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Sebecia
Sebecia is an extinct clade of mesoeucrocodylian crocodyliforms that includes peirosaurids and sebecids. It was first constructed in 2007 to include ''Hamadasuchus'', Peirosauridae, and ''Sebecus''. It was initially considered to be the sister taxon of the clade Neosuchia, which includes living crocodilians, although some later studies have placed it within Neosuchia as a basal clade. Sebecians were terrestrial crocodyliforms characterized by their deep snouts and ziphodont dentition. They first appeared in the Late Cretaceous, survived the Cretaceous–Paleogene extinction event, and became extinct in the Miocene epoch. According to paleontologists Hans Larsson and Hans-Dieter Sues, who constructed the clade in 2007, Sebecia also includes genera that were once assigned to Baurusuchidae, namely ''Pabwehshi''. However, other baurusuchids, namely ''Baurusuchus'', were placed outside Sebecia. Therefore, Baurusuchidae was considered polyphyletic and thus not a true clade. Below is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baurusuchidae
Baurusuchidae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It is a group of terrestrial hypercarnivorous crocodilians from South America (Argentina and Brazil) and possibly Pakistan. Baurusuchidae has been, in accordance with the PhyloCode, officially defined as the least inclusive clade containing ''Cynodontosuchus rothi, Pissarrachampsa sera,'' and ''Baurusuchus pachecoi.'' Baurusuchids have been placed in the suborder Baurusuchia, and two subfamilies have been proposed: Baurusuchinae and Pissarrachampsinae. Genera Several genera have been assigned to Baurusuchidae. ''Baurusuchus'' was the first, being the namesake of the family. Remains of ''Baurusuchus'' have been found from the Late Cretaceous Bauru Group of Brazil in deposits that are Turonian - Santonian in age. In addition to ''Baurusuchus'', five other South American crocodyliforms have been assigned to Baurusuchidae: ''Campinasuchus'', ''Cynodontosuchus'', ''Pissarrachampsa'', ''Stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamadasuchus
''Hamadasuchus'' is an extinct genus of sebecian crocodylomorph. Fossils have been found from the Kem Kem Formation outcropping in southeastern Morocco. These beds date back to the Albian and Cenomanian stages of the Late Cretaceous. It was first assigned to the family Trematochampsidae. Diagnostic features of the genus include its lateromedially compressed and serrated teeth. It was deep-snouted and had a slightly heterodont dentition with three distinct tooth morphologies present from sections of the lower jaw.Larsson, H. C. E. and Sidor, C. A. (1999). Unusual crocodyliform teeth from the Late Cretaceous (Cenomanian) of southeastern Morocco. ''Journal of Vertebrate Paleontology'' 19(2):398-401. References External links''Hamadasuchus''in the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
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 taxonomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. ource for pronunciation./ref> It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthetic plants, and edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes. Researchers concerned more with ecology than with systema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baurusuchus
''Baurusuchus'' is an extinct member of the ancestral crocodilian lineage, which lived in Brazil from 90 to 83.5 million years ago, in the Late Cretaceous period. Technically, it is a genus of baurusuchid mesoeucrocodylian. It was a terrestrial predator and scavenger, about long and in weight. ''Baurusuchus'' lived during the Turonian to Santonian stages of the Late Cretaceous Period, in Adamantina Formation, Brazil. It gets its name from the Brazilian Bauru Group ("Bauru crocodile"). It was related to the earlier-named ''Cynodontosuchus rothi'', which was smaller, with weaker dentition. The three species are ''B. pachechoi'', named after Eng Joviano Pacheco, its discoverer, ''B. salgadoensis'' (named after General Salgado County in São Paulo, Brazil) and ''B. albertoi'' (named after Alberto Barbosa de Carvalho, Brazilian paleontologist). The latter species is disputed (see phylogeny section). Its relatives include the similarly sized ''Stratiotosuchus'' from the Adamanti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pabwehshi
''Pabwehshi'' (meaning "Pab ormationbeast Urdu.html"_;"title="wehshi"_in_Urdu">wehshi"_in_Urdu)_is_an_extinct.html" ;"title="Urdu">wehshi"_in_Urdu.html" ;"title="Urdu.html" ;"title="wehshi" in Urdu">wehshi" in Urdu">Urdu.html" ;"title="wehshi" in Urdu">wehshi" in Urdu) is an extinct">Urdu">wehshi"_in_Urdu.html" ;"title="Urdu.html" ;"title="wehshi" in Urdu">wehshi" in Urdu">Urdu.html" ;"title="wehshi" in Urdu">wehshi" in Urdu) is an extinct genus of mesoeucrocodylian. It is holotype, based on Geological Survey of Pakistan, GSP-UM 2000, a partial snout and corresponding lower jaw elements, with another snout assigned to it. These specimens were found in Maastrichtian-age Upper Cretaceous rocks of the Pab Formation in Balochistan, Pakistan, and represent the first diagnostic crocodyliform fossils from Cretaceous rocks of South Asia. ''Pabwehshi'' had serrated interlocking teeth in its snout that formed a "zig-zag" cutting edge. ''Pabwehshi'' was named in 2001 by Jeffrey A. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans-Dieter Sues
Hans-Dieter Sues (born January 13, 1956) is a German-born American paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He received his education at Johannes Gutenberg-Universität Mainz (University of Mainz), University of Alberta, and Harvard University (Ph.D., 1984). Before assuming his present position, Sues worked at the Royal Ontario Museum and the University of Toronto and at the Carnegie Museum of Natural History in Pittsburgh. He is interested in the diversity, paleoecology, and evolutionary history of Paleozoic and Mesozoic tetrapods, especially archosaurian reptiles and cynodont therapsids, and the history of biology and paleontology. Sues has discovered numerous new dinosaurs and other extinct terrestrial vertebrates in Paleozoic and Mesozoic continental strata in North America and Europe. He has authored or co-authored over 150 articles and book chapte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Larsson (paleontologist)
Hans Larsson (18 February 1862 in Östra Klagstorp, Malmöhus län – 16 February 1944, Lund) was a Swedish Professor of Philosophy at Lund University, Sweden and a Member of the Swedish Academy (1925-1944), chair no. 15. He was known in Sweden as ''Kloke-Hans'' ("Clever Hans").Anders Wedberg, article in ''Svenska män och Kvinnor 4'' (Stockholm: 1948) Prof. Larsson was a humanist and an author. He was also a mentor for several Swedish authors and a prominent essayist. Biography Prof. Larsson was the son of the farmer Lars Persson and Kersti Nilsdotter, and cousin of author Ola Hansson. After ''studentexamen'' in 1881 he began his studies at Lund University. He received his Bachelor of Arts in 1888. In 1893 he received the titles Licentiate of Philosophy, Doctor of Philosophy and Docent in Theoretical Philosophy with a doctoral dissertation entitled ''Kants transcendentala deduktion af kategorierna'' ("The transcendental deduction of categories in Kant"). In 1884 he t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as sea turtles and crocodilians, no tetrapods weighing more than survived. It marked the end of the Cretaceous Period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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