1
|
Jenkins KM, Foster W, Napoli JG, Meyer DL, Bever GS, Bhullar BAS. Cranial anatomy and phylogenetic affinities of Bolosaurus major, with new information on the unique bolosaurid feeding apparatus and evolution of the impedance-matching ear. Anat Rec (Hoboken) 2024. [PMID: 39072999 DOI: 10.1002/ar.25546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/27/2024] [Accepted: 07/09/2024] [Indexed: 07/30/2024]
Abstract
Resolving the phylogenetic relationships of early amniotes, in particular stem reptiles, remains a difficult problem. Three-dimensional morphological analysis of well-preserved stem-reptile specimens can reveal important anatomical data and clarify regions of phylogeny. Here, we present the first thorough description of the unusual early Permian stem reptile Bolosaurus major, including the first comprehensive description of a bolosaurid braincase. We describe previously obscured details of the palate, allowing for insight into bolosaurid feeding mechanics. Aspects of the rostrum, palate, mandible, and neurocranium suggest that B. major had a particularly strong bite. We additionally found B. major has a surprisingly slender stapes, similar to that of the middle Permian stem reptile Macroleter poezicus, which may suggest enhanced hearing abilities compared to other Paleozoic amniotes (e.g., captorhinids). We incorporated our new anatomical information into a large phylogenetic matrix (150 OTUs, 590 characters) to explore the relationship of Bolosauridae among stem reptiles. Our analyses generally recovered a paraphyletic "Parareptilia," and found Bolosauridae to diverge after Captorhinidae + Araeoscelidia. We also included B. major within a smaller matrix (10 OTUs, 27 characters) designed to explore the interrelationships of Bolosauridae and found all species of Bolosaurus to be monophyletic. While reptile relationships still require further investigation, our phylogeny suggests repeated evolution of impedance-matching ears in Paleozoic stem reptiles.
Collapse
Affiliation(s)
- Kelsey M Jenkins
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
- Yale Peabody Museum, New Haven, Connecticut, USA
| | - William Foster
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - James G Napoli
- Division of Paleontology, North Carolina Museum of Natural Sciences, Raleigh, North Carolina, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Division of Paleontology, American Museum of Natural History, New York, New York, USA
| | - Dalton L Meyer
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
| | - Gabriel S Bever
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Bhart-Anjan S Bhullar
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
- Yale Peabody Museum, New Haven, Connecticut, USA
| |
Collapse
|
2
|
Hernández-Morales C, Ngo A, Abdelhadi L, Schargel WE, Daza JD, Yánez-Muñoz MH, Smith EN. The skull of the semi-aquatic neotropical lizard Echinosaura horrida (Gymnophthalmidae: Cercosaurinae) reveals new synapomorphies within Gymnophthalmoidea. Anat Rec (Hoboken) 2024. [PMID: 38965784 DOI: 10.1002/ar.25530] [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: 04/16/2024] [Revised: 06/07/2024] [Accepted: 06/14/2024] [Indexed: 07/06/2024]
Abstract
The rough teiid or water cork lizard (Echinosaura horrida) is a small reptile from Colombia and Ecuador placed in a genus that contains eight species and well-known phylogenetic relationships. Here we provide a detailed description and illustrations, bone by bone, of its skull, while we discussed its intraspecific variation by comparing high-resolution computed tomography data from two specimens and the variation within the genus by including previously published data from Echinosaura fischerorum. This allowed to propose putative diagnostic character states for Echinosaura horrida and synapomorphies for Echinosaura. In addition, our discussion includes broader comparisons of new character transformations of the jugal, vomer, orbitosphenoid, and hyoid. These characters are important for diagnosing clades at different levels of the Gymnophthalmoidea phylogeny.
