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Occidens Portlocki
''Occidens'' is an extinct genus of stem tetrapod that lived during the earliest part of the Carboniferous in what is now Northern Ireland. It is known from a single type species, ''Occidens portlocki'', named in 2004 on the basis of a left lower jaw described by British geologist Joseph Ellison Portlock in 1843. History Portlock attributed the original fossil to the lobe-finned fish ''Holoptychius,'' and it was housed in the collections of the British Geological Survey for over a century before being reevaluated. In 2004, it was redescribed by vertebrate paleontologists Jenny Clack and Per E. Ahlberg, who reclassified it as a new genus and species of early tetrapod. They established the genus name ''Occidens,'' referring to its presence west of better-known early tetrapod assemblages in Great Britain. The species name honors Portlock. The jaw likely comes from the Altagoan Formation and, based on an analysis of fossilized pollen, dates to the late Tournaisian stage of the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Carboniferous
Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * Early (Scritti Politti album), ''Early'' (Scritti Politti album), 2005 * Early (A Certain Ratio album), ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) {{disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Line
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial cells, known as hair cells, which respond to displacement caused by motion and transduce these signals into electrical impulses via excitatory synapses. Lateral lines serve an important role in schooling behavior, predation, and orientation. Fish can use their lateral line system to follow the vortices produced by fleeing prey. Lateral lines are usually visible as faint lines of pores running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. In some species, the receptive organs of the lateral line have been modified to function as electroreceptors, which are organs used to detect electrical impulses, and as such, these systems remain closely linked. Most amphibian larvae and some fully aquatic adult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Tetrapod Genera
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] |
Carboniferous Tetrapods
Carboniferous tetrapods include amphibians and reptiles that lived during the Carboniferous Period. Though stem-tetrapods originated in the preceding Devonian, it was in the earliest Carboniferous that the first crown tetrapods appeared, with full scaleless skin and five digits. During this time, amphibians (including many extinct groups unrelated to modern forms, referred to as "basal tetrapods") were the predominant tetrapods, and included the Temnospondyli, Lepospondyli, and Anthracosauria. The first amniotes appeared during the middle Carboniferous ( Early Pennsylvanian) from the lattermost group, and included both sauropsids and synapsids, but it was not until the very end of the Carboniferous, during a rainforest collapse, and afterwards that they began to diversify. Classification The following list of families of Carboniferous tetrapods is based mostly on Benton ed. 1993. The classification followBenton 2004 Superclass Tetrapoda * Basal Tetrapods ** Family Whatch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigournea Multidentata
''Sigournea'' is a genus of stem tetrapod from the Early Carboniferous. The genus contains only one species, the type species ''Sigournea multidentata'', which was named in 2006 by paleontologists John R. Bolt and R. Eric Lombard on the basis of a single lower jaw from Iowa. The jaw came from a fissure-fill deposit of the St. Louis Limestone that was exposed in a quarry near the town of Sigourney and dates to the Viséan stage, making it approximately 335 million years old. Bolt and Lombard named the genus after Sigourney. The species name ''multidentata'' alludes to the many teeth preserved in the jaw. The jaw, which is housed in the Field Museum and cataloged as FM PR 1820, curves strongly downward but was probably straight to begin with, having been deformed by the process of fossilization after the individual died. Rooted in the dentary bone along the outermost edge of the jaw are 88 small, pointed marginal teeth. An additional row of even smaller teeth runs along the corono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcello Ruta
