Alxasaurus

Alxasaurus
Temporal range: Albian,
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Restored skeleton mount at the Royal Tyrrell Museum of Palaeontology
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Therizinosauria
Superfamily: Therizinosauroidea
Genus: Alxasaurus
Russell & Dong, 1993
Type species
Alxasaurus elesitaiensis
Russell & Dong, 1993

Alxasaurus (/ˌɑːlʃəˈsɔːrəs/; meaning "Alxa lizard") is a genus of therizinosauroid theropod dinosaurs from the Early Cretaceous (Albian age) Bayin-Gobi Formation of Inner Mongolia. It is known from five specimens, recovered from the Bayin-Gobi in 1988, as part of the China-Canada Dinosaur Project. During their preparation, palaeontologists Dong Zhiming and Dale Russell noted strong similarities to Segnosaurus. In 1993, they described Alxasaurus and named its type species, A. elesitaiensis. While therizinosaurs had previously been tentatively seen as late-surviving basal sauropodomorphs, the description of Alxasaurus lent credence to the idea that they were instead highly derived coelurosaurs.

While outside of Therizinosauridae itself, Alxasaurus had many of the traits characteristic of derived therizinosaurs, such as an abbreviated tail, shortened metatarsals and broad feetconvergent with those of basal sauropodomorphs, and fairly long, recurved hand claws. Like related genera, it likely would have had a beak and a large gut, both adaptations for a herbivorous diet.