A New Dinosaur Ichnotaxon from the Lower Cretaceous Patuxent Formation of Maryland and Virginia

Abstract

In recent years, numerous dinosaur footprints have been discovered on bedding surfaces within the Lower Cretaceous Patuxent Formation of Maryland and Virginia. Among these, distinctive small tracks that display a combination of small manus with five digit impressions and a relatively much larger pes with four toe impressions evidently were made by animals belonging to the ornithischian family Hypsilophodontidae. These tracks differ from any ornithischian ichnotaxon previously described. We here name them Hypsiloichnus marylandicus and provide a description of their diagnostic characteristics. Although hypsilophodontid skeletal remains have not been found in the Patuxent, their skeletal remains are known from Lower Cretaceous strata of similar age in both western North America and Europe. Therefore, it is not surprising to find that an Early Cretaceous representative of this family also existed in eastern North America.

Keywords:

• Hypsiloichnus
• Zephyrosaurus
• Hypsilophodon
• Hypsilophodontidae
• Lower Cretaceous
• Patuxent Formation
• Atlantic Coastal Plain
• Maryland
• Virginia

ACKNOWLEDGEMENTS

The authors wish to thank Hendrick Klein and Rubén Rodríguez-de la Rosa for their helpful and insightful reviews of this manuscript. We also wish to thank Sheila Stanford for her invaluable assistance in compiling and improving the figures.

Notes

¹Not illustrated.

²Divarication point different from that of digits I through IV (see Fig. 5).