|
Rajouria
''Rajouria'', named after the Rajouri district in the Indian province of Jammu and Kashmir, is an extinct raoellid artiodactyl from the middle-upper Eocene (early Lutetian). There is only a single species of ''Rajouria'', ''Rajouria gunnelli'', which is named after Dr. Greg Gunnell. ''Rajouria'' is known from relatively little remains, with only mandibular and maxillary fragments with their respective teeth being preserved. Discovery ''Rajouria'' was discovered near the town of Aiji in the East-Aiji 2 locality. The initial remains of ''Rajouria'' were all found in proximity to each other and are the only remains assigned to ''Rajouria''. Classification When it was first discovered, ''Rajouria'' was placed within Raoellidae. Its position as a raoellid has remained stable, although it is not certain where exactly it is within Raoellidae. In the phylogenetic analysis of Raoellidae by Rana et al., ''Rajouria'' was placed as the most basal raoellid due to the presence of the par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raoellidae
Raoellidae, previously grouped within Helohyidae, are an extinct family of semiaquatic digitigrade artiodactyls in the clade Whippomorpha. Fossils of Raoellids are found in Eocene strata of South Asia and Southeast Asia. An exceptionally complete skeleton of ''Indohyus,'' the best preserved Raoellid, from Kashmir suggests that Raoellids are the " missing link" sister group to whales (Cetacea). All other Artiodactyla are relatives of these two groups. δO18 values and osteosclerotic bones indicate that the raccoon-like ''Indohyus'' was habitually aquatic. However, it is still unclear if ''Indohyus'' primarily fed on land or in water. It is hypothesized that cetaceans evolved from ancestors similar to Raoellids and later fully adapted to aquatic life. Taxonomy *'' Rajouria'' **''Rajouria gunnelli'' *'' Haqueina?'' **''Haqueina haquei'' **''Haqueina haichinensis'' *''Indohyus'' **''Indohyus indirae'' **''Indohyus major?'' *'' Kunmunella'' **''Kunmunella kalakotensis'' **''Kunmunella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kunmunella
''Kunmunella'' is an extinct raoellid artiodactyl which inhabited what is now northern India during the middle-upper Eocene (Ypresian). There are two species of ''Kunmunella'': ''K. kalakotensis'' and ''K. transversa''. The former species was named after the town of Kalakote within Jammu and Kashmir, the place from which it was found, while the latter species was named after the transverse nature of the upper teeth. ''K. kalakotensis'' is known from a palate with its respective teeth, a left maxillary ramus, a left mandible, two poorly preserved maxillas, and two isolated molars. ''K. transversa'' is known from only a right maxilla. Discovery The remains of ''Kunmunella'' were first found by Ranga Rao, 1971. He found only a left mandible, and assigned it to a new species of ''Indohyus'', ''I. kalakotensis'', after the region in which he discovered the animal. In the following year, an isolated upper third molar would be found by Sahni and Khare, which would be assigned to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lutetian
The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene Subepoch. Stratigraphic definition The Lutetian was named after Lutetia, the Latin language, Latin name for the city of Paris. The Lutetian Stage was introduced in scientific literature by French geologist Albert de Lapparent in 1883 and revised by A. Blondeau in 1981. The base of the Lutetian Stage is at the first appearance of the nanofossil ''Blackites inflatus'', according to an official reference profile (GSSP) established in 2011. Of two candidates located in Spain, the Gorrondatxe section was chosen.See thwebsite of Eustoquio Molinafor these candidates. The top of the Lutetian (the base of the Bartonian) is at the first appearance of calcareous nannofossils, calcareous nanoplankton s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indohyus
''Indohyus'' (Meaning "India's pig" from the Greek words ''Indos'', "from India" and ''hûs'', "pig") is an extinct genus of artiodactyl known from Eocene fossils in Asia. This small chevrotain-like animal found in the Himalayas is among the closest known non-cetacean relatives of whales. Discovery The fossils were discovered among rocks that had been collected in 1971 in Kashmir by the Indian geologist A. Ranga Rao who found a few teeth and parts of a jawbone; when he died, however, many rocks had yet to be broken open. Ranga Rao's widow gave the rocks to Hans Thewissen, who was working on them. When his technician accidentally broke one of the skulls they had found, Thewissen recognised the ear structure of the auditory bulla, formed from the ectotympanic bone in a shape which is highly distinctive, found only in the skulls of cetaceans both living and extinct, including '' Pakicetus''. Paleobiology About the size of a fox, this omnivorous pig-like creature shared some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pakicetus
