Top--Exposures of the richly fossiliferous upper Cretaceous to middle Eocene Sheep Pass Formation, White Pine County, Nevada, occur in the hills in middleground of photograph. The Sheep Pass deposit yields locally abundant fresh water gastropods, pelecypods (AKA, the bivalves), and ostrocods (a minute bivalved crustacean--sometimes colloquially called a seed shrimp)--in addition to roughly 40 species of vertebrate remains: amphibians (spectacular complete frog skeletons, in particular), reptiles, birds, and early extinct mammals--the first confirmed Eocene vertebrate fossil-bearing geologic rock unit recognized from the Great Basin district.

Bottom--Geologist/paleontologist Dr. Peter A. Druschke (who's discovered several fantastic fossil frog specimens in Nevada) examines the amphibian-bearing upper Cretaceous to middle Eocene Sheep Pass Formation in White Pine County, Nevada.

Photographs courtesy Amy Henrici--collection manager for the Section of Vertebrate Paleontology at Carnegie Museum of Natural History Museum; I edited and processed the images through photoshop.