Arkhane, a new species of dinosaur in world exclusivity at the Museum
Arkhane, a new species of dinosaur in world exclusivity at the Museum
link to this article: //www.naturalsciences.be/fr/news/item/17601
This authentic fossil, 70% complete, 8.7 m long and dating from the Upper Jurassic (about 155,000,000 years ago), is the skeleton of a new allosaurus species. It has its world premiere in the Evolution Gallery from May 7, 2019 to March 31, 2020.
Arkhane – whose name is a contraction of the secret, mysterious Latin arcanus and the formidable conqueror Genghis Khan – is an authentic skeleton that is 70% complete, which is exceptional. It is 8.7 m long and 2.6 m high. It dates from the Upper Jurassic, more precisely from Kimmeridgian (157 000 000 – 152 000 000). It was discovered in 2014 at the Barnum-Kaycee site in Wyoming, Morrison Formation.
Carnivorous (observe its front claws and teeth), bipedal (its hind legs and muscular tail counterbalanced the front of its body) and fast (it could reach 30 to 55 km/h): Arkhane must have been a formidable predator.
Arkhane arrived at the Museum via a private collector, neophyte but passionate, who wishes to remain anonymous. He acquired it at an auction in France with the objective of unlocking the mysteries of the specimen and making it accessible to as many people as possible. For six months, our paleontologist, Pascal Godefroit, studied the fossil skeleton. Here are his conclusions.
This specimen belongs to the genus Allosaurus
In particular, it has the highly profiled skull typical of allosaurs, as well as a bony protuberance, probably corneous, in front of and above the orbit (at the lacrimal level).
Allosaurs were the top predators of the Upper Jurassic in North America: 60% of the theropods in the Morrison Formation belong to the genus Allosaurus. Their prey were sauropods (Diplodocus, Apatosaurus, Brachiosaurus, Camarasaurus…), ornithopods (especially Nanosaurus) and stegosaurids, or even occasionally other predators.
The genus Allosaurus currently includes A. fragilis (known by more than 60 more or less complete skeletons), A. maximus and “A. jimmadseni” (known by an almost complete specimen and skull), all from the Morrison Formation, as well as A. europaeus, the allosaurus found at the Porto Novo site in Portugal.
It is not an Allosaurus fragilis but a new species
Several anatomical characteristics tend to show this, including :
the mandible (lower jaw) very thin with very small teeth compared to those of the upper jaw
the claw of the first finger of the hand proportionally more massive than in Allosaurus fragilis
the tip of the pubis – foot-shaped – smaller than in Allosaurus fragilis, while the base of the pubis is wider the angle of the femur head is larger than in Allosaurus fragilis
Arkhane and “Allosaurus jimmadseni” date from the same period (Kimmeridgian, 152-157 million years ago) and are slightly older than A. fragilis found in the upper part of the Morrison Formation.
Unlike Big Al, another famous allosaurus, Arkhane does not have any obvious signs of injuries (repaired fractures…) or diseases. So we don’t know how he died.
You can admire Arkhane in the Evolution Gallery, in the part dedicated to Jurassic animals. The fossils exposed so far in this area are all marine animals. It is therefore with enthusiasm that we welcome, for 11 months, this magnificent Jurassic terrestrial predator.
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