Megaraptor

Megaraptor (lit. 'large thief') is a genus of large theropod dinosaur, the type genus and namesake of the clade Megaraptora and family Megaraptoridae. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America, dating to the Turonian and Coniacian ages of the Late Cretaceous, roughly 90–88 million years ago. One species of Megaraptor, M. namunhuaiquii, has thus been named, known from seven partial or fragmentary skeletons, with only two including skull elements. The type specimen of Megaraptor consists of a fragmentary assemblage of limb bones, discovered in 1996 by Argentine palaeontologist Fernando E. Novas. Believing that a large claw found at the site came from the animal's foot, he determined that it was probably a coelurosaur related to dromaeosaurs and troodontids, and named it accordingly in 1998. While Novas never stated that Megaraptor belonged to either family, contemporary depictions often portrayed it as a giant dromaeosaurid. The discovery of another specimen revealed that Megaraptor's large claw actually came from its hand, and it was surmised in 2004 to belong to a novel lineage predating the carnosaur–coelurosaur split. Subsequent analyses recovered Megaraptor and related genera (collectively known as megaraptorans) as relatives of the allosauroid Neovenator, However, since the description of a relatively complete juvenile skull in 2014, Megaraptor has primarily been recovered within Coelurosauria, and may have been a close relative, or member of, Tyrannosauroidea. No complete skeletons of Megaraptor are known, so its anatomy has been pieced together over the years through only a few fragmentary specimens. It has been estimated that Megaraptor measured 8 m (26 ft) in length, and weighed around 1 t (2,200 lb). Its skull, the anatomy of which is known primarily from a juvenile specimen, was long, low, and slender, though in adults it was likely deeper and more robust, with...