Phareodus testis, unrestored specimen with dendritic patterning
Eocene (52.3 Million Years Ago)
Green River Formation, Wyoming, USA
In Stone Fossils Private Quarry
Plate size approx: 3.5" x 2"
Phareodus size approx: 2.25"
This Phareodus testis, smaller than it's Phareodus encaustus counterpart, was a predator in ancient Fossil Lake. Featuring pointy teeth a long pectoral fin. and natural shifting of the scales during decomposition. Also a natural fault in the rock that travels through the phareodus anal fin, that has since healed over many thousands of years ago.
The dendrite patterns are like a tree-like structure and it is growing when the melt is freezing and the main growth direction is against the heat flow direction. The dendrite has the primary arm or the main branch and then arms of higher orders as the secondary arms, tertiary arms, etc.
This specimen was so well preserved, no restorative practices were necessary and was left exactly the way it was found.
Bony-Tongue Fish - 2 Species Identified: Phareodus encaustus & Phareodus testis
Order Osteoglossiformes, Family Osteoglossidae
Living members of the Osteoglossidae family:
- include 10 modern species
- live exclusively in tropical freshwaters
- found in South America, Africa, Asia, and Australia
- mouth-brooders (parents hold eggs and hatchlings in their mouths)
- adult specimens usually found alone, but juveniles known from mass mortalities
- indicates that Phareodus schooled as a juvenile and became solitary as an adult
- often preserved with smaller fish in their jaws and stomach, indicating they were predators
- rearward oriented fins on back and underside, adaptation for speed
- large, sharp teeth
- max known size of P. encaustus: 30 inches
- max known size of P. testis: 20 inches