page_title: Rajasaurus
section_title: Description
hierarchical_section_title: Rajasaurus / Description
caption_attribution_description: English: Restoration of Rajasaurus narmadensis based on GSI 21141/1–33.
context_page_description: Rajasaurus is a genus of carnivorous abelisaurid theropod dinosaur from the Late Cretaceous of India, containing one species: Rajasaurus narmadensis. The bones were excavated from the Lameta Formation in the Gujarat state of Western India, probably inhabiting what is now the Narmada River Valley. It was formally described by palaeontologist Jeffrey A. Wilson and colleagues in 2003 based on a partial skeleton comprising the braincase, spine, hip bone, legs, and tail–a first for an Indian theropod. The dinosaur likely measured 6.6 metres, and had a single horn on the forehead which was probably used for display and head-butting. Like other abelisaurids, Rajasaurus was probably an ambush predator.
  India at this time was an island, due to the break-up of the supercontinent Gondwana, though it is possible animals still were able to migrate to and from nearby continents. The creation of the subfamily Majungasaurinae, and its inclusion of abelisaurids from India, Madagascar, and Europe–including Rajasaurus–further reiterates this. The Lameta Formation has yielded several other dinosaur species, including abelisaurids and titanosaurian sauropods, similar to other Gondwanan landmasses.
context_section_description: In 2010, palaeontologist Gregory S. Paul estimated the body length of Rajasaurus at 11 metres (36 ft) and weight at 4 metric tons (4.4 short tons). In 2016, its length was estimated to be 6.6 metres (22 ft). The same year another estimation listed it at 10.5 metres (34.5 feet) and 3 metric tons (3.3 short tons). Rajasaurus closely resembled the Madagascan abelisaurid Majungasaurus, with a 20 million year separation. Abelisaurids typically had four fingers, short arms, and, to compensate, a heavily-constructed head which was the primary tool for hunting; however, the skull was short, they probably had modest jaw musculature, and the teeth were short. Abelisaurids probably had a bite force similar to Allosaurus at around 3,500 newtons (790 lbf).
   
  On the braincase, only the left sides of the parietal and frontal bones are preserved. The braincase is thick, with the frontals achieving a maximum thickness of 4 centimetres (1.6 in) above the eye socket. On the frontals near the midline is a path for the olfactory tract which is a part of smelling. The rims of the supratemporal fossae, depressions on either side of the top of the skull, form a low sagittal crest along the middle of the top of the skull. The front rims of the fossae are unusually steep. Abelisaurids, typically, had elongated fenestrae (holes in the skull) below the quadrate bone near the bottom of the skull, but Rajasaurus had elongated supratemporal fenestrae near the top of the skull. Unlike in other theropods but similar to Majungasaurus, the crista prootica, which is typically a ridge along the otic capsule bone in the ear, more so juts outward as a stump.
  Rajasaurus had a low horn on its forehead that is primarily made of nasal bone more than frontal, unlike the horn on Majungasaurus. The horn in life was probably the same size as the fossilized horn, unlike in Carnotaurus where in life the horn was extended by a thickened layer skin. Though Rajasaurus did have a thickened layer of skin, it probably did not add to the overall length of the horn. A trough-like groove bordered by a raised wall is present where the frontal meets the nasal, decreasing in height and width towards the midline, serving to support the horn on the nasal.
  Only one neck vertebra–likely a middle vertebra–is preserved, and it is proportionally shorter than that of other ceratosaurs, broader than is tall, and spool-shaped. Like in other ceratosaurs, the back face of the vertebra where it connects to another vertebra is very concave; however, unlike in other ceratosaurs, the front face is also concave. Like other ceratosaurs, the neck vertebra has two air pockets, though they are unusually close to the head. Eleven partial spool-shaped dorsal vertebrae were found, but only one–most likely the fourth thoracic vertebra–is well preserved; the faces are concave, and more deeper than broad, in contrast to the neck vertebra which is the opposite. These vertebrae contain many air pockets. The bottom-side of six sacral vertebrae are preserved; they are elongated and have a decreasing width towards the ends, and have no arching. Three partial tail vertebrae were found, likely from the middle-section of the tail, and they also have concave faces, but are more cylindrical than spool-shaped.
  The part of the hip that juts out to attach to the ischium, the ischial peduncle, projects farther out than the pubic peduncle, which causes the hip-joint to be farther down on the back-underside of the hip. The iliac crests, on the other side of the hip from the ischium and pubic bone, are thin compared to the hip-joint area, 1 and 8 centimetres (0.39 and 3.15 in) respectively in thickness. The fibula, on the outside portion of the lower leg below the knee, decreases in width from top to bottom and is slightly concave. Similar to Ceratosaurus, the second metatarsal bone which connects the ankle bone to the second toe, is robust, has an oval-shaped and slightly concave joint between it and the ankle, and the width does not decrease as it gets nearer the toes. The fourth metatarsal bone has similar proportions to
caption: Life restoration
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