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Alopias Palatasi
''Alopias palatasi'', commonly referred to as the serrated giant thresher, is an extinct species of giant thresher shark that lived approximately 20.44 to 13.7 million years ago during the Miocene epoch, and is known for its uniquely serrated teeth. It is only known from such isolated teeth, which are large and can measure up to an excess of , equating to a size rivaling the great white shark, but are rare and found in deposits in the East Coast of the United States and Malta. Teeth of ''A. palatasi'' are strikingly similar to those of the giant thresher ''Alopias grandis'', and the former has been considered as a variant of the latter in the past. Scientists hypothesized that ''A. palatasi'' may have had attained lengths comparable with the great white shark and a body outline similar to it. Discovery and taxonomy In 2002, rumors began about discoveries of a new type of large serrated shark teeth pertaining to an undescribed species of mackerel shark from Miocene deposits in S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burdigalian
The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (stage), Aquitanian, the Burdigalian was the first and longest warming period of the MioceneEdward Petuch, Ph.D. Florida Atlantic University, Department of Geosciences. and is succeeded by the Langhian. Stratigraphic definition The name Burdigalian comes from ''Burdigala'', the Latin name for the city of Bordeaux, France. The Burdigalian Stage was introduced in scientific literature by Charles Depéret in 1892. The base of the Burdigalian is at the first appearance of foram species ''Globigerinoides altiaperturus'' and the top of magnetic chronozone C6An. , an official GSSP for the Burdigalian had not yet been assigned. The top of the Burdigalian (the base of the Langhian) is defined by the first appearance of foram species ''Praeorbulina gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Species
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Crown
In dentistry, crown refers to the anatomical area of teeth, usually covered by tooth enamel, enamel. The crown is usually visible in the mouth after tooth development, developing below the gingiva and then tooth eruption, erupting into place. If part of the tooth gets chipped or broken, a dentist can apply an crown (dentistry), artificial crown. Crowns are used most commonly to entirely cover a damaged tooth or cover an implant. Bridges are also used to cover a space if one or more teeth is missing. They are cemented to natural teeth or implants surrounding the space where the tooth once stood. There are various materials that can be used including a type of cement or stainless steel. The cement crowns look like regular teeth while the stainless steel crowns are silver or gold. References *Ash, Major M. and Stanley J. Nelson. ''Wheeler’s Dental Anatomy, Physiology, and Occlusion.'' 8th edition. 2003. . Parts of tooth Human mouth anatomy {{dentistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Shark
The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is notable for its size, with larger female individuals growing to in length and in weight at maturity. However, most are smaller; males measure , and females measure on average. According to a 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates, making it one of the longest lived cartilaginous fishes currently known. According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring. Great white sharks can swim at speeds of 25 km/h (16 mph) for short bursts and to depths of . The great white shark is an apex predator, as it has no known natural predators other than, on v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvert County, Maryland
Calvert County is located in the U.S. state of Maryland. As of the 2020 census, the population was 92,783. Its county seat is Prince Frederick. The county's name is derived from the family name of the Barons of Baltimore, the proprietors of the English Colony of Maryland Calvert County is included in the Washington–Arlington–Alexandria, DC–VA–MD–WV Metropolitan Statistical Area. It occupies the Calvert Peninsula, which is bordered on the east by Chesapeake Bay and on the west by the Patuxent River. Calvert County is part of the Southern Maryland region. The county has one of the highest median household incomes in the United States. It is one of the older counties in Maryland, after St. Mary's, Kent County and Anne Arundel counties. History Early History In 1608, Captain John Smith was the first European to sail past Calvert County while exploring the western shore of the Chesapeake Bay. On his map, he accurately represented the Patuxent River as well as several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choptank Formation
