MEANING: Giant thief
PERIOD: Late Cretaceous
CONTINENT: Asia
Gigantoraptor is the the largest known oviraptorsaur, at 8 m in length, and weighing up to 2 t. It required large amounts of energy to sustain itself, and is thought to have been a dietary generalist, able to consume any food it could find. It had a deep toothless beak, which could cut through plants, while also being adapted to process meat. Unlike other oviraptorsaurs, Gigantoraptor may not have been fully feathered. Larger animals rely more on body mass for temperature regulation, which could have led to some loss of feather covering as Gigantoraptor evolved. However, arm and tail feathers were likely still present, being useful for display behavior and covering eggs while brooding.
Gigantoraptor is from the Cretaceous. The Cretaceous is a geological period that lasted from about 145 to 66 million years ago. It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period.
The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct flora and fauna, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, coincident with the decline and extinction of previously widespread gymnosperm groups.
The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs, and large marine reptiles, died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction that lies between the Mesozoic and Cenozoic Eras.
Gigantoraptor is an oviraptorosaur. Oviraptorosauria is a group of feathered theropod dinosaurs from the Cretaceous Period of what are now Asia and North America. They are known for their short, beaked, parrot-like skulls and bony crests that many had atop the head. They ranged in size from the turkey-sized Caudipteryx, to the 8-meter-long, 1.4-ton Gigantoraptor.
Oviraptorosaurs are closely related to birds. They had shortened beaklike jaws, and few or no teeth. The long hands typically had three long fingers each. Their tails are very short compared to other maniraptorans, and show evidence of fused vertebrae, which imply the presence of a fan of feathers. Fossilized remains have been found with impressions of well developed feathers, most notably on the wings and tail, suggesting that they functioned at least partially for display.
A number of oviraptorid specimens have been discovered in a nesting position similar to that of modern birds. The arms of these specimens are positioned in such a way that they could perfectly cover their eggs if they had small wings and a substantial covering of feathers.