A NEW LUNGFISH (DIPNOI: CERATODONTIDAE) FROM THE CRETACEOUS WOODBINE FORMATION, ARLINGTON ARCHOSAUR SITE, NORTH TEXAS.

A significant number of lungfish dentitions are now known from the Cretaceous (Cenomanian) Woodbine Formation, primarily from one new locality, the Arlington Archosaur Site of northeast Tarrant County, Texas. The Arlington Archosaur Site preserves a diverse coastal ecosystem within the interbedded coals, mudstones and sand lenses of a delta plain environment. The new lungfish specimens pertain to previously undescribed species from the Cenomanian. Previously recorded from but one specimen, this taxon is now represented by both prearticular and pterygopalatine dental plates of sectorial aspect. This species is similar to, and presumably descended from, one that has been previously recorded from various formations of Albian age. Measurements of the angles of the dental plate margins and crests confirm that it is distinct. Two small specimens appear to represent an earlier ontogenetic stage. Although dipnoan evolution generally appears to have proceeded slowly, the taxa from the Cretaceous (Albian -- Cenomanian) of Texas may possibly provide some stratigraphic indices, based on what is now known. The new Woodbine lungfish is herein referred to a new species; Ceratodus carteri. [ABSTRACT FROM AUTHOR]