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Mioplosus labracoides and Phareodus testis with Phareodus scale | Green River Formation | Wyoming

Original price $1,200.00 - Original price $1,200.00
Original price
$1,200.00 - $1,200.00
Current price $1,200.00
Mioplosus labracoides and Phareodus testis
Eocene (51.98 Million Years Ago)
Private Quarry, Green River Formation, Wyoming, USA
Preparation by Jim Tynsky
Obtained from the collection of Dr. William Rieger


Plate approx. size: 15" x 8.25" x 1"

Mioplosus approx. size: 6.25"

Phareodus approx. size: 4"

Phareodus scale approx. size: 0.75" x 0.75"


Order Perciformes

  • Family Latidae - M. labracoides

M. labracoides specimens:

  • are characterized by 2 dorsal fins and a forked tail
  • known to reach 20 inches
  • juveniles commonly found in mass mortalities and adults found alone, indicating M. labracoides traveled in schools as a juvenile and became solitary as an adult
  • juvenile and adult specimens often found preserved with smaller fish in the jaw or stomach


This Phareodus testis, smaller than it's Phareodus encaustus counterpart, was a predator in ancient Fossil Lake. Featuring pointy teeth and a long pectoral fin. 

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)
Phareodus fossils:
  • 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