What is a new kind of mammal "crazy beast" that lived 70 million years ago like the dinosaur?
In 1999MadagascarFossils found almost completely from the Earth's strata in the Southern Hemisphere of the ancient EarthGondwana continentA research paper has been published which states that it belongs to a new genus and new species of mammals that inhabited. A researcher at the Denver Natural Science MuseumDavid ClausThe research team led by him calls this mammal "the crazy beast."Adalatherium huiIt was named.
Skeleton of a Cretaceous mammal from Madagascar reflects long-term insularity | Nature
Fossil of 'crazy beast' skeleton uncovered-Scimex
Strange 'Crazy Beast' Skeleton May Be Oldest Mammal Unearthed in Southern Hemisphere
Fossils of Adalatherium huiCretaceousAt the end ofMaastrichtianIt was excavated in 1999 from a stratum of about 72.1 million to 66 million years ago, and it is considered to be a mammal belonging to the "Gondowanaterium suborder" that was said to have inhabited the Gondwana continent. Excavated in the southern hemisphereMammalsIt is said to be the oldest fossil.
Although fossils of mammals belonging to the subgenus Gondwanaterium have been excavated so far, only fossils of jaws, teeth, and skulls have been found in pieces, and the suborders of Gondwana theterium are anatomical and paleontological. Little was known about what kind of creature was scientifically and phylogenetically. The fossils discovered this time were of an immature individual, but they kept almost the whole body, and small bones and cartilage tissues were also preserved.
The fossil from which the following image was excavated. The head, front legs, hind legs, spine, ribs and almost all of the bones of the whole body are arranged.
— IFLScience (@IFLScience) April 29, 2020
One of the authors of the paper, Associate Professor Alistair Evans, who studies phylogenetic chemistry at Monash University, said that the results of the research on fossils uncovered in 1999 were finally reported in 2020. It took me about 20 years to study and show what kind of mammal it was and how it lived. "
According to Associate Professor Evans, a huge amount of work was required to restore fossils. It seems that it took work to combine more than 100 pieces to repair one tooth of Adalatherium hui. You can see the CG model of the teeth of Adalatherium hui in the following movie released by Associate Professor Evans.
(embed) https://www.youtube.com/watch?v=s5wNuqkaIlQ (/ embed)
The image of Adalatherium hui based on fossils of the whole body is shown below. Adalatherium hui has short legs and tail and a sturdy skeleton, but is believed to have been unable to swim. The estimated weight is 3.1 kg, and it seems to be about the size of a cat, but it is said to be the largest size among mammals that inhabited the Gondwana continent. The scientific name Adalatherium hui seems to be given from the Madagascar word meaning "madness" and the Greek word meaning "beast".
Crazy beast from the south-new research involving @MonashUni palaeontologists has revealed the full fossil skeleton of an unprecedentedly bizarre mammal from the Age of Dinosaurs.https://t.co/OYZgezPDTx@MonashBiol @DrTeethAl pic.twitter.com/qmrRRWYSvp
— Monash Science (@Monash_Science) April 29, 2020
Adalatherium hui, which inhabits much of the Jurassic and Cretaceous period, was extinct about 35 million years ago.Taoka TeethThe research team says that the fossil of Adalatherium hui was found on Madagascar Island, which means that it has great significance.
Madagascar Island, located in the southeastern part of Africa,Continental migrationIt was separated from Gondwana continent about 90 million years ago and became an island. Therefore, it is considered that Madagascar Island has developed its own unique ecosystem that is different from the continent.
by Hannes Grobe / AWI
For example, the primitive intramembranous bone in the skull of Adalatherium hui is a bone lost in the process of evolution about 100 million years ago and is not found in many existing mammals. The skull also has more openings than known mammals, which may have been pathways for nerves and blood vessels to increase sensitivity of the nose and mustache, the team said.
The research team commented, “ In Madagascar, in addition to limited resources, competition between species was reduced compared to the Gondwana continent, predators and parasites were fewer, so it is thought that a unique evolutionary system was established. '' I will.
Little is known about how Adalatherium hui evolved and became extinct, but there are many unknowns about the ecosystem of Gondwana continent, so almost complete Adalatherium hui fossil is a great discovery. I will. "The Adalatherium hui is an important piece of a big puzzle in the early stages of mammalian evolution in the Southern Hemisphere, but few other pieces yet," said Evans.