Collapse
Affiliation(s)
| | - Alison Ngo
- Department of Biology, The University of Texas at Arlington, Arlington, Texas, USA
| | - Leila Abdelhadi
- Department of Biology, The University of Texas at Arlington, Arlington, Texas, USA
| | - Walter E Schargel
- Department of Biology, The University of Texas at Arlington, Arlington, Texas, USA
| | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Mario H Yánez-Muñoz
- Unidad de Investigación, Instituto Nacional de Biodiversidad (INABIO), Quito, Pichincha, Ecuador
| | - Eric N Smith
- Department of Biology, The University of Texas at Arlington, Arlington, Texas, USA
| |
Collapse
|
3
|
Araújo Salvino C, Hernandéz-Morales C, Daza JD, Nunes PMS. Comparative anatomy and evolution of the atlantoaxial complex in the fossorial lineage Amphisbaenia (Squamata: Lacertoidea). Anat Rec (Hoboken) 2024. [PMID: 38618897 DOI: 10.1002/ar.25448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/16/2024]
Abstract
The atlas and axis are the first two vertebrae from the cervical series; these two vertebrae are responsible for neck flexion, extension, and rotation movements, while providing insertion points for muscles and tendons. Amphisbaenia is a group of fossorial squamates known for having four distinctive head shapes, which are related to different excavation methods. However, little is known about the relationship between these different digging patterns and the anatomy and evolution of the atlantoaxial complex. In this study, we used computed microtomography data to describe in detail of the atlantoaxial complex for 15 species, belonging to all six current families of Amphisbaenia. Furthermore, we evaluate evolutionary scenarios of selected characters related to the atlantoaxial complex in the most recent phylogeny for Amphisbaenia, using the criteria of parsimony and maximum likelihood. Our results indicate that the evolutionary pattern of the atlantoaxial complex presents a diversification in its morphology that is not always correlated with the shape of the head. This analysis reinforces the hypothesis of remarkable morphological convergences in the evolutionary history of Amphisbaenia. Additionally, some of the characters studied may represent independent evolution through convergence in some cases (e.g., horizontal axis of the neural column) and parallelism in others (e.g., present or absent from the transverse process).
Collapse
Affiliation(s)
- Clara Araújo Salvino
- Graduate Program in Animal Biology, Department of Zoology, Federal University of Pernambuco, Recife, Brazil
| | | | - Juan Diego Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Pedro M Sales Nunes
- Graduate Program in Animal Biology, Department of Zoology, Federal University of Pernambuco, Recife, Brazil
| |
Collapse
|
4
|
Meza A, Bell CJ, Daza JD, Thies ML, Lewis PJ. Variation in the cranial osteology of the amphisbaenian genus Zygaspis based on high-resolution x-ray computed tomography. Anat Rec (Hoboken) 2024; 307:475-494. [PMID: 37849441 DOI: 10.1002/ar.25321] [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: 06/01/2023] [Revised: 07/26/2023] [Accepted: 08/25/2023] [Indexed: 10/19/2023]
Abstract
Amphisbaenians are a specialized fossorial group of reptiles, having developed head-first burrowing, a specialized skull architecture, and an elongated body. This group is generally small-bodied, with some species possessing skulls only a few millimeters long. In this study, we used high-resolution x-ray computed tomography to compare the skulls of 15 specimens from seven of the eight species in the amphisbaenian genus Zygaspis (Zygaspis dolichomenta, Zygaspis ferox, Zygaspis quadrifrons, Zygaspis kafuensis, Zygaspis nigra, Zygaspis vandami, and Zygaspis violacea). Both interspecific and intraspecific variation, including asymmetry, is observed among the cranial bones of the specimens. There are unique morphological features on some cranial bones, including the premaxilla and ectopterygoid of Z. quadrifrons, the pterygoid and vomer of Z. kafuensis, and the extracolumella of Z. nigra. Sexual dimorphism has been previously reported for the species Z. quadrifrons and is observed here as well.
