Anaspidomorphi

	Anaspidomorphi Anaspidomorphi (anaspidomorphs) is an extinct superclass of jawless fish. According to the newer taxonomy based on the work of Nelson, Grande and Wilson 2016 and van der Laan 2018, the phylogeny of Anaspidomorphi looks like this: * Superclass †Anaspidomorphi Order †Euphanerida * Family †Euphaneropidae Woodward, 1900 Order †Jamoytiiformes Halstead-Tarlo, 1967 * Family †Achanarellidae Newman, 2002 * Family †Jamoytiidae White, 1946 Class †Anaspida Janvier, 1996 non Williston, 1917 * Order †Endeiolepidiformes Berg, 1940 Family †Endeiolepididae Stensio, 1939 * Order †Birkeniiformes Stensiö, 1964 ** Family †Pharyngolepididae Kiær, 1924 Family †Pterygolepididae Obručhev, 1964 Family †Rhyncholepididae Kiær, 1924 Family †Tahulalepididae Blom, Märss & Miller, 2002 Family †Lasaniidae Goodrich, 1909 Family †Ramsaasalepididae Blom, Märss & Miller, 2003 Family †Birkeniidae Traquair, 1899 Family ... [...More Info...] [...Related Items...] OR:** [Wikipedia] [Google] [Baidu]
	Euphaneropidae Euphaneropidae is an extinct family of prehistoric jawless fishes in the extinct order Euphanerida. These fishes are characterised by a greatly elongated branchial apparatus which covers most of the length of the body. Fossils are known from the Lower Silurian and Middle Devonian of Scotland, and the Upper Devonian of Canada. In particular, ''Euphanerops'' is unique in that it has two anal fins. References * Super-Class Agnatha. T. Jeffery Parker and William A. Haswell, Textbook of Zoology Vertebrates pp 164–202 External links * * Anaspidomorphi Prehistoric jawless fish families {{paleo-jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Jamoytiiformes ''Jamoytius kerwoodi'' is an extinct species of primitive, eel-like jawless fish known from the Patrick Burn Formation in Scotland, dating to the Llandovery epoch of the Early Silurian period. Long thought of as a "basal anaspid," ''J. kerwoodi'' is now recognized as the best-known member of the Hyperoartian order (biology), order Jamoytiiformes. It had an elongated body, and is thought to have had, in comparison with relatives known from intact bodies like ''Euphanerops'', a dorsal fin and an anal fin near the rearmost third of its body. Earlier reconstructions depict the creature as having side-fins running the length of its body, starting from behind the branchial openings to the tip of its tail: new research demonstrates that such "fins" are actually deformations of the bodywall as the corpse was being squished post-burial. In life, ''J. kerwoodi'' resembled a lamprey with a very small mouth. Because the fossil had no teeth, teeth-like structures, nor suggestions of either in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Euphanerida Euphaneropidae is an extinct family of prehistoric jawless fishes in the extinct order Euphanerida. These fishes are characterised by a greatly elongated branchial apparatus which covers most of the length of the body. Fossils are known from the Lower Silurian and Middle Devonian of Scotland, and the Upper Devonian of Canada. In particular, ''Euphanerops'' is unique in that it has two anal fins. References * Super-Class Agnatha. T. Jeffery Parker and William A. Haswell, Textbook of Zoology Vertebrates pp 164–202 External links * * Anaspidomorphi Prehistoric jawless fish families {{paleo-jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Pterygolepididae ''Pterygolepis'' is an extinct genus of jawless fish belonging to the order Birkeniiformes Anaspida ("shieldless ones") is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analy .... File:Pterygolepis nitidus Tuebingen.jpg, Fossil of ''Pterygolepis nitidus'', an extinct fish. Took the picture at Museum of Paleontology, Tübingen File:Pterygolepis.jpeg, ''Pterygolepis nitidus'' from Lower Silurian of Norway References External links * Birkeniiformes Silurian fish of Europe Silurian jawless fish Fossil taxa described in 1920 Birkeniiformes genera {{paleo-jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Septentrioniidae Anaspida ("shieldless ones") is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analysis, although some analysis show these group would be at least related. Anaspids were small marine fish that lacked a heavy bony shield and paired fins, but were distinctively hypocercal. Anatomy Compared to many other ostracoderms, such as the Heterostraci and Osteostraci, anaspids did not possess a bony shield or armor, hence their name. The anaspid head and body are instead covered in an array of small, weakly mineralized scales, with a row of massive scutes running down the back, and, at least confirmed among the birkeniids, the body was covered in rows of tile-like scales made of aspidine, an acellular bony tissue. Anaspids all had prominent, laterally placed eyes with no sclerotic ring, with the gills opened as a row of holes along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Birkeniidae Birkeniidae is an extinct family of jawless fish belonging to the order Birkeniiformes Anaspida ("shieldless ones") is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analy .... They were defined in 1899 by Ramsay H. Traquair, and were a successful family among the many jawless fish in the Silurian seas. Morphology Birkeniidae had a large body which was ovular in shape, and a strong, mobile tail. Their eyes were positioned on either side of the head. Their mouth was large for the jawless fish, but contained no teeth. Birkeniidae are distinguished by the crown shaped projection on their back, and the other smaller projections which run down its tail. They also possessed fins which faced downwards, an uncommon trait among the jawless fish. They had typical scaly skin. References External links * Birkeniifor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Ramsaasalepididae ''Ramsaasalepis'' is an extinct genus of jawless fish. It is the type and the only known genus of the family Ramsaasalepididae, one of many families of prehistoric jawless fish, and contains the single species ''Ramsaasalepis porosa''. It was described based on a number of fossilized, disarticulated thelodont scales that may have had a ridged texture. The species had a well-developed vascular canal system. Based on these characteristics and its stratigraphical range, is speculated to be most closely related to the genera '' Septentrionia'' and '' Tahulalepis''. ''Ramsaasalepis'' lived during the Silurian period. Competition with recently evolved jawed fish has been suggested as a reason for the extinction of this and many other jawless fish species. It probably was a filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Lasaniidae ''Lasanius'' is a genus of basal jawless fish from the Early Silurian, around 443.8 million years ago, known from fossils found near Lesmahagow, Scotland. Specimens range from 13.3 to 74.5 mm in length. ''Lasianus'' has a pair of eyes, and a notochord, and while it has rows of bony scutes running along its back, it lacks the armour typical of other Paleozoic jawless fish like ostracoderms. There are also structures close to the front of the animal dubbed "chains" and "rods", of unclear function. At the end of the body a hypocercal tail fin was present in the form of a caudal lobe. Historically, it has often been allied with the anaspids, though other studies found it to be unrelated. A comprehensive redescription published in 2023 found that it was a stem-group cyclostome, more closely related to hagfish and lampreys than to jawed fish Gnathostomata (; from Ancient Greek: (') 'jaw' + (') 'mouth') are jawed vertebrates. Gnathostome diversity comprises roughly 60,000 spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Tahulalepididae Anaspida ("shieldless ones") is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analysis, although some analysis show these group would be at least related. Anaspids were small marine fish that lacked a heavy bony shield and paired fins, but were distinctively hypocercal. Anatomy Compared to many other ostracoderms, such as the Heterostraci and Osteostraci, anaspids did not possess a bony shield or armor, hence their name. The anaspid head and body are instead covered in an array of small, weakly mineralized scales, with a row of massive scutes running down the back, and, at least confirmed among the birkeniids, the body was covered in rows of tile-like scales made of aspidine, an acellular bony tissue. Anaspids all had prominent, laterally placed eyes with no sclerotic ring, with the gills opened as a row of holes along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]