They say about 1,400 skeletal elements have been recovered, including two skulls and a plethora of bones of the crocodile-like phytosaur Redondasaurus and limb bones from a new form of a large, heavily armored aetosaur
The largest species of aetosaur grew up to 5 meters long, although the two new specimens, representing a species called Typothorax coccinarum, were smaller growing up to 2.5 meters long.
Spencer Lucas, curator at the New Mexico Museum of Natural History, said: "Brachychirotherium tracks are known from various localities around the world, and they are an almost perfect match to the arrangement of bones in the aetosaur foot.
Reminiscent of giant armadillos, aetosaurs were widespread during Late Triassic times (230 - 200 million years ago).
However, the exquisitely preserved feet in the new specimens demonstrate for the first time that trackways known as Brachychirotherium were almost certainly made by aetosaurs.
Re-evaluation of "Typothorax" meadei, a Late Triassic aetosaur
from the United States.
15B) is referable to aetosaurs based on the large posteromedial tuber on the proximal end and the structure of the fourth trochanter (Nesbitt 2011).
Recent finds of extensive skeletal remains of Revueltosaurus callenderi from the Chinle Formation (Late Triassic: Norian) of Arizona have now established that this taxon is a pseudosuchian closely related to aetosaurs, not an ornithischian dinosaur (Parker et al.
Though some dinosaurs, such as a theropod called Coelophysis (D), did live in the late Triassic, they did not rule the landscape, Existing non-dinos included large armored herbivores called aetosaurs
(C and E), mammal-like reptiles known as dicynodonts (A), land-dwelling ancestors of today's crocodiles (B), salamander-like amphibians (G) and other aquatic predators (F and H).
Stretching along six miles of parkland (and extending as far as Utah), the huge formation contains remains dating back 220 million years, from crocodile-like phytosaurs to armored, plant-eating aetosaurs
Late Triassic aetosaurs
as the trackmaker of the tetrapod footprint ichnotaxon Brachychirotherium.