Sauropodomorpha
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Live reconstruction of the Upper Jurassic sauropod Diplodocus |
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| Temporal occurrence | ||||||||||||
| Upper Triassic to Upper Cretaceous ( Carnian to Maastrichtian ) | ||||||||||||
| 235 to 66 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Sauropodomorpha | ||||||||||||
| Huene , 1932 |
The Sauropodomorpha (from ancient Greek σαῦρος sauros 'lizard', πούς pous 'foot' and μορφή morphé 'shape') are one of the two main groups of the lizard basin dinosaurs (Saurischia). They have been found in fossils from the Upper Triassic to the end of the Mesozoic Era ( Cretaceous-Tertiary boundary ) and include basal forms that were classified in the past in the paraphyletic group of prosauropods and the sauropods , which produced the largest land-dwelling animals in geological history . The largest sauropods reached more than 40 meters in length, 17 meters in height and an estimated weight of 50 to 80 tons.
Important characteristics ( synapomorphies ) include a small head on a long neck and special detailed structures on the pelvis and hand. It is not clear whether the Sauropoda descend from the Prosauropoda or whether there is a sister group relationship . The oldest representative of the Sauropodomorpha is Saturnalia from the South American Upper Triassic ( Carnian ) from about 235 to 228 million years ago.
In contrast to the Theropoda , its sister group within the pelvis dinosaurs, the Sauropodomorpha comprised four-legged dinosaurs ( quadruped ) and dinosaurs specialized in plant food (herbivory) to varying degrees . While the sauropods were quadruped herbivores , the prosauropods, which were considerably smaller on average, could also move on their hind legs ( bipedes ), and their food spectrum was shifted towards omnivores (omnivory).
features
All of the basic features of the Sauropodomorpha also showed basal forms, such as B. Thecodontosaurus , a 2.5 meter long, from the Upper Triassic of England originating, herbivores (plant eaters): With approximately 5% of the body length is skull relatively small. At the tip, the dental is bent downwards. The jaws have lanceolate teeth with serrated crowns. The trunk goes into a long neck with at least 10 vertebrae . The Sauropodomorpha has a large thumb claw, the 4th and 5th fingers do not have the claw. At the end of the iliac bone is a short "shovel". The Sauropodomorpha has special detailed structures on the pelvis and hand. The further developed " prosauropods " and especially the sauropods ran obligatorily quadruped , i.e. on four feet .
Internal system
The taxon Sauropodomorpha developed in the Upper Triassic, probably from basal Saurischiern such as Saturnalia . The early types of Sauropodomorpha from Upper Triassic and Lower Jurassic are grouped together as Prosauropoda . However, it has been discussed whether the prosauropods form a monophyletic clade . Most of the arguments speak against it; thus the species that were grouped together as "prosauropods" form outer groups of sauropods. The sauropods developed in the Upper Triassic in South Africa and underwent radiation in the Lower Jurassic .
Phylogeny according to Pol, Garrido & Cerda, 2011:
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literature
- Wilfried Westheide , Reinhard Rieger (Hrsg.): Special zoology. Part 2: vertebrates or skulls. Gustav Fischer, Stuttgart et al. 2004, ISBN 3-8274-0900-4 .
Individual evidence
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , pp. 162-213, online .
- ^ Wilhelm Gemoll : Greek-German school and hand dictionary. 9th edition, reviewed and expanded by Karl Vretska . With an introduction to the history of language by Heinz Kronasser. Freytag et al., Munich et al. 1965.
- ^ P. Martin Sander , Marcus Clauss: Sauropod Gigantism. In: Science . Vol. 322, No. 5899, 2008, pp. 200-201, doi : 10.1126 / science.1160904 .
- ^ Gregory S. Paul: The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 163, online .
- ↑ Michael J. Benton : Paleontology of the vertebrates. Translation of the 3rd English edition. Pfeil, Munich 2007, ISBN 978-3-89937-072-0 .
- ^ Diego Pol, Alberto Garrido, Ignacio A. Cerda: A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum. In: PLoS ONE . Vol. 6, No. 1, 2011, e14572, doi : 10.1371 / journal.pone.0014572 .
