1
|
Mooney ED, Maho T, Philp RP, Bevitt JJ, Reisz RR. Paleozoic cave system preserves oldest-known evidence of amniote skin. Curr Biol 2024; 34:417-426.e4. [PMID: 38215745 DOI: 10.1016/j.cub.2023.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/29/2023] [Accepted: 12/05/2023] [Indexed: 01/14/2024]
Abstract
The richest and most diverse assemblage of early terrestrial tetrapods is preserved within the infilled cave system of Richards Spur, Oklahoma (289-286 Mya1). Some of the oldest-known terrestrial amniotes2,3 are exquisitely preserved here because of early impregnation and encasement of organic material by oil-seep hydrocarbons within rapidly deposited clay-rich cave sediments under toxic anoxic conditions.4 This phenomenon has also afforded the preservation of exceedingly rare integumentary soft tissues, reported here, providing critical first evidence into the anatomical changes marking the transition from the aquatic and semiaquatic lifestyles of anamniotes to the fully terrestrial lifestyles of early amniotes. This is the first record of a skin-cast fossil (3D carbonization of the skin proper) from the Paleozoic Era and the earliest known occurrence of epidermal integumentary structures. We also report on several compression fossils (carbonized skin impressions), all demonstrating similar external morphologies to extant crocodiles. A variety of previously unknown ossifications, as well as what are likely palpebral ossifications of the deeper dermis layer of the skin, are also documented. These fossils also serve as invaluable references for paleontological reconstructions. Chromatographic analysis of extractable hydrocarbons from bone and cave samples indicates that the source rock is the Devonian age Woodford Shale. Hydrocarbons derived from ancient marine organisms interacting with geologically younger terrestrial vertebrates have therefore resulted in the oldest-known preservation of amniote skin proper.
Collapse
Affiliation(s)
- Ethan D Mooney
- Dinosaur Evolution Research Center, International Center of Future Science, Jilin University, 2699 Qianjin Str., Changchun, Jilin Province 130012, China; Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga L5L1C6, Ontario, Canada.
| | - Tea Maho
- Dinosaur Evolution Research Center, International Center of Future Science, Jilin University, 2699 Qianjin Str., Changchun, Jilin Province 130012, China; Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga L5L1C6, Ontario, Canada.
| | - R Paul Philp
- School of Geosciences, University of Oklahoma, 1000 Asp Avenue, Norman 73019, Oklahoma, USA
| | - Joseph J Bevitt
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, New Illawarra Rd., Lucas Heights 2234, New South Wales, Australia
| | - Robert R Reisz
- Dinosaur Evolution Research Center, International Center of Future Science, Jilin University, 2699 Qianjin Str., Changchun, Jilin Province 130012, China; Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga L5L1C6, Ontario, Canada.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Vasconcelos IAD, Souza JOD, de Castro JS, Santana CJCD, Magalhães ACM, Castro MDS, Pires Júnior OR. Salamanders and caecilians, neglected from the chemical point of view. TOXIN REV 2021. [DOI: 10.1080/15569543.2021.1977326] [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]
Affiliation(s)
| | | | | | - Carlos José Correia de Santana
- Department of Physiological Sciences, University of Brasilia, Brasilia, Brazil
- Department of Cell Biology, University of Brasilia, Brasilia, Brazil
| | | | - Mariana de Souza Castro
- Department of Physiological Sciences, University of Brasilia, Brasilia, Brazil
- Department of Cell Biology, University of Brasilia, Brasilia, Brazil
| | | |
Collapse
|