Esox moldavicus Sytchevskaya, 1974

Kovalchuk, Oleksandr M., Wilson, Mark V. H. & Grande, Terry, 2017, A review of Neogene and Quaternary pikes of southeastern Europe and a new species from the early Pleistocene of Nogaisk, Ukraine, Acta Palaeontologica Polonica 62 (1), pp. 121-135 : 126-127

Esox moldavicus Sytchevskaya, 1974

1974 Esox moldavicus sp. nov.; Sytchevskaya 1974: 229, pl. 1: 2–6, pl. 2: 10.

1976 Esox moldavicus Sytchevskaya, 1974 ; Sytchevskaya 1976: 110, pl. 9: 2–9.

1980 Esox moldavicus Sytchevskaya, 1974 ; Sytchevskaya 1980: 36– 37, pl. 10: 6–9.

2014 Esox moldavicus Sytchevskaya, 1974 ; Kovalchuk et al. 2014b: 51, fig. 7a–c.

Material.—Early Pliocene: one right dentary (NMNHU-P 53/4245, Obukhovka 1); one left and two right dentaries (NMNHU-P 42/513, 532, 1252, Kamenskoe). Late Pliocene: two palatines (NMNHU-P 53/4246, 4247, Obukhovka 2); one left dentary (NMNHU-P 53/4248, Kryzhanovka); one left and one right dentary (NMNHU-P 45/6017, 6018, Cherevichne 2). Early Pleistocene: one left dentary and one palatine (NMNHU-P 41/2452, 2453, Kotlovina 2); two left dentaries and two palatines (NMNHU-P 41/2454–2457, Kotlovina 3).

Emended diagnosis.— Esox moldavicus differs from other esocids by (i) the predominance of one-row dentition on dentary; (ii) moderately developed dental shelf; (iii) high articular wall (articular angle more than 60°); (iv) caudally narrowed anterior medial crest on parasphenoid; (v) weakly visible grooves of carotid arteries on parasphenoid; (vi) presence of groove on anterior part of palatine.

Description.—The dentary has a moderately developed shelf, without symphysial notch ( Fig. 3A, C–F, H ; Table 3 ). There is one complete tooth row at the symphysis, and a few small teeth in a second row. The profile of the dentary is low, and the ventral bulge near the symphysis is almost not expressed. The ventral keel is narrow, as is especially clearly visible in the symphysial area.

The toothed surface on the palatine is short and not concave, extending under the maxillary process. The dorsal surface of the bone is curved. There are four or five rows of small tooth bases on the ventral side of the palatine ( Fig. 3B, G ). Widths of bones from the Obukhovka 2 are 3.1 and 4.2 mm, and from Kotlovina 2 4.7 mm.

Remarks.—Described bones are comparable in morphology to those of Esox moldavicus . This species resembles Esox sibiricus in the structure of the dentigerous surface of the palatine, but differs in the predominance of the one-row dentition at the dentary symphysis. The orientation of the maxillary process on the palatine and the low dentary are similar to those in Esox lucius , but differ from features of E. reichertii (Sytchevskaya, 1976) .

Stratigraphic and geographic range.—Early Pliocene– early Pleistocene of southeastern Europe.

Figures

Fig. 3. Isolated elements assigned to a pike Esox moldavicus Sytchevskaya, 1974 from Southeastern Europe; Pliocene (A, C–E, G), and Pleistocene (B, F, H). A. Left dentary (NMNHU-P 45/6017), Cherevichne 2, occlusal view. B. Right palatine (NMNHU-P 41/2556), Kotlovina 3, ventral view. C. Left dentary (NMNHU-P 42/513), Kamenskoe, occlusal view. D. Left dentary (NMNHU-P 53/4248), Kryzhanovka, occlusal (D1) and medial (D2) views. E. Right dentary (NMNHU-P 53/4245), Obukhovka 1, occlusal view. F. Left dentary (NMNHU-P 41/2452), Kotlovina 2, occlusal view. G. Palatine fragment (NMNHU-P 53/4246), Obukhovka 2, ventral view. H. Left dentary (NMNHU-P 41/2454), Kotlovina 3, occlusal view. E, D2, anterior to right; C, D1, A, F, H, anterior to left; G, B, anterior towards top. Scale bars: E, D, 10 mm; C, G, F, H, B, 5 mm; A, 2 mm.