1
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Yuan ML, Westeen EP. Decoupled evolution of ventral and dorsal scales in agamid lizards: ventral keels are associated with arboreality. Biol Lett 2024; 20:20240171. [PMID: 38955224 DOI: 10.1098/rsbl.2024.0171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/03/2024] [Indexed: 07/04/2024] Open
Abstract
Arboreality has evolved in all major vertebrate lineages and is often associated with morphological adaptations and increased diversification concomitant with accessing novel niche space. In squamate reptiles, foot, claw, and tail morphology are well-studied adaptations shown to be associated with transitions to arboreality. Here, we examined a less well understood trait-the keeled scale-in relation to microhabitat, climate, and diversification dynamics across a diverse lizard radiation, Agamidae. We found that the ancestral agamid had keeled dorsal but not ventral scales; further, dorsal and ventral keels are evolutionarily decoupled. Ventral keeled scales evolved repeatedly in association with arboreality and may be advantageous in reducing wear or by promoting interlocking when climbing. We did not find an association between keeled scales and diversification, suggesting keels do not allow finer-scale microhabitat partitioning observed in other arboreal-associated traits. We additionally found a relationship between keeled ventral scales and precipitation in terrestrial species where we posit that the keels may function to reduce scale degradation. Our results suggest that keeled ventral scales facilitated transitions to arboreality across agamid lizards, and highlight a need for future studies that explore their biomechanical function in relation to microhabitat and climate.
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Affiliation(s)
- Michael L Yuan
- Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, CA, USA
| | - Erin P Westeen
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
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2
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Maliuk A, Marghoub A, Williams CJA, Stanley E, Kéver L, Vickaryous M, Herrel A, Evans SE, Moazen M. Comparative analysis of osteoderms across the lizard body. Anat Rec (Hoboken) 2024. [PMID: 38396371 DOI: 10.1002/ar.25418] [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: 09/21/2023] [Revised: 12/12/2023] [Accepted: 02/11/2024] [Indexed: 02/25/2024]
Abstract
Osteoderms (ODs) are mineralized tissue embedded within the skin and are particularly common in reptiles. They are generally thought to form a protective layer between the soft tissues of the animal and potential external threats, although other functions have been proposed. The aim of this study was to characterize OD variation across the lizard body. Adults of three lizard species were chosen for this study. After whole body CT scanning of each lizard, single ODs were extracted from 10 different anatomical regions, CT scanned, and characterized using sectioning and nanoindentation. Morphological analysis and material characterization revealed considerable diversity in OD structure across the species investigated. The scincid Tiliqua gigas was the only studied species in which ODs had a similar external morphology across the head and body. Greater osteoderm diversity was found in the gerrhosaurid Broadleysaurus major and the scincid Tribolonotus novaeguineae. Dense capping tissue, like that reported for Heloderma, was found in only one of the three species examined, B. major. Osteoderm structure can be surprisingly complex and variable, both among related taxa, and across the body of individual animals. This raises many questions about OD function but also about the genetic and developmental factors controlling OD shape.
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Affiliation(s)
- Anastasiia Maliuk
- Department of Mechanical Engineering, University College London, London, UK
- Department of Zoology, National Museum of Natural History, NAS of Ukraine, Kyiv, Ukraine
| | - Arsalan Marghoub
- Department of Mechanical Engineering, University College London, London, UK
| | - Catherine J A Williams
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Biology, Aarhus University, Aarhus, Denmark
- Department of Animal and Veterinary Sciences, Aarhus University, Tjele, Denmark
| | - Edward Stanley
- Department of Natural History, Florida Museum of Natural History, Gainesville, Florida, USA
| | - Loïc Kéver
- Département Adaptations du Vivant, UMR7179 CNRS/MNHN, Paris, France
| | - Matthew Vickaryous
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Anthony Herrel
- Département Adaptations du Vivant, UMR7179 CNRS/MNHN, Paris, France
- Department of Biology, Evolutionary Morphology of Vertebrates, Ghent University, Ghent, Belgium
- Department of Biology, University of Antwerp, Wilrijk, Belgium
- Naturhistorisches Museum Bern, Bern, Switzerland
| | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Mehran Moazen
- Department of Mechanical Engineering, University College London, London, UK
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3
