Rahiolisaurus
| Rahiolisaurus | ||||||||||
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| Temporal occurrence | ||||||||||
| Upper Cretaceous ( Maastrichtian ) | ||||||||||
| 72 to 66 million years | ||||||||||
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Rahiolisaurus | ||||||||||
| Novas et al., 2010 | ||||||||||
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Rahiolisaurus is a genus of theropod dinosaur from the group of Abelisauridae . Fossils come from the Upper Cretaceous ( Maastrichtian ) of the Lameta Formation in India . All fossils come from a single quarry in the Indian state of Gujarat , but belonged to at least 7 different individuals.
The animal was scientifically described in 2010 by Fernando Novas and colleagues with the only species R. gujaratensis . The relationships of the genus within the Abelisauridae have not yet been investigated.
Rahiolisaurus is named after the village of Rahioli , where the fossils were found. The second part of the species name, gujaratensis , refers to the Indian state of Gujarat .
features
Rahiolisaurus was a large abelisaurid. A fully grown specimen with a thighbone 77 centimeters long is estimated to be eight meters long, based on comparisons with the better-known Majungasaurus . Compared to the Rajasaurus, also from the Lameta formation, the physique was relatively graceful, the legs were relatively slim. Only one right intermaxillary bone (premaxillary) is known of the skull - as with other abelisaurids, it has a rugose surface and contains four teeth, a number typical for original theropods.
This genus can be differentiated from related Abelisaurids by a number of unique features: For example, the teeth of the intermaxillary bone were teardrop-shaped in cross-section, while the post-acetabular process of the ilium has a deep notch.
Find
The fossils come from a single, 50 square meter quarry near the village of Rahioli in the Kheda district in western India. They were discovered during excavation work in 1995 and 1997 and are now kept at the Indian Statistical Institute in Calcutta . Chatterjee and Rudra (1996) originally assigned the finds to the genus Indosuchus . Most of the fossils were found disarticulated (outside of the original anatomical structure), which is why each bone was given its own specimen number. The holotype specimen consists of three associated bones: a right iliac bone (ISIR 550), a right pubic bone (ISIR 554) and a right femur (ISIR 558). The fossils come from at least seven different individuals from different ages, as indicated by the seven discovered right shins. Since these skeletal elements, which have been found several times, show no variations that could indicate different types, all bones at the site are assigned to a single type.
literature
- Fernando E. Novas, Sankar Chatterjee, Dhiraj K. Rudra, PM Datta: Rahiolisaurus gujaratensis, n. Gen. N. Sp., A New Abelisaurid Theropod from the Late Cretaceous of India . In: Saswati Bandyopadhyay (Ed.): New Aspects of Mesozoic Biodiversity . Springer Berlin / Heidelberg, 2010, ISBN 978-3-642-10310-0 , pp. 45-62 , doi : 10.1007 / 978-3-642-10311-7 .