Titanis

Titanis (for the mythological Greek Titans) is a genus of phorusrhacid ("terror birds", a group originating in South America), an extinct family of large, predatory birds, in the order Cariamiformes (an order including phorusrhacids and the extant seriemas) that inhabited the United States during the Pliocene and earliest Pleistocene. The first fossils were unearthed by amateur archaeologists Benjamin Waller and Robert Allen from the Santa Fe River in Florida and were named Titanis walleri by ornithologist Pierce Brodkorb in 1963, the species name honoring Waller. The holotype material is fragmentary, consisting of only an incomplete right tarsometatarsus (lower leg bone) and phalanx (toe bone), but comes from one of the largest phorusrhacid individuals known. In years following the description, many more isolated elements have been unearthed from sites from other areas of Florida, Texas, and California. However, Titanis remains poorly known. It was classified in the subfamily Phorusrhacinae, which includes some of the last and largest phorusrhacids like Devincenzia and Kelenken. Titanis, like all phorusrhacids, had elongated hind limbs, a thin pelvis, proportionally small wings, and a large skull with a hooked beak. Titanis was one of the largest phorusrhacids, rivaling Kelenken and Phorusrhacos in size based on preserved material. A 2005 estimate placed Titanis at in height and in weight. Due to the fragmentary fossils, the anatomy is poorly known, but several distinct characters on the tarsometatarsus have been observed. The skull is estimated to have been between and in length, one of the largest known from any bird. Phorusrhacids are thought to have been ground predators or scavengers, and have often been considered apex predators that dominated Cenozoic South America in the absence of placental mammalian predators, though they did co-exist with some large, carnivorous borhyaenid mammals. Titanis co-existed with many placental predators in North America and was likely one of several apex predators in its ecosystem.