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Ichthyosauridae
Ichthyosauridae is an extinct family of thunnosaur ichthyosaurs from the latest Triassic and Early Jurassic (Rhaetian to Pliensbachian stages) of Europe, and possibly also from the middle Early Cretaceous (Hauterivian or Barremian stage) of Iraq. Named by Charles Lucien Bonaparte, in 1841, it is usually thought to contain a single genus, '' Ichthyosaurus'', which is known from several species from the Early Jurassic. In 2013, Fischer ''et al.'' named and described '' Malawania anachronus'' from the middle Early Cretaceous of Iraq. It was found to share several synapomorphies with the type species of this family, ''Ichthyosaurus communis'', and a large phylogenetic analysis recovered these species as sister taxa. Despite its geologically younger age, ''M. anachronus'' was also assigned to Ichthyosauridae. Phylogeny Fischer ''et al.'' (2013) applied the name Ichthyosauridae Bonaparte, 1841 for the clade that contains '' Malawania anachronus'' and ''Ichthyosaurus communis''. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoichthyosaurus
''Protoichthyosaurus'' is a genus of ichthyosaur from the early Jurassic of southern England. Two species are known, ''P. prostaxalis''—the type species, named by Appleby in 1979—and ''P. applebyi''. A third species, ''P. prosostealis'', was named by Appleby, but it was removed from the genus in 2017 due to its similarity to '' Ichthyosaurus''. The genus ''Protoichthyosaurus'' was synonymized with ''Ichthyosaurus'' by Maisch and Hungerbuhler in 1997, and again by Maisch and Matzke in 2000. However, it was found to be distinct in 2017 by Dean Lomax and colleagues, who separated it from ''Ichthyosaurus'' on account of differences in the arrangement and shape of the carpal ossifications, as well as the absence of the fifth digit. The species most likely lived during the Hettangian stage, but may have lived as early as the Rhaetian and as late as the Sinemurian. Species belonging to the genus were medium-sized, with ''P. prostaxalis'' measuring no more than in length and ''P. a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malawania
''Malawania'' is an extinct genus of basal thunnosaur ichthyosaur known from the middle Early Cretaceous (Hauterivian or Barremian stage) of Iraq. ''Malawania'' was named by Valentin Fischer, Robert M. Appleby, Darren Naish, Jeff Liston, Riding, J. B., Brindley, S. and Pascal Godefroit in 2013 and the type species is ''Malawania anachronus''. It is unusual as it is much more primitive than other Cretaceous ichthyosaurs, being most closely related to '' Ichthyosaurus'' from the Late Triassic and Early Jurassic, over 70 million years earlier than ''Malawania'', with all other known ichthyosaurs from the Late Jurassic onwards belonging to the family Ophthalmosauridae. Discovery The holotype and only known specimen was discovered in 1952 by British petroleum geologists D. M. Morton, F. R. S. Henson, R. J. Wetzel and L. C. F. Damesin while working in Chia Gara, Amadia in Iraqi Kurdistan. The slab was being used to dam a small river and was part of a mule track. It was then trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosaur
Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria). Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago ( Ma) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution. Ichthyosaurs were particularly abundant in the Late Triassic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baracromia
Thunnosauria ( Greek for "tuna lizard" – ''thunnos'' meaning "tuna" and ''sauros'' meaning "lizard") is an extinct clade of parvipelvian ichthyosaurs from the Early Jurassic to the early Late Cretaceous (Hettangian–Cenomanian) of Asia, Australia, Europe, North America, and South America. Named by Ryosuke Motani in 1999, it contains the basal taxa '' Ichthyosaurus'' and ''Stenopterygius'' and the family Ophthalmosauridae. In thunnosaurs, the fore fin is at least twice as long as the hind fin. Phylogeny Thunnosauria is a node-based taxon defined in 1999 as "the last common ancestor of ''Ichthyosaurus communis'' and ''Stenopterygius quadriscissus ''Stenopterygius'' is an extinct genus of thunnosaur ichthyosaur known from Europe (England, France, Germany, Luxembourg and Switzerland). This genus of ichthyosaur was about long and weighed .Huene F. von 1939. Ein ganzes Ichthyosaurier-Skelett ...'' and all of its descendants". The cladogram below follows the topology from a 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thunnosaur
Thunnosauria (Greek for "tuna lizard" – ''thunnos'' meaning "tuna" and ''sauros'' meaning "lizard") is an extinct clade of parvipelvian ichthyosaurs from the Early Jurassic to the early Late Cretaceous (Hettangian–Cenomanian) of Asia, Australia, Europe, North America, and South America. Named by Ryosuke Motani in 1999, it contains the basal taxa ''Ichthyosaurus'' and '' Stenopterygius'' and the family Ophthalmosauridae. In thunnosaurs, the fore fin is at least twice as long as the hind fin. Phylogeny Thunnosauria is a node-based taxon defined in 1999 as "the last common ancestor of '' Ichthyosaurus communis'' and ''Stenopterygius quadriscissus'' and all of its descendants". The cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... below follows the topology from a 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malawania Anachronus
''Malawania'' is an extinct genus of basal thunnosaur ichthyosaur known from the middle Early Cretaceous (Hauterivian or Barremian stage) of Iraq. ''Malawania'' was named by Valentin Fischer, Robert M. Appleby, Darren Naish, Jeff Liston, Riding, J. B., Brindley, S. and Pascal Godefroit in 2013 and the type species is ''Malawania anachronus''. It is unusual as it is much more primitive than other Cretaceous ichthyosaurs, being most closely related to '' Ichthyosaurus'' from the Late Triassic and Early Jurassic, over 70 million years earlier than ''Malawania'', with all other known ichthyosaurs from the Late Jurassic onwards belonging to the family Ophthalmosauridae. Discovery The holotype and only known specimen was discovered in 1952 by British petroleum geologists D. M. Morton, F. R. S. Henson, R. J. Wetzel and L. C. F. Damesin while working in Chia Gara, Amadia in Iraqi Kurdistan. The slab was being used to dam a small river and was part of a mule track. It was then trans ... [...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 archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and Kuwait to the southeast, Saudi Arabia to the south, Jordan to Iraq–Jordan border, the southwest and Syria to Iraq–Syria border, the west. The Capital city, capital and largest city is Baghdad. Iraq is home to diverse ethnic groups including Iraqi Arabs, Kurds, Iraqi Turkmen, Turkmens, Assyrian people, Assyrians, Armenians in Iraq, Armenians, Yazidis, Mandaeans, Iranians in Iraq, Persians and Shabaks, Shabakis with similarly diverse Geography of Iraq, geography and Wildlife of Iraq, wildlife. The vast majority of the country's 44 million residents are Muslims – the notable other faiths are Christianity in Iraq, Christianity, Yazidism, Mandaeism, Yarsanism and Zoroastrianism. The official langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Analysis
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphies
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] |
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.See Gradstein ''et al.'' (2004) for a detailed geologic timescale Stratigraphic definitions The Hauterivian was introduced in scientific literature by Swiss geologist Eugène Renevier in 1873. It is named after the Swiss town of Hauterive at the shore of Lake Neuchâtel. The base of the Hauterivian is defined as the place in the stratigraphic column where the ammonite genus ''Acanthodiscus'' first appears. A reference profile for the base (a GSSP) was officially ratified by the International Union of Geological Sciences in December of 2019, and is placed in La Charce, France. The top of the Hauterivian (the base of the Barremian) is at the first appearance of ammonite species ''Spitidiscus hugii'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxa
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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