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Proconodontida
Proconodontida is an Order (biology), order of conodonts which originated in the late Cambrian (Furongian) and persisted partly through the Ordovician. The ancestral proconodont, ''Proconodontus'', was one of the earliest euconodonts ("true conodonts") to appear. Proconodonts are often equated with the broader group Cavidonti, which occupies one side of a basal division in the evolution of early euconodonts in the Cambrian. All other euconodonts occupy Conodonti, the other side of the Cambrian split. Proconodontida may be ancestral to another order, Belodellida. Belodellids originate in the Ordovician and survive up to the Devonian or even the Permian (if ''Caenodontus'' qualifies as a member of the order). Description Cavidonts were simple conodonts, tending to maintain smooth and thin-walled elements with a hyaline structure. They were often coniform (horn- or tooth-shaped) with a semi-symmetrical or elliptical cross-section. The basal cavity was deeper than in early members ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conodont
Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard, mineralised tooth-like structures called "conodont elements" that in life were present in the oral cavity and used to process food. Rare soft tissue remains suggest that they had elongate eel-like bodies with large eyes. Conodonts were a long-lasting group with over 300 million years of existence from the Cambrian (over 500 million years ago) to the beginning of the Jurassic (around 200 million years ago). Conodont elements are highly distinctive to particular species and are widely used in biostratigraphy as indicative of particular periods of geological time. 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
