Anabisetia
Skeletal reconstruction of Anabisetia saldiviai
- Argentina ( Lisandro - Formation)
- Anabisetia saldiviai
Anabisetia is a genus of basal ornithopoder dinosaur from the early Late Cretaceous of Argentina. This genus is known by four fragmentary skeletons that originate from the Lisandro Formation in the Neuquén province. Anabisetia was described in 2002 with the single species Anabisetia saldiviai scientifically. It was a small, about two feet long -legged herbivores.
Features
A few fragmentary bones of the skull are only preserved in the holotype specimen and include fragments of the upper jaw (maxilla ), lower jaw ( dentary ) and an incomplete skull one. The teeth of the lower jaw show convex tooth crowns. In the upper jaw, only one complete, sheet-like tooth is obtained, which has a crest on the labial side shows - a well-known feature of Euiguanodontiern.
The Postkranium ( skeleton without skull), is considered one every four finds, almost completely known. Of all the other ornithopods to Anabisetia characterized by various anatomical features ( autapomorphies ) of: For example, the fifth metacarpal bone ( metacarpal ) was flattened, the shoulder blade (scapula ) shows a very pronounced Acromialprozess, and the ilium ( ilium ) has a Präacetabularprozess, the more than half as long as the total length was the ilium.
System
The descriptor of this genus ( Coria and Calvo, 2002) presented Anabisetia to Euiguanodontia within the Iguanodontia. Indicate that Anabisetia is more advanced than Thescelosaurus and some features with the Dryomorpha has in common, which include, inter alia Dryosaurus, Camptosaurus and Iguanodon. When the closest related genus is Gasparinisaura, which also comes from Patagonia, but is smaller and geologically younger than Anabisetia. According to these researchers could Anabisetia with Gasparinisaura a new monophyletic group have formed basal Iguanodontia, which was restricted to South America. Alternatively, it could have been a sister taxon of Dryomorpha Anabisetia. Norman and colleagues ( 2004), however, found Anabisetia and Gasparinisaura clearly primitive, and set it outside the Iguanodontia but within the Euornithopoda. Butler and colleagues ( 2008) provide Anabisetia only to the ornithopods.
Fund and naming
In 1993 he discovered the farmer Roberto Saldivia some bone fragments in Cerro Bayo Mesa, a locality 30 km south of Plaza Huincul. Saldivia presented the findings at the Museo Carmen Funes, which led to the discovery of four incomplete skeletons. 2002 described Rodolfo Coria and Jorge Calvo, the finds as a new genus ornithopoder dinosaurs, which they called Anabisetia. The name honors Anabisetia Ana M. Biset, an archaeologist of the Direccion General de Cultura de Neuquén, which contributed significantly to the laws of the Province in terms of fossils. The species name honors Roberto saldiviai Saldivia, who discovered the first fossils and had helped in the excavations. The skeletons are now kept in the Museo Carmen Funes in Plaza Huincul.
Stratigraphic origin of the finds from the Lisandro Formation, a layer member of the Neuquén Group. They are about 95-92 million years old (late Cenomanian to early Turonian ). The holotype specimen ( specimen number MCF- PVPH -74 ) is the skeleton most complete and is next to a few skull bones, among other things from the entire left shoulder girdle with arm and hand, the almost complete left hind leg including foot, mostly incomplete vertebrae ( four cervical vertebrae, four vertebrae, four sacral vertebrae, twelve vertebrae of the tail ), and the coracoid ( coracoid ). Another skeleton, copy number MCF- PVPH -75, consists among other things of some vertebrae fragments, both shoulder blades, some pelvic bones, leg bones and foot bones together. A third skeleton, copy number MCF- PVPH -76, in addition to vertebral fragments shows the complete right scapula and right pelvis, leg bones, and two foot bones. The Fourth skeleton, copy number MCF- PVPH -77, meanwhile, consists of the majority of articulated tail, scapula, humerus and foot.