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Indocetus
''Indocetus'' is a protocetid early whale known from the late early Eocene (Lutetian, ) Harudi Formation (, paleocoordinates ) in Kutch, India. The holotype of is a partial skull in two pieces with the frontal shield and the right occiput and auditory bulla preserved. described postcranial remains from the Sulaiman Range, Punjab, Pakistan, and attributed them to ''Indocetus''. , however, withdrew this assignment and instead attributed this postcranial material to ''Remingtonocetus'' because of similarities to the then newly discovered remingtonocetid ''Dalanistes'', including a longer neck and fused sacral vertebral elements. This leaves ''Indocetus'' without postcranial remains, but undescribed material (as of 1998) from Kutch most likely include some that can be attributed to ''Indocetus''. Furthermore, ''Rodhocetus'', also from Sulaiman, is very similar to ''Indocetus'' and it is possible that these genera are synonyms. ''Indocetus'' is known from a partial skull, two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodhocetus
''Rodhocetus'' (from ''Rodho'', the geological anticline at the type locality, and ''cetus'', Latin for whale) is an extinct genus of protocetid early whale known from the Lutetian of Pakistan. The best-known protocetid, ''Rodhocetus'' is known from two partial skeletons that taken together give a complete image of an Eocene whale that had short limbs with long hands and feet that were probably webbed and a sacrum that was immobile with four partially fused sacral vertebrae. It is one of several extinct whale genera that possess land mammal characteristics, thus demonstrating the evolutionary transition from land to sea. Description left, Size of ''Rodhocetus'' relative to a human. ''Rodhocetus'' was a small whale measuring long. Throughout the 1990s, a close relationship between cetaceans and mesonychids, an extinct group of cursorial, wolf-like ungulates, was generally accepted based on morphological analyses. In the late 1990s, however, cladistic analyses based on mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeoceti
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene (). Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of both modern cetacean suborders, Mysticeti and Odontoceti. This initial diversification occurred in the shallow waters that separated India and Asia , resulting in some 30 species adapted to a fully oceanic life. Echolocation and filter-feeding evolved during a second radiation . All archaeocetes from the Ypresian (56–47.8 mya) and most from the Lutetian (47.8–41.3 mya) are known exclusively from Indo-Pakistan, but Bartonian (41.3–38.0 mya) and Priabonian (38.0–33.9 mya) genera are known from across Earth, including North America, Egypt, New Zealand, and Europe. Although no consensus exists regarding the mode of locomotion of which cetaceans were capable during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babiacetus
''Babiacetus'' is an extinct genus of early cetacean that lived during the late Lutetian middle Eocene of India ().. Retrieved April 2013. It was named after its type locality, the Harudi Formation in the Babia Hills (: paleocoordinates ), Kutch District, Gujarat, India. ''Babiacetus'' was named by in an abstract based on the specimen's type (GSI 19647, left and right dentaries with cheek teeth). Gingerich and colleagues found a skull (GSP-UM 3005, much of a skull and lower jaws) while collecting a skeleton of a new species of Protosiren (''Protosiren sattaensis'') in the Drazinda Formation (, paleocoordinates ) in the Sulaiman Range of Punjab, Pakistan. described both the original find and their new specimen. described '' B. mishrai'' from the specimen (RUSB 2512, a partial skull) collected in the Harudi Formation.. Retrieved March 2013. ''Babiacetus'' is one of the larger protocetids. Its hydrodynamic skull and pointed, anteroposteriorly (front-back) oriented incisor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocetidae
Protocetidae, the protocetids, form a diverse and heterogeneous group of extinct cetaceans known from Asia, Europe, Africa, South America, and North America. Description There were many genera, and some of these are very well known (e.g., '' Rodhocetus''). Known protocetids had large fore- and hindlimbs that could support the body on land, and it is likely that they lived amphibiously: in the sea and on land. It is unclear at present whether protocetids had flukes (the horizontal tail fin of modern cetaceans). However, what is clear is that they are adapted even further to an aquatic life-style. In '' Rodhocetus'', for example, the sacrum – a bone that in land-mammals is a fusion of five vertebrae that connects the pelvis with the rest of the vertebral column – was divided into loose vertebrae. However, the pelvis retain a sacroiliac joint. Furthermore, the nasal openings are now halfway up the snout; a first step towards the telescoped condition in modern whale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1975
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] |
Hans Thewissen
