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Ponce DA, Scheyer TM, Cerda IA, Desojo JB. Palaeobiological inferences of "rauisuchians" Fasolasuchus tenax (Los Colorados Fm., Argentina) and Prestosuchus chiniquensis (Santa Maria Super sequence, Brazil) from the Middle-Upper Triassic of South America based on microstructural analyses. J Anat 2023; 243:893-909. [PMID: 37519277 PMCID: PMC10641045 DOI: 10.1111/joa.13937] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
"Rauisuchia" is a non-monophyletic group of quadrupedal and carnivorous pseudosuchians that inhabited the entire world during the Middle-Upper Triassic period (Anisian/Ladinian-Rhaetian). In South America, "rauisuchians" reached the largest sizes among continental carnivores. Despite their important ecological role, some aspects of their palaeobiology have been poorly examined. Here, we study appendicular bones, dorsal ribs and osteoderms of two genera, the Argentinean Fasolasuchus tenax (PVL 3850, holotype) and the Brazilian Prestosuchus chiniquensis (SNSB-BSPG AS XXV) respectively. The femur of F. tenax is formed by laminar fibrolamellar bone, which is composed of non-fully monorefringent woven-fibred matrix and primary osteons; the dorsal rib has a Haversian bone composition with an external fundamental system recorded and the osteoderm is formed by well-organised parallel-fibred bone. The femur, humerus and fibula of P. chiniquensis are mostly composed of strongly arranged parallel-fibred bone and a laminar vascularisation. The minimal ages obtained correspond to 9 years for F. tenax (based on the maximum number of growth marks in the osteoderm) and 4 years for P. chiniquensis (obtained from the highest count of growth marks in the femur and in the humerus). F. tenax attained somatic and skeletal maturity, while P. chiniquensis was near to reaching skeletal and sexual maturity, but it was somatically immature. The overall rapid growth rate and the high and uniform vascularisation seems to imply that these features are common in most of "rauisuchians", except in P. chiniquensis.
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Affiliation(s)
- Denis A Ponce
- Instituto de Investigación en Paleobiología y Geología (IIPG), CONICET-Universidad Nacional de Río Negro, General Roca, Argentina
- Museo Provincial 'Carlos Ameghino', Cipolletti, Argentina
| | | | - Ignacio A Cerda
- Instituto de Investigación en Paleobiología y Geología (IIPG), CONICET-Universidad Nacional de Río Negro, General Roca, Argentina
| | - Julia B Desojo
- CONICET-División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Buenos Aires, Argentina
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Iijima M, Qiao Y, Lin W, Peng Y, Yoneda M, Liu J. An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction. Proc Biol Sci 2022; 289:20220085. [PMID: 35259993 PMCID: PMC8905159 DOI: 10.1098/rspb.2022.0085] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A solid phylogenetic framework is the basis of biological studies, yet higher level relationships are still unresolved in some major vertebrate lineages. One such group is Crocodylia, where the branching pattern of three major families (Alligatoridae, Crocodylidae and Gavialidae) has been disputed over decades due to the uncertain relationship of two slender-snouted lineages, gavialines and tomistomines. Here, we report a bizarre crocodylian from the Bronze Age of China, which shows a mosaic of gavialine and tomistomine features across the skeleton, rendering support to their sister taxon relationship as molecular works have consistently postulated. Gavialine characters of the new Chinese crocodylian include a novel configuration of the pterygoid bulla, a vocal structure known in mature male Indian gharials. Extinct gavialines have repeatedly evolved potentially male-only acoustic apparatus of various shapes, illuminating the deep history of sexual selection on acoustic signalling in a slender-snouted group of crocodylians. Lastly, a cutmark analysis combined with accelerator mass spectrometry (AMS) radiocarbon dating of bone remains demonstrated that two individuals from Shang and Zhou dynasties in Guangdong, China, suffered head injuries and decapitation. Archaeological evidence together with historical accounts suggests the human-induced extinction of this unique crocodylian only a few hundred years ago.
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Affiliation(s)
- Masaya Iijima
- School of Resource and Environmental Engineering, Hefei University of Technology, 193 Tunxi Road, Baohe, Hefei, Anhui 230009, People's Republic of China,Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA,Nagoya University Museum, Furocho, Chikusa-Ku, Nagoya, Aichi 464-8601, Japan
| | - Yu Qiao
- School of Resource and Environmental Engineering, Hefei University of Technology, 193 Tunxi Road, Baohe, Hefei, Anhui 230009, People's Republic of China
| | - Wenbin Lin
- Xinhui Museum, 12 Gongyuan Road, Xinhui, Jiangmen, Guangdong 529199, People's Republic of China
| | - Youjie Peng
- Shunde Museum, Bishui Road, Shunde, Foshan, Guangdong 528300, People's Republic of China
| | - Minoru Yoneda
- The University Museum, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033, Japan
| | - Jun Liu
- School of Resource and Environmental Engineering, Hefei University of Technology, 193 Tunxi Road, Baohe, Hefei, Anhui 230009, People's Republic of China
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