Fossil Bird Species

Over 30 species of birds, belonging to more than 20 families, have been identified from the Fossil Butte Member (FBM). The bird fossils include:
  • Isolated feathers (the most common bird fossil from the FBM)
  • Isolated feet, wings, and other body parts
  • More than 200 skulls and relatively complete skeletons

See what fossil birds are on display in our museum exhibits.
cast of complete bird fossil, legs spread, small black and white ruler underneath
P. cercanaxius cast of private specimen

NPS Photo

Shoreline Bird - Pseudocrypturus cercanaxius

Order Lithornithiformes, Family Lithornithidae
P. cercanaxius had long legs and a long, narrow beak. It was likely a wading bird that inhabited the shoreline of Fossil Lake, using its long beak to search for insects and other invertebrates.
The wing and foot structure suggest that, unlike its living relatives in the superorder Paleognathae, P. cercanaxius was capable of sustained flight and perching.
cast of fossil bird on its side with long legs and long neck, bent neck and one visible wing
G. wyomingesis cast of MCZ342221 specimen

NPS Photo

Land Fowl - Gallinuloides wyomingesis

Order Galliformes, Family Gallinuloidade
The Galliformes order has over 200 living species, divided into 8 families. Most of these species are ground-feeding herbivores, including pheasants, turkeys, chickens, and quails. These species are capable of flight, but are commonly known to run in the escape of a predator.
G. wyomingesis is the oldest known species of the Galliformes order. It was also the first bird species discovered in the FBM.
G. wyomingesis is considered a non-aquatic bird, but it has been found in both near-shore and mid-lake deposits. This indicates that G. wyomingesis may have attempted to fly over Fossil Lake on occasion.

disarticulated bird fossil, feathers preserved with feet spread out at bottom.
P. mcgrewi FOBU13681 specimen

NPS Photo

Early Roller - Primobucco mcgrewi

Order Coraciiformes, Family Primobucconidae
Modern members of the Coraciiformes include "true" roller birds. Modern rollers are:
  • strong fliers
  • characterized by large heads and short legs
  • insectivores, typically catching and eating insects while in flight
  • found in the tropical and warm temperate regions of Africa, Europe, Asia, and Australia
P. mcgrewi is the only species in the Primobucconidae family, and is considered a stem roller. It may have been more omnivorous than modern rollers. P. mcgrewi is one of the most common bird species found from Fossil Lake.

Parrots - 4 Species Identified: Cyrilavis colburnorum & Cyrilavis olsoni & Avolatavis tenens & Tynskya eocaena

Order Prittaciformes
  • Family Halcyornithidae - C. colburnorum & C. olsoni
  • Family Quercypsittidae - A. tenens
  • Family Messelasturidae - T. eocaena
The modern Prittaciformes (parrot) family:
  • includes almost 400 living species
  • found primarily in tropical and subtropical regions
  • live in the Caribbean, Pacific Islands, South America, Central America, southern North America, southern Asia, Australia, and Africa
  • identifiable by strong, curved beaks, necessary for feeding on nuts and large seeds
Fossil Lake is thought to have been a hot-spot for early parrot diversity.
  • the FBM contains the earliest, well-preserved fossil parrots in the world
  • FBM parrots lack the modern parrots' characteristic beak, suggesting their diet was less specialized

Last updated: February 24, 2024

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