Acanthodii

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Acanthodii

an order of placoderm fossil fish, whose members bear spines along the anterior margin of the fins.
References in periodicals archive ?
(2016) reporting the Orcadian Basin acanthodian, Diplacanthus crassisimus Duff 1842 in the Moroch Beds.
Few Silurian vertebrate sites have been described from the USA, and even fewer have been studied for vertebrate microfossils (hereafter microvertebrates) such as thelodont and acanthodian remains.
Meanwhile, some acanthodian species turned out to be primitive sharks, while others were relatives of the common ancestor of sharks and bony fishes.
In addition, acanthodian fish scales and a portion of a fin spine, and numerous actinopterygian and sarcopterygian fish scales and tips of actinopterygian teeth from the MNSC were identified by Kenaga and Sellepack (1995).
These substages correspond to the acanthodian zones established by Valiukevicius [5].
The lowermost vertebrate-bearing layer (layers 7 and 8) yields rare isolated skeletal elements of the psammosteid Psammolepis sp., arthrodire Plourdosteus livonicus (Eastman), antiarch Asterolepis sp., acanthodian Haplacanthus sp., an unidentifiable dipnoan fish, as well as porolepiforms Glyptolepis sp.
A fin spine identified as belonging to the acanthodian Ankylacanthus incurvus (NBMG 11976) (see Burrow et al.
More juvenile dipnoan tooth plates as well as acanthodian scales and conodonts were obtained from a new sample.
Don and Eldon collected skull roofs of haplolepidid fishes and a fin-spine of a small acanthodian fish (Gyracanthus) that Don later described in detail (Baird 1962a, 1978a).
According to a report in National Geographic News, the specimen is of a 415-million-year-old Ptomacanthus, which is only the second known example of a braincase from an Acanthodian, a long-extinct group of fossil fish.