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Cosmacanthus
''Cosmacanthus'' is an extinct genus of placoderms in the extinct family Groenlandaspididae that lived during the Late Devonian in Ireland, the UK, Russia and North America. It was named by Louis Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he rec ... in 1845.Monographie des poissons fossiles du vieux grés rouge: ou système Dévonien (Old red sandstone) des Iles Britanniques et de Russie. L Agassiz, 1845 ; Names brought to synonymy: * †''Cosmacanthus elegans'', a synonym for †'' Nemacanthus elegans'' Evans, 1904 (elasmobranch) See also * List of placoderm genera References External links * * Arthrodire genera {{placoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemacanthus Elegans
''Nemacanthus'' (from el, νέμω , 'to distribute' and el, ἄκανθα , 'spine') is an extinct genus of prehistoric sharks in the family Palaeospinacidae. The species ''N. elegans'' is from the Triassic of Idaho, United States.H. M. Evans. 1904. A new cestraciont spine from the Lower Triassic of Idaho. University of California Publications, Bulletin of the Department of Geology 3(18), pages 397-402 See also * List of prehistoric cartilaginous fish genera This list of prehistoric cartilaginous fish genera is an attempt to create a comprehensive listing of all genera that have ever been included in the class chondrichthyes ''and'' are known from the fossil record. This list excludes purely vernacul ... References * Maisey, J. G. (1977). "The fossil selachian fishes Palaeospinax Egerton, 1872 and Nemacanthus Agassiz, 1837". Zoological Journal of the Linnean Society. 60 (3): 259–273. External links * * * * Palaeospinacidae Prehistoric shark genera Taxa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Placoderm Genera
This list of placoderms is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be members of the class Placodermi. This list excludes purely vernacular terms. It includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomina dubia''), or were not formally published ('' nomina nuda''), as well as junior synonyms of more established names, and genera that are no longer considered placoderms. The modern descendants of placoderms, the bony and cartilaginous fishes, and their extinct descendants, the Acanthodii (without cartilaginous fishes), are not included here. This list includes 334 generic names. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, 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#Bilate ... [...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 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] |
Arthrodira
Arthrodira (Greek for "jointed neck") is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine ecological niches. Arthrodires were the largest and most diverse of all groups of Placoderms. Description Arthrodire placoderms are notable for the movable joint between armor surrounding their heads and bodies. Like all placoderms, they lacked distinct teeth; instead, they used the sharpened edges of a bony plate on their jawbone as a biting surface. The eye sockets are protected by a bony ring, a feature shared by birds and some ichthyosaurs. Early arthrodires, such as the genus ''Arctolepis'', were well-armoured fishes with flattened bodies. The largest member of this group, ''Dunkleosteus'', was a true superpredator of the latest Devonian period, reaching as much as 6 m in length. In contrast, the long-nosed ''Rolfosteus'' measured just ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groenlandaspididae
''Groenlandaspis'' is an extinct genus of arthrodire from the Late Devonian. Fossils of the different species are found in late Devonian strata in all continents except eastern Asia. The generic name commemorates the fact that the first specimens of the type species were found in Greenland. Description As with all other arthrodires, ''Groenlandaspis'' had a joint in the back of its head with its thoracic armor, allowing for its head to be thrown back, increasing its gape. However, as its head is somewhat compressed in comparison with many other arthrodires, and as the dorsal side came to a low, pyramid-like peak, it is believed that ''Groenlandaspis'' could not crane its head back very far. It was a relatively small fish, only in length on average, though one unusually large species, ''G. riniensis'', reached almost a metre in length Gess, Robert W.; Whitfield, Alan K. (August 22, 2020). "Estuarine fish and tetrapod evolution: insights from a Late Devonian (Famennian) Gondwanan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he received a PhD at Erlangen and a medical degree in Munich. After studying with Georges Cuvier and Alexander von Humboldt in Paris, Agassiz was appointed professor of natural history at the University of Neuchâtel. He emigrated to the United States in 1847 after visiting Harvard University. He went on to become professor of zoology and geology at Harvard, to head its Lawrence Scientific School, and to found its Museum of Comparative Zoology. Agassiz is known for observational data gathering and analysis. He made institutional and scientific contributions to zoology, geology, and related areas, including multivolume research books running to thousands of pages. He is particularly known for his contributions to ichthyological classification, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oliver Perry Hay
Oliver Perry Hay (May 22, 1846 – November 2, 1930) was an American herpetologist, ichthyologist, and paleontologist. Hay was born in Jefferson County, Indiana, to Robert and Margaret Hay. In 1870, Hay graduated with a bachelor of arts from Eureka College in Illinois. He taught at the college as a sciences professor from 1870–1873. He married Mary E. Howsmon of Eureka, Illinois, in 1870. He was a professor at Oskaloosa College in Iowa from 1874–1876. He was a student at Yale University from 1876–1877. Seventeen years after earning his bachelors, he earned his PhD from Indiana University in Bloomington, Indiana. From 1877–1879, he taught at Abingdon College just before it was incorporated into his alma mater, Eureka College. His longest professorship was at Butler University from 1879–1892. From 1894 to 1895, he worked at the Field Museum of Natural History as assistant curator of zoology, where despite his specialty in ichthyology, he worked in all nonornithological f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