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Fierro-Estrada N, Méndez-de la Cruz FR, Tellez-Valdes O. Living in the mountains: Thermal ecology and freezing tolerance of the lizard Abronia taeniata (Squamata: Anguidae). J Therm Biol 2023; 117:103679. [PMID: 37625341 DOI: 10.1016/j.jtherbio.2023.103679] [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: 12/20/2021] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023]
Abstract
The impact of daily and seasonal variation in environmental temperature on lizards is important, since their physiological processes are body temperature dependent. Lizards that occupy mountainous areas must have been favoured to colonize such habitats through selection on thermal biology traits to thermoregulate effectively. Moreover, mountain lizards may be able to maintain their activity near their minimum critical temperature and even have antifreeze mechanisms. Tolerance of freezing is related to the biosynthesis of cryoprotective molecules, such as glucose, whose concentration may increase after freezing. The aims of the present work were: (1) study the thermoregulation of the viviparous lizard Abronia taeniata, and (2) determine its survival and/or tolerance to freezing. This species occurs in pine forests, pine-oak forests, and mountain mesophilic forests in areas that reach freezing temperatures. In the field, we recorded air, substrate, and body temperatures at capture time of the lizards, and registered operative temperatures at the study area. In the laboratory, we determined thermal preferences, crystallization point, and blood glucose levels of individuals before and after freezing. We found out that A. taeniata sustains activity in a wide range of temperatures, actively avoids thermally favourable microhabitats in spring, and is a moderate thermoregulator during autumn and winter. In A. taeniata, the body temperatures are tightly linked to air and substrate temperatures. Seasonality had an effect over body temperature, preferred temperatures and thermoregulatory effectiveness indices. When exposed to temperatures below zero, A. taeniata showed an increase in blood glucose levels, which aided them in surviving freezing. Taken together, our results suggest that A. taeniata may sustain activity at low environmental temperatures, due to an effective behavioural thermoregulation, and in case temperatures of its habitat go below zero, is also capable of tolerate freezing.
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Affiliation(s)
- Natalia Fierro-Estrada
- Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Iztacala, Unidad de Biotecnología y Prototipos, Laboratorio de Recursos Naturales, Avenida de los Barrios Núm. 1, Col. Los Reyes Ixtacala, 54090 Tlalnepantla, Estado de México, México; Posgrado en Ciencias Biológicas, Unidad de Posgrado, Edificio D, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, C.P. 04510, CDMX, México.
| | - Fausto R Méndez-de la Cruz
- Universidad Nacional Autónoma de México, Instituto de Biología, Departamento de Zoología, Laboratorio de Herpetología, Apartado postal 70515, 04510 CDMX, México
| | - Oswaldo Tellez-Valdes
- Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Iztacala, Unidad de Biotecnología y Prototipos, Laboratorio de Recursos Naturales, Avenida de los Barrios Núm. 1, Col. Los Reyes Ixtacala, 54090 Tlalnepantla, Estado de México, México
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4
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Marghoub A, Kéver L, Williams CJA, Abzhanov A, Vickaryous M, Herrel A, Evans SE, Moazen M. The role of cranial osteoderms on the mechanics of the skull in scincid lizards. Anat Rec (Hoboken) 2023; 306:2415-2424. [PMID: 36748783 DOI: 10.1002/ar.25168] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 02/08/2023]
Abstract
Osteoderms (ODs) are calcified organs formed directly within the skin of most major extant tetrapod lineages. Lizards possibly show the greatest diversity in ODs morphology and distribution. ODs are commonly hypothesized to function as a defensive armor. Here we tested the hypothesis that cranial osteoderms also contribute to the mechanics of the skull during biting. A series of in vivo experiments were carried out on three specimens of Tiliqua gigas. Animals were induced to bite a force plate while a single cranial OD was strain gauged. A finite element (FE) model of a related species, Tiliqua scincoides, was developed and used to estimate the level of strain across the same OD as instrumented in the in vivo experiments. FE results were compared to the in vivo data and the FE model was modified to test two hypothetical scenarios in which all ODs were (i) removed from, and (ii) fused to, the skull. In vivo data demonstrated that the ODs were carrying load during biting. The hypothetical FE models showed that when cranial ODs were fused to the skull, the overall strain across the skull arising from biting was reduced. Removing the ODs showed an opposite effect. In summary, our findings suggest that cranial ODs contribute to the mechanics of the skull, even when they are loosely attached.
