Juvenile Notogoneus osculus | Green River Formation | Wyoming
Eocene (51.98 Million Years Ago)
Private Quarry, Green River Formation, Wyoming, USA
Obtained from the collection of Dr. William Rieger
Specimen approx. size: 7.25"
Matrix approx. size: 12" x 10"
Beaked Sandfish - Notogoneus osculus
Order Gonorynchiformes, Family Gonorynchidae
N. osculus was the last survivor of the Gonorynchiformes order in North America. There are 5 modern species in the Gonorynchidae family. They inhabit tropical marine regions of the Indo-Pacific Oceans.
Very young juveniles and large adults are the only N. osculus specimens found from Fossil Lake. This could indicate that N. osculus was a migratory species. Their lifecycle may have consisted of:
- Hatching in Fossil Lake
- Migrating to connecting streams to mature
- Returning to Fossil Lake as an adult to spawn and die
N. osculus had a down-turned, sucker-like mouth. Its toothless mouth suggests that this was a bottom-feeding species. The highly salty water conditions at the bottom of Fossil Lake should have excluded most scavengers and bottom-feeders. Yet, N. osculus is found exclusively in deep-water deposits. This suggests that N. osculus spent most of its life outside of Fossil Lake in connecting rivers and streams.