|
Ziliujing Formation
The Ziliujing Formation is a geological formation in China, It is Early Jurassic in age. It is part of the stratigraphy of the Sichuan Basin. The dinosaur ''Gongxianosaurus'' and indeterminate theropod material are known from the Dongyuemiao Member of the formation, as well as dinosaur footprints, ''Zizhongosaurus'' and indeterminate prosauropods from the Da'anzhai Member. The basal sauropod ''Sanpasaurus'' is known from the Maanshan Member. An unnamed stegosaur and the pliosauroid plesiosaur ''Sinopliosaurus'' are also known from this formation but they were found an indeterminate member. An unnamed teleosaurid known from a complete skull has also been found in the formation, pending a formal description. The deposition environment during the Da'anzhai Member in the lower Toarcian is thought to have been that of a giant freshwater lake encompassing the whole of the Sichuan basin, around 3 times larger than Lake Superior Lake Superior in central North America is the large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinopliosaurus
''Sinopliosaurus'' (meaning "Chinese more lizard"; in reference to ''Pliosaurus'') is a genus of pliosauroid plesiosaur, a type of short-necked marine reptile, alive during the Aptian and Albian stages of the Early Cretaceous (disputed ''Sinopliosaurus'' remains have been dated to the Toarcian age and were found in the Ziliujing Formation) of the People's Republic of China - its exact age is unknown. The type species, ''Sinopliosaurus weiyuanensis'', was named and described in 1944 by Yang Zhongjian.C.-C. Young. (1944). On the reptilian remains from Weiyuan, Szechuan, China. ''Bulletin of the Geological Society of China'' 24(3–4):187-205 One species, "S." ''fusuiensis'', was later shown to be based on teeth from a spinosaurid theropod dinosaur which is now known as ''Siamosaurus''. ''S. weiyuanensis'' would have lived near a coastal environment. The holotype, IVPP V140, consists of three vertebrae and a tooth, discovered in a layer of the Lianmugin Formation (Tugulu Group).Z. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unionida
Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs.Bieler R., Carter J.G. & Coan E.V. (2010). ''Classification of Bivalve families''. pp. 113–133, in: Bouchet P. & Rocroi J.-P. (2010), ''Nomenclator of Bivalve Families''. Malacologia 52(2): 1–184. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment. Taxonomy Fossil evidence suggests a Permian origin for the order, making it incredibly ancient and a survivor of the Permian-Triassic mass extinction. Morphology The shells of these mussels are variable in shape, but usually equivalve and elongate. They have solid, nacreous valves with a pearly interior, radia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unionidae
The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse in North America, with about 297 recognised taxa, but China and Southeast Asia also support very diverse faunas. Freshwater mussels occupy a wide range of habitats, but most often occupy lotic waters, i.e. flowing water such as rivers, streams and creeks. Origin and early diversification The recent phylogenetic study reveals that the Unionidae most likely originated in Southeast and East Asia in the Jurassic, with the earliest expansions into North America and Africa (since the mid-Cretaceous) followed by the colonization of Europe and India (since the Paleocene). Life history Unionidae burrow into the substrate, with their posterior margins exposed. They pump water through the incurrent aperture, obtaining oxygen and food. They remove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
