Arvoaurus

Arvoaurus is a genus of extinct theropod dinosaur described from Early Jurassic deposits in the Arvo Basin. The genus name combines the locality name with the Greek -saurus meaning lizard. The type specimen consists of a partial skull and associated postcranial elements recovered during field work in 2004–2006 by researchers from the University of X. The holotype is cataloged as ARVO-001 and dates to about 190 million years ago.

Arvoaurus is small to medium in size for a theropod, with an estimated length of 2.0–2.5 meters and a light, agile skeleton. The skull is elongated with sharp, serrated teeth and a shallow crest along the top of the snout. Limbs are proportionally elongated, indicating a tendency toward cursorial locomotion. The hands retain three digits but are relatively non-specialized for grasping, consistent with early theropod anatomy.

Classification remains unsettled. Phylogenetic analyses place Arvoaurus within Theropoda, but its exact position is equivocal; some treatments align it with early neotheropods, others with more basal coelophysoids. Additional fossils are needed to resolve relationships.

Paleoecology suggests a semi-arid floodplain environment with seasonal rivers. Arvoaurus likely occupied a generalist carnivorous niche, preying on small vertebrates and scavenging when opportunities arose. Its limb proportions imply pursuit hunting rather than ambush. Co-occurring fauna include earlier ornithischians and contemporaneous sauropodomans, indicating a diverse ecosystem.

Arvoaurus contributes to understanding the early diversification of theropods in this region and highlights the patchy nature of the early Jurassic fossil record.