Anabisetia
| Anabisetia | ||||||||
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Skeletal reconstruction of Anabisetia saldiviai |
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| Temporal occurrence | ||||||||
| Upper Cretaceous (late Cenomanian to early Turonian ) | ||||||||
| 95.5 to 92.19 million years | ||||||||
| Locations | ||||||||
| Systematics | ||||||||
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| Scientific name | ||||||||
| Anabisetia | ||||||||
| Coria & Calvo , 2002 | ||||||||
| Art | ||||||||
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Anabisetia is a genus of basal ornithopic dinosaur from the early Upper Cretaceous Argentina . This genus is known by four fragmentary skeletons that come from the Lisandro Formation in the Neuquén province . Anabisetia wasscientifically described in 2002 with the only species Anabisetia saldiviai . It was a small, two- legged herbivore about six feet long.
features
Few fragmentary cranial bones have survived only in the holotype specimen and include fragments of the upper jaw (maxilla), lower jaw (dentals) and an incomplete cranium . The teeth of the lower jaw show convex crowns. In the upper jaw only a single complete, leaf-like tooth is preserved, which shows a ridge on the labial side - a feature known from Euiguanodontists .
The postcranium (skeleton without skull) is, if you consider all four finds, almost completely known. Anabisetia is distinguished from all other ornithopods by various anatomical features ( autapomorphies ): For example, the fifth metacarpal bone was flattened, the shoulder blade (scapula) shows a very pronounced acromial process, and the ilium (ilium) has a pre-acetabular process that is more than half as long as the total length of the iliac bone.
Systematics
The descriptors of this genus (Coria and Calvo, 2002) put Anabisetia among the Euiguanodontia within the Iguanodontia . They state that Anabisetia is more advanced than Thescelosaurus and shares some characteristics with the Dryomorpha , including Dryosaurus , Camptosaurus, and Iguanodon , among others . The most closely related genus is Gasparini's aura , which also comes from Patagonia, but is smaller and geologically younger than Anabisetia . According to these researchers, Anabisetia may have formed a new monophyletic group of basal Iguanodontia with Gasparini's aura that was restricted to South America. Alternatively, Anabisetia could have been a sister taxon of the Dryomorpha. Norman and colleagues (2004), however, found Anabisetia and Gasparinisaura to be much more primitive and placed them outside the Iguanodontia, but within the Euornithopoda. Butler and colleagues (2008) place Anabisetia only among the ornithopods.
Find and naming
In 1993 the farmer Roberto Saldivia discovered some bone fragments in Cerro Bayo Mesa, a locality 30 km south of Plaza Huincul. Saldivia handed the finds over to the Museo Carmen Funes , which led to the discovery of four incomplete skeletons. In 2002, Rodolfo Coria and Jorge Calvo described the finds as a new genus of ornithopod dinosaurs, which they named Anabisetia . The name Anabisetia honors Ana M. Biset, an archaeologist from the Direccion General de Cultura de Neuquén, who made a decisive contribution to the province's legislation on fossils. The species name saldiviai honors Roberto Saldivia, who discovered the first fossils and who helped with the excavations. The skeletons are now kept in the Museo Carmen Funes in Plaza Huincul.
Stratigraphically , the finds come from the Lisandro Formation , a member of the Neuquén group . They are around 95 to 92 million years old (Late Cenomanian to Early Turonian ). The holotype -Exemplar (copy number MCF-PVPh-74) is the skeleton obtained at the most and is in addition to a few skull bones including some from the entire left shoulder belt with arm and hand, the almost complete left hind leg, including the foot, mostly incomplete vertebrae (four cervical vertebrae, four vertebrae, four sacral vertebrae, twelve caudal vertebrae) and the coracoid (coracoid). Another skeleton, specimen number MCF-PVPH-75, is made up of some vertebral fragments, both shoulder blades, some pelvic bones, leg bones and foot bones. A third skeleton, copy number MCF-PVPH-76, shows vertebral fragments, the complete right shoulder blade and right pelvis, leg bones, and two foot bones. The fourth skeleton, specimen number MCF-PVPH-77, meanwhile consists of the majority of an articulated tail, shoulder blade, humerus and foot.
literature
- Rodolfo A. Coria , Jorge O. Calvo : A new iguanodontian ornithopod from Neuquen Basin, Patagonia, Argentina. In: Journal of Vertebrate Paleontology. Vol. 22, No. 3, 2002, ISSN 0272-4634 , pp. 503-509, doi : 10.1671 / 0272-4634 (2002) 022 [0503: ANIOFN] 2.0.CO; 2 .
Individual evidence
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ 2010, ISBN 978-0-691-13720-9 , p. 277, online .
- ↑ Anabisetia saldiviai. In: DinoData. Archived from the original on April 24, 2007 ; accessed on August 30, 2014 .
- ^ David B. Norman , Hans-Dieter Sues , Lawrence M. Witmer, Rodolfo A. Coria : Basal Ornithopoda. 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 , pp. 393-412.
- ^ Richard J. Butler, Paul Upchurch , David B. Norman: The phylogeny of the ornithischian dinosaurs. In: Journal of Systematic Palaeontology. Vol. 6, No. 1, 2008, ISSN 1477-2019 , pp. 1-40, doi : 10.1017 / S1477201907002271 .