Xartchetia




 * Class Paramammalia
 * Clade Xartchetia

One of the more bizarre and poorly understood paramammals, the Xartchetia are the rarest animals on the entire planet. Their can be identified by their thick digits which thick claws, like those seen in giant ground sloths. Two definitive living species are known (see later in the essay for more) and are both incredibly rare and similar in appearance.

However, fossil species show that they were once very diverse, with fossils coming from as far south as Vietnam, and as far west as Portugal. The earliest fossil species, †Sarcophygraus manicephalus from Eocene Germany, was a pangolin like predator, except it had a thick pelage of fur like integument, like all paramammals. They had short limbs, but most paleontologists agree that it was a facultative biped. The teeth and stomach contents suggest that the metre long †Sarcophygraus fed on small vertebrates, mainly lizards and small temnospondyls. †Sarcophygraus is the only known member of the subgroup, the †Sarcophygrauia.

The next subgroup were the †Cingulitoidea. These included two groups, the first being the †Pilosamimids, which were anteater and tamandua like forms. Some evolved enormous forms, the largest being †Isopteravenator. They had enormously long tongues, and large claws used to dig up termite mounds, followed by slurping up nearly a million termites in less than two minutes. The second group was the †Glyptomimids, very bizarre armadillo like animals from Poland, Vietnam, and Brazil. These are the biggest Xartchetia. They still had a thick pelage, but underneath was flexible, armoured skin. They also typically had large tail clubs which were spiky, analogous to the thagomizers of stegosaurs. Most were herbivorous or even insectivorous, bur a few terrifying forms were predators, specifically the †Carnodasypods, from Brazil. They had competition with the sabretooth cynodonts, which eventually drove them to extinction.

The third, least understood fossil subgroup were the †Ornithomimids. They had long limbs, and more resembled coelurosarian theropods that other Xartchetia. One two species are known, an alverezsaur like form called †Ornithomimus from Norway, and a hypercarnivorous troodontid like form †Dynesptos from Wales. They evolved and existed only in the late Miocene.

The fourth and final subgroup are the Xietchmalids. They are more sloth like, but have shorter limbs, and longer necks. A few semi-aquatic forms existed, primarily along the coast, and ate mostly sea grass and sea conifers. They first evolved in the mid Miocene. The only living genus, Xartcheliodon, first popped up in the fossil record about 4 million years ago, during the Pliocene. They are purely endemic to Siberia. When the Quaternary Ice Age began, nearly all Xietchmalids went extinct, with the exception for Xartcheliodon, which is a specially cold adapted genus living in the forests of Northern Siberia.

Only two species remain, Xartcheliodon sibiricus, and Xartcheliodon jiansicus. However, there are some taxonomists who argue that there are actually five species. The more southern morphs of X. jiansicus are divided into two new species, X. ciaguls and X. micromisis. Then a northern morph of X. sibiricus would be X. sibiricumimis. However, the majority of geneticists and taxonomists agree that there is not enough genetic distinction to have there be five species.

Both species are entirely nocturnal, and rarely observed. Nothing is known about their reproductive cycles, relationship with other animals, or predators. All that is known is that in total only 300 Xartcheliodons remain in the wild, and that they are arboreal creatures that climb like sloths and feed on toxic plants. It is unknown if a conservation effort should be adopted, as their disappearance is causing more animals to diversify, and if they don't go extinct, they could end up disrupting the ecosystem. A breeding programme is underway to keep these animals alive at least in some form, and prevent these amazing unique creatures from disappearing forever.