Rare Aesopichthys Bear Gulch Actinopterygian Fish Fossil

Description: The Bear Gulch Limestone is a deposit of some 70 square km in extent and 30 m in depth that has been a source of one of the most diverse assemblages of fossil fish with some 110 species having been described over the past 30 years. Most were new to science, and provided a unique view of the marine environment of Mississippian times. Fine preservation of both fish and invertebrates is a hallmark of these deposits, presumably due to an anoxic depositional environment. This fine specimen is an example of a rarely seen bony fish known as Aesopicthys erinaceus. The genus derives its name from Aesop, the Greek teller of fables, who was known for his humped back. Its relatively short, deep body, the extended dorsal and anal fins, as well as the lobe-based pectoral fins are indicative of an adaptation to maneuvering in a complex geometrical environment. Their closest relatives are thought to be the rhadinicthyids such as Wendyicthys and Cyranoris. At almost 90 mm overall length this fine part and counterpart specimen is near the upper limit of recorded size. Re[paired cracks detract but little from this fine specimen.

Reference: Journal of Vertebrtae Paleontology, 20(3), September 2000 pp 426-44.