Related Research Articles
Gnathostomata are the jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates, including humans. In addition to opposing jaws, living gnathostomes have true teeth, paired appendages, the elastomeric protein of elastin, and a horizontal semicircular canal of the inner ear, along with physiological and cellular anatomical characters such as the myelin sheaths of neurons, and an adaptive immune system that has the discrete lymphoid organs of spleen and thymus, and uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene.
Thelodonti is a class of extinct Palaeozoic jawless fishes with distinctive scales instead of large plates of armor.
Anaspida 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.
The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.
The Greek lamprey is a species of jawless fish in the Petromyzontidae family. It is endemic to Greece. Its natural habitats are rivers and freshwater springs. It is threatened by habitat loss. Originally considered a species of the genus Eudontomyzon, later phylogenetic analyses suggested that a placement within Caspiomyzon was more likely. It is the most endangered species of lamprey, living only in the Strymon and Louros river basins.
Auchenaspis salteri is an extinct species of armored jawless fish of the order Thyestiida from the Late Silurian of England. In England, A. salteri's fossils are found in extreme abundance in the Lower Old Red Sandstone strata in Ledbury, Herefordshire.
Zenaspis is an extinct genus of jawless fish which existed during the early Devonian period. Due to it being jawless, Zenaspis was probably a bottom feeder. The fish was around 10 inches (25 cm) in length. It had a horseshoe shaped head that probably sheltered a small brain.
C. sulcata may refer to:
Myllokunmingiidae is a group of very early, jawless prehistoric fish (Agnathans) which lived during the Cambrian period. The Myllokunmingiids are the earliest known group of craniates. The group contains three genera, Haikouichthys, Myllokunmingia, and Zhongjianichthys. Their fossils have been found only in the Maotianshan Shales lagerstätte.
Canonia is an extinct genus of jawless fish found in Canada. There are two species in this genus, C. grossi and C. costulata.
C. solida may refer to:
Erepsilepis is an extinct thelodont agnathan genus in the family Phlebolepididae.
Pipiscius zangerli is an extinct species of lamprey that lived about 300 million years ago, during the Middle Pennsylvanian Epoch of the Carboniferous Period.
Anaspidomorphi (anaspidomorphs) is an extinct superclass of jawless fish.
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.
The following are lists of prehistoric animals:
References
- ↑ Pander, C. H., 1856. Monographie der fossilen Fische des silurischen Systems der russisch-baltischen Gouvernments. Buchdruckerei der Kaiserlichen Akademie der Wissenschaften, St. Petersburg, 91 pp.
