Sarahsaurus

• North America

• Sarahsaurus aurifontanalis

Sarahsaurus is a genus original sauropodomorpher dinosaur that lived in the Lower Jurassic of North America. Fossils currently the only way Sarahsaurus aurifontanalis were found in the Kayenta Formation near Gold Springs in Arizona.

So far, the remains of three individuals have been found: The holotype specimen consists of a fragmentary skull and the almost complete skeleton rest, while a second specimen includes a nearly complete skull and one copy is an almost complete skeleton with rest. From other Sauropodomorphen Sarahsaurus to be distinguished among other things by an opening ( foramen ) in the pubic bone ( pubis ) and by a Phalangenformel the hand skeleton of 2-3-4-2-2.

Sarahsaurus was named in 2010 by Timothy B. Rowe, Hans -Dieter Sues and Robert R. Reisz, and is the third known genus sauropodomorpher original dinosaurs from North America.

• 3.1 type material
• 3.2 taxonomy

Description

Sarahsaurus was about 4 meters long and weighed probably about 110 kg. He had, like other basal dinosaurs sauropodomorphe a long neck, wearing a small head in relation to the fuselage, and a long muscular tail. The arms were much shorter than the legs, but very strong. The hand, about the size of a human, was very strong and wore large claws. A large difference in length between the front and hind limbs indicated at related " prosauropods " on a pure bipedalism back. However, the femurs of Sarhasaurus were in lateral view straight, and not curved, as is typical for much larger, and four-legged sauropods.

Reference and excavation

Sarahsaurus holotype and the amount allocated in the first description finds come from the middle third of the ' Silty Facies "of the Kayenta Formation ( Glen Canyon Group ). The site is located in northeastern Arizona on the northern edge of the dewatered by Gold Spring Wash Basin, near the Grand Canyon. The references are from the Lower Jurassic ( Sinemurian - Pliensbach ).

Etymology

The genus name honors Sarahsaurus Sarah Butler, through a project managed by their fundraising a high amount for the " Dino Pit " collected, an interactive exhibition at the Austin Nature and Science Center. The " Dino Pit " was co-founded by Timothy Rowe, one of the authors who Sarahsaurus described. Rowe promised Mrs. Butler, to name a dinosaur after her, when they collect a million dollars. The second part of the name of the genus name goes back to Greek sauros / σαῦρος, " lizard ", " Salamander"

The species name aurifontanalis formed from aurum ( Latin for " gold " ) and fontanalis ( Latin for " from the source " ) refers to the locality near the town of Gold Springs in Arizona.

Type material and systematic classification

Type material

In the original description Rowe et al list next to the holotype two other individuals as assigned Finds ( referred by specimens ) on. The holotype is an incomplete skull with associated almost complete skeleton of an adult animal, and carries the collection number TMM 43646-2 of the Texas Natural Science Center. From the skull premaxilla, frontal, Quadruatum and the braincase are preserved. The postcranial skeleton was largely found in the natural compound. The merger of the various cranial bones to each other as well as the neural arches of the vertebrae along the spine and the show at the rib in the pelvic area and tail with their associated eddies that the animal was fully grown.

The assigned Fund TMM 43646-3 is a postkraniales skeleton from the same locality as the holotype. At the Museum of Comparative Zoology at Harvard University is kept MCZ 8893, a nearly complete skull with lower jaw and some fragments of vertebrae and leg bones. This specimen shows open sutures of the skull, and was therefore not fully grown.

Taxonomy

The position of Sarahsaurus in the pedigree of Sauropodomorpha is not clearly determined. Two different matrices yield drastically different positions: when using the matrix of Yates gives a position at the base of Sauropodomorpha for Sarahsaurus, as a sister group to the Plateosauria plus Riojasaurus and Ruehleia. The matrix of Upchurch, Barrett and Galton placed Sarahsaurus contrast than basal sauropods. This discrepancy is that the result based on the Yates matrix by Homoplasien ( convergence ) has been corrupted, for which the temporal and spatial distribution of basal prosauropods speak. A position at the base of Sauropoda, however, seems more credible and less affected by methodological problems.

Paleobiology

Over the life of Sarahsaurus is not yet much known. The for " prosauropods " typical dentition indicated in the analog circuit to similar genera indicate that the animals were probably herbivores, but may also ate small vertebrates and insects.