of a lizard (Tupinambis merianae) with in vivo measurements, using anatomical data collected from the same specimen. This subject-specific model predicts bite forces that are very close to the in vivo measurements and also shows a consistent increase in bite force as the bite position is moved posteriorly on the jaw. However, the model is very sensitive to changes in muscle attributes such as fibre length, intrinsic muscle strength and force orientation, with bite force predictions varying considerably when these three variables are altered. We conclude that accurate muscle measurements are crucial to building realistic multi-body models and that subject-specific data should be used whenever possible.
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Affiliation(s)
- Flora Gröning
- Department of Engineering, Medical and Biological Engineering Research Group, University of Hull, Hull, UK.
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