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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] |
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 spin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 are usually found in isolation and are now called conodont elements. Knowledge about soft tissues remains limited. They existed in the world's oceans for over 300 million years, from the Cambrian to the beginning of the Jurassic. Conodont elements are widely used as index fossils, fossils used to define and identify geological periods. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity. Discovery and understanding of conodonts The teeth-like fossils of the conodont were first discovered by Heinz Christian Pander and the results published in Saint Petersburg, Russia, in 1856. The name ''pander'' is commonly used in scientific names of conodonts. It was only in the early 1980s that the first fossil evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mongolodus
''Mongolodus'' is an extinct genus of 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 conodonts. The conodonts themselves, how ...s. References * * External links * * Conodont genera Cambrian conodonts Paleozoic life of Newfoundland and Labrador Fossil taxa described in 1977 {{conodont-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 are usually found in isolation and are now called conodont elements. Knowledge about soft tissues remains limited. They existed in the world's oceans for over 300 million years, from the Cambrian to the beginning of the Jurassic. Conodont elements are widely used as index fossils, fossils used to define and identify geological periods. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity. Discovery and understanding of conodonts The teeth-like fossils of the conodont were first discovered by Heinz Christian Pander and the results published in Saint Petersburg, Russia, in 1856. The name ''pander'' is commonly used in scientific names of conodonts. It was only in the early 1980s that the first fossil evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conodont Taxonomy 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 are usually found in isolation and are now called conodont elements. Knowledge about soft tissues remains limited. They existed in the world's oceans for over 300 million years, from the Cambrian to the beginning of the Jurassic. Conodont elements are widely used as index fossils, fossils used to define and identify geological periods. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity. Discovery and understanding of conodonts The teeth-like fossils of the conodont were first discovered by Heinz Christian Pander and the results published in Saint Petersburg, Russia, in 1856. The name ''pander'' is commonly used in scientific names of conodonts. It was only in the early 1980s that the first fossil evidence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] |
