Saurornitholestes

Phylogeny: Dinosauria > Saurischia > Theropoda > Neotheropoda > Tetanurae > Avetheropoda > Coelurosauria > Maniraptora > Pennaraptora > Paraves > Dromaeosauridae > Eudromaeosauria > Saurornitholestinae

Overview: Saurornitholestes was a dromaeosaurid, or “raptor” dinosaur, that could’ve inhabited a vast range across North America, over a fair amount of time in the Late Cretaceous. The original holotype specimen of the genus was unearthed in Alberta, Canada, back in the mid-1970’s. Fossils recovered included parts of the skull, vertebrae, ribs, and some limb bones. Described as a genus in 1978, the name of Saurornitholestes means “lizard-bird robber”, chosen in reference to a family of birdlike dinosaurs then known as the Saurornithoididae, nowadays known as the Troodontidae. In a number of ways, Saurornitholestes resembled troodontids, but most of its features place it firmly within the related Dromaeosauridae. Following its description, many other fossils, often consisting of partial remains, would be referred to the animal. Some were found much farther south in states like New Mexico, or possibly even in the eastern United States, in South Carolina and Alabama. It’s debated if all of these fossils actually belong to it, due to this unusually widespread range. Some of the referred material consists of scattered teeth, hard to associate with a specific taxon.

The overall anatomy of Saurornitholestes was similar to that of other dromaeosaurids. It had fairly long legs, with an overall slender build, suggesting it was relatively agile. Enlarged talons were fixed to the second toe of each foot – the famous dromaeosaur “killing claws”. These claws were used to hook into the flesh of its prey as it attacked with its jaws and other claws. Saurornitholestes was around the same size as Dromaeosaurus and Velociraptor, or about two meters long. Smaller prey would’ve been its preference, but larger prey may’ve been vulnerable if it was a pack hunter (proof for such behavior is actually fairly scant for dromaeosaurids). Saurornitholestes is the namesake of a subfamily within the Dromaeosauridae called the Saurornitholestinae. Other potential members included Atrociraptor or even Acheroraptor. Saurornitholestines tended to have fairly deep snouts, unusual tooth serrations, unique sinuses, and a few other distinguishing features. The original fossil specimen of Saurornitholestes comes from the Dinosaur Park Formation, meaning it would’ve lived alongside dinosaurs like Lambeosaurus, Styracosaurus, Daspletosaurus, and Gorgosaurus.