Naturalist Charles Pickering was the librarian and a curator of the Academy of Natural Sciences. In 1843, he traveled to Africa and India to research human races. In 1848, Pickering published Races of Man and Their Geographical Distribution, which enumerated eleven races.
It lived from 98 to 83 million years ago, separating itself from the Velociraptor by roughly 10 million years. You might say it's an ancestor of the actual Velociraptor, even though the original specie of raptor was almost the size of modern chicken and the Achillobator was roughly 1 ft taller than the average person.
As distinguishing features, A. tetraptera has an oval esophageal bulb, smaller lips and broader cervical alae. Female A. tetraptera are 3â4 mm long and approximately 250 Î¼m wide, while males are 2â4 mm long and approximately 160 Î¼m wide.