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Affiliation(s)
- Arsalan Marghoub
- Department of Mechanical Engineering, University College London, London, UK
| | - Loïc Kéver
- Département Adaptations du Vivant, Bâtiment, UMR 7179 MECADEV C.N.R.S/M.N.H.N, d'Anatomie Comparée, Paris, France
| | - Catherine J A Williams
- Department of Biology, Aarhus University, Aarhus C, Denmark
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Arkhat Abzhanov
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, Silkwood Park Campus, Berkshire, UK
| | - Matthew Vickaryous
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Anthony Herrel
- Département Adaptations du Vivant, Bâtiment, UMR 7179 MECADEV C.N.R.S/M.N.H.N, d'Anatomie Comparée, Paris, France
| | - Susan E Evans
- Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, London, UK
| | - Mehran Moazen
- Department of Mechanical Engineering, University College London, London, UK
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5
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Alibardi L. General aspects on skin development in vertebrates with emphasis on sauropsids epidermis. Dev Biol 2023; 501:60-73. [PMID: 37244375 DOI: 10.1016/j.ydbio.2023.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/02/2023] [Accepted: 05/25/2023] [Indexed: 05/29/2023]
Abstract
General cellular aspects of skin development in vertebrates are presented with emphasis on the epidermis of sauropsids. Anamniote skin develops into a multilayered mucogenic and soft keratinized epidermis made of Intermediate Filament Keratins (IFKs) that is reinforced in most fish and few anurans by dermal bony and fibrous scales. In amniotes, the developing epidermis in contact with the amniotic fluid initially transits through a mucogenic phase recalling that of their anamniotes progenitors. A new gene cluster termed EDC (Epidermal Differentiation Complex) evolved in amniotes contributing to the origin of the stratum corneum. The EDC contains numerous genes coding for over 100 types of corneous proteins (CPs). In sauropsids 2-8 layers of embryonic epidermis accumulate soft keratins (IFKs) but do not form a compact corneous layer. The embryonic epidermis of reptiles and birds produces small amount of other, poorly known proteins in addition to IFKs and mucins. In the following development, a resistant corneous layer is formed underneath the embryonic epidermis that is shed before hatching. The definitive corneous epidermis of sauropsids is mainly composed of CBPs (Corneous beta proteins, formerly indicated as beta-keratins) derived from the EDC. CBPs belong to a gene sub-family of CPs unique for sauropsids, contain an inner amino acid region formed by beta-sheets, are rich in cysteine and glycine, and make most of the protein composition of scales, claws, beaks and feathers. In mammalian epidermis CPs missing the beta-sheet region are instead produced, and include loricrin, involucrin, filaggrin and various cornulins. Small amount of CPs accumulate in the 2-3 layers of mammalian embryonic epidermis and their appendages, that is replaced with the definitive corneous layers before birth. Differently from sauropsids, mammals utilize KAPs (keratin associated proteins) rich in cysteine and glycine for making the hard corneous material of hairs, claws, hooves, horns, and occasionally also scales.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova, Italy; Department of Biology, University of Bologna, Bologna, Italy.
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6
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Soon RH, Yin Z, Dogan MA, Dogan NO, Tiryaki ME, Karacakol AC, Aydin A, Esmaeili-Dokht P, Sitti M. Pangolin-inspired untethered magnetic robot for on-demand biomedical heating applications. Nat Commun 2023; 14:3320. [PMID: 37339969 PMCID: PMC10282021 DOI: 10.1038/s41467-023-38689-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/11/2023] [Indexed: 06/22/2023] Open
Abstract
Untethered magnetic miniature soft robots capable of accessing hard-to-reach regions can enable safe, disruptive, and minimally invasive medical procedures. However, the soft body limits the integration of non-magnetic external stimuli sources on the robot, thereby restricting the functionalities of such robots. One such functionality is localised heat generation, which requires solid metallic materials for increased efficiency. Yet, using these materials compromises the compliance and safety of using soft robots. To overcome these competing requirements, we propose a pangolin-inspired bi-layered soft robot design. We show that the reported design achieves heating > 70 °C at large distances > 5 cm within a short period of time <30 s, allowing users to realise on-demand localised heating in tandem with shape-morphing capabilities. We demonstrate advanced robotic functionalities, such as selective cargo release, in situ demagnetisation, hyperthermia and mitigation of bleeding, on tissue phantoms and ex vivo tissues.
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Affiliation(s)
- Ren Hao Soon
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Zhen Yin
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Control Science and Engineering, Tongji University, Shanghai, China
- Frontiers Science Center for Intelligent Autonomous Systems, Shanghai, China
| | - Metin Alp Dogan
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Nihal Olcay Dogan
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Mehmet Efe Tiryaki
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Alp Can Karacakol
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Asli Aydin
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Pouria Esmaeili-Dokht
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany.
- Institute for Biomedical Engineering, ETH Zürich, 8092, Zürich, Switzerland.
- School of Medicine and College of Engineering, Koç University, 34450, Istanbul, Turkey.
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7
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Maden M, Polvadore T, Polanco A, Barbazuk WB, Stanley E. Osteoderms in a mammal the spiny mouse Acomys and the independent evolution of dermal armor. iScience 2023; 26:106779. [PMID: 37378333 PMCID: PMC10291248 DOI: 10.1016/j.isci.2023.106779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/06/2023] [Accepted: 04/25/2023] [Indexed: 06/29/2023] Open
Abstract
Osteoderms are bony plates found in the skin of vertebrates, mostly commonly in reptiles where they have evolved independently multiple times, suggesting the presence of a gene regulatory network that is readily activated and inactivated. They are absent in birds and mammals except for the armadillo. However, we have discovered that in one subfamily of rodents, the Deomyinae, there are osteoderms in the skin of their tails. Osteoderm development begins in the proximal tail skin and is complete 6 weeks after birth. RNA sequencing has identified the gene networks involved in their differentiation. There is a widespread down-regulation of keratin genes and an up-regulation of osteoblast genes and a finely balanced expression of signaling pathways as the osteoderms differentiate. Future comparisons with reptilian osteoderms may allow us to understand how these structures have evolved and why they are so rare in mammals.
