5.75" Diplomystus dentatus | 100% Natural | Green River Formation | Wyoming

Diplomystus unrestored specimen 100% Natural 

Eocene (51.98 Million Years Ago) 

Green River Formation, Wyoming, USA 

In Stone Fossils Private Quarry

Plate size approx: 7.75" x 6"

Diplomystus approx: 5.75"

Found in our private quarry with beautiful reddish-gold toned iron mineral replacement of which our quarry is prized for. 

We take great pride in hand selecting the best specimens out of our private quarry. Our Green River Formation specimens are all prepared using surgical grade microscopes and the very best fossil preparation tools available. We pride ourselves on delivering the highest quality specimens available. 

Diplomystus is an extinct genus of freshwater clupeomorph fish distantly related to modern-day extant herrings, alewives, and sardines. The genus was first named and described by Edward Drinker Cope in 1877.

Ray-finned Fish - Diplomystus dentatus

Order Ellimmichthyiformes, Family Paraclupeidae

The last known species of the Ellimmichthyiformes order went extinct sometime in the middle Eocene. D. dentatus is a primitive relative of the modern day herring. The genus Diplomystus is also known from fossil deposits in China.

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.