Amphiplaga brachyptera Cope, 1877

Taxonomy

Trout-Perch

Kingdom: Animalia
Phylum: Chordata
Class: Actinopteri Cope 1871
Order: Percopsiformes
Family: Percopsidae
Genus: Amphiplaga
Species: Amphiplaga brachyptera
Author Citation Cope, 1877

Geological Time Scale

Eon: Phanerozoic
Era: Cenozoic
Period: Paleogene
Sub Period: None
Epoch: Eocene
International Age: Ypresian

Stratigraphy

Green River Formation
Lake Gossiute, F-2

Provenance

Collector: T. Bastelberger
Date Collected: 01/01/1996
Acquired by: Field Collection

Dimensions

Length: 22 mm

Location

Warfield Quarry
Kemmerer, Lincoln County
Wyoming
United States

• amphiplaga
• eocene
• fossil lake
• green river formation
• tff-oilshale-ch651
• warfield

Comments

Amphiplaga is one of the rarer of the Green River fish fossils, making up some 1% of the total from Fossil Lake, its only known location. Amphiplaga belongs to the family Percopsidae within the order Percopsiformes.    

The Order Percopsiformes is a small order of North American freshwater fishes that includes three families: Amblyopsidae (cavefishes); Aphredoderidae (pirate perches); and Percopsidae (trout-perches).  Closely related to neither trout nor perch, trout-perches have characteristics of both the trout and perch families. They exhibit characters of the salmonids, such as an adipose fin, cycloid scales, and soft fin rays, as well as characters of the percids, such as dorsal and anal fin spines, and ctenoid scales.    

Trout-perch are generally silvery in appearance, often with a partially transparent appearance, and relatively large heads and eyes. They are small fish with weak fin spines, and an adipose fin similar to those of trouts. Amphiplaga grew to as much as 150 mm. long; the average length was 100 mm. They feed on insects and small crustaceans.
 

Fossil percopsids are only known from North America, the current home of the extant genus Percopsis.

 

References:

Grande, L. (1984): PALEONTOLOGY OF THE GREEN RIVER FORMATION, WITH A REVIEW OF THE FISH FAUNA. THE GEOLOGICAL SURVEY OF WYOMING, BULLETIN 63