| Eohyrax Temporal range: Middle Eocene ~ | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | † Notoungulata |
| Family: | † Archaeohyracidae |
| Genus: | † Eohyrax Ameghino 1901 |
| Type species | |
| †Eohyrax rusticus Ameghino, 1901 | |
| Species | |
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| Synonyms | |
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Eohyrax is an extinct genus of Notoungulate, belonging to the suborder Typotheria. It lived during the Middle Eocene, and its remains were discovered in South America.
This animal is mostly known from fossils of its dentition, which suggests it was an animal between the size of a racoon and a red fox ; it would have looked like a marmot from comparison with its better known relatives, such as Archaeohyrax . It had very high-crowned (hypsodont) teeth in its cheek region.
The genus Eohyrax was first described in 1901 by Florentino Ameghino, based on fossils found in Late Eocene terrains of Argentina. Ameghino thought the fossils dated from the Late Cretaceous, and this assumption was only corrected much later. Similarly, Ameghino thought that some of the South American mammals he described were the ancestors of the fauna of other continents, and therefore considered Eohyrax as a relative of hyraxes, hence its name, Eohyrax, meaning "Hyrax of the dawn". The real affinities of Eohyrax within Notoungulata were only recognized later, as it was reclassified as a member of the subgroup of rodent-like notoungulates Typotheria. Eohyrax was approached of the genus Archaeohyrax within Archaeohyracidae a family thought to be ancestral to Hegetotheriidae ; however, further researches tend to indicate that Archaeohyracidae are a paraphyletic group, and that Eohyrax itself would be a basal member of a clade including Mesotheriidae and Hegetotheriidae.
Various species have been attributed to the genus Eohyrax ; after the type species Eohyrax rusticus, Ameghino described E. brachyodus, E. isotemnoides, E. platyodus and E. praerusticus. It is probable that several of these species were in fact identical to the type species.
Henricosborniidae is a family of extinct notoungulate mammals known from the Late Paleocene to Middle Eocene of Argentina, Bolivia and Brazil. The name honors U.S. paleontologist Henry Fairfield Osborn.
Prosotherium is an extinct genus of hegetotheriid notoungulate. It lived during the Late Oligocene, and its fossilized remains were found in South America.
Ernestokokenia is an extinct genus of mammal, belonging to the Didolodontidae. It lived during the Early Eocene and the Middle Eocene, and its fossils were discovered in South America.
Paulogervaisia is an extinct genus of mammal, belonging to the family Didolodontidae. Its fossilized remains have been found in South America.
Paginula is an extinct genus of oldfieldthomasiid notoungulate. It lived during the Eocene in what is now Argentina.
Henricosbornia is an extinct genus of henricosborniid notoungulate that lived from the Late Paleocene to the Middle Eocene of what is now Argentina and Brazil.
Pseudhyrax is an extinct genus of archaeohyracid notoungulate. It lived from the Late Eocene to the Early Oligocene, of what is now South America.
Transpithecus is an extinct genus of Notoungulates, belonging to the suborder Typotheria. It lived during the Middle Eocene in what is today South America.
Propachyrucos is an extinct genus of hegetotheriid notoungulate. It lived from the Late Oligocene to the Early Miocene, in what is today South America.
Isotemnus is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived from the Late Paleocene to the Middle Eocene of what is now Argentina.
Periphragnis is an extinct genus of isotemnid notoungulates that lived from the Middle Eocene to the Early Oligocene in what is now Argentina and Chile.
Pleurostylodon is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived during the Middle Eocene, in what is now Argentina.
Eomorphippus is an extinct genus of notohippid notoungulate that lived from the Late Eocene to the Early Oligocene in what is today South America.
Morphippus is an extinct genus of notohippid notoungulate that lived during the Middle to Late Oligocene in what is now South America.
Ancylocoelus is an extinct genus of mammal, belonging to the order Notoungulata. It lived during the Late Oligocene, in what is today Argentina, 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.
Ultrapithecus is an extinct genus of oldfieldthomasiid notoungulate that lived during the Middle Eocene of what is now Argentina.
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.
Glyptatelus is an extinct genus of glyptodont. It lived from the Late Eocene to the Middle Oligocene in what is now Argentina and Bolivia.
Eopachyrucos is an extinct genus of interatheriid notoungulates that lived from the Middle Eocene to the Late Oligocene of Argentina and Uruguay. Fossils of this genus have been found in the Sarmiento Formation of Argentina and the Fray Bentos Formation of Uruguay.