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Affiliation(s)
- Malcolm Maden
- Department of Biology & UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Trey Polvadore
- Department of Biology & UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Arod Polanco
- Department of Biology & UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - W. Brad Barbazuk
- Department of Biology & UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Edward Stanley
- Florida Museum of Natural History, University of Florida, Museum Road, Gainesville, FL 32611, USA
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8
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Cherepanov GO, Gordeev DA, Melnikov DA, Ananjeva NB. Osteoderm Development during the Regeneration Process in Eurylepis taeniolata Blyth, 1854 (Scincidae, Sauria, Squamata). J Dev Biol 2023; 11:22. [PMID: 37367476 DOI: 10.3390/jdb11020022] [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: 04/05/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023] Open
Abstract
Osteoderms are bony structures that develop within the dermal layer of the skin in vertebrates and are very often found in different lizard families. Lizard osteoderms are diverse in topography, morphology, and microstructure. Of particular interest are the compound osteoderms of skinks, which are a complex of several bone elements known as osteodermites. We present new data on the development and regeneration of compound osteoderms based on the results of a histological and Computed Microtomography (micro-CT) study of a scincid lizard: Eurylepis taeniolata. The specimens studied are stored in the herpetological collections of the Saint-Petersburg State University and Zoological Institute of the Russian Academy of Sciences located in St. Petersburg, Russia. The topography of osteoderms in the integuments of the original tail area and its regenerated part was studied. A comparative histological description of the original and regenerated osteoderms of Eurylepis taeniolata is presented for the first time. The first description of the development of compound osteoderm microstructure in the process of caudal regeneration is also presented.
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Affiliation(s)
- Gennady O Cherepanov
- Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 St. Petersburg, Russia
| | - Dmitry A Gordeev
- Department of Biology and Bioengineering, Institute of Natural Sciences, Volgograd State University, 400062 Volgograd, Russia
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9
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Schuett GW, Peterson KH, Powell AR, Taylor JD, Alexander JR, Lappin AK. Female-female aggression in the Gila monster ( Heloderma suspectum). ROYAL SOCIETY OPEN SCIENCE 2023; 10:221466. [PMID: 37181791 PMCID: PMC10170349 DOI: 10.1098/rsos.221466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 04/14/2023] [Indexed: 05/16/2023]
Abstract
Historically, the role of aggression in the social lives of animals overwhelmingly focused on males. In recent years, however, female-female aggression in vertebrates, particularly lizards, has received increasing attention. This growing body of literature shows both similarities and differences to aggressive behaviours between males. Here, we document female-female aggression in captive Gila monsters (Heloderma suspectum). Based on four unique dyadic trials (eight adult female subjects), we developed a qualitative ethogram. Unexpected and most intriguing were the prevalence and intensity of aggressive acts that included brief and sustained biting, envenomation, and lateral rotation (i.e. rolling of body while holding onto opponent with closed jaws). Given specific behavioural acts (i.e. biting) and the results of bite-force experiments, we postulate that osteoderms (bony deposits in the skin) offer some degree of protection and reduce the likelihood of serious injury during female-female fights. Male-male contests in H. suspectum, in contrast, are more ritualized, and biting is rarely reported. Female-female aggression in other lizards has a role in territoriality, courtship tactics, and nest and offspring guarding. Future behavioural research on aggression in female Gila monsters is warranted to test these and other hypotheses in the laboratory and field.
