Fossil Wiki:Featured articles/Aetosauria



Aetosaurs, (meaning "Eagle Lizards") are an extinct clade of heavily armored, medium to large-sized Late Triassic quadrupedal archosaurs that were mostly herbivorous. Aetosaurs are widely characterized by their dorsal and ventral surfaces being encased in parallel rows of subrectangular osteoderms, some of which sported spikes in some species. Aetosaurs ranged in size from 1–5 meters (3–16 ft), with the average size being between 2.5–3 meters (8–10 ft). Some of the smallest aetosaurs were Aetosaurus and Coahomasuchus, reaching no more than a meter in length. Aetosaur fossils were first documented by paleontologist Louis Agassiz (1807-1873) in 1844, although they were originally attributed armored fish, instead of archosaurs. Two distinct subdivisions of aeotosaurs are currently recognized, the Desmatosuchinae and the Aetosaurinae, based primarily on differences in the morphology of the bony scutes of the two groups. Aetosaurs first appeared during the Late Carnian epoch of the Late Triassic, roughly the same time that phytosaurs and ornithosuchids appeared. From that point on, they quickly diversified, into various genera, with the most notable being Aetosaurus, Stagonolepis, and Desmatosuchus, and existed for nearly the entirety of the Late Triassic. Aetosaurs quickly became widespread across the the supercontinent Pangaea, with their fossils being found in Europe (Scotland, Germany), India, Northern Africa, North (United States) and South America (Argentina), Greenland and Madagascar. (Read more...)