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Molluscs Described In 1925
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater and even terrestrial species. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known extant invertebrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terreneuvian
The Terreneuvian is the lowermost and oldest Series (stratigraphy), series of the Cambrian geological System (stratigraphy), system. Its base is defined by the first appearance datum of the trace fossil ''Treptichnus pedum'' around million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around million years ago. This series' name was formally accepted by the International Commission on Stratigraphy in 2007. The Fortunian Stage (stratigraphy), stage and presently unnamed Cambrian Cambrian Stage 2, Stage 2 are the stages within this series. The Terreneuvian corresponds to the pre-trilobite, trilobitic Cambrian. The name Terreneuvian is derived from ''Terre Neuve'', the French name for the island of Newfoundland (island), Newfoundland, Canada, where many rocks of this age are found, including the type section. GSSP The type locality (Global Boundary Stratotype Section and Point, GSSP) of the Terreneuvian is in Fortune Head, at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthozanclus
''Orthrozanclus'' (from Greek + ( + ), "dawn scythe") is a genus of sea creatures known from two species, ''O. reburrus'' from the Middle Cambrian (~) Burgess shale and ''O. elongata'' from Early Cambrian (~) Maotianshan Shales. Animals in this genus were one to two centimeters long, with spikes protruding from their armored bodies. The placement of this genus into a specific family is not universally accepted. History of discovery Jean-Bernard Caron and Donald A. Jackson found a specimen in the Burgess Shale and in 2006 referred to it as "scleritomorph C" without a detailed description. In 2007 Caron and Simon Conway Morris published a description and named the fossil ''Orthrozanclus reburrus''. The genus name means "Dawn scythe" and derives from Greek, with the species name meaning "bristling hair" in Latin. The two known specimens of ''O. elongata'' were discovered from Maotianshan Shales, Maotianshan Shale in 2015 and 2016 and formally described the following year. Descrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
