Photo: National Park Service, Fossil Butte National Monument
- Order
- Ellimmichthyiformes
- Family
- Paraclupeidae
- Size
- From about 0.7 in embryos to about 26 in adults
The second-most common Fossil Lake fish — a primitive herring relative with an upturned mouth.
D. dentatus is a primitive relative of the modern day herring. The genus Diplomystus is also known from fossil deposits in China. The last known species of the Ellimmichthyiformes order went extinct sometime in the middle Eocene.
D. dentatus is the 2nd most common fossil fish found from Fossil Lake. Specimens ranging from embryonic size (about 0.7 inches) to full-grown adults (about 26 inches) are common. Smaller-sized specimens are more commonly found in mid-lake than near-shore deposits. This suggests that D. dentatus spawned in open water.
This species' upturned mouth indicates it fed at the surface of Fossil Lake. D. dentatus specimens are commonly found with other fish stuck in their mouths, including other D. dentatus specimens.
Species text: National Park Service, Fossil Butte National Monument — Fossil Fish Species.