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Cairanoolithus Scale
''Cairanoolithus'' is an oogenus of dinosaur egg which is found in Southwestern Europe. The eggs are large ( in diameter) and spherical. Their outer surface is either smooth, or covered with a subdued pattern of ridges interspersed with pits and grooves. Multiple fossil egg clutches are known but the nest structure is unclear. The parent of ''Cairanoolithus'' is probably some kind of non-ornithopod ornithischian, possibly the nodosaurid ''Struthiosaurus''. The eggs were first named in 1994, when the two oospecies were classified in distinct oogenera as ''Cairanoolithus dughii'' and ''Dughioolithus roussetensis''. They are now considered to belong in a single oogenus, possibly even a single oospecies. Though it has been classified as a megaloolithid, ''Cairanoolithus'' is now placed in its own oofamily, Cairanoolithidae. Description ''Cairanoolithus'' eggs are spherical and fairly large, measuring in diameter. The outer surface is smooth or covered with a subdued netlik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodylomorpha
Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. During Mesozoic and early Cenozoic times, crocodylomorphs were far more diverse than they are now. Triassic forms were small, lightly built, active terrestrial animals. The earliest and most primitive crocodylomorphs are represented by " sphenosuchians", a paraphyletic assemblage containing small-bodied forms with elongated limbs that walked upright, which represents the ancestral morphology of Crocodylomorpha. These forms persisted until the end of the Jurassic. During the Jurassic, Crocodylomorphs morphologically diversified into numerous niches, including into the aquatic and marine realms. Evolutionary history When their extinct species and stem group are examined, the crocodylian lineage (clade Pseudosuchia, formerly Crurotarsi) proves to have been a very diverse and adaptive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabdodon
''Rhabdodon'' (meaning "fluted tooth") is a genus of ornithopod dinosaur that lived in Europe approximately 70-66 million years ago in the Late Cretaceous. It is similar in build to a very robust "hypsilophodont" (non-iguanodont ornithopod), though all modern phylogenetic analyses find this to be an unnatural grouping, and ''Rhabdodon'' to be a basal member of Iguanodontia. It was large amongst its relatives, measuring long and weighing , with some specimens possibly reaching up to long. Discovery Two species of ''Rhabdodon'' are known, ''Rhabdodon priscus'', the type species, and ''R. septimanicus'' (Buffetaut and Le Loeuff, 1991). ''Rhabdodon'' remains are currently known from southern France, although fragmentary remains from eastern Spain have been assigned to the genus. ''Rhabdodon'' was large compared to its nearest relatives, and indeed one recent paper ( Ősi ''et al.'' (2012)) determined it is larger than the basal rhabdodontid status; from this they suggested that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanosaurs
Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as ''Patagotitan''—estimated at long with a weight of —and the comparably-sized ''Argentinosaurus'' and ''Puertasaurus'' from the same region. The group's name alludes to the mythological Titans of ancient Greek mythology, via the type genus (now considered a ''nomen dubium)'' ''Titanosaurus''. Together with the brachiosaurids and relatives, titanosaurs make up the larger sauropod clade Titanosauriformes. Titanosaurs have long been a poorly-known group, and the relationships between titanosaur species are still not well-understood. Description Titanosauria have the largest ran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistic Analysis
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics (synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. Radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago ( Ma) and included all the large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 10,500 living species. Biology Diet and teeth Theropods exhibit a wide range of diets, from insectivores to herbivores and carnivores. Strict carnivory has always been considered the ancestral diet for theropods as a group, and a wider variety of diets was historically considered a characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropod
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include ''Brachiosaurus'', ''Diplodocus'', ''Apatosaurus'' and ''Brontosaurus''. The oldest known unequivocal sauropod dinosaurs are known from the Early Jurassic. ''Isanosaurus'' and ''Antetonitrus'' were originally described as Triassic sauropods, but their age, and in the case of ''Antetonitrus'' also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation (Greenland) might, however, indicate the occurrence of the group in the Late Triassic. By the Late Jurassic (150 million yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovaloolithus
''Ovaloolithus'' is an oogenus of dinosaur egg. Eggs of the genus have been found in China, Mongolia and Utah. Species Oospecies attributed to this genus include:''Ovaloolithus'' in the * ''O. chinkangkouensis'' - - , Mongolia, |
Spheroolithus
''Spheroolithus'' is an oogenus of dinosaur egg.Wang Q, Wang X L, Zhao Z K, and Jiang Y G. (2012).A new oofamily of dinosaur egg from the Upper Cretaceous of Tiantai Basin, Zhejiang Province, and its mechanism of eggshell formation Chinese Science Bulletin. 57: 3740-3747. doi: 10.1007/s11434-012-5353-2 Oospecies The following species are described:''Spheroolithus'' in the * ''Paraspheroolithus sanwangbacunensis'' * ''Paraspheroolithus yangchengensis'' * ''Spheroolithus albertensis'' * ''Spheroolithus choteauensis'' * ''Spheroolithus europaeus'' * ''Spheroolithus irenensis'' * ''Spheroolithus jincunensis'' * ''Spheroolithus maiasauroides'' * ''Spheroolithus meg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guegoolithus
''Guegoolithus'' is an oogenus of fossil egg from the early Cretaceous of Spain. It is classified in the oofamily Spheroolithidae, and was probably laid by an ornithopod dinosaur. Distribution ''Guegoolithus'' is known from the Early Cretaceous of Spain. It is common in the Maestrazgo Basin, dating to the lower Barremian. Fossils have been found in the Blesa, El Castellar, Camarillas, and Mirambel Formations. It has also been found at the slightly older El Hocajo, a part of the Cameros Basin which dates to the Valanginian or Hauterivian ages, up to 7 million years older than the Maestrazgo specimens. Description ''Guegoolithus'' is known from over 400 fossil eggshell fragments, but no complete eggs have been found. They are very thin for spheroolithids, ranging from 0.42 to 1.5 mm in thickness.Moreno-Azanza, M., J.I. Canudo, and J.M. Gasca. (2014)Spheroolithid eggshells in the Lower Cretaceous of Europe. Implications for eggshell evolution in ornithischian dinosaurs. ''C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
