Laosuchus naga gen. nov. sp. nov., a new chroniosuchian from Southeast Asia (Laos) with internal structures revealed by micro-CT scan and discussion of its palaeobiology
| Autor: | Thomas Arbez, Christian A. Sidor, J. Sébastien Steyer |
|---|---|
| Přispěvatelé: | Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Washington [Seattle] |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
010506 paleontology Permian [SDV.BID]Life Sciences [q-bio]/Biodiversity tomography phylogeny 010603 evolutionary biology 01 natural sciences Paleontology stomatognathic system Genus medicine Foramen 0105 earth and related environmental sciences geography geography.geographical_feature_category biology sensory system Reptiliomorpha biology.organism_classification braincase Skull medicine.anatomical_structure Ridge palaeobiogeography Otic notch Crest [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology Geology |
| Zdroj: | Journal of Systematic Palaeontology Journal of Systematic Palaeontology, Taylor & Francis, In press, ⟨10.1080/14772019.2018.1504827⟩ |
| ISSN: | 1477-2019 1478-0941 |
| Popis: | International audience; Chroniosuchians were a clade of non-amniotic tetrapods known from the Guadalupian (middle Permian) to Late Triassic, mainly from Russia and China. The rarity of complete or articulated remains means that relatively little is known about this group in terms of its anatomy, palaeobiology, or evolutionary history. Based on a nearly complete skull with a left hemimandible, we describe the first chroniosuchian from Laos from rocks preserving the Permian-Triassic boundary in the Luang Prabang Basin, which is located on the tectonic Indochina Block. This specimen is referred to a new genus and species, Laosuchus naga, based on numerous diagnostic features, including an extremely reduced pineal foramen; absence of palatal dentition; well-developed transverse flange of the pterygoid that contacts the maxilla; internal crest on and above the dorsal side the palate; otic notch closed by the tabular horn and the posterior part of the squamosal, forming a continuous wall; thin and high ventromedial ridge on parasphenoid. A phylogenetic analysis of 51 characters and 25 taxa reveals a basal position for Laosuchus naga among Chroniosuchia. In addition, CT scan data reveal internal structures and provide new insights about the anatomy and palaeobiology of chroniosuchians. Laosuchus naga was likely amphibious and spent most of its time in water, rather than in terrestrial environments. As chroniosuchians are nonmarine tetrapods previously known on the North 2 China Block, South China Block, and Laurussia, the occurrence of Laosuchus naga on the Indochina Block supports the hypothesis of physical connections between all these tectonic plates by the time of the Permo-Triassic boundary. |
| Databáze: | OpenAIRE |
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