| Maraapunisaurus | |
|---|---|
| |
| An artist's illustration of Maraapunisaurus fragillimus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Sauropsida |
| clade: | Dinosauria |
| Superorder: | Sauropodomorpha |
| Family: | †Rebbachisauridae |
| Genus: | †Maraapunisaurus Carpenter, 2018 |
| Type species | |
| †M. fragilimus Cope, 1878a | |
Maraapunisaurus is a genus of rebbachisaurid sauropod dinosaur. It it is known only from what has sometimes been estimated to be the largest dinosaur specimen ever discovered, originally named Amphicoelias fragillimus. Based on surviving descriptions of a single fossil bone, scientists have produced numerous size estimates over the years; the largest estimate M. fragillimus to have been the longest known animal at 58 metres (190 feet) in length and with a mass of 122.4 tonnes (120.5 long tons; 134.9 short tons). However, because the only fossil remains were lost at some point after being studied and described in the 1870s, evidence survived only in drawings and field notes.
More recent studies have made a number of suggestions regarding the possibility of such an animal. One analysis of the surviving evidence, and the biological plausibility of such a large land animal, has suggested that the enormous size of this animal were over-estimates due partly to typographical errors in the original 1878 description. However; recently, it was suggested by paleontologist Kenneth Carpenter that the species is a rebbachisaurid, rather than a diplodocid sauropod. He therefore used Limaysaurus instead of Diplodocus as a basis for size estimates. This resulted in a smaller, 30.3 metres (99 feet) animal, and he dismissed the idea that there must have been typographical errors.
Description[]
Any size estimate of M. fragillimus must be careful because there are a lack of specimens that may be detailed later, and accurate representation of its fossils will be revealed in later updates, in case there is any misleading info about them.
Paul assumed that Maraapunisaurus would be 40-60 meters long, due to the proportions of the Diplodocus, which was thought to be 58 meters long by Carpenter.
When the taxon was changed to a rebbachisaurid instead of a diplodocid by Carpenter, he made new size estimates in 2018. He decided to use Limaysaurus as a model instead, which was one of the rebbachisaurids, it was chosen due to its completeness because fossils of most other species are mostly fragmentary & pending. Scaling Limaysaurus directly, he estimated the length of Maraapunisaurus to be 30.3 meters long, 7.95 meters tall at the hips and the vertebra being 2.4 meters. However, he noted that a study from a 2006 book calculated that the neck length of a sauropod scales with the length of the torso by a power of 1.35 meters. He changed his mind and estimated Maraapunisaurus to be 32 meters long. The neck of the animal in the smaller estimate was about 6 meters long, although there was a larger scale for the neck to be 7.6 meters long.
Classification[]
Paleobiology[]
In 1921, Osborn and Mook assigned A. fragillimus in Diplodocidae. This was accepted until 2018. In that year, Carpenter concluded from a qualitative anatomical comparison that the species was a basal member of the Rebbachisauridae, and assigned it the new name Maraapunisaurus, after a Southern Ute word maraapuni that defines "huge". The basal position would be shown by its hyposphene, which is shared with rebbachisaurids: Histriasaurus, Comahuesaurus and Demandasaurus. Although Maraapunisaurus is older than Histriasaurus, it's more derived than Histriasaurus as it was proved by the pneumatisation and the neural arch base in a few ways.
Since Maraapunisaurus belongs to Rebbachisauridae, it would be considered as the oldest member of its group known and the only one discovered from the Jurassic. The previous one was Xenoposeidon. Maraapunisaurus would also be the only one from North America.
Paleoecology[]
Like sauropods, Maraapunisaurus lived in savannas.
In popular culture[]
- Maraapunisaurus appeared in the documentary series called Paleoworld in the episode "Earthshakers" when it was still called Amphicoelias fragillimus.
Gallery[]
