|
Anaspid
Anaspida ("without shield") is an extinct group of primitive jawless vertebrates that lived primarily during the Silurian period, and became extinct soon after the start of the Devonian. They were classically regarded as the ancestors of lampreys. Anaspids were small marine agnathans that lacked a heavy bony shield and paired fins, but have a striking highly Fish fin#AnchCaudal, hypocercal tail. They first appeared in the early Silurian, and flourished until the early Devonian, when they disappear from the fossil record. Anatomy Compared to other prehistoric agnathan groups, such as the Heterostraci and Osteostraci, anaspids did not possess a bony shield or armor, hence their name. The anaspid head and body are instead covered in an array of small, weakly mineralized scales, with a row of massive scutes running down the back, and, at least confirmed among the birkeniids, the body was covered in rows of tile-like scales made of aspidine, an acellular bony tissue. Anaspids all had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaspida
Anaspida ("without shield") is an extinct group of primitive jawless vertebrates that lived primarily during the Silurian period, and became extinct soon after the start of the Devonian. They were classically regarded as the ancestors of lampreys. Anaspids were small marine agnathans that lacked a heavy bony shield and paired fins, but have a striking highly hypocercal tail. They first appeared in the early Silurian, and flourished until the early Devonian, when they disappear from the fossil record. Anatomy Compared to other prehistoric agnathan groups, such as the Heterostraci and Osteostraci, anaspids did not possess a bony shield or armor, hence their name. The anaspid head and body are instead covered in an array of small, weakly mineralized scales, with a row of massive scutes running down the back, and, at least confirmed among the birkeniids, the body was covered in rows of tile-like scales made of aspidine, an acellular bony tissue. Anaspids all had prominent, latera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkenia Elegans
''Birkenia'' is a genus of extinct anaspid fish from Middle Silurian strata of Northern Europe, and Middle Silurian to possibly Earliest Devonian strata of Arctic Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ....Blom, Henning, T. Märss, and C. G. Miller. "Silurian and earliest Devonian birkeniid anaspids from the Northern Hemisphere." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 92.03 (2001): 263-323/ref> Birkeniid anaspids are covered by a series of small plates on the head and rod-shaped scales in a cheveron-like pattern on the trunk. Intact fossil specimens of ''B. elegans'' suggest the living animal reached a length of up to , and was an active swimmer. In addition to whole specimens and scale microfossils of ''B. elegans'', which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkeniids
Birkeniiformes (Birkeniida or Birkeniids) is an extinct order of jawless fish belonging to the class Anaspida. Subtaxa A newer taxonomy based on the work of Mikko's Phylogeny Archive, Nelson, Grande and Wilson 2016 and van der Laan 2018. * Genus †'' Cowielepis'' Blom 2008 * Genus †'' Hoburgilepis'' Blom, Märss & Miller 2002 * Genus †'' Kerreralepis'' Blom 2012 * Genus †'' Maurylepis'' Blom, Märss & Miller 2002 * Genus †'' Rytidolepis'' Pander 1856 * Genus †'' Schidiosteus'' Pander 1856 * Genus †'' Silmalepis'' Blom, Märss & Miller 2002 * Genus †'' Vesikulepis'' Blom, Märss & Miller 2002 * Family † Pharyngolepididae Kiær 1924 corrig. ** Genus †'' Pharyngolepis'' Kiaer 1911 * Family † Pterygolepididae Obručhev 1964 corrig. ** Genus †'' Pterygolepis'' Cossmann 1920 'Pterolepis'' Kiaer 1911 non Rambur 1838 non De Candolle ex Miquel 1840; ''Pterolepidops'' Fowler 1947 * Family † Rhyncholepididae Kiær 1924 corrig. ** Genus †''Rhyncholepis'' Kiær 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkeniiformes
Birkeniiformes (Birkeniida or Birkeniids) is an extinct order of jawless fish belonging to the class Anaspida. Subtaxa A newer taxonomy based on the work of Mikko's Phylogeny Archive, Nelson, Grande and Wilson 2016 and van der Laan 2018. * Genus †''Cowielepis'' Blom 2008 * Genus †'' Hoburgilepis'' Blom, Märss & Miller 2002 * Genus †'' Kerreralepis'' Blom 2012 * Genus †'' Maurylepis'' Blom, Märss & Miller 2002 * Genus †'' Rytidolepis'' Pander 1856 * Genus †'' Schidiosteus'' Pander 1856 * Genus †'' Silmalepis'' Blom, Märss & Miller 2002 * Genus †'' Vesikulepis'' Blom, Märss & Miller 2002 * Family † Pharyngolepididae Kiær 1924 corrig. ** Genus †'' Pharyngolepis'' Kiaer 1911 * Family † Pterygolepididae Obručhev 1964 corrig. ** Genus †'' Pterygolepis'' Cossmann 1920 'Pterolepis'' Kiaer 1911 non Rambur 1838 non De Candolle ex Miquel 1840; ''Pterolepidops'' Fowler 1947 * Family † Rhyncholepididae Kiær 1924 corrig. ** Genus †''Rhyncholepis'' Kiær 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkeniida
