Green River Fish Fossil
mm = 1 inch): Fish fossil is 92 mm in length (tip of nose to tip of
tail along backbone) on a 150 mm by 85 mm matrix.
Site: Green River Formation,
Fossil Lake, Kemmerer, Wyoming
50 million year old, Eocene-Era fossil fish comes from one of
the world's famous Laggerstatten, the Green River Formation in
Wyoming. A small portion of the fish fossils from Green River
exhibits such fine preservation.
is one of the more rare of the Green River fish fossils, making
up some 1% of the
total from Fossil Lake, its only known location.
Named by the famous 19th Century paleontologist E.D. Cope, the
name Amphiplaga is thought to mean "ambiguous wound", pointing
to the fact that the holotype specimen was headless.. Shaped rather
like a cross between a trout and a perch, the Percopsidae are colloquially
termed “trout perches”. Fossil percopsids are only
known from North America, the current home of the extant genus
With a maximum total length of 150 mm and an average of 100 mm
this is a subadult specimen of this rarely-offered taxon. Note
soft tissue preservation with many of the scales even visible.