Collapse
Affiliation(s)
- Antonio Meza
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Christopher J Bell
- Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Monte L Thies
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Patrick J Lewis
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| |
Collapse
|
5
|
Bell CJ, Cadena C, Meza A, Rudie L, Lewis PJ. Cranial anatomy of the "round-headed" Amphisbaenian Zygaspis quadrifrons (Squamata, Amphisbaenia) based on high-resolution x-ray computed tomography. Anat Rec (Hoboken) 2024; 307:495-532. [PMID: 37849246 DOI: 10.1002/ar.25304] [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: 06/01/2023] [Revised: 07/26/2023] [Accepted: 08/02/2023] [Indexed: 10/19/2023]
Abstract
Amphisbaenians are a poorly understood clade of fossorial lizards. Because of their derived anatomy and relative scarcity, the systematics of the clade and its placement within squamates has long been controversial. Traditional approaches grouped species into four assemblages according to burrowing behavior and cranial morphology, resulting in the recognition of "shovel-headed," "round-headed," "keel-headed," and "spade-headed" morphotypes. Recent phylogenetic analyses do not support the monophyly of the taxa that share those morphotypes. Detailed analyses of cranial osteology were previously accomplished using high-resolution x-ray computed tomography (HRXCT) for the "shovel-headed" Rhineura hatcherii (Rhineruidae) and the "spade-headed" Diplometopon zarudnyi (Trogonophidae). A detailed description of the "round-headed" Amphisbaena alba was previously completed based upon traditional "dry" skeletal specimens. Seven species of the "round-headed" Blanus (Blanidae) were also analyzed using HRXCT. The goal of that project was a comparative analysis of all extant species of Blanus rather than a detailed, bone-by-bone description of one species, but certainly is useful for comparison with another "round-headed" taxon. The "round-headed" morphotype is by far the most common among amphisbaenians and is much in need of further documentation. We use HRXCT imagery to provide additional data about the disparity in cranial morphology among amphisbaenians. Those data allow us to provide another detailed description of a "round-headed" amphisbaenian, the poorly known southern African species Zygaspis quadrifrons. HRXCT is ideal for this relatively rare and diminutive species. We are able to visualize and describe a detailed reconstruction of the entire skull as well as individual cranial elements. Comparisons with other species that were described in similar detail-D. zarudnyi, Spathorhynchus fossorium, R. hatcherii, and A. alba-and to a lesser degree with Blanus, reveal a complex mosaic of morphological features of the skull in Zygaspis. Preliminary data suggest that intraspecific variation is present within Z. quadrifrons, and interspecific variation among other species of Zygaspis may be sufficient for species-level recognition based on cranial osteology. Our description is, therefore, also intended to serve as a baseline for comparative analysis of other specimens of Z. quadrifrons and of other species within the genus.
Collapse
Affiliation(s)
- Christopher J Bell
- Department of Earth and Planetary Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Cristhian Cadena
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Antonio Meza
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Lauren Rudie
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Patrick J Lewis
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| |
Collapse
|
6
|
Hartstone-Rose A. Intra-terrestrial aliens-Visualizing the bizarre cranial anatomy of the worm-lizard! Anat Rec (Hoboken) 2024; 307:533-534. [PMID: 38009940 DOI: 10.1002/ar.25347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 11/29/2023]
|
7
|
Hawkins RK, Bell CJ, Olori JC, Stocker MR. Intraspecific variation in the cranial osteology of Diplometopon zarudnyi (Squamata: Amphisbaenia: Trogonophidae). J Morphol 2022; 283:1359-1375. [PMID: 35998301 PMCID: PMC9826134 DOI: 10.1002/jmor.21508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/06/2022] [Accepted: 08/17/2022] [Indexed: 01/11/2023]
Abstract
A snake-like body plan and burrowing lifestyle characterize numerous vertebrate groups as a result of convergent evolution. One such group is the amphisbaenians, a clade of limbless, fossorial lizards that exhibit head-first burrowing behavior. Correlated with this behavior, amphisbaenian skulls are more rigid and coossified than those of nonburrowing lizards. However, due to their lifestyle, there are many gaps in our understanding of amphisbaenian anatomy, including how their cranial osteology varies among individuals of the same species and what that reveals about constraints on the skull morphology of head-first burrowing taxa. We investigated intraspecific variation in the cranial osteology of amphisbaenians using seven individuals of the trogonophid Diplometopon zarudnyi. Variation in both skull and individual skull element morphology was examined qualitatively and quantitatively through three-dimensional (3D) models created from microcomputed tomography data. Qualitative examination revealed differences in the number and position of foramina, the interdigitation between the frontals and parietal, and the extent of coossification among the occipital complex, fused basioccipital and parabasisphenoid ("parabasisphenoid-basioccipital complex"), and elements X. We performed 3D landmark-based geometric morphometrics for the quantitative assessment, revealing shape differences in the skull, premaxilla, maxilla, frontal, and parietal. The observed intraspecific variation may be the result of different stages of ontogenetic development or biomechanical optimization for head-first burrowing. For example, variation in the coossification of the occipital region suggests a potential ontogenetic coossification sequence. Examination of these areas of variation across other head-first burrowing taxa will help determine if the variation is clade-specific or part of a broader macroevolutionary pattern of head-first burrowing.
