Pleistogyps rex Skull measures 9x4x4 inches. Pleistogyps rex or Teratornis Merriamai Skull is museum quality polyurethane cast. Made in USA. 2-part skull (separate cranium and jaw)

According to description of 1945, Pleistogyps rex or Teratornis merriami had a wingspan of around 11 to 12 feet and a wing area of 17.5 square meters, standing an estimated 30 in. tall.

It was somewhat larger than the extant Andean condor, and by calculating the area of the organism’s sternum and synsacrum, Teratornis was estimated to weigh about 50 lb., which was nearly double the weight of an average Californian condor.

The Pleistogyps rex or Teratornis was similar to condors, although an analysis of the functional morphology of its skull, namely its larger bill and ability to spread its mandibles and swallow its prey whole, suggests that it was an active and carnivorous predator rather than a scavenger.

Pleistogyps rex was also well adapted to hunt for smaller animals which are also known to have utilized the pools. Analysis of the skull and bill shapes suggests that fish may have constituted a major part of its diet.

Taking into account the strong legs, stout claws, and a gripping power not quite as developed as in eagles, it is rather likely that Pleistogyps rex would have hunted for aquatic prey in the manner of an osprey, which also provides a reasonable explanation of how such large numbers of powerful, well-flying birds could have become stuck in the asphalt.

Other anatomical features, such as the relatively small and sideward facing orbits and the low skull, are also consistent with a scavenging lifestyle.

Teratornis had legs that were too short for it to take flight by running on flat ground. It is theorized that the Teratornis primarily inhabited cliff terrain, where it could take off and soar through the air easily.

Many Pleistogyps rex bone samples contributing to modern research have been found at the La Brea Tar Pits in Los Angeles, California.

Teratornis merriami are thought to have been attracted by Pleistocene megafauna that became stuck and died in the viscous asphalt while trying to drink from pools of water that gathered on the surface, with the teratorns subsequently falling victim to the sticky deposits.

For the Teratornis merriami, small prey such as frogs, lizards, young birds, and small mammals were swallowed whole, while carrion would have been fed on in a manner similar to that of condors or vultures.