Dromicosuchus (Ancient Greek, meaning "fleet or quickly walking crocodile") is an extinct genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It was found in Upper Triassic rocks of North Carolina, United States, and is known from a nearly complete skull and partial skeleton. This specimen is unusual in that it was found beneath the skeleton of a larger rauisuchian and has apparent bite damage, suggesting that it was attacked by the larger carnivore before both died and were buried together.
Discovery[]
The holotype of Dromicosuchus is a partial skeleton[1] including a nearly complete skull and lower jaws, articulated vertebrae from the atlas to the second tail vertebra, bony armor from the back, ribs and the dermal bones called gastralia, partial shoulder girdles, most of the left arm and leg, and the right upper arm, thigh bone, and shin bone. It was found with the fossils of several other animals in a brick-clay quarry in Durham County, North Carolina, in blocks excavated by University of North Carolina at Chapel Hill students in fall 1994. The fossils came from a mudstone next to a river channel deposit, in Lithofacies Association II of the Deep River basin, part of the extensive Newark Supergroup, dated as pertaining to either the late Carnian or early Norian faunal stages of the Late Triassic. The type species is D. grallator, meaning "one who walks on stilts" in Greek, in reference to its long slender limbs. It was named and described by Hans-Dieter Sues and colleagues in 2003.[2]
When the students excavated the blocks, the fossils were tentatively identified remains as those of a large, unnamed new genus of popsaurid rauisuchian.[3] Upon preparation, however, it was discovered that there was the skeleton of a smaller archosaur under its pelvis, and the bones of several different animals as gut contents that remained in place in the rauisuchian fossil: these included bones and scutes of the aetosaur Stegomus, some with tooth marks; bones from the snout, arm, and shoulder of the traversodont cynodont Plinthogomphodon; phalanx bones of a dicynodont; and a bone fragment from a possible temnospondyl. Additionally, the small archosaur, later named Dromicosuchus, had damage to its neck armor and lower jaw that appears to have been caused by rauisuchian teeth, perhaps those of the animal that was found above it.[2]