Brontomerus
Brontomerus Temporal range:
Lower Cretaceous , | |
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Holotype ilium | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | †Sauropodomorpha |
Clade: | †Sauropoda |
Clade: | †Macronaria |
Clade: | †Somphospondyli |
Genus: | †Brontomerus Taylor, Wedel & Cifelli, 2011 |
Species | |
B. mcintoshi Taylor, Wedel & Cifelli, 2011 (type) |
Brontomerus (from Greek bronte meaning "thunder", and merós meaning "thigh") is a possibly
Description
Brontomerus is known from two fragmentary specimens differing in size, likely a juvenile and an adult.
Discovery
Fossils of Brontomerus were recovered from a
Classification
Based on phylogenetic analysis using a 50% majority rule tree, Brontomerus was initially placed as a basal somphospondyl within Titanosauriformes, in a trichotomy with Euhelopus and the Titanosauria. A strict consensus tree was also calculated, but yielded poorly resolved results. The tree can be seen below:[1]
Macronaria |
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In 2012, D'Emic concluded that Brontomerus to be a nomen dubium due to the holotype's fragmentary, nondiagnostic nature, but regarded it referable to Titanosauriformes.[7]
In 2013, Mannion et al. found Brontomerus to be securely classified as a basal somphospondyl, but were not able to resolve its affinities more precisely.[8]
Paleobiology
Dr. Michael Taylor, one of the dinosaur's describers, hypothesizes that the strong thigh muscles of Brontomerus were probably used for functions other than speed. He points out that for fast movement, the strong muscles would be oriented at the back of the leg to pull it along, but the actual positioning of the muscles indicates they were more likely used to deliver a kick.[3] This is due to the apparent anchoring of large femoral protraction muscles, which would have been used to move the leg forward powerfully. Large femoral retraction muscles, on the other hand, are needed for fast forward locomotion, and the ilium of Brontomerus offers little attachment area for these, though this does not necessarily imply weak retraction muscles as these would have been mostly anchored on the tail-base rather than the ilium.[1] The supposed kicks would have possibly been used for fighting over mates or in defense against predators,[3] such as Utahraptor and Deinonychus.[2]
Dr. Matthew Wedel, assistant professor of anatomy at the Western University of Health Sciences in Pomona, California, has stated that since it has been commonly been assumed that sauropods tend to prefer drier, upload areas, perhaps Brontomerus may have used its powerful leg muscles for traversing rough, hilly terrain. He described the theoretical use of such muscles in this terrain as "a sort of dinosaur four-wheel drive."[4]
In addition to powerful protraction muscles, the ilium of Brontomerus would have also anchored
Despite these theories, the actual data on the ilium and its powerful muscles indicates only that the animal was "unusually athletic for a sauropod". The authors acknowledge that while the unusual qualities of the hipbone probably have some functional significance, it is difficult to assess without further information about the pelvis, femora and proximal caudals.[1]
References
- ^ .
- ^ a b "Cosmos - New dinosaur had biggest known hips, thighs". Cosmos magazine. 2011-02-22. Archived from the original on 2011-07-08. Retrieved 2011-02-22.
- ^ a b c d "BBC News - Dinosaur had 'thunder-thighs'". Bbc.co.uk. 2011-02-22. Retrieved 2011-02-22.
- ^ a b "News.com.au - 'Thunder Thighs' dinosaur Brontomerus discovered". news.com.au. 2011-02-22. Archived from the original on 2011-02-24. Retrieved 2011-02-22.
- ^ "NewsOK - Oklahoma researchers from Sam Noble museum instrumental in new dinosaur discovery". NewsOK news. 2011-02-22. Retrieved 2011-02-22.
- ^ a b "Sify news - Scientists name new dino species 'thunder thighs'". Sify news. 2011-02-22. Archived from the original on 2012-10-19. Retrieved 2011-02-22.
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- ISSN 0024-4082.