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Proadiantus
''Proadiantus'' (Ameghino, 1897) is an extinct genus of adianthid litoptern. It lived during the Late Oligocene, in what is today South America. It consists of only 1 species, ''Proadiantus excavatus.'' Description This animal is mainly known from fossil remains of its teeth, maxilla and mandible, and its appearance is therefore difficult to restore. It is assumed, from comparison with its better known relatives ''Adianthus'' and '' Adiantoides'', that it was a small and slender litoptern. ''Proadiantus'' differs from ''Adiantoides'' by its significantly larger size, and it may have been as large as a coyote. The molars had rather low upper crowns ; the upper molars had a mesostyle, but no clearly defined metastyle ; the hypoconus was elongated. The talonid of the second lower molar had a complex structure. Classification ''Proadiantus'' was one of the Adianthidae, a family of small sized litopterns with a characteristic dentition. ''Proadiantus'' seems to have been on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thadanius
''Thadanius'' is an extinct genus of Litoptern, belonging to the family Adianthidae. It lived during the Late Oligocene, in what is today Bolivia. Description Only known from the fossilized remains of its mandible and teeth, this animal may have been similar to its relatives ''Adianthus'' and ''Adiantoides'', and probably was a small animal, the size of a small dog and slender in build. ''Thadanius'' was characterized by moderately high crowned teeth ; the lower molars were devoid of anterior cingulum, while the hypoconulid was not expanded as in other contemporary Adianthidae, such as ''Tricoelodus'' and ''Proadiantus'' to form a third lobe on the third molar. The entoconid did not reach the apex of the hypoconulid, but was connected to an hypoconulid-entoconid crest, and a rudimentary entolophid was present, especially on the third lower molar. There was no basin on the lower third molar. Classification ''Thadanius'' was a member of the Adianthidae, a clade of small-sized lit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthidae
Adianthidae is an extinct family of Litopterna, litopterns that existed from the Middle Eocene (Mustersan) to the Early Miocene (Santacrucian). Description These Arboreal locomotion, scansorial, Viviparity, viviparous animals were actively mobile and were Herbivore, herbivores. They were small in size when compared to most litopterns. Most species did not exceed the size of a cat. Although small in size, the adianthids showed dental features that were already specialized even in the Oligocene genera. The molars were equipped with ridges, and the upper molars were provided with crescent-shaped Cusp (anatomy), metacones and Paracone, paracones, with a columnar parastyle and a very reduced or absent mesostyle. The lower fourth premolar was provided with a crested Molar (tooth), talonid, and the lower molars were double crescent-shaped or nearly so. The upper fourth premolar was molar-shaped, and the teeth from the third premolar to the upper third molar had three primary dimples and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthidae
Adianthidae is an extinct family of Litopterna, litopterns that existed from the Middle Eocene (Mustersan) to the Early Miocene (Santacrucian). Description These Arboreal locomotion, scansorial, Viviparity, viviparous animals were actively mobile and were Herbivore, herbivores. They were small in size when compared to most litopterns. Most species did not exceed the size of a cat. Although small in size, the adianthids showed dental features that were already specialized even in the Oligocene genera. The molars were equipped with ridges, and the upper molars were provided with crescent-shaped Cusp (anatomy), metacones and Paracone, paracones, with a columnar parastyle and a very reduced or absent mesostyle. The lower fourth premolar was provided with a crested Molar (tooth), talonid, and the lower molars were double crescent-shaped or nearly so. The upper fourth premolar was molar-shaped, and the teeth from the third premolar to the upper third molar had three primary dimples and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litoptern
Litopterna (from grc, λῑτή πτέρνα "smooth heel") is an extinct order of fossil hoofed mammals from the Cenozoic era. The order is one of the five great orders of South American ungulates that were endemic to the continent, until the Great American Biotic Interchange brought new ungulate species. Like other endemic South American mammals, their relationship to other mammal groups had long been unclear, but recent genetic and proteomic evidence indicates that their closest living relatives are Perissodactyls (odd-toed ungulates) including horses, rhinoceros, and tapirs, and that litopterns are closely related to notoungulates, another widespread group of South American ungulates. There were two major groups of litopterns: Proterotheriidae and Macraucheniidae. Proterotheriids were medium to large animals that evolved adaptations for fast running, and occupied a variety of niches that elsewhere were filled by animals such as goats and antelopes, mouse deer, and hors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litopterns
Litopterna (from grc, λῑτή πτέρνα "smooth heel") is an extinct order of fossil hoofed mammals from the Cenozoic era. The order is one of the five great orders of South American ungulates that were endemic to the continent, until the Great American Biotic Interchange brought new ungulate species. Like other endemic South American mammals, their relationship to other mammal groups had long been unclear, but recent genetic and proteomic evidence indicates that their closest living relatives are Perissodactyls (odd-toed ungulates) including horses, rhinoceros, and tapirs, and that litopterns are closely related to notoungulates, another widespread group of South American ungulates. There were two major groups of litopterns: Proterotheriidae and Macraucheniidae. Proterotheriids were medium to large animals that evolved adaptations for fast running, and occupied a variety of niches that elsewhere were filled by animals such as goats and antelopes, mouse deer, and horses. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarmiento Formation
The Sarmiento Formation (Spanish: ''Formación Sarmiento''), in older literature described as the Casamayor Formation, is a geological formation in Chubut Province, Argentina, in central Patagonia, which spans around 30 million years from the mid-Eocene to the early Miocene. It predominantly consists of pyroclastic deposits, which were deposited in a semi-arid environment. It is divided up into a number of members. The diverse fauna of the Sarmiento Formation, including a variety of birds, crocodilians, turtles and snakes, also includes many mammals such as South American native ungulates (notoungulates, litopterns, astrapotheres) as well as armadillo Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order Cingulata. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, along wi ...s, and caviomorph rodents. Material was copied from this source, which is availabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthinae
Adianthidae is an extinct family of litopterns that existed from the Middle Eocene (Mustersan) to the Early Miocene (Santacrucian). Description These scansorial, viviparous animals were actively mobile and were herbivores. They were small in size when compared to most litopterns. Most species did not exceed the size of a cat. Although small in size, the adianthids showed dental features that were already specialized even in the Oligocene genera. The molars were equipped with ridges, and the upper molars were provided with crescent-shaped metacones and paracones, with a columnar parastyle and a very reduced or absent mesostyle. The lower fourth premolar was provided with a crested talonid, and the lower molars were double crescent-shaped or nearly so. The upper fourth premolar was molar-shaped, and the teeth from the third premolar to the upper third molar had three primary dimples and (in the more derived forms) a few accessory dimples behind the prostylar ''cingulum'' in front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1897
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the abso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Argentina
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene Argentina
The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The earlier term Tertiary Period was used to define the span of time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognised as a formal stratigraphic term, 'Tertiary' is still widely found in earth science literature and remains in informal use. Paleogene is often abbreviated "Pg" (but the United States Geological Survey uses the abbreviation PE for the Paleogene on the Survey's geologic maps). During the Paleogene, mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Mammals Of South America
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
