Eucnemesaurus

Eucnemesaurus
Temporal occurrence
	Upper Triassic
	225 to 210 million years
Locations
	South Africa (Lower Elliot Formation );
Systematics
	Dinosaur (dinosauria)
	Lizard dinosaur (Saurischia)
	Sauropodomorpha
	Sauropods (Sauropoda)
	Riojasauridae
	Eucnemesaurus
Scientific name
	Eucnemesaurus
	van Hoepen , 1920
Art
	Eucnemesaurus fortis;

Eucnemesaurus is a basal (original) genus of sauropodomorphic dinosaurs . It was first scientifically described by van Hoepen in 1920, based on fragmentary remains from the Upper Triassic of South Africa ( Elliot Formation ). For a long time this genus was considered invalid - it was declared either as a synonym of Euskelosaurus or as a noun dubium ("naked name"). A study by Adam Yates (2007), however, comes to the conclusion that Eucnemesaurus was identicalto Aliwalia , which is traditionally thought to be a large, basal theropod and was oftenassigned tothe Herrerasauridae . Yates showed that it was actually a basal sauropodomorpha from the relationship of the sauropods . Since Eucnemesaurus is the first name described, Eucnemesaurus would bevalid and Aliwalia would beinvalid as a younger synonym. The only species is Eucnemesaurus fortis .

The name eucnemesaurus ( gr . Eu - "well," kneme "lower leg" sauros - "lizard") has the tibia to the robust construction.

Systematics and characteristics

A cladistic analysis by Adam Yates (2007) comes to the conclusion that Eucnemesaurus was closely related to Riojasaurus . To combine both genera, Yates creates a new group, the Riojasauridae . The Riojasauridae were more closely related to the sauropods than to the Plateosauridae , but more basal than the Massospondylidae .

Like the related Riojasaurus , Eucnemesaurus was a large, robustly built sauropodomorpha. According to Yates (2007), the genus can be distinguished from other genera by a characteristic on the vertebrae and by two characteristics of the morphology of the trochanter, a section of the upper part of the femur.

Finds

The holotype material described by van Hoepen as Eucnemesaurus (copy number TM 119) consists of fragments of dorsal vertebrae, four caudal vertebrae, fragments of the pubis , the upper end of the thigh bone (femur) and a shin (tibia). This find was discovered on the site of a farm near Slabberts in the South African province of Free State . Aliwalia rex's holotype material, meanwhile, includes the ends of a left femur. This find comes from Aliwal North in the Eastern Cape Province . Another find an incomplete skeleton includes a back and a caudal vertebrae, a coracoid (coracoid), fragments of the shoulder blades (scapula) and a fragment of a femur and two ribs fragments with a. This skeleton was excavated in Rosendal in the province of Free State.

Individual evidence

^ Egbert CN van Hoepen: Contributions to the knowledge of the reptiles of the Karroo Formation. 6. Further dinosaurian material in the Transvaal Museum. In: Annals of the Transvaal Museum. Vol. 7, No. 2, 1920, ISSN 0041-1752 , pp. 93-141.
↑ ^a ^b ^c ^d Adam M. Yates: Solving a dinosaurian puzzle. The identity of Aliwalia rex Galton. In: Historical Biology. Vol. 19, No. 1, 2007, ISSN 0891-2963 , pp. 93-123, doi : 10.1080 / 08912960600866953 .
↑ Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento of October 13, 2011 in the Internet Archive )

[hoepen_20-1] Egbert CN van Hoepen: Contributions to the knowledge of the reptiles of the Karroo Formation. 6. Further dinosaurian material in the Transvaal Museum. In: Annals of the Transvaal Museum. Vol. 7, No. 2, 1920, ISSN 0041-1752 , pp. 93-141.

[yates_07-2] Adam M. Yates: Solving a dinosaurian puzzle. The identity of Aliwalia rex Galton. In: Historical Biology. Vol. 19, No. 1, 2007, ISSN 0891-2963 , pp. 93-123, doi : 10.1080 / 08912960600866953 .

[creisler-3] Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento of October 13, 2011 in the Internet Archive )