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Perochelys
''Perochelys'' is an extinct genus of turtle that inhabited Liaoning during the Aptian. It is known from a single species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ..., ''P. lamadongensis''. References {{Taxonbar, from=Q130472915 Monotypic prehistoric reptile genera Trionychinae Prehistoric turtle genera Fossil taxa described in 2015 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other Amniote, amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed Turtle shell#Carapace, carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scale (anatomy), scales made of keratin, the material of hair, horns, and claws. The carapace bones deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liaoning
) , image_skyline = , image_alt = , image_caption = Clockwise: Mukden Palace in Shenyang, Xinghai Square in Dalian, Dalian coast, Yalu River at Dandong , image_map = Liaoning in China (+all claims hatched).svg , mapsize = 275px , map_alt = Map showing the location of Liaoning Province , map_caption = Map showing the location of Liaoning Province , coordinates = , subdivision_type = Country , subdivision_name = China , named_for = —"Liao River, Liao (River)" —"pacification" "Pacified of the Liao (River)" , seat_type = Capital , seat = Shenyang , seat1_type = , seat1 = , parts_type = Divisions , parts_style = para , p1 = 14 Prefectures of China, prefectures , p2 = 100 Counties of China, counties , p3 = 1511 Townships of China, townships , government_type = Provinces of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aptian
The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), Series and encompasses the time from 121.4 ± 1.0 annum, Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. The Aptian partly overlaps the upper part of the Western Europe, Western European Urgonian Stage. The Selli Event, also known as OAE1a, was one of two oceanic anoxic events in the Cretaceous Period, which occurred around 120 annum, Ma and lasted approximately 1 to 1.3 million years, being marked by enhanced silicate weathering, as well as ocean acidification. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma. Stratigraphic definitions The Aptian was named after the small city o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knowledge
Knowledge is an Declarative knowledge, awareness of facts, a Knowledge by acquaintance, familiarity with individuals and situations, or a Procedural knowledge, practical skill. Knowledge of facts, also called propositional knowledge, is often characterized as Truth, true belief that is distinct from opinion or guesswork by virtue of Justification (epistemology), justification. While there is wide agreement among philosophers that propositional knowledge is a form of true belief, many controversies focus on justification. This includes questions like how to understand justification, whether it is needed at all, and whether something else besides it is needed. These controversies intensified in the latter half of the 20th century due to a series of thought experiments called ''Gettier cases'' that provoked alternative definitions. Knowledge can be produced in many ways. The main source of empirical knowledge is perception, which involves the usage of the senses to learn about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Vertebrate Paleontology
The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolution, functional morphology, taxonomy, biostratigraphy, paleoecology, paleobiogeography, and paleoanthropology. The journal is published by Taylor & Francis on behalf of the Society of Vertebrate Paleontology. According to ''Journal Citation Reports'', the journal has a 2017 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 2.190. References External links * Paleontology journals Academic journals established in 1980 Quarterly journals English-language journals Taylor & Francis academic journals {{Oklahoma- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Prehistoric Reptile 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] |
Trionychinae
The Trionychinae are a subfamily of turtles in the family Trionychidae. Classification The subfamily has 11 extant genera: *''Amyda'' *''Apalone'' *''Axestemys'' *''Chitra (turtle), Chitra'' *''Dogania'' *''Drazinderetes'' *''Gobiapalone'' *''Khunnuchelys'' *''Murgonemys'' *''Nilssonia (turtle), Nilssonia'' *''Oliveremys'' *''Palea (turtle), Palea'' *''Palaeoamyda'' *''Pelochelys'' *''Pelodiscus'' *''Rafetoides'' (nomen dubium) *''Rafetus'' *''Trionyx'' References {{Taxonbar, from=Q2036081 Trionychinae, Reptile subfamilies Taxa named by John Edward Gray ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Turtle Genera
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
