What Has Been Found

The Arlington Archosaur Site has produced numerous fossils from various species of animal, the most prominent of course being from dinosaurs. A skeleton of a large herbivorous dinosaur was excavated from the northern hillside at the site. The herbivorous dinosaur was an ornithopod, a large "duck billed" hadrosaur or iguanodont. The fossils found at the site were primarily post cranial (everything other than the skull), along with a small partial lower jaw and shed teeth. The dinosaurs pelvis (hip), shoulder and most of the vertebrae were excavated from the hillside. The only duck billed dinosaur known from the Woodbine Formation is Protohadros byrdi. Protohadros was discovered in Woodbine Formation sediments in the North Texas town of Flower Mound by Gary Byrd in the early 1990's. A complete skull was recovered from a roadside contruction site and taken to the Shuler Museum of Paleontology at SMU for scientific study. SMU graduate student Jason Head studied the dinosaur skull for his masters thesis and named it Protohadros, meaning primitive hadrosaur (Protohadros on Wikipedia). Hadrosaurs evolved from iguanodonts at some point during the Mid-Cretaceous. Protohadros is important to science as it is a transitional species, or "missing link", in the evolution of iguanodonts into hadrosaurs. The Arlington Archosaur Site duck billed dino is likely a new species of Protohadros, however it may be a new taxon, a closely related new genus of dinosaur. Other dinosaur fossils found at the site belong to a carnivorous dinosaur, a new species of theropod. Theropod fossils are rare in the Woodbine Formation, and as yet a theropod has not been named. The Arlington theropod is represented by a partial femur, a phalange, several vertebra, teeth and an interesting claw.

Crocodile fossils are among the most common found at the Arlington Archosaur Site. However, the greatest accumulation of fossils from the Arlington Archosaur Site crocodile were found up the hill and to the east of the dinosaur quarry. The crocodile site was named by Art Sahlstein as "Mr. Croc". Most of the crocodile fossils found at the site were scutes (dorsal osteoderms) and teeth. A partial jaw, along with numerous vertebrae and a few minor limb bones were also found. The only documented crocodile from the Woodbine Formation is Woodbinesuchus; literally "Woodbine crocodile". Woodbinesuchus was named by SMU graduate student Young Nam Lee in 1997 for fossils found in Fort Worth. The Arlington Archosaur Site has produced numerous crocodile fossils, some of which can be assigned to Woodbinesuchus, others however represent a new genus and species.

The Arlington Archosaur Site is unique in that it is a major dinosaur excavation in the middle of a large metropolitan setting and in that it preserves so many fossils from different animals. In fact, it preserves a near complete ecosystem. Aside from dinosaur and crocodile fossils, the Arlington Archosaur Site also preserves fossils from turtles, lungfish, fish and sharks. The Arlington lungfish was discovered by Brad Carter while surface collecting fossils at the site. Lungfish from the Cretaceous of North America are quite rare, and the Arlington lungfish represents a new species. Throughout the site, coprolites (fossil feces; poop) have been found, representing nearly every animal. Thin sections cut of the coprolites have revealed interesting aspects on the animals diets, as some coprolite samples contained bone fragments. Within a peat bed at the base of the dinosaur quarry, numerous fossil logs and plant material were found in the fall 2008 and winter 2009 excavations. The logs varied in size, but the longest were 3 meters (over 9 ft). In the summer of 2009, Austin Motheral discovered a large new crocodile at the base of the AAS hill using his fathers tractor. Tractor paleontology, only in Texas! His discovery lead to a week long marathon dig we call Crocorama!

Since Austin's discovery of Crocorama in the summer of 2009, the Archosaur crew has continued to excavate the Crocorama site, still finding crocodile fossils, along with turtle and some fish. In fact, Austin's 2009 Crocorama site has produced enough fossils to name a new genus and species of prehistoric croc! The new croc will be named in Austin's honor. So many turtle fossils were recovered by May of 2010, that Archosaur crew member Darlene Sumerfelt referred to it as a "Turtle Buffet." Hence the new name of this site. Also in May of 2010, Dallas Paleo Society Member and UTA Alumni Phil Scoggins discovered the remains of infant crocodiles at the far edge of our previous seasons Crocorama site. These amazing new baby croc fossils are among the latest and most interesting discoveries at the Arlington Archosaur Site.

The Arlington Archosaur Site preserves an ancient coastal ecosystem, from coastal embayments, to delta plains and distributary channels to the near shore marine waters of the ancient Cretaceous Texas coastline. The Arlington Archosaur Site is among the most prolific North Texas fossil localities discovered to date and represents a unique chance to study the evolution of Mid-Cretaceous coastal ecosystems from a lost world.

Copyright © 2013 Derek J. Main | Dallas Web Design: Bottle Rocket Corp
About The Arlington Archosaur Site
The Geological History
What Has Been Found
The Team
Clinton Crowley
UTA artist Clinton Crowley's interpretation of the
Arlington Archosaur Site. North Texas during the
Cretaceous (95 Million yrs ago); Woodbinesuchus
and Protohadros on a coastal plain.
Clinton Crowley
Protohadros hiding in the coastal swamp from Crocomama!