Ronald S. Tykoski

Anatomy, Ontogeny, and Phylogeny of Coelophysoid Theropods [electronic resource] (2005)

Tykoski, Ronald S., Tykoski, Ronald S.

Coelophysoid theropods (Dinosauria: Saurischia) were viewed as members of Ceratosauria in early cladistic phylogenetic hypotheses, but more recent analyses placed Coelophysoidea and Dilophosaurus as...

CALSOYASUCHUS VALLICEPS, A NEW CROCODYLIFORM FROM THE EARLY JURASSIC KAYENTA FORMATION OF ARIZONA (2002)

RONALD S. TYKOSKI, TIMOTHY B. ROWE, RICHARD A. KETCHAM, MATTHEW W. COLBERT

We describe a new fossil crocodyliform archosaur from the Early Jurassic Kayenta Formation of the Navajo Nation that is surprisingly derived for so ancient a specimen. High-resolution X-ray CT...