Notogoneus osculus and Diplomystus dentatus | 100% Natural | Green River Formation | Wyoming
Notogoneus osculus and Diplomystus dentatus
Unrestored specimen, 100% Natural
Eocene (51.98 Million Years Ago)
Green River Formation, Wyoming, USA
In Stone Fossils Private Quarry
Plate approx. size: 29.75" x 41.75"
Notogoneus approx. size: 22.5"
Diplomystus approx. size: 16.5"
**Due to the size of this specimen, it will be shipped in an internationally compliant wooden crate. The plate itself is backed with 3/4" plywood for durability and easy wall hanging. We recommend a french cleat system for hanging purposes.
Shipping costs will be calculated and billed after purchase. Please contact us if you need a specific shipping rate prior to purchase. You may opt in for in-store pickup to cut your shipping costs all together and pick up your specimen in person. You can pick up from our store location in Kemmerer, Wyoming, or we deliver to both the Denver Gem & Mineral show in the Fall and the Tucson Gem & Mineral show in the winter. For any questions, please don't hesitate to contact us directly.
Beaked Sandfish - Notogoneus osculus
Order Gonorynchiformes, Family Gonorynchidae
Notogoneus osculus was the final North American member of the Gonorynchidae family. There are 5 modern species within the family that inhabit tropical marine regions of the Indo-Pacific Oceans. Notogoneus did not have teeth; instead, it had a "beak" adapted for bottom feeding. This beaked mouth was well-suited for its bottom-feeding and scavenging lifestyle.
Fossils of Notogoneus found in Fossil Lake show two distinct size distributions:
- Fry (juveniles): range from 1"-2" in length.
- Adults: range from 10"-35" in length. The average size for an adult specimen is around 18".
Specimens of intermediate size are notably rare in Fossil Lake. This is thought to indicate that Notogoneus was a migratory species. It might have hatched in Fossil Lake, migrated to connecting streams or rivers for development, then returned as adults to spawn and perish in deep-water zones. The large adult fossils are found almost exclusively in the 18-inch layer.
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.