Paper No. 9
Presentation Time: 8:00 AM-12:00 PM
AN EARLY CRETACEOUS THEROPOD FOOT FROM SOUTHWESTERN ARKANSAS AS A POSSIBLE TRACK MAKER IN CENTRAL TEXAS AND SOUTHWESTERN UTAH
The remains of the right pes of a theropod were found in 1972 by J.B. Friday in the Early Cretaceous Trinity Group stratigraphically above the De Queen Limestone in Sevier County, southwest Arkansas. This fossil is the first and only dinosaur remains recognized from the state. Characterized by differentiated pedal unguals and closely appressed metatarsals, the specimen appears to be closely associated with the small late Jurassic theropod Ornitholestes. The size and shape of the Arkansas remains resemble the smaller tracks in the Glen Rose Formation (Early Cretaceous) near Glen Rose, Texas and larger tacks found in the Moenave Formation (Early Jurassic) near St. George, Utah. Research is in progress to compare the articular cartilage from the ends of the unguals of emus (Dromaius novaehollandiae) and alligators (Alligator mississipiensis) to better understand the fleshed out morphology of this theropod in life. A small percentage increase in the elongation of the foot due to the presence of this articular cartilage is expected and will provide a better match of the foot to the track occurrences.