Eucnemesaurus

Eucnemesaurus is a genus represented by two species of riojasaurid prosauropod dinosaurs, which lived at the end of the Triassic period, approximately 225 and 210 million years ago, in the Carnian, in what is now Africa.

## Description

Presumably Eucnemesaurus had the typical construction of a Prosauropoda, a long neck and tail but walking on two legs. The latter becomes somewhat uncertain due to the size of the animal: the remains indicate a body length of about 10 to 11 meters and the weight is estimated at 1.50 to 2 tons.

Generally considered a synonym for Euskelosaurus . Yates' recent study, however, indicates that it is valid and the same animal as the "supposed giant herrerasaurid, Aliwalia , which was thought to represent the largest known carnivorous dinosaur from the Triassic, was a chimera consisting of a femur of Eucnemesaurus and the jaw of an indeterminate Crurotarsi. Eucnemesaurus was named in 1920 by Egbert Cornelis Nicolaas van Hoepen. The type species is Eucnemesaurus fortis . The genus name is derived from the Classical Greek eu , "well-formed", and knemè , "warm" with saurus , "lizard". The type-specific name means "strong" in Latin. It is based on the holotype, housed in the Transvaal Museum, TrM 119 , a partial skeleton including vertebrae, part of a pubis, femur, and two The remains were found and excavated by Van Hoepen at Slabberts on the Sin Wood Farm, in a layer of the lower Elliot Formation district of Slabberts, Free State Province, South Africa. A second species, Eucnemesaurus entaxonis , was named by McPhee et al in 2015. The species designation refers to entaxonia, the phenomenon that the inner toes are more developed than the outer toes. This species differs from E. fortis in adaptations on the shaft of the femur and on the underside of the shin band to a supporting function of the hind leg.

## Aliwalia

Fossil material now assigned to Eucnemesaurus was once placed in a separate genus, Aliwalia rex . Comparable fossil evidence for this species was small, as for many years only fragments of femurs and a maxilla were known. The size of the femur led many paleontologists for many years to believe that along with the clearly carnivorous maxilla, that Aliwalia was that of a carnivorous dinosaur of notable size for the time in which it lived. It would have been comparable to the large theropods of the Jurassic and Cretaceous, such as Allosaurus , which evolved at least tens of million years after Aliwalia . The original material was considered to bear a strong resemblance to the South American Herrerasaurus , so much so that Aliwalia was originally classified within Herrerasauridae by Peter Galton. However, recent re-evaluation of the material has shown that the maxilla assigned to Aliwalia is no different from other material, belonging to Eucnemesaurus , as it clearly is from a carnivore. Furthermore, the new material clearly demonstrates affinities with sauropodomorphs.

Van Hoepen assigned the species to Plateosauridae. Friedrich von Huene included it in Melanorosauridae in 1941. A cladistic analysis by Adam Yates in 2006 concludes that Eucnemesaurus was closely related to Riojasaurus . To include both genera, Yates creates a new group, Riojasauridae. The Riojasauridae were more closely related to sauropods than to the Plateosauridae, but more basal than the Massospondylidae, which was confirmed in 2015.