Suchomimus

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Suchomimus
Temporal range: Early Cretaceous, 121–112Ma
Cast of the skull, ROM
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Theropoda
Family: Spinosauridae
Subfamily: Baryonychinae
Genus: Suchomimus
Sereno et al., 1998
Species: † S. tenerensis
Binomial name
Suchomimus tenerensis
Sereno et al., 1998
Synonyms

Baryonyx tenerensis (Sereno et al., 1998 [originally Suchomimus])

Suchomimus ("crocodile mimic") is a genus of large spinosaurid dinosaur with a crocodile-like mouth that lived between 121–112 million years ago, during the late Aptian stage of the Cretaceous period in Niger, Africa.[1] The only species in the genus is Suchomimus tenerensis.

Description[edit]

Life restoration

Unlike most giant theropods, Suchomimus had a very long, low snout and narrow jaws, formed by expansion of the premaxilla and the anterior ramus of the maxilla. The jaws have about 130 teeth, pointed but not very sharp and curving slightly backward, with fine serrations. The tip of the snout was enlarged and carried a "rosette" of longer teeth, seven per side on the top and about the same number in the lower jaw. Further back, there are 22 teeth per side on top and 31 per side on the bottom.[2] The animal is reminiscent of crocodilians that eat mainly fish.

Suchomimus also had blade-shaped extensions on its vertebrae which may have held up some kind of low flap, ridge or sail of skin that was highest over its hips, lower and further back than that of Spinosaurus.[2] Detailed study shows that the specimen of Suchomimus was a subadult about 11 m (36 ft) in length and with mass estimates between 2.6 and 5.2 tonnes (2.6 and 5.1 long tons; 2.9 and 5.7 short tons)[3]The overall impression is of a massive and powerful creature that ate fish and presumably other sorts of meat (carrion, if nothing else) more than 100 million years ago, when the Sahara was a lush, swampy habitat.

Discovery, naming, and taxonomy[edit]

Mounted skeleton, Chicago

In 1997, palaeontologist Paul Sereno and his team discovered fossils that represented about two-thirds of the skeleton of a huge meat-eater in the Tegama Bed of the Elrhaz Formation in Niger. They named the genus Suchomimus ("crocodile mimic") after the shape of the animal's head and the species tenerensis after the Ténéré Desert where it was found.[2]

Suchomimus has been placed among the spinosaurids, a group of large predator-scavengers with jaws adapted for hunting fish and with less heavily built skulls when compared to other similarly-sized theropods, like the tyrannosaurids. The teeth were adapted for grasping rather than slicing and the roof of the mouth was more solid, allowing the spinosaurids to resist twisting forces exerted by prey. The rest of the body was not particularly adapted to the water.[4] Apart from the back ridge, Suchomimus was very similar to the spinosaurid Baryonyx which also had strong forelimbs and a huge sickle-curved claw on its "thumb". And, as with Baryonyx, the claw was the first fossil part to be noticed by palaeontologists. The holotype and only known individual of Suchomimus was considerably larger than that of Baryonyx, but the ages of the two individuals are not known. It may also be a synonym of Cristatusaurus.

Sereno et al. (1998) analyzed 45 factors to produce a cladogram that showed Suchominus and Baryonyx to be distinct but closely related.

References[edit]

  1. ^ Holtz,, Thomas R. Jr. (2008). "Winter 2011 Appendix". Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages. Random House. Retrieved 2013-03-19.  ].
  2. ^ a b c Sereno, P.C.; Beck, A.L.; Dutheil, D.B.; Gado, B.; Larsson, H.C.E.; Lyon, G.H.; Marcot, J.D.; Rauhut, O.W.M.; Sadleir, R.W.; Sidor, C.A.; Varricchio, D.D.; Wilson, G.P; and Wilson, J.A. (1998). "A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids". Science 282 (5392): 1298–1302. Bibcode:1998Sci...282.1298S. doi:10.1126/science.282.5392.1298. PMID 9812890. Retrieved 2013-03-19. 
  3. ^ Therrien, François; Henderson, Donald M. (2007). "My theropod is bigger than yours … or not: estimating body size from skull length in theropods". Journal of Vertebrate Paleontology 27 (1): 108–115. doi:10.1671/0272-4634(2007)27[108:MTIBTY]2.0.CO;2. Retrieved 2013-03-19. 
  4. ^ Holtz, T.R., Jr (1998). "Spinosaurs as crocodile mimics". Science 282 (5392): 1276−1277. doi:10.1126/science.282.5392.1276. Retrieved 2013-03-19. 

External links[edit]