on the inside surface of the maxilla. This keel runs the whole length of the maxilla in A. laaroussii, but is only found along the back half of it in A. madagaskarensis. Any other possible differences between the two species cannot be determined without rest of the skull and skeleton. Skeleton All the known post-cranial information for the skeleton of Azendohsaurus comes from A. madagaskarensis. Much of the vertebral column is known in Azendohsaurus, and although incomplete, it is estimated to have 24 presacral vertebrae (including the atlas and axis). The sacrum of the hips has only two vertebrae, and the full number of caudal vertebrae in the tail is unknown, but it is estimated to be only around 45–55 (low for an archosaur). The cervical vertebrae change shape down the neck, beginning as characteristically elongated with long and low neural spines, and getting progressively shorter in length towards the base of the neck, but with increasingly taller and narrower neural spines. This shortening is seen in the necks of other allokotosaurs like Trilophosaurus, but is not found in other long-necked archosauromorphs (e.g. the middle cervicals are the longest in tanystropheids). The neck would have been held raised up above the body, indicated by the inclined angle of the zygapophyses that connect each vertebra, as well as the front zygapophyses of each vertebra being higher than those at the back. The neck was also likely held in a gentle arc, based on an articulated set of cervicals in this position. The dorsal vertebrae of the back generally resemble the last cervicals, with tall, vertical neural spines. These vertebrae also decrease in length down the back, but less dramatically than in the neck. The last dorsal is unique, however, as it has a neural spine angled forward. Of the two sacrals, the first vertebra is larger and more robust, with a tall neural spines over its rear half. Both sacrals have large ribs completely fused to the vertebrae that articulate with the ilia (see below). The caudal vertebrae resemble the other vertebrae, but with backward inclined neural spines. The length of the caudals and the height of the neural spines gradually decreases down the tail, unlike some other archosauromorphs where the vertebrae elongate towards the tip. This implies that the tail was short and not tapering, but the very tip of the tail is unknown. They consistently have chevron facets from