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Dapediiforms
Dapediidae is an extinct family of neopterygian ray-finned fish that lived from the Middle Triassic to Jurassic, Late Jurassic (Ladinian to Tithonian). It is the only family of the order Dapediiformes. Its members were historically placed within the ginglymodian family Semionotidae, but were moved to their own family in 1966, and subsequently to the separate order Dapediiformes in 2016. Description Dapediids had deep, laterally flattened circular bodies covered in thick ganoid scales, which gave them a resemblance to the pycnodontiforms, a group they may or may not be related to. Their teeth were adapted towards a durophagous diet; some dapediids fed on hard-shelled invertebrates, while at least one genus (''Hemicalypterus'') may have been herbivorous. Classification Dapediids are usually considered to be either basal ginglymodians or stem group representatives of the wider clade Holostei, but some studies have found them to be early-diverging stem-teleosts instead. Referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pycnodontiform
Pycnodontiformes is an extinct order of primarily marine bony fish. The group first appeared during the Late Triassic and disappeared during the Eocene. The group has been found in rock formations in Africa, Asia, Europe, North and South America. They were small to middle-sized fish, generally with laterally-compressed deep bodies, some with almost circular outlines, adapted for manuverability in reef-like environments, though the group was morphologically diverse. Most, but not all members of the groups had jaws with round and flattened teeth, well adapted to crush food items (durophagy), such as echinoderms, crustaceans and molluscs. Some pycnodontiformes developed piranha like teeth used for eating flesh. Most species inhabited shallow marine reef environments, while a handful of species lived in freshwater or brackish conditions. While rare during the Triassic and Early-Middle Jurassic, Pycnodontiformes became abundant and diverse during the Late Jurassic, exhibiting a high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