Collapse
Affiliation(s)
- Rebecca K. Hawkins
- Department of Fish and Wildlife ConservationVirginia TechBlacksburgVirginiaUSA,Present address:
Museum Studies Program, Lippincott Hall Room 61410 Jayhawk BlvdLawrenceKansasUSA
| | - Christopher J. Bell
- Department of Geological SciencesThe University of Texas at AustinAustinTexasUSA
| | - Jennifer C. Olori
- Biological Sciences DepartmentState University of New York at OswegoOswegoNew YorkUSA
| | | |
Collapse
|
8
|
Bestwick J, Jones AS, Nesbitt SJ, Lautenschlager S, Rayfield EJ, Cuff AR, Button DJ, Barrett PM, Porro LB, Butler RJ. Cranial functional morphology of the pseudosuchian Effigia and implications for its ecological role in the Triassic. Anat Rec (Hoboken) 2021; 305:2435-2462. [PMID: 34841701 DOI: 10.1002/ar.24827] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/10/2021] [Accepted: 10/07/2021] [Indexed: 11/06/2022]
Abstract
Pseudosuchians, archosaurian reptiles more closely related to crocodylians than to birds, exhibited high morphological diversity during the Triassic with numerous examples of morphological convergence described between Triassic pseudosuchians and post-Triassic dinosaurs. One example is the shuvosaurid Effigia okeeffeae which exhibits an "ostrich-like" bauplan comprising a gracile skeleton with edentulous jaws and large orbits, similar to ornithomimid dinosaurs and extant palaeognaths. This bauplan is regarded as an adaptation for herbivory, but this hypothesis assumes morphological convergence confers functional convergence, and has received little explicit testing. Here, we restore the skull morphology of Effigia, perform myological reconstructions, and apply finite element analysis to quantitatively investigate skull function. We also perform finite element analysis on the crania of the ornithomimid dinosaur Ornithomimus edmontonicus, the extant palaeognath Struthio camelus and the extant pseudosuchian Alligator mississippiensis to assess the degree of functional convergence with a taxon that exhibit "ostrich-like" bauplans and its closest extant relatives. We find that Effigia possesses a mosaic of mechanically strong and weak features, including a weak mandible that likely restricted feeding to the anterior portion of the jaws. We find limited functional convergence with Ornithomimus and Struthio and limited evidence of phylogenetic constraints with extant pseudosuchians. We infer that Effigia was a specialist herbivore that likely fed on softer plant material, a niche unique among the study taxa and potentially among contemporaneous Triassic herbivores. This study increases the known functional diversity of pseudosuchians and highlights that superficial morphological similarity between unrelated taxa does not always imply functional and ecological convergence.
