Silurus glanis Linnaeus, 1758

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 : 9-11

Silurus glanis Linnaeus, 1758

Figure 5.1 -12

1989 Silurus glanis ; Kobayakawa, p. 158, figure 4d.

2015 Silurus glanis ; Kovalchuk et al., p. 54, figure 4.

2015 Silurus glanis ; Kovalchuk, p. 205, figure 3.

Material. 1 dentary fragment, 2 isolated jaw teeth, 1 cleithrum, 1 distal and 4 proximal portions of pectoral-fin spines ( NMNHU-P 41/2529-2536, Kotlovina 1); 1 dentary fragment, 1 articular bone, 1 quadrate, 3 parasphenoids, cranial bones, 1 cleithrum, 4 pectoral-fin spines, 2 abdominal centra ( NMNHU-P 41/52, 218, 543, 545, 579, 609, 615, 617-620, 623-624, 626, 717, 1137, 1233, Shkodova Gora); pectoral-fin spines – 3 prox., 1 dist. ( NMNHU-P 53/4693-4696, Obukhovka 2), 4 prox., 1 dist. ( NMNHU-P 41/2537-2541, Kotlovina 3), 1 prox. ( NMNHU-P 53/4697, Semibalka 1).

Description. Massive pectoral-fin spine ( Figure 5.1-2 ) is straight or slightly curved in medial projection. The bone is oval or rounded in cross-section, with a weakly expanded and dorsoventrally compressed base ( Figure 5.3 ). Medial margin of the shaft yielded long concrescent denticulations ( Figure 5.4 ), located on distal one-third of the spine. Lateral margin of the shaft is usually smooth. Dorsal process of the spine has narrow edge; ventral process is small-sized, anterior is wide and flattened. Parasphenoid ( Figure 5.9 -10) is robust and wide (especially in its medial part), trapezoidal in cross-section. Proximal and distal portions of the bone are slightly expanded. Ventral surface ( Figure 5.9 ) is smooth, dorsal surface with well-developed carotid grooves ( Figure 5.10 ). Wide articular facet of quadrate is nearly rectangular ( Figure 5.11 ), with caudally deflected posterior process. Articular bone ( Figure 5.7 -8) is massive, with a partly broken distal end. Anterior part of its oval articular facet is expanded, and the posterior part is smoothly rounded. Dentary ( Figure 5.6 ) has flattened dentigerous surface yielding numerous tooth rows (n=17). The lateral surface of the dentary has well-developed sensory-canal pores. Jaw tooth ( Figure 5.5 ) is small and conical; its crown is posteriorly curved, circular at the base and pointed at the tip. Cleithrum ( Figure 5.12 ) has high and robust ascending process. Its long vertical branch is deflected posterodorsally and compressed at the base. The cavity for the articular part of the pectoral spine is anteriorly narrowed and posteriorly expanded.

Remarks. All described bones are morphologically identical to those in extant Silurus glanis . Judging by their sizes, it appears that they belonged to relatively large adult individuals.

Figures

FIGURE 5. Isolated bones assigned to Silurus glanis Linnaeus, 1758. 1-4, right pectoral-fin spines (NMNHU-P 41/ 609, 621, Shkodova Gora): dorsal view (1), lateral view (2), proximal articulation surface (3), fragment of the shaft with denticulations (4). 5, isolated jaw tooth (NMNHU-P 41/2530, Kotlovina 1), lateral view. 6, fragment of left dentary (NMNHU-P 41/52, Shkodova Gora): dorsal view. 7-8, right articular (NMNHU-P 41/626, Shkodova Gora): lateral view (7), dorsal view (8). 9-10, parasphenoid with basioccipital bone (NMNHU-P 41/717, Shkodova Gora): ventral view (9), dorsal view (10). 11, fragment of quadrate (NMNHU-P 41/623, Shkodova Gora), anterior view on the articular facet. 12, fragment of cleithrum (NMNHU-P 41/615, Shkodova Gora), lateral view. Scale bars equal 20 mm (Figure 5.9-10, 5.12), 10 mm (Figure 5.1-4, 5.6-8, 5.11) and 5 mm (Figure 5.5).