Photo: National Park Service, Fossil Butte National Monument
- Order
- Percopsiformes
- Family
- Percopsidae
- Size
- About 2.7 cm / 1.1 in (juvenile specimen noted)
The earliest known trout-perch, known only from Fossil Lake deposits.
The Percopsidae family has one modern genus with 2 species. They are restricted to freshwater rivers and lakes of North America. A. brachyptera is the earliest known member of the Percopsidae family, and is known exclusively from Fossil Lake deposits.
Larval-size A. brachyptera specimens are almost completely absent from the Fossil Butte Member. This suggests that A. brachyptera spawned in rivers. A. brachyptera is also never found in mass mortality plates, indicating this species was solitary and not a schooling fish.
Species text: National Park Service, Fossil Butte National Monument — Fossil Fish Species.