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Azendohsauridae is a family of archosauromorphs that lived during the Middle Triassic to Late Triassic period, around 242-216 million years ago. The family was originally named solely for the eponymous Azendohsaurus, marking out its distinctiveness from other allokotosaurs, but the family now includes four other Genus: the basal genus Pamelaria, the large horned herbivore Shringasaurus, and two carnivorous genera grouped into the subfamily-level subclade Malerisaurinae, Malerisaurus and Puercosuchus, and potentially also the dubious genus Otischalkia. Most fossils of azendohsaurids have a distribution, with multiple species known across Morocco and Madagascar in Africa as well as India, although fossils of malerisaurine azendohsaurids have also been found in the southwestern United States of North America.
Azendohsaurids are notable for the various dinosaur-like traits found in some species, including the sauropodomorph-like neck, jaws and teeth of Azendohsaurus, the ceratopsid-like horns of Shringasaurus, and theropod-like teeth of Puercosuchus. These traits are all convergently evolved with later dinosaurs, and some similarities are so striking that it is difficult to distinguish isolated azendohsaurid teeth and jaw bones from those of dinosaurs. Indeed, Azendohsaurus itself was initially described as a herbivorous dinosaur until better remains of its skull and skeleton were found.
Azendohsaurids lack a prenarial process, the bony splint of the premaxilla that otherwise divides the two external nares in typical reptile skulls, giving them a single fused (confluent) opening for their nostrils. Another characteristic of azendohsaurids is that they often possess palatal teeth on the roof of their mouths similar in size and shape to those along the jaw margins, including serrations, compared to the typical tiny and conical palatal teeth of other reptiles. Such large and specialised palatal teeth are known definitively in Pamelaria, Azendohsaurus and Shringasaurus, while simpler but notably large palatal teeth with coarse serrations are found in Malerisaurus. The palatal teeth of Puercosuchus, however, are simply described as "peg-like".
All known azendohsaurids have long necks, with neck vertebrae very similar in shape and construction to those of early sauropodomorph dinosaurs, and held them raised above their shoulders. The themselves are tall and very well developed, with long blades. Azendohsaurids had a sprawling gait like other early archosauromorphs, although their shoulder joint faces back as well as out to the sides, suggesting they may have been able to hold their forelimbs closer to their body. Their bodies are deep, ranging from relatively narrow-bodied in Pamelaria to barrel-shaped in Azendohsaurus, and their tails are proportionally shorter and stockier compared to other archosauromorphs.
A phylogenetic analysis performed by palaeontologist Sterling J. Nesbitt and colleagues in 2021 included all recognised azendohsaurids and other allokotosaurian taxa. Their results found Pamelaria to be the earliest branching azendohsaurid, with the remaining azendohsaurids divided into two subclades, one containing the herbivores Shringasaurus and two species of Azendohsaurus, and the Malerisaurinae containing both species of Malerisaurus and similar larger material (including the material that would be named Puercosuchus). The cladogram below depicts the simplified consensus result of their analysis, where the uncertain relationships within Malerisaurinae are presented as a polytomy:
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