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Phareodus testis and Diplomystus | Green River Formation | Wyoming

Phareodus testis and Diplomystus | Green River Formation | Wyoming

by In Stone Fossils
$1,395.00 - $1,395.00
$1,395.00
$1,395.00 - $1,395.00
$1,395.00

Phareodus testis and Diplomystus 
Eocene (51.98 Million Years Ago)
In Stone Fossils Private Quarry from the Exclusive Phareodus Layer
Green River Formation, Wyoming, USA
100% Natural, zero restoration 

 

Phareodus Specimen approx. size: 8.25"

Diplomystus Specimen approx. size: 6.5"

Matrix approx. size: 17.25" x 14"

 

**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 hanging system for hanging purposes.
 
Please contact us for a specific shipping rate. 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.

 

In the ancient waters of Fossil Lake, a formidable predator roamed. The Phareodus testis, a smaller but equally fascinating cousin of Phareodus encaustus. Both species boasted striking features, including pointy teeth and an impressive pectoral fin.

 

*The Bony-Tongue Fish Family*

Phareodus encaustus and Phareodus testis belong to the order Osteoglossiformes and family Osteoglossidae. Today, this family comprises 10 modern species that thrive in tropical freshwater habitats across South America, Africa, Asia, and Australia. Interestingly, these fish are mouth-brooders, where parents carefully nurture eggs and hatchlings in their mouths.

 

*Fossil Discoveries*

Fossil records reveal that adult Phareodus specimens often went solo, whereas juveniles frequently gathered in large groups. This suggests that Phareodus fish schooled together during their youth before becoming solitary predators as adults. The presence of smaller fish in their jaws and stomachs confirms their predatory nature. Adaptations like rearward-oriented fins and large, sharp teeth enabled Phareodus to chase down prey with ease.

 

*Size Comparison*

While Phareodus encaustus reached an impressive 30 inches in length, its smaller counterpart, Phareodus testis, measured around 20 inches. Despite their size difference, both species played vital roles in their ancient ecosystem.

 

*Diplomystus, An Ancient Fish with Modern Relatives

Diplomystus, an extinct genus of freshwater fish, shares a distant connection with modern-day herrings, alewives, and sardines. This ancient fish was first described by Edward Drinker Cope in 1877.

 

*Classification and Evolutionary Significance*

Diplomystus dentatus belongs to the order Ellimmichthyiformes and family Paraclupeidae. As a member of this order, D. dentatus represents a primitive relative of the modern-day herring. The Ellimmichthyiformes order faced extinction by the middle Eocene.

 

*Fossil Record and Distribution*

Fossil deposits in China and Fossil Lake have yielded Diplomystus specimens. Notably, D. dentatus is the second most common fossil fish found in Fossil Lake. Specimens range from embryonic (0.7 inches) to adult sizes (26 inches).

 

*Insights into Diplomystus' Life Cycle and Behavior*

The distribution of smaller-sized specimens in mid-lake deposits suggests that D. dentatus spawned in open water. The upturned mouth of this species indicates surface feeding behavior. Interestingly, D. dentatus fossils are often found with other fish, including conspecifics, stuck in their mouths, revealing their predatory nature.

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