Bothriolepis leptocheira Traquair, 1893

Lukševičs, Ervīns, Beznosov, Pavel & Stūris, Valdemārs, 2017, A new assessment of the Late Devonian antiarchan fish Bothriolepis leptocheira from South Timan (Russia) and the biotic crisis near the Frasnian-Famennian boundary, Acta Palaeontologica Polonica 62 (1), pp. 97-119 : 100-101

Bothriolepis leptocheira Traquair, 1893

1869 Pterichthys major ; Geikie 1869 (after Miles 1968): 12–13.

1888 Bothriolepis major Agassiz ; Traquair 1888 (after Miles 1968): 510.

1893 Bothriolepis leptocheirus sp. nov.; Traquair 1893: 285–286.

1900 Bothriolepis jeremejevi sp. nov.; Rohon 1900: 30, fig. 18, 19.

1917 Bothriolepis leptocheira Traquair, 1893 ; Evans 1917 (after Miles 1968): 112.

1932 Bothriolepis jeremejewi Rohon, 1900 ; Gross 1932: 34.

1942 Bothriolepis curonica sp. nov.; Gross 1942: 420, 421, abb. 10.

1948 Bothriolepis curonica Gross, 1942 ; Stensiö 1948: 615.

For a full list of synonyms before 1965 see Miles (1968).

Lectotype: RSM 1859.33.19A, AVL plate selected by Gross (1932: 26), illustrated by Traquair (1906: pl. 29: 3).

Type locality: Bracken Bay, Ayrshire (Heads of Ayr), Scotland;

Type horizon: Upper Old Red Sandstone, Upper Devonian.

Emended diagnosis.— Differs from all other Bothriolepis in possessing long supraoccipital groove extending to the Pn plates, sometimes fused with a long middle pit-line, and rather slender proximal segment of the pectoral appendage, which is more than 5 times as long as it is broad. Characterised by a rather large size with a median dorsal armour length of at least 240 mm. Preorbital recess of trifid type. The orbital fenestra is relatively small and narrow. Prm broad, orbital margin is much shorter than rostral margin. Nu with rather short orbital facets. AMD relatively narrow, B/L index about 0.8 (N = 22), with a relatively short anterior margin. PMD broad with narrow anterior margin. Median dorsal ridge poorly developed in posterior part of PMD. Dorso-lateral and ventro-lateral ridges are wellmarked. Both AVL and PVL are elongated. Cv 4 and Cd 5 plates are present in the pectoral fin armour. Ornamentation is fine and basically of reticular type.

Stratigraphic and geographic range.—This species has also been reported from western Latvia, where the material has been collected in the right bank of the river Imula, near Bienes hamlet, and in the left bank of the river Amula, 1 km upstream from water-mill Kalnamuiža; Purviņi Member of the Eleja Formation, lowermost Famennian ( Lukševičs 2001). A possible new subspecies of B. leptocheira occurs in the Malyutka Formation of Severnaya Zemlya, outcrops along the Matusevich River ( Lukševičs 1999a, b). The material described in this paper comes from the geological monument “Sosnovskiy” (Sosnogorsk locality) at the right bank of the river Izhma opposite Sosnogorsk, Komi Republic, Russia; Sosnogorsk Formation, lowermost Famennian.