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Pristiosomus
''Pristiosomus'' is an extinct genus of prehistoric bony fish. It was discovered and named by Priem in 1924. ''Pristiosomus'' lived in the Triassic Period. Like other similar fish, it had thick layers of bony scales, which probably helped protect it from predation by other fish and nothosaurs. Taxonomy There is one known species, ''Pristiosomus merlei.'' It has been classified in both the Semionotiformes and the Pholidopleuroformes at different times. It was placed in the Pholidopleuroformes due to its similarity to '' Australosomus merlei'' (Piveteau). Etymology ''Pristiosomus'' comes from the Latin 'pristis' meaning 'sea monster' or 'shark' and the Greek 'soma' meaning 'body'. ''merlei'' refers to a person after whom it was named. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College Albert A. List College of Jewish Studies, k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semionotiformes
Semionotiformes is an order of primitive, ray-finned, primarily freshwater fish from the Middle Triassic (Anisian) to the Late Cretaceous (Maastrichtian). The best-known genus is ''Semionotus'' of Europe and North America. Their closest living relatives are gars (Lepisosteidae), with both groups belonging to the clade Ginglymodi within the Holostei. Classification * Order †Semionotiformes Arambourg & Bertin 1958 sensu López-Arbarello 2012 ** Genus ?†'' Orthurus'' Kner 1866 ** Genus †'' Sangiorgioichthys'' Tintori & Lombardo 2007 ** Genus †'' Luoxiongichthys'' Wen et al. 2011 ** Genus †'' Aphanepygus'' Bassani 1879 ** Genus †'' Placidichthys'' Brito 2000 ** Family † Pleurolepididae Lütken 1871 *** Genus †'' Pleurolepis'' Agassiz 1863 non Quenstedt 1852 ** Family † Macrosemiidae Wagner 1860a corrig. Cope 1889 sensu Murray & Wilson 2009 acrosemii Wagner 1860a*** Genus †'' Eusemius'' Vetter 1881 *** Genus †'' Blenniomoeus'' Costa 1850 Calignathus.html" ;"tit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ... Epoch. The Oligocene is the third and final epoch of ... [...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 Symmetry in biology#Bilateral symmetry, bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordata
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 bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit 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 cephalochordates. These CSIs provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinopterygii
Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines (rays), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii (lobe-finned fish). These actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connection between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). By species count, actinopterygians dominate the vertebrates, and they constitute nearly 99% of the over 30,000 species of fish. They are ubiquitous throughout freshwater and marine environments from the deep sea to the highest mountain streams. Extant species can range in size from '' Paedocypris'', at , to the massive ocean sunfish, at , and the long-bodied oarfish, at . The vast majority of Act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holostei
Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by a single living species, the bowfin ('' Amia calva''), as well as the Ginglymodi, the sole living representatives being the gars (Lepisosteidae), represented by seven living species in two genera ('' Atractosteus'', ''Lepisosteus''). The earliest members of the clade appeared during the Early Triassic, over 250 million years ago. Holostei was thought to be regarded as paraphyletic. However, a recent study provided evidence that the Holostei are the closest living relates of the Teleostei, both within the Neopterygii. This was found from the morphology of the Holostei, for example presence of a paired vomer. Holosteans are closer to teleosts than are the chondrosteans, the other group intermediate between teleosts and cartilaginous fish, which are regarded as (at the nearest) a sister group to the Neopterigii. The spiracles of holosteans are reduced to vesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bony Fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today. The group Osteichthyes is divided into the ray-finned fish ( Actinopterygii) and lobe-finned fish ( Sarcopterygii). The oldest known fossils of bony fish are about 425 million years old, which are also transitional fossils, showing a tooth pattern that is in between the tooth rows of sharks and bony fishes. Osteichthyes can be compared to Euteleostomi. In paleontology the terms are synonymous. In ichthyology the difference is that Euteleostomi presents a cladistic view which includes the terrestrial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nothosaur
Nothosaurs (order Nothosauroidea) were Triassic marine sauropterygian reptiles that may have lived like seals of today, catching food in water but coming ashore on rocks and beaches. They averaged about in length, with a long body and tail.F. v. Huene. 1956. Paläontologie und Phylogenie der Niederen Tetrapoden aleontology and Phylogeny of the Lower Tetrapods ''VEB Gustav Fischer Verlang, Jena'' 1-716 The feet were paddle-like, and are known to have been webbed in life, to help power the animal when swimming. The neck was quite long, and the head was elongated and flattened, and relatively small in relation to the body. The margins of the long jaws were equipped with numerous sharp outward-pointing teeth, indicating a diet of fish and squid. Taxonomy The Nothosauroidea consist of two suborders: * Pachypleurosauria, small primitive forms, and * Nothosauria (including two families Nothosauridae and Simosauridae), which evolved from pachypleurosaurs. The placement of pachyple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pholidopleuriformes
Pholidopleuriformes is an extinct order of ray-finned fish. Classification ** Family †Pholidopleuridae Abel 1919/Wade 1932 *** Genus †''Gracilignathichthys'' Bürgin 1992 **** †''Gracilignathichthys microlepis'' Bürgin 1992 *** Genus †''Arctosomus'' Berg 1941 Neavichthys.html" ;"title="'Neavichthys">'Neavichthys'' Whitley 1951**** †''Arctosomus sibiricus'' Berg 1941 *** Genus †''Macroaethes'' Wade 1932 **** †''Macroaethes alta, M. alta'' Wade 1935 **** †''Macroaethes brookvalei, M. brookvalei'' Wade 1932 *** Genus †''Pholidopleurus'' Bronn 1858 **** †'' P. ticinensis'' Bürgin 1992 **** †'' P. xiaowaensis'' Liu & Yin 2006 **** †'' P. typus'' Bronn 1858 Timeline of genera ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-251 till:-199.6 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:5 start:-251 ScaleMinor = unit:year increment:1 start:-251 TimeAxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australosomus
''Australosomus'' is an extinct genus of prehistoric ray-finned fish that lived during the Early Triassic epoch. The interlocking scales (3 to 4 times long as wide), deeply forked caudal fin all help to distinguish this genus, which is known from Triassic rocks in Greenland, Africa, Madagascar, British Columbia and Vancouver.Ludvigsen, Rolf & Beard, Graham. 1997. West Coast Fossils: A Guide to the Ancient Life of Vancouver Island. pg. 78-79 ''Australosomus'' is one of many genera to arise after the Permian extinction, only to die out during the Early Triassic, possibly during a subsequent extinction event. See also * Prehistoric fish * List of prehistoric bony fish A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union ... References Pholidopleuriformes Prehistoric ray-finned f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Fish
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include '' Haikouichthys''. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate ancient pre-jawed fish. Lampreys belong to the Cyclostomata, which includes the extant hagfish, and this group may have split early on from other agnathans. The earliest jawed vertebrates probably developed during the late Ordovician period. They are first represented in the fossil record from the Silurian by two groups of fish: the armoured fish known as placoderms, which evolved from the ostracoderms; and the Acanthodii (or s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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