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Affiliation(s)
- Gordon W. Schuett
- Department of Biology | Neuroscience Institute, Georgia State University, Atlanta, GA, USA
- Chiricahua Desert Museum, Rodeo, NM, USA
| | | | - Anthony R. Powell
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, USA
| | - John D. Taylor
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, USA
| | - Jennifer R. Alexander
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, USA
| | - A. Kristopher Lappin
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, USA
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10
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Frýdlová P, Janovská V, Mrzílková J, Halašková M, Riegerová M, Dudák J, Tymlová V, Žemlička J, Zach P, Frynta D. The first description of dermal armour in snakes. Sci Rep 2023; 13:6405. [PMID: 37076516 PMCID: PMC10115820 DOI: 10.1038/s41598-023-33244-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 04/10/2023] [Indexed: 04/21/2023] Open
Abstract
Osteoderms, also called dermal armour, often play a role in predator defence. The presence of osteoderms is highly irregularly distributed across the squamate phylogeny and they have not been found in snakes. In this study, we searched for candidate snake species that would benefit from such armour to protect their body, focusing primarily on fossorial species with defensive tail displays. We examined the tail morphology of 27 snake species from different families using micro-computed tomography (µCT) and micro- radiography. We discovered dermal armour in four species of sand boas (Erycidae) that also feature enlarged and highly modified caudal vertebrae. This is the first description of dermal armour in snakes. Ancestral state reconstructions revealed that osteoderms likely evolved once or multiple times in Erycidae. We have not found osteoderms in any other examined snake species. Nevertheless, similar structures are known from unrelated squamate clades, such as gerrhosaurids and geckos. This supports the idea of underlying deep developmental homology. We propose the hypothesis that osteoderms protect sand boas like the "brigandine armour" of medieval warriors. We interpret it as another component of the sand boas' rich defence strategy.
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Affiliation(s)
- Petra Frýdlová
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic
- Department of Anatomy, Third Faculty of Medicine, Charles University, 100 00, Prague, Czech Republic
| | - Veronika Janovská
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic
| | - Jana Mrzílková
- Department of Anatomy, Third Faculty of Medicine, Charles University, 100 00, Prague, Czech Republic
| | - Milada Halašková
- Department of Histology and Embryology, Third Faculty of Medicine, Charles University, 100 00, Prague, Czech Republic
| | - Markéta Riegerová
- Department of Histology and Embryology, Third Faculty of Medicine, Charles University, 100 00, Prague, Czech Republic
| | - Jan Dudák
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, 110 00, Prague, Czech Republic
| | - Veronika Tymlová
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, 110 00, Prague, Czech Republic
| | - Jan Žemlička
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, 110 00, Prague, Czech Republic
| | - Petr Zach
- Department of Anatomy, Third Faculty of Medicine, Charles University, 100 00, Prague, Czech Republic
| | - Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic.
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11
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Powell GL, Russell AP. The veritable horns of a dilemma: Assessing homology of the parietal and squamosal asperities of
Phrynosoma
(Squamata: Iguania: Phrynosomatidae). ACTA ZOOL-STOCKHOLM 2023. [DOI: 10.1111/azo.12454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- G. Lawrence Powell
- Department of Biological Sciences University of Calgary Calgary Alberta Canada
| | - Anthony P. Russell
- Department of Biological Sciences University of Calgary Calgary Alberta Canada
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12
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Pochat-Cottilloux Y, Martin JE, Amiot R, Cubo J, de Buffrénil V. A survey of osteoderm histology and ornamentation among Crocodylomorpha: A new proxy to infer lifestyle? J Morphol 2023; 284:e21542. [PMID: 36533737 PMCID: PMC10108047 DOI: 10.1002/jmor.21542] [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: 07/26/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022]
Abstract
Osteoderms of eight extant and extinct species of crocodylomorphs are studied histologically and morphologically. Most osteoderms display the typical "crocodilian" structure with a woven-fibered matrix surrounded by an upper and a lower parallel fibered matrix. The dorsal ornamentation of those specimens consists of a pit-and-ridge structure, with corresponding remodeling mechanisms. However, an osteoderm of Iberosuchus, studied here for the first time, differs in being nearly devoid of ornamentation; moreover, it shows strong bundles of straight Sharpey's fibers perpendicular to the surface in its lateral and dorsal walls, along with a rough plywood-like structure in its basal plate. This suggests that this osteoderm was more deeply anchored within the dermis than the other osteoderms studied hitherto. This peculiar structure might have been linked to a terrestrial ecology and a specific thermoregulation strategy. Some other notosuchians in our sample do not exhibit ornamentation on their osteoderms, as opposed to neosuchians. Considering current interpretations of osteoderm function(s) in crocodilians, our observations are discussed in reference to possible ecophysiological peculiarities of Notosuchia in general, and Iberosuchus in particular.
