Brachyacanthus, Brochoadmones and Ptomacanthus

Brachyacanthus scutiger (originally Climatius scutiger, Egerton 1860; Hunterian Museum and Art Gallery 298251; 3.5 cm in length; Early Devonian) is a tiny acanthodian or 'spiny shark'. The skull bones are subdivided more than any othe rtested taxon in the LRT. Several thin and parallel fin spines coalesce to form sharp, thick combined spines. Contra Carroll 1988, the small scales/bones that cover the head CAN be directly compared with the dermal skull bones of other taxa, including its sister, Paratarrasius.

Diplacanthus horridus (Woodward 1892; Gangnier 1996; Early to Middle Devonian, 380 mya; 15cm long) has some of the longest spines among spiny sharks and nests basal to placoderms and cafish in the LRT. Note the resemblance to Eurynotus. Diplacanthus retained a maxilla prior to loss or fusion with the jugal in higher taxa. It also had a lateral temporal fenestra.

Above a short-body specimen is shown. Scale unkown.

Brochoadmones milesi (Bernacsek and Dineley 1977; Hanke and Wilson 2006; Early Devonian) is associated with Brachyacanthus in the LRT.

Ptomacanthus anglicus (Miles 1973; Brazeau 2012) is a spiny shark related to Brachyacanthus and Brochoadmones.

Agassiz L 1845. Monographie de poissons fossiles des Vieux Grés Rouges ou Systéme Dé´vonien (Old Red Sandstone) des ˆIles Bri tanniques et de Russie. Imprimerie de Petitpierre et Prince, Neuchatel, 171 pp.

Bernascek GM and Dineley DL 1977. New acanthodians from the Delorme Formation (Lower Devonian) of N.W.T., Canada. Palaeontographica, Abteilung A 159:1–25.

Brazeau MD 2012. A revision of the anatomy of the Early Devonian jawed vertebrate Ptomacanthus anglicus Miles PDF. Palaeontology. 55 (7227): 355–367.

Carroll RL 1988. Vertebrate paleontology and evolution. W. H. Freeman, New York.

Egerton P de MG 1860. Report of the British Association for Science for 1859.
Transactions of the Sections. 116.

Gagnier P-Y 1996. Acanthodii, p. 149-164. In Schultze, H.-P. and Cloutier, R. (eds.), Devonian Fishes and Plants of Miguasha, Quebec, Canada . Pfeil, Munich.

Hanke GF and Wilson MVH 2006. Anatomy of the Early Devonian acanthodian Brochoadmones milesi based on nearly complete body fossils, with comments on the evolution and development of paired fins. Journal of Vertebrate Paleontology. 26 (3): 526–537.

Miles R 1973. Articulated acanthodian fishes from the Old Red Sandstone of England, with a review of the structure and evolution of the acanthodian shoulder-girdle. Bulletin of the British Museum (Natural History), 24, 111–213.

Woodward AS. 1889. Acanthodian fishes from the Devonian of Canada. Ann Mag Nat Hist 4:183–184.

wiki/Brachyacanthus
wiki/Acanthodii
wiki/Ptomacanthus
wiki/Brochoadmones
wiki/Diplacanthus

Siluriformes

Clarias

Guiyu

Hoplosternum

Ictalurus

Electrophorus

Acanthodii

Brachyacanthus

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