Gnathostomata

Gnathostome infection in swamp eels, Fluta alba, in central Thailand.

Furthermore, the analysis demonstrated that all of these early members of the modern gnathostomes are clearly separated from what now appear to be the most primitive vertebrates with jaws: a collection of armored fishes called placoderms.

In these jawed vertebrates (gnathostomes), the hyomandibula played a dual role in feeding and gill ventilation.

Because they resemble later sharks so closely, the Ordovician animals qualify as the closest relatives of the gnathostomes, or jawed vertebrates.

When the first gnathostomes evolved during the Silurian, not only were teeth already formed, but the ability to form denticles like those found over the external surface of cartilaginous fishes had evolved and was found to extend throughout the entire oral mucosa (Kemp, 1999).

His major research area is foodborne zoonotic parasites, including echinostomes, heterophyids, and gnathostomes.

Exoskeletal elements such as scales, tesserae and bony plates of Palaeozoic jawless vertebrates (agnathans) and fishes with jaws (gnathostomes) have been shown to exhibit characteristic morphology, sculpture and microstructure, all of which have been useful for taxonomic identification, systematics and phylogenetic analyses of these fossils (Gross 1967; Karatajute-Talimaa 1978; Marss & Ritchie 1998; Wilson & Caldwell 1998; Wilson & Marss 2004, 2009; Marss et al.

Remarks about the cladistic analysis in connection with myopterygian hypothesis and the problem of the origin of gnathostomes. In Morfologiya i evolyutsiya zhivotnykh [Morphology and evolution of animals] (Vorobyeva, E.

As a basal vertebrate, lamprey possesses a bona fide neural crest and many neural crest-derived structures found in gnathostomes, though they lack several important neural crest derivatives, including sympathetic chain ganglia (Johnels, 1956; Butler and Hodos, 1996).

All modern-day gnathostomes, from mammals to elasmobranches, have structurally and compositionally similar myelin sheaths.