Marcello Ruta is an Italian paleontologist. Ruta's research primarily has focused on the anatomy and evolutionary significance of Paleozoic tetrapods Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct therapsi .... Selected publications *Ruta, M., Coates, M. I. and Quicke, D. L. J. 2003. Early tetrapod relationships revisited. ''Biological Reviews'' 78: 251-345. *Ruta, M., Jeffery, J. E. and Coates, M. I. 2003. A supertree of early tetrapods. ''Proceedings of the Royal Society of London Series B-Biological Sciences'' 270: 2507-2516. *Ruta, M. and Coates, M. I. 2007. Dates, nodes and character conflict: Addressing the lissamphibian origin problem. ''Journal of Systematic Palaeontology'' 5: 67-122. *Ruta, M., Pisani, D., Lloyd, G. T. and Benton, M. J. 2007. A supertree of Temnospondyli: clado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalocephalus
''Megalocephalus'' (meaning "big head") is an extinct genus of baphetid animal from the late Carboniferous ( Westphalian A-C) of the British Isles and the United States (Ohio). It contains two species, ''M. pachycephalus'' and ''M. lineolatus''. History ''Megalocephalus pachycephalus'' ''Megalocephalus pachycephalus'' is one of the most common large amphibians from the Carboniferous of Britain, and is known from several sites in England, Scotland, and Ireland. The first known fossils of the genus were cranial fragments which were misattributed to ''Rhizodus'' jaw bones upon their discovery in 1864. These fragments, and many subsequent discoveries, were recovered from a quarry near Newsham, Northumberland. Other ''Megalocephalus'' fossils found in the 1860s had been referred to other large amphibians, namely ''Pteroplax and'' ''Anthracosaurus''. Two well-preserved skulls and associated jaw bones were found in Newsham in 1870 and 1871, though these were also mistakenly refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greererpeton
''Greererpeton burkemorani'' ("crawler from Greer, West Virginia") is an extinct genus of colosteid stem-tetrapods from the Early Carboniferous period (late Viséan) of North America. ''Greererpeton'' was first described by famed vertebrate paleontologist Alfred S. Romer in 1969. The skull was redescribed by Timothy R. Smithson in 1982, while postcranial remains were redescribed by Stephen J. Godfrey in 1989. ''Greererpeton'' were probably aquatic, with an elongated body adapted for swimming. Adults have overall length of or , similar in size to modern Asian giant salamanders (''Andrias''). The body was elongated, with about 40 vertebrae, while the flattened skull reached about long in adult specimens. The most complete adult specimen only preserved 12 tail vertebrae, only about a third the length of the body as in ''Andrias''. However, smaller specimens have been found preserving over 30 vertebrae, so it is not inconceivable that a complete tail was approximately as long a ... [...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] |
Tulerpeton
''Tulerpeton'' is an extinct genus of Devonian four-limbed vertebrate, known from a fossil that was found in the Tula Region of Russia at a site named Andreyevka. This genus and the closely related ''Acanthostega'' and ''Ichthyostega'' represent the earliest tetrapods. Description ''Tulerpeton'' is considered one of the first "tetrapods" (in the broad sense of the word) to have evolved. It is known from a fragmented skull, the left side of the pectoral girdle, and the entire right forelimb and right hindlimb along with a few belly scales. This species is differentiated from the less derived "aquatic tetrapods" (such as ''Acanthostega'' and ''Ichthyostega'') by a strengthened limb structure. These limbs consist of 6 toes and fingers. Additionally, its limbs appear to have evolved for powerful paddling rather than walking. The fossil fragments also indicate that its head was disconnected from the pectoral girdle. From the absence of the rough postbranchial lamina of the pectoral gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Tree
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whatcheeriid
Whatcheeriidae is an extinct family of tetrapods which lived in the Mississippian sub-period, a subdivision of the Carboniferous period. It contains the genera ''Pederpes'', '' Whatcheeria'', and possibly '' Ossinodus''. Fossils of a possible whatcheeriid have been found from the Red Hill locality of Pennsylvania. If these remains are from a whatcheeriid, they extend the range of the family into the Late Devonian and suggest that advanced tetrapods may have lived alongside primitive tetrapod ancestors like ''Hynerpeton'' and ''Densignathus''. They also imply that a very long ghost lineage of whatcheeriids lived through Romer's gap, a period during the Early Carboniferous conspicuously lacking in tetrapod remains. Classification Currently, using modern cladistic taxonomy, Whatcheeriidae is not placed in Amphibia Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