Birkeniiformes (Birkeniida or Birkeniids) is an extinct order of jawless fish belonging to the class Anaspida. Subtaxa A newer taxonomy based on the work of Mikko's Phylogeny Archive, Nelson, Grande and Wilson 2016 and van der Laan 2018. * Genus †'' Cowielepis'' Blom 2008 * Genus †'' Hoburgilepis'' Blom, Märss & Miller 2002 * Genus †'' Kerreralepis'' Blom 2012 * Genus †'' Maurylepis'' Blom, Märss & Miller 2002 * Genus †'' Rytidolepis'' Pander 1856 * Genus †'' Schidiosteus'' Pander 1856 * Genus †'' Silmalepis'' Blom, Märss & Miller 2002 * Genus †'' Vesikulepis'' Blom, Märss & Miller 2002 * Family † Pharyngolepididae Kiær 1924 corrig. ** Genus †'' Pharyngolepis'' Kiaer 1911 * Family † Pterygolepididae Obručhev 1964 corrig. ** Genus †'' Pterygolepis'' Cossmann 1920 'Pterolepis'' Kiaer 1911 non Rambur 1838 non De Candolle ex Miquel 1840; ''Pterolepidops'' Fowler 1947 * Family † Rhyncholepididae Kiær 1924 corrig. ** Genus †''Rhyncholepis'' Kiær 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jamoytiiformes
Jamoytiiformes is an extinct order of prehistoric jawless fish in the superclass Anaspidomorphi. Taxonomy Taxonomy is based on Mikko's Phylogeny Archive * Family † Achanarellidae Newman 2002 ** Genus †'' Achanarella'' Newman 2002 'Achanarella'' Saxon 1978 nomen nudum*** †'' Achanarella trewini'' Newman 2002 * Family † Jamoytiidae White 1946 ** Genus †'' Conopiscius'' Briggs & Clarkson 1987 *** †'' Conopiscius clarki'' Briggs & Clarkson 1987 ** Genus †''Jamoytius ''Jamoytius kerwoodi'' was a species of primitive, eel-like jawless fish that lived in the Llandovery epoch of the Early Silurian period. Long thought of as a "basal anaspid," ''J. kerwoodi'' is now recognized as the best-known member of the H ...'' White 1946 *** †'' Jamoytius kerwoodi'' White 1946 References * A New Interpretation of Jamoytius Kerwoodi White. Alexander Ritchie, Nature, volume 188, pages 647–649 (19 November 1960), External links Prehistoric jawless fish orders [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jamoytius
''Jamoytius kerwoodi'' was a species of primitive, eel-like jawless fish that lived in the Llandovery epoch of the Early Silurian period. Long thought of as a "basal anaspid," ''J. kerwoodi'' is now recognized as the best-known member of the Hyperoartian order Jamoytiiformes. It had an elongated body, and is thought to have had, in comparison with relatives known from intact bodies like ''Euphanerops'', a dorsal fin and an anal fin near the rearmost third of its body. Earlier reconstructions depict the creature as having side-fins running the length of its body, starting from behind the branchial openings to the tip of its tail: new research demonstrates that such "fins" are actually deformations of the bodywall as the corpse was being squished post-burial. In life, ''J. kerwoodi'' resembled a lamprey with a very small mouth. Because the fossil had no teeth, teeth-like structures, nor suggestions of either in its mouth, it was not carnivorous like many modern lampreys. It was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cowielepis
''Cowielepis'' is an extinct genus of jawless fish in the class Anaspida. It is from the middle Silurian Cowie Harbour fish bed of Stonehaven, Scotland. Habits It was possibly a nectonic filter, of active locomotion, due to its physiognomy. Distribution Lochkovian of United Kingdom (Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to ...). References External links * Birkeniiformes genera Fossil taxa described in 2008 {{paleo-jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lasanius
''Lasanius'' is a genus of basal anaspida from the Early Silurian. Its fossils are around 10 mm to 150 mm in length. Fossils have been found in Early Silurian-aged strata in Ayrshire, Muirkirk, Scotland Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ... and Seggholm. References R.H. Traquair M.D. LL.D. F.R.S. (1898) IX.—''Notes on Palœozoic fishes.''—No. II, Annals and Magazine of Natural History, 2:7, 67–70, DOI: 10.1080/00222939808678013 Traquair, R. (1899). XXXII.—Report on Fossil Fishes collected by the Geological Survey of Scotland in the Silurian Rocks of the South of Scotland. ''Transactions of the Royal Society of Edinburgh,'' ''39''(3), 827–864. doi:10.1017/S0080456800035237 External links Underwhelming Fossil Fish of the Month: Februa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by ' (of uncertain family), ' (of uncertain suborder), ' (of uncertain order) and similar terms. Examples *The fossil plant '' Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Bocage's longbill, ''Motacilla bocagii' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Wiley & Sons
John Wiley & Sons, Inc., commonly known as Wiley (), is an American multinational publishing company founded in 1807 that focuses on academic publishing and instructional materials. The company produces books, journals, and encyclopedias, in print and electronically, as well as online products and services, training materials, and educational materials for undergraduate, graduate, and continuing education students. History The company was established in 1807 when Charles Wiley opened a print shop in Manhattan. The company was the publisher of 19th century American literary figures like James Fenimore Cooper, Washington Irving, Herman Melville, and Edgar Allan Poe, as well as of legal, religious, and other non-fiction titles. The firm took its current name in 1865. Wiley later shifted its focus to scientific, technical, and engineering subject areas, abandoning its literary interests. Wiley's son John (born in Flatbush, New York, October 4, 1808; died in East Orange, New Je ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
