Definitions for gnathostomata
gnathos·tom·a·ta

Princeton's WordNetRate this definition:0.0 / 0 votes

1. Gnathostomata, superclass Gnathostomatanoun

   comprising all vertebrates with upper and lower jaws

WikipediaRate this definition:0.0 / 0 votes

1. Gnathostomata

   Gnathostomata (; from Greek: γνάθος (gnathos) "jaw" + στόμα (stoma) "mouth") 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 (a characteristic which has subsequently been lost in some), paired appendages (pectoral and pelvic fins, arms, legs, wings, etc.), 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.It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins. Until recently these ancestors, known as antiarchs, were thought to have lacked pectoral or pelvic fins. In addition to this, some placoderms (extinct fish with bony plates) were shown to have a third pair of paired appendages, that had been modified to claspers in males and basal plates in females—a pattern not seen in any other vertebrate group.The Osteostraci (bony armored jawless fish) are generally considered the sister taxon of Gnathostomata.Jaw development in vertebrates is likely a product of the supporting gill arches. This development would help push water into the mouth by the movement of the jaw, so that it would pass over the gills for gas exchange. The repetitive use of the newly formed jaw bones would eventually lead to the ability to bite in some gnathostomes.Newer research suggests that a branch of Placoderms was most likely the ancestor of present-day gnathostomes. A 419-million-year-old fossil of a placoderm named Entelognathus had a bony skeleton and anatomical details associated with cartilaginous and bony fish, demonstrating that the absence of a bony skeleton in Chondrichthyes is a derived trait. The fossil findings of primitive bony fishes such as Guiyu oneiros and Psarolepis, which lived contemporaneously with Entelognathus and had pelvic girdles more in common with placoderms than with other bony fish, show that it was a relative rather than a direct ancestor of the extant gnathostomes. It also indicates that spiny sharks and Chondrichthyes represent a single sister group to the bony fishes. Fossil findings of juvenile placoderms, which had true teeth that grew on the surface of the jawbone and had no roots, making them impossible to replace or regrow as they broke or wore down as they grew older, proves the common ancestor of all gnathostomes had teeth and place the origin of teeth along with, or soon after, the evolution of jaws.Late Ordovician-aged microfossils of what have been identified as scales of either acanthodians or "shark-like fishes", may mark Gnathostomata's first appearance in the fossil record. Undeniably unambiguous gnathostome fossils, mostly of primitive acanthodians, begin appearing by the early Silurian, and become abundant by the start of the Devonian.

ChatGPTRate this definition:0.0 / 0 votes

1. gnathostomata

   Gnathostomata is a taxonomic group within the animal kingdom which includes all vertebrates that have jaws. This includes major groups such as reptiles, mammals, birds, and fish. The word "gnathostomata" is derived from Greek, meaning "jaw-mouth". The group is notable for their hinged jaws and paired appendages, and have dominated the ocean, land and sky for hundreds of millions of years.

WikidataRate this definition:0.0 / 0 votes

1. Gnathostomata

   Gnathostomata are the jawed vertebrates. The term derives from Greek γνάθος "jaw" + στόμα "mouth". Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates. In addition to opposing jaws, living gnathostomes also have teeth, paired appendages, and a horizontal semicircular canal of the inner ear, along with physiological and cellular anatomical characters such as the myelin sheathes of neurons. Another is an adaptive immune system that uses VJ recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene. New fossil finds suggests thelodonts as the closest relatives of the Gnathostomata. It is believed that the jaws evolved from anterior gill support arches that had acquired a new role, being modified to pump water over the gills by opening and closing the mouth more effectively — the buccal pump mechanism. The mouth could then grow bigger and wider, making it possible to capture larger prey. This close and open mechanism would with time become stronger and tougher, being transformed into real jaws. Placoderms used sharp bony plates as teeth instead, and newer research indicates the jaws in placoderms evolved independently of those in the other Gnathostomata.

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Numerology

1. Chaldean Numerology

   The numerical value of gnathostomata in Chaldean Numerology is: 4

2. Pythagorean Numerology

   The numerical value of gnathostomata in Pythagorean Numerology is: 1

References

1. ^ Princeton's WordNet
   http://wordnetweb.princeton.edu/perl/webwn?s=gnathostomata
2. ^ Wikipedia
   https://en.wikipedia.org/wiki/Gnathostomata
3. ^ ChatGPT
   https://chat.openai.com
4. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=gnathostomata