Riojasuchus
This article has been registered in the quality assurance biology for improvement due to formal or content-related deficiencies . This is done in order to bring the quality of the biology articles to an acceptable level. Please help improve this article! Articles that are not significantly improved can be deleted if necessary.
Read the more detailed information in the minimum requirements for biology articles .
| Riojasuchus | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Live reconstruction of Riojasuchus |
||||||||||||
| Temporal occurrence | ||||||||||||
| Upper Triassic ( Norium to Rhaetium ) | ||||||||||||
| 228 to 201.3 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Riojasuchus | ||||||||||||
| Bonaparte , 1967 | ||||||||||||
| Art | ||||||||||||
|
Riojasuchus is an extinct genus of the Ornithosuchidae from the group of archosaurs . Riojasuchus fossilswere found in the Los Colorados Formation in Argentina and are dated to the Upper Triassic . The holotype, PVL 3827, consists of a complete skull and part of the postcranial skeleton . It wasfirst scientifically describedin 1967 by the Argentine paleontologist José Fernando Bonaparte .
features
Riojasuchus reached a length of about 2 meters. An oversized premaxillary was typical for this genus . The antorbital window is reduced by the fossa of the skull. The lacrimal bone and the post orbitals were fused together. The atlas , the 2nd cervical vertebra, was twice as large as the other cervical vertebrae. There was a small window in the lower jaw. In contrast to other ornithosuchids, Riojasuchus had relatively large spinous processes. The hind limbs of this animal were robustly built. The tibia was twice the diameter of the fibula . The metatarsal (metatarsal bone) III. was longer than the IV metatarsal.
Systematics
Riojasuchus was a member of the Ornithosuchidae . Other members of this family were Ornithosuchus , the eponymous genus, and Venaticosuchus . The external systematics of the Ornithosuchidae is unclear. A study by Brusatte et al. (2010) came to the conclusion that the sister taxon of the Ornithosuchidae is Revueltosaurus ; both form the sister group of the Rauisuchia . According to Nesbitt (2011), the Ornithosuchidae is a basal (primeval) family of the Pseudosuchia . This group within the Crurotarsi contains the Ornithosuchidae as well as the recent crocodiles . The sister taxon of the Ornithosuchidae finally forms the group of Suchia .
Nesbitt (2011) cladogram:
| Pseudosuchia |
|
|||||||||||||||||||||||||||||||||||||||
|
|
Paleoecology
Riojasuchus was found in the Los Colorados Formation in Argentina . The deposits probably come from the Upper Triassic . Other predators of this fauna are the 4 meter long Zupaysaurus from the group of Coelophysoidea ( dinosaurs ). The top predator among the carnivores was probably Fasolasuchus , an animal of the Crurotarsi , which with a length of about 8 to 10 meters was probably the largest predator of the Triassic. Herbivores (herbivores) were represented by the " prosauropods " Coloradisaurus , Lessemsaurus and Riojasaurus . Riojasuchus probably imitated smaller synapsids such as dicynodonts .
Finds
The first find of Riojasuchus , the holotype PVL 3827, was scientifically described by José Fernando Bonaparte in 1967 . The remains consisted of a complete skull , part of the spine , a shoulder blade (scapula), a coracoid , parts of the ulna (ulna) and radius (radius), a pubis , an ilium , and a part of the leg skeleton as well as a foot skeleton. Other finds were PVL 3828, consisting of a nearly complete skull, a part of the spine, parts of the pelvic girdle, arm and leg skeleton and a heel bone , PVL 2826, which consists of almost all parts of the holotype, and PVL 3814, of which only vortex , a humerus and a shin are known.
Individual evidence
- ↑ a b c d e Sterling J. Nesbitt: The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades (= Bulletin of the American Museum of Natural History. No. 352). American Museum of Natural History, New York NY 2011, doi : 10.1206 / 352.1 , digital version (PDF; 32.69 MB) .
- ↑ José Fernando Bonaparte : Dos nuevas "Faunas" de reptiles Triasicos de Argentina. In: Gondwana Stratigraphy. IUGS Symposium Buenos Aires 1–15 October 1967. = La estratigrafía del Gondwana. (= Earth Sciences. 2, ZDB -ID 448604-3 = United Nations Educational. Scientific and Cultural Organization. SC.68 / XVII.2 / AS). UNESCO, Paris 1969, pp. 283-306.
- ↑ Stephen L. Brusatte, Michael J. Benton , Julia B. Desojo, Max C. Langer: The higher-level phylogeny of Archosauria (Tetrapoda: Diapsida). In: Journal of Systematic Palaeontology. Volume 8, No. 1, 2010, pp. 3-47, doi : 10.1080 / 14772010903537732 .
- ^ A b David B. Weishampel , Paul M. Barrett , Rodolfo Coria , Jean Le Loeuff, Xing Xu , Xijin Zhao , Ashok Sahni, Elizabeth Gomani, Christopher R. Noto: Dinosaur distribution. (Late Triassic, South America). In: David B. Weishampel, Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , S, pp. 527-528.
- ^ José F. Bonaparte: Faunas y paleobiogeografía de los tetrápodos mesozoicos de América del Sur. In: Ameghiniana. Volume 16, No. 3/4, 1979, pp. 217-238.
- ^ José F. Bonaparte: Faunal replacement in the Triassic of South America. In: Journal of Vertebrate Paleontology. Volume 2, No. 3, 1982, pp. 362-371, doi : 10.1080 / 02724634.1982.10011938 .