Collapse
Affiliation(s)
- Jordan Bestwick
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Andrew S Jones
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Andrew R Cuff
- Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, York, UK
| | - David J Button
- Department of Earth Sciences, The Natural History Museum, London, UK
| | - Paul M Barrett
- Department of Earth Sciences, The Natural History Museum, London, UK
| | - Laura B Porro
- Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, London, UK
| | - Richard J Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
9
|
Amador LI. Sesamoids and Morphological Variation: a Hypothesis on the Origin of Rod-like Skeletal Elements in Aerial Mammals. J MAMM EVOL 2021. [DOI: 10.1007/s10914-021-09571-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
10
|
Stepanova N, Bauer AM. Phylogenetic history influences convergence for a specialized ecology: comparative skull morphology of African burrowing skinks (Squamata; Scincidae). BMC Ecol Evol 2021; 21:86. [PMID: 33993867 PMCID: PMC8127277 DOI: 10.1186/s12862-021-01821-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 05/09/2021] [Indexed: 11/30/2022] Open
Abstract
Background Skulls serve many functions and as a result, are subject to many different evolutionary pressures. In squamates, many fossorial species occupy a unique region of skull morphospace, showing convergence across families, due to modifications related to head-first burrowing. As different substrates have variable physical properties, particular skull shapes may offer selective advantages in certain substrates. Despite this, studies of variation within burrowers have been limited and are typically focused on a single origin of fossoriality. We focused on seven skink genera (Acontias, Typhlosaurus, Scelotes, Sepsina, Feylinia, Typhlacontias, and Mochlus; 39 sp.) from southern Africa, encompassing at least three independent evolutions of semi-fossoriality/fossoriality. We used microCT scans and geometric morphometrics to test how cranial and mandibular shape were influenced by phylogenetic history, size, and ecology. We also qualitatively described the skulls of four species to look at variation across phylogenetic and functional levels, and assess the degree of convergence. Results We found a strong effect of phylogenetic history on cranial and mandibular shape, with size and substrate playing secondary roles. There was a clear gradient in morphospace from less specialized to more specialized burrowers and burrowers in sand were significantly different from those in other substrates. We also created an anatomical atlas for four species with each element described in isolation. Every bone showed some variation in shape and relative scaling of features, with the skull roofing bones, septomaxilla, vomer, and palatine showing the most variation. We showed how broad-scale convergence in traits related to fossoriality can be the result of different anatomical changes. Conclusions Our study used geometric morphometrics and comparative anatomy to examine how skull morphology changes for a highly specialized and demanding lifestyle. Although there was broad convergence in both shape and qualitative traits, phylogenetic history played a large role and much of this convergence was produced by different anatomical changes, implying different developmental pathways or lineage-specific constraints. Even within a single family, adaptation for a specialized ecology does not follow a singular deterministic path. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01821-w.
Collapse
Affiliation(s)
- Natasha Stepanova
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, Villanova, PA, USA. .,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA.
| | - Aaron M Bauer
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, Villanova, PA, USA
| |
Collapse
|
11
|
Ponssa ML, Abdala V. Sesamoids in Caudata and Gymnophiona (Lissamphibia): absences and evidence. PeerJ 2021; 8:e10595. [PMID: 33384907 PMCID: PMC7751427 DOI: 10.7717/peerj.10595] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 11/26/2020] [Indexed: 11/30/2022] Open
Abstract
An integrative definition of sesamoid bones has been recently proposed, highlighting their relationship with tendons and ligaments, their genetic origin, the influence of epigenetic stimuli on their development, and their variable tissue composition. Sesamoid bones occur mainly associated with a large number of mobile joints in vertebrates, most commonly in the postcranium. Here, we present a survey of the distribution pattern of sesamoids in 256 taxa of Caudata and Gymnophiona and 24 taxa of temnospondyls and lepospondyls, based on dissections, high-resolution X-ray computed tomography from digital databases and literature data. These groups have a pivotal role in the interpretation of the evolution of sesamoids in Lissamphibia and tetrapods in general. Our main goals were: (1) to contribute to the knowledge of the comparative anatomy of sesamoids in Lissamphibia; (2) to assess the evolutionary history of selected sesamoids. We formally studied the evolution of the observed sesamoids by optimizing them in the most accepted phylogeny of the group. We identified only three bony or cartilaginous sesamoids in Caudata: the mandibular sesamoid, which is adjacent to the jaw articulation; one located on the mandibular symphysis; and one located in the posterior end of the maxilla. We did not observe any cartilaginous or osseous sesamoid in Gymnophiona. Mapping analyses of the sesamoid dataset of urodeles onto the phylogeny revealed that the very conspicuous sesamoid in the mandibular symphysis of Necturus beyeri and Amphiuma tridactylum is an independent acquisition of these taxa. On the contrary, the sesamoid located between the maxilla and the lower jaw is a new synapomorphy that supports the node of Hydromantes platycephalus and Karsenia coreana. The absence of a mandibular sesamoid is plesiomorphic to Caudata, whereas it is convergent in seven different families. The absence of postcranial sesamoids in salamanders might reveal a paedomorphic pattern that would be visible in their limb joints.
