Eocene Green River Bird Feather and Asineops
Bird Feather with Asineops squamifrons
Green River Formation
Middle Eocene
Lincoln County, Wyoming
Green River Formation
Middle Eocene
Lincoln County, Wyoming
This specimen is a really good fossilized bird feather from the Green River Formation. The feather has excellent detail. The feather is at least 6 cm long and probably continues under the fish. Also on the slab is a juvenile Asineops squamifrons.
Even though the Green River Formation is most well known for its fossil fishes, in terms of biological diversity the Eocene birds that lived around the ancient lake were a more diverse faunal community. There are presently known at least 34 species and 27 families with others still not scientifically described. The fossil birds of the Green River are among the best preserved in the world and the avifauna provides documentation of the early diversification of major lineages after the Late Cretaceous mass extinction.
The fish skeleton seen on this slab is a very good example of the species from the Fossil Butte Member of the Green River Formation. This specimen has very good preservation and detail for this locality. The skeletal bones are present. The fish is 8.5 cm long. This example is not repaired or restored.
Asineops is distinguished from other Green River fishes by its numerous short dorsal spines, rounded tail margin, and the morphology of its enormous mouth. The species ranges into the Laney Member of the Green River Formation and is also found in fossil Lake Uinta. The taxonomy of Asineops is poorly known because the relation among the species of spiny-rayed fish (Acanthomorpha) are not completely understood. The largest known specimen of Asineops is 13 inches.
Even though the Green River Formation is most well known for its fossil fishes, in terms of biological diversity the Eocene birds that lived around the ancient lake were a more diverse faunal community. There are presently known at least 34 species and 27 families with others still not scientifically described. The fossil birds of the Green River are among the best preserved in the world and the avifauna provides documentation of the early diversification of major lineages after the Late Cretaceous mass extinction.
The fish skeleton seen on this slab is a very good example of the species from the Fossil Butte Member of the Green River Formation. This specimen has very good preservation and detail for this locality. The skeletal bones are present. The fish is 8.5 cm long. This example is not repaired or restored.
Asineops is distinguished from other Green River fishes by its numerous short dorsal spines, rounded tail margin, and the morphology of its enormous mouth. The species ranges into the Laney Member of the Green River Formation and is also found in fossil Lake Uinta. The taxonomy of Asineops is poorly known because the relation among the species of spiny-rayed fish (Acanthomorpha) are not completely understood. The largest known specimen of Asineops is 13 inches.