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Affiliation(s)
| | - Jeremy E Martin
- Univ Lyon, Univ Lyon 1, ENSL, CNRS, LGL-TPE, Villeurbanne, France
| | - Romain Amiot
- Univ Lyon, Univ Lyon 1, ENSL, CNRS, LGL-TPE, Villeurbanne, France
| | - Jorge Cubo
- Centre de Recherche en Paléontologie-Paris (CR2P), Sorbonne Université, Paris, France
| | - Vivian de Buffrénil
- Centre de Recherche en Paléontologie-Paris (CR2P), Sorbonne Université, Paris, France
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13
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Sena MVDA, Marinho TDS, Montefeltro FC, Langer MC, Fachini TS, Nava WR, Pinheiro AEP, de Araújo EV, Aubier P, de Andrade RCLP, Sayão JM, de Oliveira GR, Cubo J. Osteohistological characterization of notosuchian osteoderms: Evidence for an overlying thick leathery layer of skin. J Morphol 2023; 284:e21536. [PMID: 36394285 PMCID: PMC10107732 DOI: 10.1002/jmor.21536] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/12/2022] [Accepted: 11/16/2022] [Indexed: 11/18/2022]
Abstract
Osteoderms are mineralized structures embedded in the dermis, known for nonavian archosaurs, squamates, xenarthrans, and amphibians. Herein, we compared the osteoderm histology of Brazilian Notosuchia of Cretaceous age using three neosuchians for comparative purposes. Microanatomical analyses showed that most of them present a diploe structure similar to those of other pseudosuchians, lizards, and turtles. This structure contains two cortices (the external cortex composed of an outer and an inner layers, and the basal cortex) and a core in-between them. Notosuchian osteoderms show high bone compactness (>0.85) with varying degrees of cancellous bone in the core. The neosuchian Guarinisuchus shows the lowest bone compactness with a well-developed cancellous layer. From an ontogenetic perspective, most tissues are formed through periosteal ossification, although the mineralized tissues observed in baurusuchid LPRP/USP 0634 suggest a late metaplastic development. Histology suggests that the ossification center of notosuchian osteoderm is located at the keel. Interestingly, we identified Sharpey's fibers running perpendicularly to the outer layer of the external cortex in Armadillosuchus arrudai, Itasuchus jesuinoi, and Baurusuchidae (LPRP/USP 0642). This feature indicates a tight attachment within the dermis, and it is evidence for the presence of an overlying thick leathery layer of skin over these osteoderms. These data allow a better understanding of the osteohistological structure of crocodylomorph dermal bones, and highlight their structural diversity. We suggest that the vascular canals present in some sampled osteoderms connecting the inner layer of the external cortex and the core with the external surface may increase osteoderm surface and the capacity of heat transfer in terrestrial notosuchians.
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Affiliation(s)
- Mariana Valéria de Araújo Sena
- Centre de Recherche en Paléontologie Paris (CR2P, UMR 7207), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, Paris, France.,Centro de Ciências Biológicas e da Saúde, Laboratório de Paleontologia da URCA, Universidade Regional do Cariri, Rua Carolino Sucupira-Pimenta, Crato, Ceará, Brazil
| | - Thiago da Silva Marinho
- Centro de Pesquisas Paleontológicas "Llewellyn Ivor Price", Complexo Cultural e Científico Peirópolis, Pró-Reitoria de Extensão Universitária, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.,Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Felipe Chinaglia Montefeltro
- Departamento de Biologia e Zootecnia, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista, Ilha Solteira, São Paulo, Brazil
| | - Max Cardoso Langer
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Laboratório de Paleontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Thiago Schineider Fachini
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Laboratório de Paleontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - William Roberto Nava
- Museu de Paleontologia de Marília, Prefeitura Municipal de Marília, Marília, São Paulo, Brazil
| | | | - Esaú Victor de Araújo
- Museu Nacional do Rio de Janeiro, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paul Aubier
- Centre de Recherche en Paléontologie Paris (CR2P, UMR 7207), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, Paris, France
| | - Rafael César Lima Pedroso de Andrade
- Centro de Ciências Biológicas e da Saúde, Laboratório de Paleontologia da URCA, Universidade Regional do Cariri, Rua Carolino Sucupira-Pimenta, Crato, Ceará, Brazil
| | - Juliana Manso Sayão
- Museu Nacional do Rio de Janeiro, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gustavo Ribeiro de Oliveira
- Laboratório de Paleontologia e Sistemática (LAPASI), Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
| | - Jorge Cubo
- Centre de Recherche en Paléontologie Paris (CR2P, UMR 7207), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, Paris, France
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14
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Marghoub A, Williams CJ, Leite JV, Kirby AC, Kéver L, Porro LB, Barrett PM, Bertazzo S, Abzhanov A, Vickaryous M, Herrel A, Evans SE, Moazen M. Unravelling the structural variation of lizard osteoderms. Acta Biomater 2022; 146:306-316. [PMID: 35552001 DOI: 10.1016/j.actbio.2022.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/12/2022] [Accepted: 05/03/2022] [Indexed: 12/15/2022]
Abstract