Hans Thewissen is a Dutch-American paleontologist. His field work has discovered fossils for the steps in the transition from land to water in whales: ''Ambulocetus'', ''Pakicetus'', '' Indohyus'' and ''Kutchicetus''. He now studies modern bowhead and beluga whales in Alaska to learn about their biology and their implications for management and conservation. Early life Thewissen has always been interested in paleontology and natural history. His mother said that when Thewissen was a small boy, she had to sort through his pockets before laundry time to take out the rocks and worms he collected. His father used to take him to the town of Maastricht, and they collected fossils from the Maastrichtian period. 12th birthday present was a rock hammer, which has accompanied him on all collecting trips since. He grew up just 2 miles from Liessel, a fossil locale that yielded the first whales he ever collected. Educational background After finishing Gymnasium secondary education in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgiacetus
''Georgiacetus'' is an extinct genus of ancient whale known from the Eocene period of the United States. Fossils are known from Georgia, Alabama, and Mississippi and protocetid fossils from the right time frame, but not yet confirmed as ''Georgiacetus'', have been found in Texas () and South Carolina (). created a new clade, Pelagiceti, for the common ancestor of Basilosauridae and all of its descendants, including Neoceti, the living cetaceans. He placed ''Georgiacetus'' near the base of this clade together with '' Eocetus'' and perhaps '' Babiacetus'' because of the assumed presence of a fluke and very compressed posterior caudal vertebrae in these genera. ''Georgiacetus'' is an extinct protocetid (early whale) which lived about and hunted the rich, Suwannee Current powered coastal sea which once covered the Southeastern United States. This was during the earliest Bartonian Stage of the Eocene Epoch (). Current research puts ''Georgiacetus'' as the link between the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocetus
''Eocetus'' is an extinct protocetid early whale known from the early late Eocene (Bartonian, ) Giushi Formation in Gebel Mokattam, (, paleocoordinates ) outside Cairo, Egypt. The specimen was first named by Fraas as ''Mesocetus schweinfurthi''. However, the name ''Mesocetus'' was previously used causing a change to the species name to ''Eocetus schweinfurthi''. Since the genus was first described in the early 20th century, several other specimens, mostly isolated vertebrae, have been attributed to ''Eocetus'', but the taxonomic status of these widely distributed specimens remain disputed. Discovery and taxonomy described "''Mesocetus schweinfurthi''" based on a dorsoventrally compressed skull with only I2 ''in situ'', a specimen supposedly originating from a 40 Ma Tethyan deposit at Mokattam. Fraas also referred two isolated teeth, P4 and M1, to the skull and the most important of his specimens is not the deformed skull, but the upper molar which retains three roots and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocetus
''Protocetus atavus'' ("first whale") is an extinct species of primitive cetacean from Egypt. It lived during the middle Eocene period 45 million years ago. The first discovered protocetid, ''Protocetus atavus'' was described by based on a cranium and a number of associated vertebrae and ribs found in middle Lutetian Tethyan marine limestone from Gebel Mokattam near Cairo, Egypt. Description ''Protocetus'' are believed to have had a streamlined, whale-like body around long, but was probably primitive in some respects.Palmer D (ed.) (1999). ''The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals''. London: Marshall Editions. p. 230. . Many protocetids (like ''Maiacetus'', ''Rodhocetus'') possessed well developed innominates and hind limbs, often attached to the backbone with a sacrum. ''Protocetus'' are known to have had at least one sacral vertebrate,Gingerich P.D. (2010). "Cetacea". In Werdelin L & Sanders W.J. (eds.). ''Cenozoic mammals of africa''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocone
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. Buccal Cusp- One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dalanistes
''Dalanistes'' is an extinct genus of remingtonocetid early whale known from the late early Eocene (Lutetian, ) of Kutch, India and Punjab and Balochistan, Pakistan. ''Dalanistes'' is closely related to ''Remingtonocetus'' (the type genus of Remingtonocetidae, a slightly more derived family of early whales), but also shares several features with ''Ambulocetus'' (the type of Ambulocetidae, earlier more primitive whales), and, with its combination of terrestrial and amphibious adaptations, ''Dalanistes'' apparently is an intermediate form between these two groups. Isotopic evidence suggest that ''Dalanistes'' had a marine diet. ''Dalanistes'' is known from several localities and collections. The holotype is a skull and a postcranial skeleton. Additional fossils referred to ''Dalanistes'' include crania, several vertebrae and sacra, possible caudals, one side of the pelvis, and a distal femur. The alveoli is all that is left of the dentition, but the dental formula apparent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
