The type species, Azendohsaurus laaroussii, was described and named by Jean-Michel Dutuit in 1972 based on partial jaw fragments and some teeth from Morocco.

Instead, Azendohsaurus was actually a more primitive archosauromorph that had convergently evolved many features of the jaws and skeleton shared with the later giant sauropod dinosaurs.

Azendohsaurus and sauropodomorphs likely independently evolved to fill a similar ecological niche as long-necked, relatively high browsing herbivores in their environments.

However, Azendohsaurus predates the large Late Triassic sauropodomorphs it resembles by several million years, and did not evolve similar body plans under the same environmental conditions.

The limbs themselves are relatively short and particularly robust, with digits that are shorter and stouter compared to other early archosauromorphs, each with notably large, curved claws on all four feet.

Superficially its appearance is comparable to that of sauropodomorph dinosaurs, along with various details of its skeleton, suggesting Azendohsaurus converged on similar traits for a relatively high-browsing, herbivorous lifestyle.

[1] The skull has a number of traits convergent with sauropodomorphs, including the downward curving dentary, a robust dorsal process of the maxilla, and several features of the teeth.

The process on the maxilla usually indicates the presence of an antorbital fenestra in archosauriforms, but in Azendohsaurus this space is occupied by the lacrimal bone in front of the eyes.

The glenoid faces laterally, typical of sprawling reptiles, however, the scapular portion is directed slightly backwards, which could indicate the humerus was held in a more raised posture.

The femur is long and vaguely S-shaped, with a slightly expanded head that is not turned inwards, unlike those of dinosaurs, indicating it was not held upright.

[6] The first fossils of Azendohsaurus laaroussii were discovered in a northern part the Timezgadiouine Formation in Morocco, which is found within the Argana Basin of the High Atlas.

He correctly concluded that the material belonged to a single taxon, but assigned the genus to "Prosauropoda" incertae sedis based again on the characteristics of the jaws and teeth.

However, he could not determine its position within "Prosauropoda" due to the ambiguous distribution of these traits in early herbivorous dinosaurs, as well as a lack of any comparable Triassic reptiles, so he referred it to incertae sedis.

[21][22][23][24][25][26] New material from the type locality of A. laaroussii, including parts of the post-cranial skeleton, was reported on in 2002 at the annual conference of the Society of Vertebrate Paleontology by Nour-Eddine Jalil and Fabien Knoll.

[2][31] All the material from A. laaroussii, including the holotype and unpublished post crania, is housed at the Muséum National d'Histoire Naturelle in Paris, France.

Based on the state of preservation, some of the bones were believed to have been buried rapidly while others were exposed for longer on the surface, where they were weathered, cracked and possibly trampled on before burial.

Most of the material was similarly sized, with a range of about 25% between the smallest and largest specimens, although the significance of this is not understood and it could be related to ontogeny, individual variation or sexual dimorphism.

[11][14][26] These misidentifications were caused by the convergence in jaw and tooth shape between it and the herbivorous dinosaurs while its true phylogenetic relationships could not be realised due to the absence of other bones of the skull and skeleton.

This was based on the presence of traits such as a solid hip socket (acetabulum), and a proximal fourth trochanter on the femur that also lacked an inward-facing head, which are typical of dinosaur skeletons.

[27] The discovery of more complete material from Madagascar prompted the first formal classification Azendohsaurus as non-dinosaurian by Flynn and colleagues in 2010 through a detailed description of its cranial anatomy and were able to clarify its relationships further.

[2] A similar result was recovered by another large analysis of archosauromorph phylogeny in 2016 by Martín D. Ezcurra, who found a monophyletic Allokotosauria containing Azendohsaurus and Trilophosaurus.

Similarities between Pamelaria and Azendohsaurus had been noted by Nesbitt and colleagues in 2015, including confluent nares, serrated teeth and low cervical spines, but their analysis favoured a position in Allokotosauria basal to azendohsaurids.

However, the convergent evolution of these traits in Azendohsaurus as adaptations towards a herbivorous lifestyle show that they may be more broadly distributed amongst Triassic archosauromorphs, and do not necessarily indicate a close relationship to sauropodomorphs in fossil taxa.

The hind limbs have been interpreted as being completely sprawled outwards from the body, with its femur held straight out and the lower leg bent 90° beneath it at the knee, like a lizard.

[2] In 2019, thin slices were cut from the humerus, femur and tibia of specimens attributed to A. laaroussii for histological examination of the microscopic bone structure to try and determine the rate of growth in Azendohsaurus.

[42] Although the two species of Azendohsaurus are known from disparate locations in North Africa and Madagascar, during the Middle to Late Triassic these regions were connected as part of the supercontinent Pangaea.

[35][43] The climate was hot and dry at this time, but with evidence suggesting higher levels of rainfall during the Carnian, interrupting the increasing aridity trend and creating wetter environments around the globe.

[44] Other reptiles from the base of the Irohalene (T5) member of the Timezgadiouine Formation contemporaneous with A. laaroussii include the phytosaur Arganarhinus,[45] the predatory rauisuchid Arganasuchus,[46] the herbivorous silesaurid Diodorus,[8] a paratypothoracisine aetosaur,[47][48] and procolophonid parareptiles,[4] as well as the stahleckeriid dicynodont Moghreberia, a synapsid.

[55][56][57] In Madagascar, Azendohsaurus co-existed with the hyperodapedontine rhynchosaur Isalorhynchus,[58] the herbivorous traversodontid cynodonts Dadadon and Menadon, and the predatory chiniquodontid cynodont Chiniquodon kalanoro,[59] as well as an undescribed kannemeyeriiform dicynodont, a sphenodontian reptile,[33] a procolophonid parareptile,[58] the diminutive lagerpetid Kongonaphon,[60] various other undescribed dinosauromorphs, and an "enigmatic archosaur" of uncertain classification.

Dadadon was inferred to be capable of feeding on tough, hardy vegetation by using complex chewing, in contrast to the simpler dentition and processing of Azendohsaurus, which was better suited for eating leaves.