Lot 29
LARGE FOSSIL FISH SPECIMEN
GREEN RIVER FORMATION, WYOMING, EOCENE, C. 50 MILLION YEARS B.P.
Auction: 28 May 2026 from 13:00 BST
Description
a superbly preserved 18.5 inch specimen of Phareodus encaustus, showing a high degree of three-dimensionality, encased within the limestone matrix and mounted on an iron frame
Dimensions
75.5 x 55cm (inc. frame)
Footnote
The present specimen was excavated from the Green River Formation, located predominantly in present day Wyoming. Today, the landscape is dry and windswept, with open plains and sparse vegetation stretching across an exposed terrain of layered limestone and shale that records ancient lake environments.
However, during the early Eocene, around 50 million years ago, this region was not arid but subtropical, with broad freshwater lakes surrounded by lush vegetation. The climate was warm and humid, supporting crocodiles, early mammals, insects, fish and dense forests along the lake margins.
With sharp teeth and a streamlined body, Phareodus encaustus was a mid-level predator within these ancient lake ecosystems. Its prey likely included schooling fish such as Knightia eocaena, one of the most abundant species found in the formation.