Vertebrate skin is a remarkable organ that supports and protects the body. It consists of two layers, the epidermis and the underlying dermis. In some tetrapods, the dermis includes mineralised organs known as osteoderms (OD). Lizards, with over 7,000 species, show the greatest diversity in OD morphology and distribution, yet we barely understand what drives this diversity. This multiscale analysis of five species of lizards, whose lineages diverged ∼100-150 million years ago, compared the micro- and macrostructure, material properties, and bending rigidity of their ODs, and examined the underlying bones of the skull roof and jaw (including teeth when possible). Unsurprisingly, OD shape, taken alone, impacts bending rigidity, with the ODs of Corucia zebrata being most flexible and those of Timon lepidus being most rigid. Macroscopic variation is also reflected in microstructural diversity, with differences in tissue composition and arrangement. However, the properties of the core bony tissues, in both ODs and cranial bones, were found to be similar across taxa, although the hard, capping tissue on the ODs of Heloderma and Pseudopus had material properties similar to those of tooth enamel. The results offer evidence on the functional adaptations of cranial ODs, but questions remain regarding the factors driving their diversity. STATEMENT OF SIGNIFICANCE: Understanding nature has always been a significant source of inspiration for various areas of the physical and biological sciences. Here we unravelled a novel biomineralization, i.e. calcified tissue, OD, forming within the skin of lizards which show significant diversity across the group. A range of techniques were used to provide an insight into these exceptionally diverse natural structures, in an integrated, whole system fashion. Our results offer some suggestions into the functional and biomechanical adaptations of OD and their hierarchical structure. This knowledge can provide a potential source of inspiration for biomimetic and bioinspired designs, applicable to the manufacturing of light-weight, damage-tolerant and multifunctional materials for areas such as tissue engineering.
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15
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Čerňanský A, Stanley EL, Daza JD, Bolet A, Arias JS, Bauer AM, Vidal-García M, Bevitt JJ, Peretti AM, Aung NN, Evans SE. A new Early Cretaceous lizard in Myanmar amber with exceptionally preserved integument. Sci Rep 2022; 12:1660. [PMID: 35102237 PMCID: PMC8803969 DOI: 10.1038/s41598-022-05735-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/12/2022] [Indexed: 12/20/2022] Open
Abstract
We here report on a well-preserved juvenile lizard specimen in Albian amber (ca. 110 mya) from the Hkamti site (Myanmar). This new taxon is represented by an articulated skull and the anterior portion of the trunk, including the pectoral girdle and forelimbs. The scleral ossicles and eyelid are also visible, and the specimen exhibits pristine detail of the integument (of both head and body). In a combined molecular and morphological analysis, it was consistently recovered as a scincoid lizard (Scinciformata), as sister to Tepexisaurus + Xantusiidae. However, the phylogenetic position of the new taxon should be interpreted with caution as the holotype is an immature individual. We explored the possibility of miscoding ontogenetically variable characters by running alternative analyses in which these characters were scored as missing data for our taxon. With the exception of one tree, in which it was sister to Amphisbaenia, the specimen was recovered as a Pan-xantusiid. Moreover, we cannot rule out the possibility that it represents a separate lineage of uncertain phylogenetic position, as it is the case for many Jurassic and Cretaceous taxa. Nonetheless, this fossil offers a rare opportunity to glimpse the external appearance of one group of lizards during the Early Cretaceous.
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Affiliation(s)
- Andrej Čerňanský
- Department of Ecology, Laboratory of Evolutionary Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, 84215, Bratislava, Slovakia.
| | - Edward L Stanley
- Department of Natural History, Florida Museum of Natural History, Gainesville, FL, USA
| | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX, USA
| | - Arnau Bolet
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain.,School of Earth Sciences, University of Bristol, Bristol, UK
| | - J Salvador Arias
- Unidad Ejecutora Lillo (CONICET, Fundación Miguel Lillo), San Miguel de Tucumán, Argentina
| | - Aaron M Bauer
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, Villanova, PA, USA
| | - Marta Vidal-García
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, Canada
| | - Joseph J Bevitt
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | - Adolf M Peretti
- GRS Gemresearch Swisslab AG, Baumschulweg 13, 6045, Meggen, Switzerland.,Peretti Museum Foundation, Baumschulweg 13, 6045, Meggen, Switzerland
| | - Nyi Nyi Aung
- Peretti Museum Foundation, Baumschulweg 13, 6045, Meggen, Switzerland.,Myanmar Geosciences Society, c/o Department of Geology, University of Yangon, 11041, Yangon, Myanmar
| | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London, UK
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16
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Bezerra AM, Citeli N, Galvão A, Carvalho-e-Silva SPD. Minimizing the damage: a methodological proposal to remove the brains of anurans and squamates. IHERINGIA. SERIE ZOOLOGIA 2022. [DOI: 10.1590/1678-4766e2022013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
| | | | - Ana Galvão
- Universidade Federal do Rio de Janeiro, Brazil
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17
