086 ornitholestes hermanni by green mamba-d5kbyo9
An artist's illustration of Ornitholestes hermanni
Scientific classification
Kingdom: Animalia
Phylum: Chordata
clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Subfamily: Ornitholestinae
Paul, 1988
Genus: Ornitholestes
Osborn, 1903
Species: O. hermanni
Binomial name
Ornitholestes hermanni
Osborn, 1903

Ornitholestes (or-NITH-oh-LESS-tees), or "bird thief", was a small carnivorous Maniraptoriform dinosaur from North America during the Late Jurassic and Early Cretaceous period.


Discovery and naming[]

Ornitholestes was the first theropod to be discovered in the 1900s. The holotype skeleton (AMNH 619) was excavated in July 1900 in the Bone Cabin Quarry in Wyoming by an American Museum of Natural History expedition by Peter C. Kaisen, Paul Miller and Frederic Brewster Loomis. It represents a partial skeleton with skull, including numerous elements of the vertebral column, the forelimbs, pelvis and hindlimbs. Henry Fairfield Osborn named and scientifically described the specimen in 1903. The genus name Ornitholestes, initially suggested by Theodore Gill, means "bird robber" and is derived from the Greek ὄρνις/ornis, ornithos ("bird") and λῃστής/lestes ("robber"). The species name (O. hermanni) honors Adam Hermann, the head preparator at the Museum, who directed the restoration and mounting of the skeleton.

General description[]

A crew from the American Museum of Natural History found the first remains of Ornitholestes (or "bird robber") at Bone Cabin Quarry near Medicine Bow, Wyoming, in 1900. It is consisted of a skull and partial skeleton. This is the same quarry where workers found Apatosaurus, now mounted in the American Museum of Natural History.

250px-Ornitholestes mount at Royal Tyrrell Museum

An Ornitholestes skeleton.

H.F. Osborn briefly described Ornitholestes in 1903. In that paper, he aslo grouped a partial hand from the same quarry, but not the same animal, in the same genus. The skull is complete, though badly crushed. Serrated teeth line the jaws. The first tooth in the upper jaw is the largest. Ornitholestes may have had a small horn over its nose, but scientists are not sure.

The hands are not complete. If the partial hand of the other animal belongs to the same genus, the first finger was short, and the second and third fingers were much longer. Ornitholestes may have caputered and held its prey with its hand. All the fingers had sharp curved claws. The animal probably weighed about 35 pounds. For many years, scientists thought Ornitholestes and Coelurus were the same genus. In 1980, however, John Ostrom showed that they weren't. It lived alongside dinosaurs like Stegosaurus, Diplodocus, Dryosaurus, Ceratosaurus, and Allosaurus, and also pterosaurs like Rhamphorhynchus.

Height. 3 feet

Length. 7 feet



"Vintage" figure of Ornitholestes with an outdated appearance

The infraorder Coelurosauria, coined in 1914 by Friedrich von Huene, was traditionally a taxonomic wastebasket into which all small theropods were placed. Ornitholestes, due to its small size, was therefore generally classified as a coelurosaur. In 1986, Jacques Gauthier redefined this and several other paleontological terms in a more rigorous fashion, based on cladistic methods. Tetanurae was defined as modern birds and all theropods more closely related to modern birds than to ceratosaurs, while Coelurosauria now comprised all members of Tetanurae more closely related to modern birds than to carnosaurs. In 1988, Gregory S. Paul suggested that Ornitholestes was very similar in skull structure to Proceratosaurus, a Middle Jurassic theropod from England. He placed these two genera together in Ornitholestinae—a new subfamily under Allosauridae—and speculated that they were more closely related to the much larger Allosaurus than to other small theropods. However, the classification of Ornitholestes and Proceratosaurus as allosaur relatives proved untenable (the latter has since proved to be a tyrannosauroid), and Paul eventually abandoned it. All published cladistic analyses have shown Ornitholestes to be a coelurosaur as defined by Gauthier. Some analysis have shown support for the hypothesis that it is the most primitive member of the group Maniraptora, though more thorough analyses have suggested it is more primitive than the Maniraptoriformes, and possibly a close relative of the "compsognathid" Juravenator.


In Popluar Culture[]

  • Ornitholestes was in the famous documentary Walking with Dinosaurs, where one stalked and killed one of the baby Diplodocus and was chased off by the adults sauropods, Allosaurus, and Stegosaurus. Some have reappeared In the Walking with Dinosaurs special "The Ballad of Big Al" where in one part, A pair of Ornitholestes watches a brood of a dozen baby Allosaurus from a distance. But they won't come any close to catch one. Not while Big Al's Mother is around. A Year later, Al was on his own hunting for other Dinosaurs. He suddenly spotted a mother Ornitholestes attending her nest. Al hopes to get one of the eggs to satisfy his hunger. But the mother Ornitholestes spotted the juvenile Allosaurus. She repels aggressively towards Al & drived him off. However the Ornitholestes is shown with a horn on its skull which in reality was a crushed nasal bone that made a horn like shape on the top of the skull.
  • It was also featured in the documentary Dinosaur Revolution where one was killed by an angry Allosaurus mother, and another lived by a dried waterhole, chased around a Rhamphorhynchus, and was chased away by a sub-adult Allosaurus named Broken Jaw and a Torvosaurus.
  • Ornitholestes also appears in the seventh episode of Primeval: New World, where its shown to resemble the design used for Walking with Dinosaurs and the Special The Ballad of Big Al, and attacks the protagonists. It reappeared in the eleventh episode where it was shown dead after being subjected to many tests by Project Magnet.
  • A group of Ornitholestes appeared in The Land Before Time III: the Time of the Great Giving crossing a river.
  • It appears in The Lost World novel. Campers find the corpse of a large reptile on the beach of Rojas. Martin "Marty" Guitierrez invites Richard Levine to identify the creature. The corpse is destroyed by soldiers shortly after the scientists arrive. Levine identifies the creature as an Ornitholestes. Levine manages to save a skin sample from the creature. The sample is send to Ian Malcolm. Elizabeth Gelman analyzes the sample and shows the results to Malcolm. The skin has a structure comparable with pelicans; although it doesn't have feathers. It also has a 2 cm square green plastic radio tag. Elizabeth Gelman also notes that the skin contains a density of chromatophores, or pigment-bearing cells. The chromatophore could open and close. Meaning that this animal could change color, like a chameleon.
  • Ornitholestes is no. 024 of the Carnivore Ones that can be created in Jurassic Park III: Park Builder.
  • In the episode of Dink, the Little Dinosaur "Scavengers", An Ornitholestes named Fleet Foot is a hunter who only eats flyers. Like Flapper he attacked & almost ate. At the end, He was driven away from the Scavengers themselves.
  • In Fantasia The Rite of Spring, during the earthquake scene, they weren't seen alive. There was a skull & whole skeleton of Ornitholestes.

Fantasia-disneyscreencaps com-6929

Skull of an Ornitholestes got smash by a rock in Fantasia





General Description Credits to "ROMTECH" Computer CD Dinosaur Discovery






Walking with Dinosaurs

Dinosaur Revolution