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Aegyptosuchus
''Aegyptosuchus'' ("Egyptian crocodile") is an extinct monospecific genus of aegyptosuchid eusuchian crocodyliform. It was found in the Bahariya Formation of Egypt, which dates back to the Cenomanian age of the Late Cretaceous. The type and only species is ''Aegyptosuchus peyeri''. ''Aegyptosuchus'' is a member of the family Aegyptosuchidae, along with the genus ''Aegisuchus''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant (living) crocodilians. The phylogeny 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 spec ... can be shown in the cladogram below: References Neosuchians Late Cretaceous crocodylomorphs of Africa Bahariya Formation Fossil taxa described in 1933 Prehist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegisuchus
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull has a rect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegyptosuchidae
Aegyptosuchidae is an extinct family of eusuchian crocodyliforms from the Cretaceous period of Africa. They are characterized by their large size and flat heads. The family includes two genera, '' Aegyptosuchus'' and '' Aegisuchus''. Aegyptosuchidae was originally established as the monotypic family name for '' Aegyptosuchus peyeri'' in 1933. Upon the discovery of the fellow aegyptosuchid '' Aegisuchus witmeri'' in 2012 by Holliday and Gardner, Aegyptosuchidae was phylogenetically defined as the least inclusive clade containing ''Aegisuchus witmeri'' and ''Aegyptosuchus peyeri'', so long as it does not include ''Alligator mississippiensis'' (American alligator), ''Bernissartia fagesii'', ''Crocodylus niloticus'' (Nile crocodile), ''Gavialis gangeticus'' (gharial), ''Hylaeochampsa vectiana'', or '' Susisuchus anatoceps''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant (living) crocodili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegisuchus And Aegyptosuchus
''Aegisuchus'' is an extinct monospecific genus of giant, flat-headed crocodyliform within the family Aegyptosuchidae. It was found in the Kem Kem Formation of southeast Morocco, which dates back to the Cenomanian age of the Late Cretaceous epoch. The type species ''Aegisuchus witmeri'' was named in 2012 by paleontologists Casey Holliday and Nicholas Gardner, who nicknamed it "Shieldcroc" for the shield-like shape of its skull. ''A. witmeri'' is known from a single partial skull including the braincase and skull roof. Description ''Aegisuchus'' is known only from a partial braincase and skull roof cataloged as ROM 54530. It is diagnosed by several autapomorphies, or unique features. At the center of the skull table is a raised and rough-surfaced boss on the parietal bone that is shaped like a circle. On either side of this boss are holes called dorsotemporal fenestrae, and the surrounding bone is relatively smooth. The quadrate bone in the temporal region of the skull ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegyptosuchid
Aegyptosuchidae is an extinct family of eusuchian crocodyliforms from the Cretaceous period of Africa. They are characterized by their large size and flat heads. The family includes two genera, ''Aegyptosuchus'' and ''Aegisuchus''. Aegyptosuchidae was originally established as the monotypic family name for ''Aegyptosuchus peyeri'' in 1933. Upon the discovery of the fellow aegyptosuchid ''Aegisuchus witmeri'' in 2012 by Holliday and Gardner, Aegyptosuchidae was phylogenetically defined as the least inclusive clade containing ''Aegisuchus witmeri'' and ''Aegyptosuchus peyeri'', so long as it does not include '' Alligator mississippiensis'' (American alligator), ''Bernissartia fagesii'', '' Crocodylus niloticus'' (Nile crocodile), ''Gavialis gangeticus'' (gharial), ''Hylaeochampsa vectiana'', or '' Susisuchus anatoceps''. Aegyptosuchidae belongs to the clade Eusuchia, and is proposed to be the sister clade to the crown group Crocodylia, which contains all extant Extant is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bahariya Formation
The Bahariya Formation (also transcribed as Baharija Formation) is a fossiliferous geologic formation dating back to the early Cenomanian, which outcrops within the Bahariya depression in Egypt, and is known from oil exploration drilling across much of the Western Desert where it forms an important oil reservoir.Weishampel, David B; et al (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604. . Extent The Bahariya Formation forms the base of the depression, the lower part of the enclosing escarpment and all of the small hills within. The type section for the formation is found at Gebel El-Dist, a hill at the northern end of the Bahariya depression. Stratigraphy and sedimentology Four depositional sequences have been recognised in the Bahariya Formation in the Bahariya depression, separated by three sub-aerial unconformities. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodylia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period (Cenomanian stage) and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the order's total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period, and diversified during the Mesozoic era. The order Crocodilia includes the true crocodiles (family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term 'crocodiles' is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group. Large, solidly built, lizard-like reptiles, crocodilians have long flattened snouts, laterally compressed tails, and eyes, ears, and nostrils at the top of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extant Taxon
Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, '' recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The moose (''Alces alces'') is an extant species, and the dodo (''Raphus cucullatus'') is an extinct species. * In the group of molluscs known as the cephalopods, there were approximately 600 extant species and 7,500 extinct species. A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species ("Lazarus species"), or if previously-known extant species are reclassified as members of the taxon. Most biologists, zoologists, and botanists are in practice neontologists, and the term neontologist is used large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogeny
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 be ... [...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] |
Theriosuchus
''Theriosuchus'' is an extinct genus of atoposaurid neosuchian from Late Jurassic to Early Cretaceous of Europe (Hungary & southern England), Southeast Asia (Thailand) and western North America (Wyoming), with fragmentary records from Middle Jurassic and Early Cretaceous sites in China, Morocco, and Scotland. Taxonomy Three valid species are currently recognized: ''Theriosuchus pusillus'' from southern England, ''T. grandinaris'' from Thailand, and ''T. morrisonensis'' from the Morrison Formation of North America. ''Theriosuchus'' was previously assigned to Atoposauridae, but a 2016 cladistic analysis recovered it as a neosuchian more closely related to members of the family Paralligatoridae than to atoposaurids. Two species previously assigned to this genus, ''Theriosuchus ibericus'' and ''T. symplesiodon'', have been reassigned to the new genus ''Sabresuchus''. On the other hand, ''Theriosuchus guimarotae'' from Portugal has been reassigned to ''Knoetschkesuchus ''Knoets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neosuchia
Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all crocodylomorphs more closely related to ''Crocodylus niloticus'' (the Nile Crocodile) than to ''Notosuchus terrestris''. Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups. The earliest neosuchian is suggested to be the Early Jurassic ''Calsoyasuchus'', which lived during the Sinemurian and Pliensbachian stages in North America. It is often identified as a member of Goniopholididae, though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic. Characteristics A tooth notch between the maxilla and premaxilla is a basal characteristic of the Neosuchia, although it is lost in some more derived forms, most nota ... [...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] |
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