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Protohertzina
''Protohertzina'' is a genus of conodonts (protoconodonts or paraconodonts) or, possibly, Chaetognaths, found at the beginning of the Cambrian explosion. Protoconodonts are an extinct taxonomic group of conodonts.Zooproblematica and mollusca from the Lower Cambrian Meishucun section (Yunnan, China) and taxonomy and systematics of the Cambrian small shelly fossils of China. P. Y. Parkhaev and Y. Demidenko, Paleontological Journal, 2010, volume 44, issue 8, pages 883-1161, Chaetognaths (also known as arrow worms) were thought possibly to be related to some of the animals grouped with the conodonts. The conodonts themselves, however, are thought to be related to the vertebrates. It is now thought that protoconodont elements (e.g., ''Protohertzina anabarica'' Missarzhevsky, 1973), are probably grasping spines of chaetognaths rather than teeth of conodonts. ''Protohertzina'' fossils have been found in the Ingta Formation of Canada. Use in stratigraphy The earliest known fossils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphigeisinidae
Amphigeisinidae is an extinct family of conodonts in the order Paraconodontida. Genera Genera are: * †'' Amphigeisina'' * †'' Gapparodus'' * †'' Hagionella'' * †'' Phakelodus'' * †''Protohertzina'' References External links Paraconodontida Conodont families {{conodont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoconodonta
Protoconodonts are an extinct taxonomic group of conodonts or, possibly, Chaetognaths. Chaetognaths (also known as arrow worms) were thought possibly to be related to some of the animals grouped with the conodonts. The conodonts themselves, however, are thought to be related to the vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, .... It is now thought that protoconodont elements (e.g., '' Protohertzina anabarica'' Missarzhevsky, 1973), are probably grasping spines of chaetognaths rather than the oropharyngeal elements of conodonts. Previously chaetognaths in the Early Cambrian were only suspected from these protoconodont elements (for example '' Phakelodus''), but the more recent discoveries of body fossils have confirmed their presence then. References * Middle and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoconodont
Protoconodonts are an extinct taxonomic group of conodonts or, possibly, Chaetognaths. Chaetognaths (also known as arrow worms) were thought possibly to be related to some of the animals grouped with the conodont Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...s. The conodonts themselves, however, are thought to be related to the vertebrates. It is now thought that protoconodont elements (e.g., '' Protohertzina anabarica'' Missarzhevsky, 1973), are probably grasping spines of chaetognaths rather than the oropharyngeal elements of conodonts. Previously chaetognaths in the Early Cambrian were only suspected from these protoconodont elements (for example '' Phakelodus''), but the more recent discoveries of body fossils have confirmed their presence then. References * Middle a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ingta Formation
The Ingta Formation is a geological unit containing green sandstones and shales; it crops out in the Canadian Mackenzie Mountains. Its age is poorly constrained, though it straddles the Precambrian/Cambrian boundary. Below the boundary its ichnofauna comprises subhorizontal ''Planolites'' burrows; above it, '' Phycodes'' burrows immediately appear, with Nemakit-Daldyn SSFs appearing soon after. Stratigraphy The formation is overlain by either the Backbone Ranges Formation and the Vampire Formation, depending on the locality. These two formations have a common base with the Ingta formation, and both continue onwards until the base of the Sekwi Formation. Depositional environment The rocks are submarine, and were deposited in a nearshore to offshore location on the continental shelf, with no freshwater influence evident—although overlying units bear evidence of deltaic and braided river deposits. Palaeontology The formation has yielded a range of SSFs including eggs and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaetognatha
The Chaetognatha or chaetognaths (meaning ''bristle-jaws'') are a phylum of predatory marine worms that are a major component of plankton worldwide. Commonly known as arrow worms, about 20% of the known Chaetognatha species are benthic, and can attach to algae and rocks. They are found in all marine waters, from surface tropical waters and shallow tide pools to the deep sea and polar regions. Most chaetognaths are transparent and are torpedo shaped, but some deep-sea species are orange. They range in size from . There are more than 120 modern species assigned to over 20 genera. Despite the limited diversity of species, the number of individuals is large. Arrow worms are usually considered a type of protostome that do not belong to either Ecdysozoa or Lophotrochozoa. Anatomy Chaetognaths are transparent or translucent dart-shaped animals covered by a cuticle. The body is divided into a distinct head, trunk, and tail. There are between four and fourteen hooked, grasping spines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conodont Genera
This is a list of conodonts genera, sorted in alphabetical order. A-C * †'' Acanthodus'' * †''Acodus'' * †'' Acuminatella'' * †'' Alternognathus'' * †'' Amorphognathus'' * †''Ancyrodella'' * †''Ancyrognathus'' * †'' Anticostiodus'' * †''Appalachignathus'' * †'' Arianagnathus'' * †'' Bactrognathus'' * †'' Baltoniodus'' * †'' Basselodus'' * †'' Belodina'' * †'' Budurovignathus'' * †''Carnepigondolella'' * †''Carniodus'' * †''Cavusgnathus'' * †''Chiosella'' * †'' Chirodella'' * †'' Chirognathus'' * †''Colaptoconus'' * †'' Complexodus'' * †''Cordylodus'' * †''Cornuodus'' * †''Clarkina'' * †''Clydagnathus'' * †''Cryptotaxis'' * †''Ctenognathodus'' * †''Culumbodina'' * †'' Curtognathus'' * †'' Cypridodella'' D-E * †'' Dapsilodus'' * †'' Declinognathodus'' * †'' Decoriconus'' * †'' Diaphorodus'' * †'' Diplognathodus'' * †'' Distomodus'' * †'' Doliognathus'' * †'' Dollymae'' * †'' Drepanodus'' * †'' Eo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Explosion
The Cambrian explosion, Cambrian radiation, Cambrian diversification, or the Biological Big Bang refers to an interval of time approximately in the Cambrian Period when practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversification in other groups of organisms as well. Before early Cambrian diversification, most organisms were relatively simple, composed of individual cells, or small multicellular organisms, occasionally organized into colonies. As the rate of diversification subsequently accelerated, the variety of life became much more complex, and began to resemble that of today. Almost all present-day animal phyla appeared during this period, including the earliest chordates. A 2019 paper suggests that the timing should be expanded back to include the late Ediacaran, rather than just the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1973
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Conodonts
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Animals Of North America
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meishucunian
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
