Azendohsaurids are one of two or three families included in the clade Allokotosauria, a group of unusual Triassic non-
archosaur archosauromorphs that also includes the families
Trilophosauridae and possibly the gliding
Kuehneosauridae. They have consistently been recognised as the
sister taxon of trilophosaurids, initially united on shared yet differing herbivorous traits. However, as more azendohsaurids have been discovered and recognised, they demonstrate that the group was likely to be ancestrally carnivorous. The oldest known azendohsaurids are
Pamelaria and
Shringasaurus, both from India and dated to the
Anisian stage of the
Middle Triassic.
Azendohsaurus itself has been dated from the end of the Middle Triassic during the
Ladinian (at least for
A. madagaskarensis) into the
Carnian stage of the earliest
Late Triassic in Morocco and Madagascar. Malerisaurines, including
Malerisaurus and
Puercosuchus, are exclusively known from the
Late Triassic during an interval from the late Carnian into the early
Norian of both North and South America as well India, and are the latest-surviving azendohsaurids known. This is in spite of their relatively
plesiomorphic (i.e. ancestral) features compared to other azendohsaurids, representing a
relictual lineage of early-diverging carnivorous azendohsaurids that survived longer than their more derived herbivorous kin. Malerisaurines were previously thought to disappear from the fossil record in North America at or the near the end of the
Adamanian teilzone (a local
biostratigraphic unit in the southwestern United States) roughly 216 million years ago, associated with a local
faunal turnover in North America. The extinction of malerisaurines in this turnover would then also have marked the extinction of azendohsaurids globally. ==References==