End of the Day: Altispinax dunkeri

An adult male Altispinax dunkeri, a rare and mysterious theropod known only from a segment of vertebrae, scavenges on a fresh carcass on an Early Cretaceous floodplain in England at dusk.

The only known remains of Altispinax is a trio of vertebrae, right before the pelvis, with lengthened neural spines. Although these vertebrae were discovered as far back as the 1850s, Altispinax has remained a little known animal. The most widely accepted position for Altispinax is somewhere in Carnosauria, and in recent years has been suggested to be a Carcharodontosaurid closely related to Concavenator; which is also noteworthy for heightened neural vertebrae just before the pelvic region.