Megaraptora

Megaraptorans Temporal range: Early - Late Cretaceous[1] 130–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Diagram showing the skull and skeleton of Murusraptor
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Avetheropoda
Clade:	†Megaraptora Benson, Carrano & Brusatte, 2010
Type species
†Megaraptor namunhuaiquii Novas, 1998
Subgroups
†Fukuiraptor[2] †Phuwiangvenator[3] †Rapator[4] †Vayuraptor[5] †Megaraptoridae Novas et al., 2013 †Aerosteon †Australovenator[6] †Maip †Megaraptor †Murusraptor †Orkoraptor †Tratayenia Uncertain or possible members †Aniksosaurus †Aoniraptor[7] †Bahariasaurus †Chilantaisaurus †Datanglong †Deltadromeus †Eotyrannus †Gualicho †Siats †Vectaerovenator †Walgettosuchus

Megaraptora is a clade of carnivorous theropod dinosaurs with controversial relationships to other tetanuran theropods. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods.

Megaraptorans are incompletely known, and no complete megaraptoran skeleton has been found. However, they still possessed a number of unique features. Their forelimbs were large and strongly built, and the ulna bone had a unique shape in members of the family Megaraptoridae, a subset of megaraptorans which excludes Fukuiraptor and Phuwiangvenator. The first two fingers were elongated, with massive curved claws, while the third finger was small.^[8] Megaraptoran skull material is very incomplete, but a juvenile Megaraptor described in 2014 preserved a portion of the snout, which was long and slender.^[9] Leg bones referred to megaraptorans were also quite slender and similar to those of coelurosaurs adapted for running.^[8] Although megaraptorans were thick-bodied theropods, their bones were heavily pneumatized, or filled with air pockets. The vertebrae, ribs, and the ilium bone of the hip were pneumatized to an extent which was very rare among theropods, only seen elsewhere in taxa such as Neovenator.^[10] Other characteristic features include opisthocoelous neck vertebrae and compsognathid-like teeth.^[8]

Megaraptorans were originally placed as basal tetanurans as part of the family Neovenatoridae within the allosauroid clade Carcharodontosauria.^[10] By the early 2020s, many studies had come to find that megaraptorans instead represented members of Coelurosauria, with their exact position within this group being uncertain.^[11] However, some studies still support an allosauroid classification.^[12]

Megaraptorans were most diverse in the early Late Cretaceous period of South America, particularly Patagonia. However, they had a widespread distribution. Phuwiangvenator and Fukuiraptor, the most basal and second most basal known members of the group, lived in Thailand and Japan, respectively. Megaraptoran material is also common in Australia,^[13] and the largest known predatory dinosaur from the continent, Australovenator, was a megaraptoran.^[14]