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Liang C, Marghoub A, Kever L, Bertazzo S, Abzhanov A, Vickaryous M, Herrel A, E Evans S, Moazen M. Lizard osteoderms - Morphological characterisation, biomimetic design and manufacturing based on three species. BIOINSPIRATION & BIOMIMETICS 2021; 16:066011. [PMID: 34525458 DOI: 10.1088/1748-3190/ac26d0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Osteoderms (OD) are mineralised dermal structures consisting mainly of calcium phosphate and collagen. The sheer diversity of OD morphologies and their distribution within the skin of lizards makes these reptiles an ideal group in which to study ODs. Nonetheless, our understanding of the structure, development, and function of lizard ODs remains limited. The specific aims of this study were: (1) to carry out a detailed morphological characterisation of ODs in three lizard species; (2) to design and manufacture biomimetic sheets of ODs corresponding to the OD arrangement in each species; and (3) to evaluate the impact resistance of the manufactured biomimetic sheets under a drop weight test. Skin samples of the anguimorphsH. suspectumandO. ventralis, and the skinkC. zebratawere obtained from frozen lab specimens. Following a series of imaging and image characterisations, 3D biomimetic models of the ODs were developed. 3D models were then printed using additive manufacturing techniques and subjected to drop weight impact tests. The results suggest that a 3D printed compound of overlapping ODs as observed inCoruciacan potentially offers a higher energy absorption by comparison with the overlapping ODs ofOphisaurusand the non-overlapping ODs ofHeloderma.Compound overlapping ODs need to be further tested and explored as a biomimetic concept to increase the shock absorption capabilities of devices and structures.
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Affiliation(s)
- Ce Liang
- Department of Mechanical Engineering, University College London, London WC1E 7JE, United Kingdom
| | - Arsalan Marghoub
- Department of Mechanical Engineering, University College London, London WC1E 7JE, United Kingdom
| | - Loic Kever
- UMR 7179 MECADEV C.N.R.S/M.N.H.N., Département Adaptations du Vivant, Bâtiment, d'Anatomie Comparée, 55 rue Buffon, 75005, Paris, France
| | - Sergio Bertazzo
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Arkhat Abzhanov
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, Silkwood18 Park Campus, Berkshire, SL5 7PY, United Kingdom
| | - Matthew Vickaryous
- Department of Biomedical Sciences, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Anthony Herrel
- UMR 7179 MECADEV C.N.R.S/M.N.H.N., Département Adaptations du Vivant, Bâtiment, d'Anatomie Comparée, 55 rue Buffon, 75005, Paris, France
| | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Mehran Moazen
- Department of Mechanical Engineering, University College London, London WC1E 7JE, United Kingdom
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18
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Paparella I, Caldwell MW. Cranial anatomy of the Galápagos marine iguana Amblyrhynchus cristatus (Squamata: Iguanidae). Anat Rec (Hoboken) 2021; 305:1739-1786. [PMID: 34652885 DOI: 10.1002/ar.24797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/24/2022]
Abstract
Amblyrhynchus cristatus, the marine iguana, is unique among the ~7,000 species of living limbed lizards as it has successfully evolved adaptations that allow it to live in both terrestrial and marine environments. This species is endemic to the Galápagos Archipelago and has evolved a specialized feeding behavior, consuming primarily the algae that grow on the rocky seafloor. The intriguing questions arising around the evolution of the marine iguana concerns the use of exaptations of terrestrial features for aquatic and specifically marine adaptations. However, the lack of fundamental information about its anatomy currently prevents us from understanding how it became adapted to such a peculiar lifestyle in comparison to all other iguanids. The goal of this study is to provide the first ever description of the skull, mandible, and hyoid of Amblyrhynchus. We examined several specimens of marine iguana, including skeletal, wet, and ct-scanned material, and individuals at different ontogenetic stages. We also analyzed specimens of all other modern iguanid genera (Conolophus, Iguana, Ctenosaura, Cyclura, Dipsosaurus, Brachylophus, Sauromalus) in order to make comparisons between Amblyrhynchus and its closest relatives. We were able to identify several autapomorphic features that distinguish the marine iguana from all other iguanids. These unique morphologies are mostly associated with the modified configuration of the snout (nasal chamber), increased muscle attachments in the temporal-postorbital region of the skull, and dentition. Since Amblyrhynchus is the only nonophidian squamate currently able to exploit the ocean at least for some vital functions (i.e., feeding), we used comparisons to fossil marine lizards (e.g., mosasaurids) to discuss some of these unique traits. The new cranial features described for Amblyrhynchus may represent a source of novel morphological characters for use in future phylogenetic analyses of iguanian (or squamate) relationships, which will then serve as the foundation for the exploration of evolutionary patterns and processes that led to the development of such unique adaptations.
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Affiliation(s)
- Ilaria Paparella
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael W Caldwell
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
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