Silurus soldatovi Nikolsky and Soin, 1948

Kovalchuk, Oleksandr & Ferraris, Carl J., 2016, Late Cenozoic catfishes of Southeastern Europe with inference to their taxonomy and palaeogeography, Palaeontologia Electronica 51 (9), pp. 1-17 : 7-9

Silurus soldatovi Nikolsky and Soin, 1948

Figure 4.1 -28

1962 Parasilurus sp. ; Tarashchuk, p. 10.

1965 Parasilurus sp. ; Tarashchuk, p. 77, figure 1.

1980 Parasilurus cf. asotus ( Linnaeus, 1758) ; Sytchevskaya, plate 13, figures 3-7.

1989 Silurus cf. soldatovi Nikolsky and Soin, 1948 ; Sytchevskaya, plate 24, figures 4-6.

2011 Silurus sp. ; Kovalchuk, p. 134, figure 2.1-2.3.

Material. pectoral-fin spines – 2 prox., 3 dist. ( NMNHU-P 41/2894-2898, Frunzovka 2), 1 prox., 2 dist. ( NMNHU-P 29/551-553, Lysa Gora 2), 2 prox., 2 dist. ( NMNHU-P 41/5376-5379, Novoelizavetovka 3), 8 prox., 1 complete ( NMNHU-P 41/ 4282-4290, Egorovka 1), 2 prox. ( NMNHU-P 38/ 1953-1954, Novoukrainka 1), 1 prox. ( NMNHU-P 41/2454, Pontian lectostratotype), 1 prox. ( NMNHU-P 41/2730, Vinogradovka 1); 1 cleithrum, pectoral-fin spines – 3 prox., 1 dist. ( NMNHU-P 45/ 5662-5666, Cherevichne 3); 1 articular bone, 5 dentary fragments, 3 cleithra, pectoral spines – 4 prox., 7 dist. ( NMNHU-P 29/1221-1240, Vasylivka 1); 4 dentary fragments, 1 cleithrum, pectoral-fin spines – 3 prox., 2 dist. ( NMNHU-P 29/662-671, Verkhnya Krynitsya 2); 3 cleithra, pectoral-fin spines – 13 prox., 12 dist. ( NMNHU-P 41/4432- 4459, Egorovka 2); 1 pectoral-fin spine ( NMNHU-P 37/736, Novopetrovka); 6 articulars, 23 dentaries, 5 quadrates, 22 cleithra, pectoral-fin spines – 61 prox., 34 dist., 20 isolated centra ( NMNHU-P 42/ 197-213, 215, 217-236, 238-240, 242-260, 441, 478, 488-499, 501-502, 504, 509, 590, 616- 618, 621-626, 659, 660-662, 664, 667, 674, 677-699, 779, 784-786, 819, 885, 1219, 1223, 1249, 1253- 1296, Kamenskoe); 2 proximal portions of pectoral-fin spines ( NMNHU-P 29/3971-3972, Shirokino); 3 dentaries, 24 articulars, 44 cleithra, 27 centra of Weberian apparatus, 60 proximal and 28 distal portions of pectoral-fin spines ( NMNHU-P 53/4507- 4692, Novokyivka).

Description. Pectoral-fin spine ( Figure 4.1 -14) is straight or slightly curved. Articular head of the bone is elongated and flattened, with small medial and ventral processes and a wide anterior process. The medial and lateral margins of the shaft have numerous uniserial small weak denticulations, and additional weaker denticulations along medial edge. Cleithrum ( Figure 4.15 -17, 4.21) are generally fragments, mostly represented by a wide medial portion. Wide crest of horizontal part of the cleithrum (crista articularis) is well-developed and extended medially. Cavity for the articular head of the pectoral-fin spine is narrow anteriorly and widened posteriorly. Slightly gracile quadrate ( Figure 4.18) has a low and narrow articular facet. Dentary ( Figure 4.19 -20, 4.22) is triangular in cross-section, with moderately wide rounded symphysal edge and convex oral surface. Articular bone ( Figure 4.23 -24) has a low wall (35-40°) with a narrow and elongated facet articularis quadrati. Ventral surface of articular is nearly straight, with a rounded ventral posterior angle. Weberian centrum ( Figure 4.25 - 27) is short and high, its articular surface is deepened, higher than wide, with the opening for the spinal cord is displaced dorsally; posterior surface is slightly deeper than wide and ventrally narrowed, with a more central position of the opening for the spinal cord. Abdominal centrum ( Figure 4.28) is round in end view and nearly rectangular in cross-section.

Remarks. The numerous pectoral-fin spines and other bones of this species, from localities different ages appear to belong to both juvenile and adult individuals. They are very similar in morphology to those of extant Silurus soldatovi , as well as Silurus cf. soldatovi from the late Miocene and Pliocene of Western Mongolia and Kazakhstan ( Sytchevskaya, 1989), and we confidently assign them to that species.