Taxonomic reassessment of archosaurs with dinosaurian affinities from the lower fauna of the Upper Triassic Maleri Formation of India and their significance

The Lower Fauna of the Upper Triassic Maleri Formation of Pranhita Godavari basin hosts a diverse array of fossil diapsids, including the putative dinosaur <i>Alwalkeria maleriensis</i> that was described based on a partial skull, several vertebrae, partial femora, and a complete astragalus. Subsequent studies have questioned its taxonomic identification, and suggested dinosaurian affinities only for the appendicular remains. The current study re-evaluated, described, and phylogenetically assessed these appendicular remains, to show that the femora belonged to a new taxon, <i>Alickmeron maleriensis</i> (new comb.) of the family Lagerpetidae. The astragalus is morphologically congruent with the left astragalus of an indeterminate herrerasaurid from the Ischigualasto Formation of Argentina, and is considered as a saurischian. Appendicular remains of another dinosaurian taxon known from the same horizon were re-examined to show that these belonged to a probable theropod. The coexistence of a dinosaur precursor, herrerasaurid-like saurischian and a possible theropod in the Lower Fauna of the Maleri Formation aligned with similar findings in other coeval horizons such as the Santa Maria Formation of Brazil, Chinle Formation of New Mexico, and Dockum Group of Texas. We propose two dispersal pathways for lagerpetid diversification from western Gondwana towards the central and eastern Gondwanan, and Laurasian regions during the Carnian and Norian, respectively. The study underscores a rich and continuous record of various avemetatarsalian lineages within the Indian subcontinent spanning from the Middle Triassic to the Cretaceous.