| Callistoe Temporal range: Early Eocene | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | † Sparassodonta |
| Family: | † Proborhyaenidae |
| Genus: | † Callistoe Babot et al, 2002 |
| Species: | †C. vincei |
| Binomial name | |
| †Callistoe vincei Babot et al, 2002 | |
Callistoe is an extinct genus of sparassodont. It lived during the Early Eocene, and its fossilized remains were found in South America.
Unlike most of its relatives, such as Proborhyaena and Arminiheringia , Callistoe had a narrow, puny snout, and the shape of its skull resembled that of a thylacine. Callistoe lacked the characteristics associated with the ability to climb in its limbs and vertebrae. The shape of its limb joints, the presence of an ossified patella and the shape of the limb bones show that it was limited to a parasagittal gait, and possessed little flexibility in its elbows, wrists, knees and ankles ; Callistoe probably specialized in walking and running. Callistoe, approximately two meters long, had a slender and light body, and weighed approximately 23 kilograms.
Callistoe vincei was first described in 2002, based on an almost complete and exceptionally preserved skeleton from the Lumbrera Formation, in the Salta Province of Argentina. Its generic name, Callistoe, derives from Callisto, a nymph loved by Zeus, and transformed by him into a bear to protect her from Hera's wrath.
Callistoe was a member of the family Proborhyaenidae, a clade of Sparassodonts typical of the Early Cenozoic, usually large-sized and with a robust build.
Argot & Babot described in 2011 very long and slightly curved claws, quite different from those of other sparassodonts ; their shape suggesting an ability to dig. What appears to be an healed fracture on the front leg of a specimen of Callistoe indicates that those were used intensively. The slender outer toes of the quite short feet indicates an aptitude for running. Callistoe lived alongside a large variety of armadillos and small notoungulates, all animals with fossorial habits, and it is possible that the animal covered large distances and was able to enter the burrows of these animals. As it lived during the Early Eocene, it may be one of the first examples of a predatory mammal with fossorial habits, millions of years before the rise of the first burrowing mustelidae on other continents.
Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs. Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating. They have a rigidly fused skull, lack pterygoid teeth and external ears. Their eyes are greatly reduced, and covered with a scale.
The pink fairy armadillo is the smallest species of armadillo, first described by Richard Harlan in 1825. This solitary, desert-adapted animal is endemic to central Argentina and can be found inhabiting sandy plains, dunes, and scrubby grasslands.
Sparassodonta is an extinct order of carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials. A number of these mammalian predators closely resemble placental predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution. They were first described by Florentino Ameghino, from fossils found in the Santa Cruz beds of Patagonia. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic; during this time, they shared the niches for large warm-blooded predators with the flightless terror birds. Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental carnivorans during the Pliocene Great American Interchange, but more recent research has showed that sparassodonts died out long before eutherian carnivores arrived in South America. Sparassodonts have been referred to as borhyaenoids by some authors, but currently the term Borhyaenoidea refers to a restricted subgroup of sparassodonts comprising borhyaenids and their close relatives.
A fossorial animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees.
Numidotherium is an extinct genus of early proboscideans, discovered in 1984, that lived during the middle Eocene of North Africa some 46 million years ago. It was about 90-100 cm tall at the shoulder and weighed about 250-300 kg.
Scalabrinitherium is an extinct genus of mammals of the family Macraucheniidae. Fossils of this animal were found among the fossils of prehistoric xenarthrans in the Ituzaingó Formation of Argentina.
Trirachodon is an extinct genus of cynodonts. Fossils have been found in the Cynognathus Assemblage Zone of the Beaufort Group in South Africa and the Omingonde Formation of Namibia, dating back to the Early and Middle Triassic.
Agriochoerus is an extinct genus of scansorial herbivore of the tylopod family Agriochoeridae, endemic to North America. Agriochoerus and other agriochoerids possessed claws, which is rare within Artiodactyla, as well as likely being scansorial. Agriochoerus was first described in 1869.
Propalaehoplophorus, also written as Propalaeohoplophorus, is an extinct genus of glyptodont, which lived in South America during the Early Miocene epoch.
Proborhyaenidae is an extinct family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of their relatives, the borhyaenids. The largest species, Proborhyaena gigantea, is estimated to be about the size of a spectacled bear, with its skull reaching 60 cm (2.0 ft) in length, and body mass estimates up to approximately 150–200 kilograms (330–440 lb), making the proborhyaenids some of the largest known metatherians. Proborhyaenid remains have been found in western Bolivia, Uruguay, southern Brazil, and the provinces of Mendoza, Salta, and Chubut, in Argentina.
Diabolotherium is an extinct genus of megatheriine ground sloth, known from the Late Pleistocene of Peru. Unlike most other extinct mainland sloths, it seems to have been a climber, similar to extinct sloths from the Caribbean. Fossils of the genus were found at the coastal Piedra Escrita site and the Andean Casa del Diablo cave.
Saltaodus is an extinct genus of mammals, belonging to the family Didolodontidae. It lived during the Late Eocene, in what is now South America.
Antofagastia is an extinct genus of Notoungulate, belonging to the family Interatheriidae. It lived during the Late Eocene in what is today South America.
Coquenia is an extinct genus of Notoungulate, belonging to the family Leontiniidae. It lived during the Middle Eocene, in what is today Argentina.
Martinmiguelia is an extinct genus of Notoungulate, belonging to the family Leontiniidae. It lived during the Middle Eocene, and its fossil remains were found in South America.
Oldfieldthomasia is an extinct genus of Notoungulate, probably related to the suborder Typotheria. It lived during the Middle Eocene, in what is today South America.
Notopithecus is an extinct genus of Notoungulate, belonging to the suborder Typotheria. It lived from the Middle to the Late Eocene and its fossilized remains were discovered in South America.
Punatherium is an extinct genus of xenarthran, belonging to the family Dasypodidae. It lived from the Middle to the Late Eocene, and its fossilized remains were discovered in South America.
Arminiheringia is an extinct genus of sparassodont. It lived during the Early Eocene in South America.
Proborhyaena is an extinct genus of proborhyaenid sparassodont that lived during the Oligocene of what is now South America. It is considered to be the largest of the sparassodonts.