Collapse
Affiliation(s)
- María Laura Ponssa
- Área Herpetología, Unidad Ejecutora Lillo (UEL), CONICET-Fundación Miguel Lillo, San Miguel de Tucumán, Tucumán, Argentina
| | - Virginia Abdala
- Instituto de Biodiversidad Neotropical (IBN), UNT-CONICET. Cátedra de Biología General, Facultad de Ciencias Naturales e IML, UNT, Yerba Buena, Tucuman, Argentina
| |
Collapse
|
12
|
Holovacs NT, Daza JD, Guerra C, Stanley EL, Montero R. You Can't Run, but You Can Hide: The Skeleton of the Sand-Swimmer Lizard Calyptommatus leiolepis (Squamata: Gymnophthalmidae). Anat Rec (Hoboken) 2019; 303:1305-1326. [PMID: 31469501 DOI: 10.1002/ar.24246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/14/2019] [Accepted: 06/24/2019] [Indexed: 12/25/2022]
Abstract
Squamates exhibit a vast diversity of body plans, which directly determines habitat use and preference. Here the skeleton of the sand-swimmer burrower gymnophthalmid, Calyptommatus leiolepis, is analyzed to investigate how its peculiar fossorial locomotion affects its osteology. Calyptommatus leiolepis is a limb-reduced, short-intermediate tailed lizard. Although there are other studies on its general anatomy, we performed a detailed description of its skeleton. Using high-resolution computer tomography, each bone element within the skeleton was digitally segmented and a detailed description rendered. Anatomical features related to burrowing include the head having a shovel-like snout with a well-developed horizontal soft tissue ridge, nasal cartilages that exclude sand from the nostrils, reduced eyes covered by a brille, lack of forelimbs, extreme reduction of hind limbs, and imbricated scales among others. The genus Calyptommatus has unique features such as a triradiate jugal (with digit-like posterior projections), a reduced pectoral girdle and forelimbs, parasternal processes that interconnect the ribs, and a single digit in the hind limbs. When comparing this species with other gymnophthalmid lizards including, fossorial species, it is clear that Calyptommatus exhibits the highest number of structural modifications within the family. Despite its specialized morphology, it still retains characters that link this genus to other members of Gymnophthalmidae when included in a phylogeny based solely on phenotypic data. Anat Rec, 303:1305-1326, 2020. © 2019 American Association for Anatomy.
