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Stromerius
''Stromerius'' is an extinct genus of basilosaurid early whale known from the Late Eocene (Priabonian, ) of Fayum, Egypt (, paleocoordinates ). ''Stromerius'' is known from several well-preserved vertebrae. Distinguishing features for the genus include: long and forward-pointing metapophyses (bony processes) on the lumbar vertebrae; a relatively short lumbar spine with only twelve vertebrae of which four are interpreted as homologous to sacral vertebrae; one of the two thoracic vertebrae found has a dorsally-pointing neural spine interpreted as anticlinal (i.e. the spines of the other vertebrae are inclined towards this specific vertebra) which is a primitive retention in ''Stromerius'' not present in other basilosaurids. ''Stromerius'' is larger than the contemporary ''Saghacetus'' but smaller than the older ''Dorudon''. made ''S. nidensis'' the type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromerius Nidensis
''Stromerius'' is an extinct genus of basilosaurid early whale known from the Late Eocene (Priabonian, ) of Fayum, Egypt (, paleocoordinates ). ''Stromerius'' is known from several well-preserved vertebrae. Distinguishing features for the genus include: long and forward-pointing metapophyses (bony processes) on the lumbar vertebrae; a relatively short lumbar spine with only twelve vertebrae of which four are interpreted as homologous to sacral vertebrae; one of the two thoracic vertebrae found has a dorsally-pointing neural spine interpreted as anticlinal (i.e. the spines of the other vertebrae are inclined towards this specific vertebra) which is a primitive retention in ''Stromerius'' not present in other basilosaurids. ''Stromerius'' is larger than the contemporary ''Saghacetus'' but smaller than the older ''Dorudon''. made ''S. nidensis'' the type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saghacetus
''Saghacetus'' is an extinct genus of basilosaurid early whale, fossils of which have been found in the Upper Eocene (middle Priabonian, ) Qasr el Sagha Formation, Egypt (, paleocoordinates ). Discovery In 1879, German botanist Georg August Schweinfurth spent many years exploring Africa and eventually discovered the first archaeocete whale in Egypt. He visited Qasr el Sagha in 1884 and 1886 and missed the now famous " Zeuglodon Valley" with a few kilometres. German palaeontologist Wilhelm Barnim Dames described the material, including a well-preserved dentary which is the type specimen of ''Zeuglodon osiris''. The generic name ''Saghacetus'' was established by to group the ancient species ''Dorudon osiris'', ''D. zitteli'', ''D. sensitivius'' and ''D. elliotsmithii'' on a single species, ''Saghacetus osiris''. This species is distinguished from other members of the subfamily Dorudontinae by its smaller size and the slightly elongated proximal lumbar and caudal vertebrae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basilosauridae
Basilosauridae is a family of extinct cetaceans that lived during the middle to late Eocene. Basilosaurids are known from all continents including Antarctica, and are probably the first fully aquatic cetaceans.Buono M, Fordyce R.E., Marx F.G., Fernández M.S. & Reguero M. (2019). "Eocene Antarctica: a window into the earliest history of modern whales". ''Advances in Polar Science'' 30(3): p. 293-302. doi:10.13679/j.advps.2019.0005 The group is noted to be a paraphyletic assemblage of stem group whales from which the monophyletic Neoceti are derived. Characteristics Basilosaurids ranged in size from and were fairly similar to modern cetaceans in overall body form and function. Some genera tend to show signs of convergent evolution with mosasaurs by having long serpentine body shape, which suggests that this body plan seems to have been rather successful. Basilosaurid forelimbs have broad and fan-shaped scapulae attached to a humerus, radius, and ulna which are flattened i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeoceti
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is an obsolete 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 capabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Eocene
The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene. ''Priabona florissantius, Priabona'', an extinct dipteran of Pipunculidae family, is named after Priabonian, the age of deposits from which this insect is known. History and naming The Priabonian Stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named after the small hamlet of Priabona (Monte di Malo), Priabona in the community of Monte di Malo, in the Veneto region of northern Italy. Stratigraphic definition The base of the Priabonian Stage is at the first appearance datum, first appearance of calcareous nannoplankton species ''Chiasmolithus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Prehistoric Cetacean Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Stromer Von Reichenbach
