Lot 8
VERY LARGE GREEN RIVER FISH FOSSIL PLAQUE
GREEN RIVER FORMATION, USA, LOWER EOCENE PERIOD, 50 MILLION YEARS B.P.
Auction: 26 November 2026 from 14:00 GMT
Description
a large an impressive limestone panel containing twenty-one Knightia eocaena specimen, and one large Diplomystus dentatus; mounted on a burr yew panel with a small ammonite inset on the bottom right
Dimensions
155cm x 85cm
Provenance
Private collection, England, acquired 2000s
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, including palms such as Sabalites, whose fronds are preserved in exceptional detail within the fine sediments, contributing to a serene depiction of this ancient environment.
The lakes themselves teemed with life. Schooling fish such as Knightia eocaena, among the most abundant species in the formation, moved in vast numbers through the water, while larger predatory fish such as Diplomystus dentatus occupied a higher position in the food chain.