Collapse
Affiliation(s)
- Nicholas T Holovacs
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas
| | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas
| | - Cecilia Guerra
- Cátedra Vertebrados, Facultad de Ciencias Naturales, Universidad Nacional de Tucumán, Instituto de Herpetología, Fundación Miguel Lillo, Tucumán, Argentina
| | - Edward L Stanley
- Department of Herpetology, Florida Museum of Natural History, Gainesville, Florida
| | - Ricardo Montero
- Cátedra Vertebrados, Facultad de Ciencias Naturales, Universidad Nacional de Tucumán, Instituto de Herpetología, Fundación Miguel Lillo, Tucumán, Argentina
| |
Collapse
|
13
|
Abdala V, Vera MC, Amador LI, Fontanarrosa G, Fratani J, Ponssa ML. Sesamoids in tetrapods: the origin of new skeletal morphologies. Biol Rev Camb Philos Soc 2019; 94:2011-2032. [PMID: 31359608 DOI: 10.1111/brv.12546] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023]
Abstract
Along with supernumerary bones, sesamoids, defined as any organized intratendinous/intraligamentous structure, including those composed of fibrocartilage, adjacent to an articulation or joint, have been frequently considered as enigmatic structures associated with the joints of the skeletal system of vertebrates. This review allows us to propose a dynamic model to account for part of skeletal phenotypic diversity: during evolution, sesamoids can become displaced, attaching to and detaching from the long bone epiphyses and diaphysis. Epiphyses, apophyses and detached sesamoids are able to transform into each other, contributing to the phenotypic variability of the tetrapod skeleton. This dynamic model is a new paradigm to delineate the contribution of sesamoids to skeletal diversity. Herein, we first present a historical approach to the study of sesamoids, discussing the genetic versus epigenetic theories of their genesis and growth. Second, we construct a dynamic model. Third, we present a summary of literature on sesamoids of the main groups of tetrapods, including veterinary and human clinical contributions, which are the best-studied aspects of sesamoids in recent decades. Finally, we discuss the identity of certain structures that have been labelled as sesamoids despite insufficient formal testing of homology. We also propose a new definition to help the identification of sesamoids in general. This review is particularly timely, given the recent increasing interest and research activity into the developmental biology and mechanics of sesamoids. With this updated and integrative discussion, we hope to pave the way to improve the understanding of sesamoid biology and evolution.
Collapse
Affiliation(s)
- Virginia Abdala
- Cátedra de Biología General, Facultad de Ciencias Naturales e IML, UNT, Miguel Lillo 205, 4000, San Miguel de Tucumán, Argentina.,Instituto de Biodiversidad Neotropical, CONICET- UNT, Horco Molle s/n Yerba Buena, 4107, Tucumán, Argentina
| | - Miriam C Vera
- Instituto de Biología Subtropical (CONICET-UNaM), Facultad de Ciencias Exactas Químicas y Naturales, Universidad Nacional de Misiones, Félix de Azara 1552, CPA N3300LQF, Posadas, Argentina
| | - Lucila I Amador
- Unidad Ejecutora Lillo, FML-CONICET, Miguel Lillo 251, 4000, San Miguel de Tucumán, Argentina
| | - Gabriela Fontanarrosa
- Instituto de Biodiversidad Neotropical, CONICET- UNT, Horco Molle s/n Yerba Buena, 4107, Tucumán, Argentina
| | - Jessica Fratani
- Unidad Ejecutora Lillo, FML-CONICET, Miguel Lillo 251, 4000, San Miguel de Tucumán, Argentina
| | - María L Ponssa
- Unidad Ejecutora Lillo, FML-CONICET, Miguel Lillo 251, 4000, San Miguel de Tucumán, Argentina
| |
Collapse
|
14
|
The Role of Developmental Integration and Historical Contingency in the Origin and Evolution of Cypriniform Trophic Novelties. Integr Comp Biol 2019; 59:473-488. [DOI: 10.1093/icb/icz056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
AbstractWhile functional morphologists have long studied the evolution of anatomical structures, the origin of morphological novelties has received less attention. When such novelties first originate they must become incorporated into an integrated system to be rendered fully functional. Thus, developmental integration is key at the origin of morphological novelties. However, given enough evolutionary time such integration may be broken, allowing for a division of labor that is facilitated by subsequent decoupling of structures. Cypriniformes represent a diverse group of freshwater fishes characterized by several trophic novelties that include: kinethmoid-mediated premaxillary protrusion, a muscular palatal and post-lingual organ, hypertrophied lower pharyngeal jaws that masticate against the base of the neurocranium, novel pharyngeal musculature controlling movement of the hypertrophied lower pharyngeal jaws, and in a few species an incredibly complex epibranchial organ used to aggregate filtered phytoplankton. Here, we use the wealth of such trophic novelties in different cypriniform fishes to present case studies in which developmental integration allowed for the origin of morphological innovations. As proposed in case studies 1 and 2 trophic innovations may be associated with both morphological and lineage diversification. Alternatively, case studies 3 and 4 represent a situation where ecological niche was expanded but with no concomitant increase in species diversity.