Ernst Freiherr Stromer von Reichenbach (born on 12th of June, 1871 in Nürnberg, died on 18th of December, 1952 in Erlangen) was a German paleontologist best remembered for his expedition to Egypt, during which the discovery of the first known remains of ''Spinosaurus'' was made. Stromer described several discoveries made in Egypt, including a few dinosaurs from the Cretaceous period discovered in Egypt ('' Aegyptosaurus,'' ''Bahariasaurus'', and '' Carcharodontosaurus''), an enigmatic theropod ('' Spinosaurus aegyptiacus'') and a giant crocodilian ('' Stomatosuchus''). In 1929 fossil bird genus ''Stromeria'' (now included in the genus ''Eremopezus'') were named in Stromer’s honour by Kálmán Lambrecht. Smith et al. (2001) also named the sauropod '' Paralititan stromeri'' in his honour. Many of the fossils discovered by Stromer were destroyed during World War II, leaving today’s scientists only a few photographs of the previously existing specimens to rely on. Bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological Type (biology), type wiktionary:en:specimen, specimen (or specimens). Article 67.1 A similar concept is used for suprageneric groups and called a type genus. In botanical nomenclature, these terms have no formal standing under the International Code of Nomenclature for algae, fungi, and plants, code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name with that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorudon
''Dorudon'' ("spear-tooth") is a genus of extinct basilosaurid ancient whales that lived alongside ''Basilosaurus'' 41.03 to 33.9 million years ago in the Eocene. It was a small whale, with ''D. atrox'' measuring long and weighing . ''Dorudon'' lived in warm seas around the world and fed on small fish and mollusks. Fossils have been found along the former shorelines of the Tethys Sea in present-day Egypt and Pakistan, as well as in the United States, New Zealand and Western Sahara. Taxonomic history described ''Dorudon serratus'' based on a fragmentary maxilla and a few teeth found in South Carolina. He concluded that the teeth must have belonged to a mammal since they were two-rooted, that they must have been teeth from a juvenile since they were hollow, and also noted their similarity to the teeth then described for ''Zeuglodon'' (''Basilosaurus''). When exploring the type locality, Gibbes discovered a lower jaw and twelve caudal vertebrae, which he felt obliged to assign to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Vertebra
The lumbar vertebrae are located between the thoracic vertebrae and pelvis. They form the lower part of the back in humans, and the tail end of the back in quadrupeds. In humans, there are five lumbar vertebrae. The term is used to describe the anatomy of humans and quadrupeds, such as horses, pigs, or cattle. These bones are found in particular cuts of meat, including tenderloin or sirloin steak. Human anatomy In human anatomy, the five vertebrae are between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process (since it is only found in the cervical region) and by the absence of facets on the sides of the body (as found only in the thoracic region). They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement. General characteristics The adjacent figure depicts the general charac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticlinal
{{disambig ...
Anticlinal may refer to: *Anticline, in structural geology, an anticline is a fold that is convex up and has its oldest beds at its core *Anticlinal, in stereochemistry, a torsion angle between 90° to 150°, and –90° to –150°; see Alkane_stereochemistry * Anticlinal division (botany) See also * Weald–Artois Anticline * Mareuil Anticline * La Tour-Blanche Anticline * Usk Anticline *Fold (geology) *Detachment fold *Stereochemistry Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereoisomers, which are defined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Spine
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species. The basic configuration of a vertebra varies; the vertebral body (also ''centrum'') is of bone and bears the load of the vertebral column. The upper and lower surfaces of the vertebra body give attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch, in eleven parts, consisting of two pedicles (pedicle of vertebral arch), two laminae, and seven processes. The laminae give attachment to the ligamenta flava (ligaments of the spine). There are vertebral notches formed from the shape of the pedicles, which form the intervertebral foramina when the vertebrae articulate. These foramina are the entry and exit conduits for the spinal nerves. The body of the vertebra and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