The Choptank Formation is a geologic formation in Virginia and Maryland. It preserves fossils dating from the Miocene epoch of the Neogene period. Fossils The Choptank Formation is extremely fossiliferous. Some of the fossil species represented include the following: Sharks *''Otodus megalodon'' *''Carcharodon hastalis'' *'' Isurus oxyrhincus'' *Carcharomodus escheri *'' Physogaleus contortus'' *''Galeocerdo aduncus'' *''Carcharhinus'' *''Hemipristis serra'' *'' Squatina sp.'' *'' Notorhyncus cepedianus'' *''Carcharias'' *'' Isurus retroflexus'' *'' Parotodus benedeni'' *''Alopias vulpinus'' *'' Alopias grandis'' *''Cetorhinus'' *'' Negaprion brevirostris'' *''Rhizoprionodon'' *'' Sphryna laevissima'' Rays and Other Cartilaginous Fish *''Aetobatus arcuatus'' *'' Pteromyaleus sp.'' *''Dasyatis rugosa'' *''Dasyatis probsti'' *'' Pinthicus stenodon'' Fish *''Acipenseridae indet.'' *''Opsanus sp.'' *''Serranidae sp.'' *'' Pogonias sp.'' *''Sciaenops sp.'' *''Tautoga sp.'' *''Acanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Ponds Nature Park
Flag Ponds Nature Park is a nature preserve located in Lusby, Maryland along the Chesapeake Bay in Calvert County, Maryland. It is operated by the Calvert County Calvert County is located in the U.S. state of Maryland. As of the 2020 census, the population was 92,783. Its county seat is Prince Frederick. The county's name is derived from the family name of the Barons of Baltimore, the proprietors of t ... Department of Natural Resources. The park includes nature trails and a beach for swimmers. Fossil shark's teeth eroded from the Calvert Cliffs formation may be collected on the beach. The area included in the park was once a center for pound net fishing from the early 1900s through 1955. One fishing shanty remained until October 2012 when it burned down. It has since been rebuilt. References Nature reserves in Maryland Parks in Calvert County, Maryland Chesapeake Bay IUCN Category V {{Maryland-protected-area-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paratype
In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Often there is more than one paratype. Paratypes are usually held in museum research collections. The exact meaning of the term ''paratype'' when it is used in zoology is not the same as the meaning when it is used in botany. In both cases however, this term is used in conjunction with ''holotype''. Zoology In zoological nomenclature, a paratype is officially defined as "Each specimen of a type series other than the holotype.", ''International Code of Zoological Nomenclature'' In turn, this definition relies on the definition of a "type series". A type series is the material (specimens of organisms) that was cited in the original publication of the new species or subspecies, and was not excluded from being type material by the author (th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkers Creek (Maryland)
Parkers Creek is a small tributary of the Chesapeake Bay located in central Calvert County, Maryland, United States. The creek entrance is just north of the bayside community of Scientists Cliffs. Most of the land surrounding the creek has been protected from development by numerous land trust purchases and conservation easements. Much of the creek is navigable by canoe A canoe is a lightweight narrow water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle. In British English, the term .... The creek's headwaters are south of the town of Prince Frederick. References Rivers of Maryland Rivers of Calvert County, Maryland {{Maryland-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvert Cliffs State Park
Calvert Cliffs State Park is a public recreation area in Lusby, Calvert County, Maryland, that protects a portion of cliffs that extend for 24 miles along the eastern flank of the Calvert Peninsula on the west side of Chesapeake Bay from Chesapeake Beach southward to Drum Point. The state park is known for the abundance of mainly Middle Miocene sub-epoch fossils that can be found on the shoreline. Natural history Geology The park contains the type locality site of the Early to Middle Miocene Calvert Formation. These rocks are the sediment from a coastal ocean that covered the area during that time. The age of the formation is (19-)18–15(-14) million years ago ( Ma), i.e. it extends essentially over the Hemingfordian stage. This formation occurs in Maryland and neighboring Virginia. In addition, rocks of the younger Choptank and the St. Marys Formations are exposed here. This makes Calvert Cliffs State Park extremely interesting for its paleoclimatology and paleontology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany, an isotype is a duplicate of the holotype, where holotype and isotypes are often pieces from the same individual plant or samples from the same gathering. A holotype is not necessarily "typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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