''Pakicetus'' (meaning 'whale from Pakistan') is an extinct genus of amphibious cetacean of the family Pakicetidae, which was endemic to the Indian Subcontinent during the Ypresian (early Eocene) period, about 50 million years ago. It was a wolf-like mammal, about long, and lived in and around water where it ate fish and other animals. The name Pakicetus comes from the fact that the first fossils of this extinct amphibious whale were discovered in Pakistan. The vast majority of paleontologists regard it as the most basal whale, representing a transitional stage between land mammals and whales. It belongs to the even-toed ungulates with the closest living non-cetacean relative being the hippopotamus. Description Based on the sizes of specimens, and to a lesser extent on composite skeletons, species of ''Pakicetus'' are thought to have been to in length. ''Pakicetus'' looked very different from modern cetaceans, and its body shape more resembled those of land-dwelling h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetacea
Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel themselves through the water with powerful up-and-down movements of their tail, which ends in a paddle-like fluke, using their flipper-shaped forelimbs to steer. While the majority of cetaceans live in marine environments, a small number reside solely in brackish water, brackish or fresh water. Having a cosmopolitan distribution, they can be found in some rivers and all of Earth's oceans, and many species migrate throughout vast ranges with the changing of the seasons. Cetaceans are famous for cetacean intelligence, their high intelligence, complex social behaviour, and the enormous size of some of the group's members. For example, the blue whale reaches a maximum confirmed length of and a weight of 173 tonne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Cetaceans
The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. Cetaceans are fully aquatic mammals belonging to the order Artiodactyla and branched off from other artiodactyls around 50 Year#Abbreviations yr and ya, mya. Cetaceans are thought to have evolved during the Eocene (56-34 mya), the second epoch of the present-extending Cenozoic Era. Molecular and morphological analyses suggest Cetacea share a relatively recent closest common ancestor with hippopotamus, hippopotamuses and that they are sister groups. Being mammals, they surface to breathe air; they have five finger bones (even-toed) in their fins; they nurse their young; and, despite their fully aquatic life style, they retain many skeletal features from their terrestrial ancestors.Thewissen, J. G. M., L. N. Cooper, J. C. George, and S. Bajpai. 2009. From land to wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Mammalian Dental Topography
Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn in 1907 and is, although with many variations, the one that continues today. Suffixes Tooth structures bear suffixes in order to note the type of structure they are and whether they are present in the upper or lower molars. * The suffix "-cones /-conids" (upper molar/lower molar) is added to the main cusps: Paracone, Metacone, Protocone and Hypocone on the upper molar, and Paraconid, Metaconid, Protoconid, Hypoconid and Entoconid on the lower molar. This name is used for both bunodont and selenodont molars, that is, as many for "buno" pillar-like cusps as for "selenes" crescent-like cusps. * The suffix "-conule /-conulid" (upper molar/lower molar) is added to the secondary cusps. For example, Metaconule, Hypoconulid. * The suffix "-style/-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnivore
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ... whose nutrition and energy requirements are met by eating, consumption of animal tissue (biology), tissues (mainly muscle, adipose tissue, fat and other soft tissues) as food, whether through predation or scavenger, scavenging. Nomenclature Mammal order The technical term for mammals in the order (biology), order Carnivora is ''carnivoran'', and they are so-named because most member species in the group have a carnivorous diet, but the similarity of the name of the order and the name of the diet causes confusion. Many but not all carnivorans are meat eaters; a few, such as the fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/ricochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include Mouse, mice, rats, squirrels, prairie dogs, porcupines, beavers, Cavia, guinea pigs, and hamsters. Once included wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat non-vascular autotrophs such as mosses, algae and lichens, but do not include those feeding on decomposed plant matters (i.e. detritivores) or macrofungi (i.e. fungivores). As a result of their plant-based diet, herbivorous animals typically have mouth structures ( jaws or mouthparts) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase) to digest polysaccharides. Grazing herbivores such as horses and cattles have wide flat- crowned teeth that are better adapted for grinding grass, tree bark and other tougher lignin-containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
