Sauropodomorpha
Live reconstruction of the Late Jurassic sauropods Diplodocus
- Worldwide
The Sauropodomorpha ( from Ancient Greek σαῦρος sauros, lizard ', πούς pous, foot ' and μορφή morphé 'shape' ) are one of two groups of lizards Beck dinosaurs ( Saurischia ). You are fossil from the Upper Triassic to the end of the Mesozoic ( Cretaceous-Tertiary boundary) demonstrated and include basal forms that were filed in the past to the paraphyletic group of Prosauropoda and the Sauropoda, which produced the largest land-living animals of the earth's history. The largest sauropods reached more than 40 meters length, 17 meters and an estimated weight of 50 to 80 tons.
Important characteristics ( synapomorphies ) include a small head on a long neck and special detail structures at basin and hand. It is not clear whether the Sauropoda descended from the Prosauropoda or whether a sister group relationship exists. As the oldest representative of the Sauropodomorpha applies Saturnalia from the South American Late Triassic ( Carnian ) of before about 235-228 million years ago.
In contrast to the theropods, their sister group within the lizards Beck dinosaur that Sauropodomorpha were specialized to varying degrees, four-legged ( quadruped ) and plant food ( herbivory ) dinosaurs. While the sauropods were quadrupede herbivores in the Middle considerably smaller prosauropods also a movement on its hind legs ( bipedalism ) was possible, and their food spectrum was shifted toward omnivores ( Omnivorie ).
Features
All the basic features of the Sauropodomorpha also showed basal forms such as Thecodontosaurus, a 2.5 -meter-long, originating from the Upper Triassic of England, herbivores ( plant eaters ): With about 5 % of the body length of the skull is relatively small. At the top of the dentary is bent downward. The jaws have lanzettartige teeth that have crowns sawed. The body goes into a long neck with a minimum of 10 vertebrae. The Sauropodomorpha has a large thumb claw, at the 4th and 5th fingers of the claw does not exist. At the end of the ilium is a quick " shovel". The Sauropodomorpha has special detail structures at basin and hand. The advanced " prosauropods " and especially the sauropods ran obligatory quadruped, so on four feet.
Inside systematics
The taxon Sauropodomorpha developed in the Upper Triassic, probably from basal Saurischiern as Saturnalia. The early types of Sauropodomorpha from Upper Triassic and Lower Jurassic are summarized as Prosauropoda. However, it was discussed whether the prosauropods form a monophyletic clade. Most of the arguments to the contrary; thus form the species that were grouped as " prosauropods ", external groups of sauropods. The sauropods evolved in the Upper Triassic in South Africa and went through the Early Jurassic a Radiation.
Phylogeny by Pol, Garrido & Cerda, 2011:
Saturnalia
Pantydraco
Thecodontosaurus
Ruehleia
Plateosaurus
Massospondylus
Coloradisaurus
Gyposaurus
Yunnanosaurus
Sauropoda
Swell
- Wilfried West Heath, Reinhard Rieger (eds): Systematic Zoology Part 2: vertebral or cranial animals. Gustav Fischer Verlag, Stuttgart • Jena • New York 2003, ISBN 3-8274-0900-4.