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Axelia Robusta
''Axelia'' is a prehistoric genus of lobe-finned fish which belonged to the family of Coelacanthidae. Species of Axelia *''Axelia elegans ''Axelia'' is a prehistoric genus of lobe-finned fish which belonged to the family of Coelacanthidae Coelacanthidae is an extinct family of coelacanths found in freshwater and marine strata throughout the world, originating during the Permi ...'' Stensio, 1921 *'' Axelia robusta'' Stensio, 1921 Coelacanthidae Late Permian fish Fossils of Svalbard Fossil taxa described in 1921 {{Svalbard-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordate
A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These five synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. The name “chordate” comes from the first of these synapomorphies, the notochord, which plays a significant role in chordate structure and movement. Chordates are also Bilateral symmetry, bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit Metameric, metameric segmentation. In addition to the morphological characteristics used to define chordates, analysis of genome sequences has identified two conserved signature indels (CSIs) in their proteins: cyclophilin-like protein and mitochondrial inner membrane protease ATP23, which are exclusively shared by all vertebrates, tunicates and cep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcopterygii
Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass including amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (with mammals being the only extant group), evolved from certain sarcopterygians; under a cladistic view, tetrapods are themselves considered a subgroup within Sarcopterygii. The known extant non-tetrapod sarcopterygians include two species of coelacanths and six species of lungfishes. Characteristics Early lobe-finned fishes are bony fish with fleshy, lobed, paired fins, which are joined to the body by a single bone. The fins of lobe-finned fishes differ from those of all other fish in that each is borne on a fleshy, lobelike, scaly stalk extending from the body. The scales of sarcopterygians are true scaloids, consisting of lamellar bone sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinistia
The coelacanths ( ) are fish belonging to the order Actinistia that includes two extant species in the genus ''Latimeria'': the West Indian Ocean coelacanth (''Latimeria chalumnae''), primarily found near the Comoro Islands off the east coast of Africa, and the Indonesian coelacanth (''Latimeria menadoensis''). The name "coelacanth" originates from the Permian genus ''Coelacanthus'', which was the first scientifically named coelacanth. Coelacanths follow the oldest-known living lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish and tetrapods (which includes amphibians, reptiles, birds and mammals) than to ray-finned fish. They are found along the coastline of Indonesia and in the Indian Ocean. The West Indian Ocean coelacanth is a critically endangered species. The oldest known coelacanth fossils are over 410 million years old. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 milli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanthiformes
The coelacanths ( ) are fish belonging to the order Actinistia that includes two extant species in the genus ''Latimeria'': the West Indian Ocean coelacanth (''Latimeria chalumnae''), primarily found near the Comoro Islands off the east coast of Africa, and the Indonesian coelacanth (''Latimeria menadoensis''). The name "coelacanth" originates from the Permian genus ''Coelacanthus'', which was the first scientifically named coelacanth. Coelacanths follow the oldest-known living lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish and tetrapods (which includes amphibians, reptiles, birds and mammals) than to ray-finned fish. They are found along the coastline of Indonesia and in the Indian Ocean. The West Indian Ocean coelacanth is a critically endangered species. The oldest known coelacanth fossils are over 410 million years old. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 milli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanthidae
Coelacanthidae is an extinct family of coelacanths found in freshwater and marine strata throughout the world, originating during the Permian, and finally dying out during the Jurassic. The modern-day genus ''Latimeria'' is often erroneously thought to be in this family, when, in fact, it is the type genus of the more advanced family Latimeriidae, which appeared some time during the Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period .... References Permian bony fish Triassic bony fish Jurassic bony fish Jurassic extinctions Prehistoric lobe-finned fish families Permian first appearances {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erik Stensiö
Prof Erik Helge Osvald Stensiö HFRSE (2 October 1891 – 11 January 1984) was a Sweden, Swedish paleozoology, paleozoologist. He later took his new surname from his place of origin and is occasionally referred to with both names (as Erik Andersson Stensiö, Erik A. Stensiö or Erik A:son Stensiö) Life Erik Helge Oswald Andersson, as his original name was, was born in the village of Stensjö by in Döderhult parish in Kalmar County, the son of Johan Fredrik Andersson (d.1907), a farmer, and his wife, Otilia Maria Erlandson (d.1940). He was educated at Linköping Gymnasium. He then studied science at the University of Uppsala, graduating BSc in 1912. He received his Ph.D. and a docentship in paleontology from Uppsala University in 1921 and became professor and keeper at the Zoopaleontological (later called the Paleozoological) department of the Swedish Museum of Natural History in Stockholm in 1923, a position he held until his retirement in 1959. Stensiö specialized in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 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 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobe-finned Fish
Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass including amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (with mammals being the only extant group), evolved from certain sarcopterygians; under a cladistic view, tetrapods are themselves considered a subgroup within Sarcopterygii. The known extant non-tetrapod sarcopterygians include two species of coelacanths and six species of lungfishes. Characteristics Early lobe-finned fishes are bony fish with fleshy, lobed, paired fins, which are joined to the body by a single bone. The fins of lobe-finned fishes differ from those of all other fish in that each is borne on a fleshy, lobelike, scaly stalk extending from the body. The scales of sarcopterygians are true scaloids, consisting of lamellar bone surro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axelia Elegans
''Axelia'' is a prehistoric genus of lobe-finned fish which belonged to the family of Coelacanthidae Coelacanthidae is an extinct family of coelacanths found in freshwater and marine strata throughout the world, originating during the Permian, and finally dying out during the Jurassic. The modern-day genus ''Latimeria'' is often erroneously tho .... Species of Axelia *'' Axelia elegans'' Stensio, 1921 *'' Axelia robusta'' Stensio, 1921 Coelacanthidae Late Permian fish Fossils of Svalbard Fossil taxa described in 1921 {{Svalbard-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