Collapse
|
15
|
Villa A, Kirchner M, Alba DM, Bernardini F, Bolet A, Luján ÀH, Fortuny J, Hipsley CA, Müller J, Sindaco R, Tuniz C, Delfino M. Comparative cranial osteology ofBlanus(Squamata: Amphisbaenia). Zool J Linn Soc 2018. [DOI: 10.1093/zoolinnean/zly082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Andrea Villa
- Dipartimento di Scienze della Terra, Università di Torino, Torino, Italy
| | - Martin Kirchner
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - David M Alba
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Barcelona, Spain
| | - Federico Bernardini
- Centro Fermi, Museo Storico della Fisica e Centro di Studi e Ricerche ‘Enrico Fermi’, Roma, Italy
- Multidisciplinary Laboratory, the ‘Abdus Salam’ International Centre for Theoretical Physics, Trieste, Italy
| | - Arnau Bolet
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Barcelona, Spain
- School of Earth Sciences, University of Bristol, Life Sciences Building, Bristol, UK
| | - Àngel H Luján
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Barcelona, Spain
- Department of Geological Sciences, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Josep Fortuny
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Barcelona, Spain
- Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements, Muséum National d’Histoire Naturelle, Bâtiment de Paléontologie, Paris, France
| | - Christy A Hipsley
- School of BioSciences, University of Melbourne, Parkville, Australia
- Museums Victoria, Melbourne, Australia
| | - Johannes Müller
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | | | - Claudio Tuniz
- Multidisciplinary Laboratory, the ‘Abdus Salam’ International Centre for Theoretical Physics, Trieste, Italy
| | - Massimo Delfino
- Dipartimento di Scienze della Terra, Università di Torino, Torino, Italy
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Barcelona, Spain
| |
Collapse
|
16
|
Amador LI, Giannini NP, Simmons NB, Abdala V. Morphology and Evolution of Sesamoid Elements in Bats (Mammalia: Chiroptera). AMERICAN MUSEUM NOVITATES 2018. [DOI: 10.1206/3905.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Lucila Inés Amador
- Unidad Ejecutora Lillo: Fundación Miguel Lillo – CONICET, Tucumán, Argentina
| | - Norberto Pedro Giannini
- Unidad Ejecutora Lillo: Fundación Miguel Lillo – CONICET, Tucumán, Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina
- Division of Vertebrate Zoology (Mammalogy), American Museum of Natural History
| | - Nancy B. Simmons
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Virginia Abdala
- Instituto de Biodiversidad Neotropical: Universidad Nacional de Tucumán – CONICET, Tucumán, Argentina
| |
Collapse
|
17
|
Ledesma DT, Scarpetta SG. The skull of the gerrhonotine lizard Elgaria panamintina (Squamata: Anguidae). PLoS One 2018; 13:e0199584. [PMID: 29953469 PMCID: PMC6023148 DOI: 10.1371/journal.pone.0199584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 06/11/2018] [Indexed: 11/30/2022] Open
Abstract
We provide the first description of the skull, osteoderms, and hyoid apparatus of the poorly known alligator lizard Elgaria panamintina, and compare the cranial osteology of that species to the widespread and well-studied taxon Elgaria multicarinata. Patterns of morphological variation resulting from ontogenetic transformations and pathology are discussed. We employed x-ray computed tomography (CT) scans to examine two adult specimens of Elgaria panamintina and two adult specimens of Elgaria multicarinata, in addition to examining multiple traditionally prepared skeletal specimens of the latter species. CT scans provide simultaneous study of both articulated and disarticulated elements, allowing us to describe and document the morphology of the skull with exceptional precision and detail. The description of the skull of Elgaria panamintina serves as a generalization for all Elgaria; here we provide the first complete description of the skull of this genus for future uses in morphological and phylogenetic studies of both extant species and fossils.
Collapse
Affiliation(s)
- David T. Ledesma
- Jackson School of Geosciences, The University of Texas, Austin, Texas, United States of America
| | - Simon G. Scarpetta
- Jackson School of Geosciences, The University of Texas, Austin, Texas, United States of America
| |
Collapse
|