Barschichthyidae family nov.

Arratia, Gloria & Schultze, Hans-Peter, 2024, The oldest teleosts (Teleosteomorpha): their early taxonomic, phenotypic, and ecological diversification during the Triassic, Fossil Record 27 (1), pp. 29-53 : 29

Family Barschichthyidae family nov.

Diagnosis.

(Based on a unique combination of characters among stem teleosts. Autapomorphies are identified with an asterisk [*].) Small fishes about 80 mm total length. The skull roof plate is unique in that its anterior region lacks the triangular nasal region [*] present in most Triassic teleosteomorphs. The anterior margin of the skull roof plate is expanded [*] and markedly lobated [*], giving a unique aspect to the skull roof among teleosteomorphs (Fig. 7 ). Anterodorsal profile of head gently rounded. Left and right lateral extrascapulars present. One median extrascapular present [*]. Extrascapulars lacking the anterior ‘roll-over’ characteristic of pholidophorids. Anterodorsal region of the posttemporal medially positioned. One large, rectangular-shaped suborbital bone. Maxillary blade expanding posteriad [*]. A tiny supramaxilla 1 contrasts with a large supramaxilla 2 covering most of dorsal margin of maxilla. Lower jaw long, slightly protruding anteriad, with articulation for quadrate placed posterior to posterior margin of orbit. Skull roof covered with tubercles of ganoine of different sizes. Supramaxilla, maxilla and lower jaw covered with longitudinal ridges of ganoine. Ganoid scales of anterior part of body with few serrations on posterior margin. Markedly difference in size between lateral line scale row and dorsal scale rows, and slight decrease in size between lateral line scale row and the next two ventral rows; oval-shaped scales or scute-like below pectoral girdles and fins.

Figures

Figure 7. Barschichthys ruedersdorfensis gen. et sp. nov. from Ruedersdorf, near Berlin, Germany (central European Basin; Germanic Basin). A. Photograph of skull roof (holotype MB. f. 19907). B. Interpretative drawing. C. Photograph of skull roof (MB. f. 19908). D. Interpretative drawing. Abbreviations: dsp, dermosphenotic; d. dsp, displaced dermosphenotic; ep, epiotic; fon, anterior cranial fontanel; i. s, incomplete suture; m. exc, median extrascapula; m. pl, middle pitline; ot. c, otic canal; pa + ppa + asp + stt [= fr + pa + asp + dpt], parietal + postparietal + autosphenotic + supratemporotabular [= frontal + parietal + autosphenotic + dermopterotic]; sor. c, supraorbital canal. Scale bars: 5 mm.