SIGNIFICANCE OF A SMALL REGURGITALITE CONTAINING LISSAMPHIBIAN BONES, FROM THE MORRISON FORMATION (UPPER JURASSIC), WITHIN A DIVERSE PLANT LOCALITY DEPOSIT IN SOUTHEASTERN UTAH, USA

Abstract

Abstract A new specimen from a plant locality in the Morrison Formation of southeastern Utah exhibits characters suggestive of a small bromalite, possibly from a fish or semi-aquatic mammal. The specimen consists of a cluster of small bones, most referable to lissamphibians, including elements of at least one small frog (possibly a tadpole) and possibly the smallest reported salamander specimen from the formation. Chemical and taphonomic characters suggest that the specimen is a regurgitalite, the first from both the Morrison Formation and the Jurassic of North America. The lissamphibian material in the bromalite represents the southernmost likely occurrence of frogs and salamanders in the formation. The possible salamander material may represent a rare juvenile rather than a new taxon, and it is morphologically more similar to Valdotriton and Comonecturoides than it is to Iridotriton. The frog material is similarly unidentifiable to specific taxon.