Wyoming Fossil Fish

PDF] Roughly fifty miles long and two miles wide, Fossil Lake was the smallest of the three major lakes in the Green River formation. The other lakes, Lake Gosiute and Lake Uinta, were orders of magnitude larger, with Gosiute estimated to be 120 miles (200 km) wide and Uinta at 185 miles (300 km) wide. Comparative geochemical studies suggest that the waters of Fossil Lake lacked the oxygen needed to sustain scavengers. Without scavengers, decaying bodies were less likely to be picked apart for meat and left undisturbed. It is also theorized that microbial mats would drift over the corpses of fish, keeping the skeletons articulated underneath a layer of pressure. Above: Map of the Fossil Lake and the other Eocene lakes in the area imposed over a modern state and city map. The red square marks the survey area in the source reference. Green marks areas elevated during Eocene. (Source: Meacham, Amanda L., 2017, Unique Preservation of Fossil Ghost Fish in Green River Formation, MS Thesis Loma Linda University) Above: The back of the specimen card.