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Thelodonti ('feeble-teeth') are a group of small, extinct jawless fishes with distinctive scales instead of large plates of armour. There is much debate over whether the group of Palaeozoic fish known as the Thelodonti (formerly coelolepids [11]) represent a monophyletic grouping, or disparate stem groups to the major lines of jawless and jawed ...
The class Osteostraci (meaning "bony shells") is an extinct taxon of bony-armored jawless fish, termed "ostracoderms", that lived in what is now North America, Europe and Russia from the Middle Silurian to Late Devonian. Anatomically speaking, the osteostracans, especially the Devonian species, were among the most advanced of all known ...
Arandaspis prionotolepis. This list of prehistoric jawless fish is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be jawless fish, excluding purely vernacular terms.
Dorsal view of right-bending (left) and left-bending (right) jaw morphs adapted for eating fish scales [68] Lepidophagy (Ancient Greek for scale-eating) is a specialised feeding behaviour in fish that involves eating the scales of other fish. [69] Lepidophagy has independently evolved in at least five freshwater families and seven marine ...
According to Philippe Janvier, anatomical similarities in the brain of Brindabellaspis stensioi and the brain of a jawless fish suggest it is a basal placoderm closest to the ancestral placoderm. Various Early to Middle Devonian placoderm incertae sedis have also been inserted in the order.
Agnatha (/ ˈ æ ɡ n ə θ ə, æ ɡ ˈ n eɪ θ ə /; [3] from Ancient Greek ἀ-(a-) 'without' and γνάθος (gnáthos) 'jaws') is a paraphyletic infraphylum [4] of non-gnathostome vertebrates, or jawless fish, in the phylum Chordata, subphylum Vertebrata, consisting of both living (cyclostomes) and extinct (conodonts, anaspids, and ostracoderms, among others).
Jawless fishes from the Ordovician Period — 488.3 million to 443.7 million years ago — are called ostracoderms, after their armored skin, and most of them are known from fossils that only ...
Lepidaspis serrata ("serrated scaly shield") is an extinct heterostracan jawless fish from Early Devonian Canada. Its scientific name refers to the fact that the armor is composed of hundreds of tiny scales with serrated edges. Lepidaspis serrata cast. Mackenzie Mountains, Northwest Territories . At the Royal Tyrrell Museum of Palaeontology.