|
Phyllodontosuchus
''Phyllodontosuchus'' ( Ancient Greek, meaning "leaf tooth crocodile", in reference to the shape of the middle and posterior teeth) is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from a skull and jaws from Lower Jurassic rocks of Yunnan, China. ''Phyllodontosuchus'' is unusual because some of its teeth were leaf-shaped, like those of some herbivorous dinosaurs, and it does not appear to have been a strict carnivore like most other crocodylomorphs. History and description ''Phyllodontosuchus'' is based on BVP568-L12, a crushed skull and jaws recovered from the Sinemurian-age Dark Red Beds of the Lufeng Formation near Dawa in Yunnan. A ''Morganucodon'' skull was also recovered from this locality. BVP568-L12 is only long and imperfectly preserved; it was first thought to represent an early ornithischian dinosaur. Sutures are not visible, so despite the small size, the specimen ... [...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 adapt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenosuchia
Sphenosuchia is a suborder of basal crocodylomorphs that first appeared in the Triassic and occurred into the Middle Jurassic. Most were small, gracile animals with an erect limb posture. They are now thought to be ancestral to crocodyliforms, a group which includes all living crocodilians. Stratigraphic range The earliest known members of the group (i.e. '' Hesperosuchus'') are early Norian in age, found in the Blue Mesa Member of the Chinle Formation. Only one sphenosuchian is currently known from the Middle Jurassic, '' Junggarsuchus'', from the Junggar Basin (Shishugou Formation) of China during either the Bathonian or the Callovian (~165 Ma) age,Clark, J.M., ''et al.'' (2004A Middle Jurassic 'sphenosuchian' from China and the origin of the crocodylian skull''Nature'' 430:1021-1024. and the Hallopodidae are known from the Late Jurassic of North America. Phylogeny The monophyly of the group is debated, although several synapomorphies characterize the clade, including extr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called "Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias limestone from South Wales was used throughout North Devon/North Cornwall as it conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Lufeng Series
The Lufeng Formation (formerly Lower Lufeng Series) is a Lower Jurassic sedimentary rock formation found in Yunnan, China. It has two units: the lower Dull Purplish Beds/Shawan Member are of Hettangian age, and Dark Red Beds/Zhangjia'ao Member are of Sinemurian age.Luo, Z., and X.-C. Wu. 1994. The small tetrapods of the Lower Lufeng Formation, Yunnan, China; pp. 251–270 in N. C. Fraser and H.-D.Sues (eds.), In the Shadow of the Dinosaurs. Cambridge University Press, New York It is known for its fossils of early dinosaurs. The Dull Purplish Beds have yielded the possible therizinosaur ''Eshanosaurus'', the possible theropod ''Lukousaurus'', and the "prosauropods" "Gyposaurus" ''sinensis'', ''Lufengosaurus'', ''Jingshanosaurus'', and ''Yunnanosaurus''. Dinosaurs discovered in the Dark Red Beds include the theropod ''Sinosaurus triassicus'', the "prosauropods" "Gyposaurus", ''Lufengosaurus'', and ''Yunnanosaurus'', indeterminate remains of sauropods, and the early armored din ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenosuchus
''Sphenosuchus'' ("wedge crocodile") is an extinct genus of crocodylomorph from the Early Jurassic Elliot Formation of South Africa, discovered and described early in the 20th century. The skull is preserved very well but other than elements of the forelimb and isolated parts of the hind limb, the ''Sphenosuchus'' material is incomplete. It was probably quadrupedal, but may have been a facultative biped. ''Sphenosuchus'' was first thoroughly described in 1972 by the British palaeontologist Alick Walker, in a paper in the journal ''Nature''. Walker suggested, based on detailed (but still preliminary at that time) studies of the skull of ''Sphenosuchus'' and modern birds, that crocodylomorphs and birds might share an immediate common ancestor. Walker recanted his hypothesis in 1985, but restated and elaborated on it (in essence 'de-recanting') in a monograph published in 1990, which provided the most comprehensive description and discussion of ''Sphenosuchus'' yet published. Broom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedeticosaurus
''Pedeticosaurus'' is an extinct genus of crocodylomorph from the Clarens Formation (Early Jurassic) of South Africa. The type species ''Pedeticosaurus leviseuri'' was named by Egbert Cornelis Nicolaas van Hoepen in 1915 on the basis of a mold of a mostly complete skeleton found in a quarry near Rosendal, Free State. The mold preserves most of the right half of the skeleton including the skull, ribs, dorsal vertebrae, forelimbs and hindlimbs, but not the tail. It is currently housed in the National Museum in Bloemfontein and cataloged as NMQR606. Taxonomy Van Hoepen originally established a new family for ''Pedeticosaurus'' called Pedeticosauridae, which he thought was closely related to the family Ornithosuchidae. In later years ''Pedeticosaurus'' was interpreted as either a member of Sphenosuchia or Protosuchia, both of which are groups of small-bodied Jurassic crocodylomorphs. Paleontologist A. D. Walker erected a new group called Pedeticosauria in 1968, which he named af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperosuchus
''Hesperosuchus'' is an extinct genus of crocodylomorph reptile that contains a single species, ''Hesperosuchus agilis''. Remains of this pseudosuchian have been found in Late Triassic (Carnian) strata from Arizona and New Mexico.Colbert, E. H. 1952. A pseudosuchian reptile from Arizona. Bulletin of the American Museum of Natural History 99:561–592. Because of similarities in skull and neck anatomy and the presence of hollow bones ''Hesperosuchus'' was formerly thought to be an ancestor of later carnosaurian dinosaurs, but based on more recent findings and research it is now known to be more closely related to crocodilians rather than dinosaurs.Brinkman, D. 1981. The origin of the crocodiloid tarsi and the interrelationships of thecodontian archosaurs. Breviora 464:1–23.Benton, M. J. and J. M. Clark. 1988. Archosaur phylogeny and the relationships of the Crocodylia. pp. 295–338. In M. J. Benton (ed.). The Phylogeny and Classification of the Tetrapods Vol. 1.Amphibians, Repti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dibothrosuchus
''Dibothrosuchus'' is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from several partial skeletons and skulls. These fossils were found in Lower Jurassic (Lower Pliensbachian, circa 186 million years old) rocks of Yunnan, China. ''Dibothrosuchus'' was a small terrestrial crocodylomorph that probably had a keen sense of hearing, and thus was probably a vocal animal like modern crocodilians. History and description ''Dibothrosuchus'' was named in 1965 by D.J. Simmons based on a partial skull and skeleton collected by Father Oehler of Fu Jen Catholic University from mudstones near Huangchiatien. The type species is ''D. elaphros''. Additional remains of this genus were recovered in 1985 by a joint Chinese-US expedition. Fossils of ''Dibothrosuchus'' come from the Zhangjiawa Formation, being originally assigned to the Reds Beds of the Lufeng Formation, thus being geologically you ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predentary
Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek stem ' (), meaning "of a bird", and ' (), plural ', meaning "hip joint". However, birds are only distantly related to this group as birds are theropod dinosaurs. Ornithischians with well known anatomical adaptations include the ceratopsians or "horn-faced" dinosaurs (e.g. ''Triceratops''), the pachycephalosaurs or "thick-headed" dinosaurs, the armored dinosaurs (Thyreophora) such as stegosaurs and ankylosaurs, and the ornithopods. There is strong evidence that certain groups of ornithischians lived in herds, often segregated by age group, with juveniles forming their own flocks separate from adults. Some were at least partially covered in filamentous (hair- or feather- like) pelts, and there is much debate over whether these filaments foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesothosaurus
''Lesothosaurus'' is a monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from Lesotho". The genus has only one valid species, ''Lesothosaurus diagnosticus''. ''Lesothosaurus'' is one of the most completely-known early ornithischians, based on numerous skull and postcranial fossils from the Upper Elliot Formation. It had a simpler tooth and jaw anatomy than later ornithischians, and may have been omnivorous in some parts of the year. Discovery and naming Fossils referrable to ''Lesothosaurus'' may have been known from as early as 1959, when a right dentary (lower jawbone) fragment bearing three teeth was collected by French geologist Jean Fabre from the Red Beds of the Upper Elliot Formation near Mapheteng in Lesotho, Southern Africa, dating to the Early Jurassic (199(?)-190 million years ago).Ginsburg, L., (1964), "Decouverte d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosauropod
Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had long necks and tails, were quadrupedal, and became the largest animals to ever walk the Earth. The '' prosauropods,'' which preceded the sauropods, were smaller and were often able to walk on two legs. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the Late Triassic (approximately 230 Ma) until their decline and extinction at the end of the Cretaceous. Description Sauropodomorphs were adapted to browsing higher than any other contemporary herbivore, giving them access to high tree foliage. This feeding strategy is supported by many of their defining characteristics, such as: a light, tiny skull on the end of a long neck (with ten or more elongated cervical verteb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterodont
In anatomy, a heterodont (from Ancient Greek, Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology (biology), morphology. In vertebrates, heterodont pertains to animals where teeth are differentiated into different forms. For example, members of the Synapsida generally possess incisors, Canine (tooth), canines ("eyeteeth"), premolars, and molars. The presence of heterodont dentition is evidence of some degree of feeding and or hunting specialization in a species. In contrast, homodont or isodont dentition refers to a set of teeth that possess the same tooth morphology. In invertebrates, the term heterodont refers to a condition where teeth of differing sizes occur in the hinge plate, a part of the Bivalvia. References See also * Diphodonty Zoology Dentition types {{animal-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
