Esox lucius Linnaeus, 1758

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 : 129-130

Esox lucius Linnaeus, 1758

Fig. 5 .

Material.—Early Pleistocene: one left cleithrum (NMNHU-P 53/4249, Nova Etuliya); one fragment of cleithrum (NMNHU-P 53/4250, Sinyaya Balka). Middle Pleistocene: one left palatine and two left dentaries (NMNHU-P 53/4253, Semibalka 1); one parasphenoid, two right palatines, two left and six right dentaries (NMNHU-P 53/4254–4264, Medzhibozh).

Emended diagnosis.— Esox lucius is characterized by a number of features distinguishing it from other species: (i) only uniserial dentition of dentary; (ii) narrow dental shelf; (iii) presence of symphysial notch; (iv) clearly expressed and anteromedially deepened carotid grooves on parasphenoid; (v) rounded articular facet on palatine; (vi) weakly expressed dorsal crest on cleithrum.

Description.—The posterior part of the parasphenoid and the dorsal medial crest are extended caudally ( Fig. 5G ). The broad anterior medial crest is well developed. There is a dorsally directed process at the base of the posterior crest. The bone is wide (6.0 mm in the medial part and 7.8 mm in the posterior part). Two shallow longitudinal grooves are expressed in the medial part of the ventral side of the bone. There is a large angle between the postcarotid crests.

The dentaries ( Fig. 5E, F ) are low, with a uniserial dentition of depressible teeth near the symphysis and a narrow dental shelf. Width of the dentary near the symphysis of these bones from Medzhibozh is 1.2–2.9 mm M 1.5 mm); height of dentary symphysis, 1.9–5.2 mm (M 3.1 mm); and width of tooth row, 1.0– 3.1 mm (M 1.9 mm). Dentaries from Semibalka 1 are comparable in size: width of the dentary near the symphysis, 2.2 and 3.0 mm; height of dentary symphysis, 3.8 and 5.6 mm; width of tooth row, 1.6 and 2.0 mm.

The palatine has a rounded fossa articularis and an uvular articular process ( Fig. 5B, C ). The dentigerous surface is relatively long and concave. There are C-shaped bases from five rows of small depressible teeth on the ventral surface of the bone (the largest of them located in the medial row). The width of the palatine from Semibalka 1 is 7.0 mm, with DFA 3.5 mm.

Cleithra are represented by their caudal parts ( Fig. 5A, D ). The thickened dorsal crest is weakly expressed. The width of the plate is 6.2 mm for those from Nova Etuliya and 7.2 mm for the cleithrum from Sinyaya Balka.

Remarks.—All described bones are indistinguishable in morphology and size from those of Esox lucius .

Stratigraphic and geographic range.—Early Pleistocene– Recent, Eurasia and North America.

Figures

Fig. 5. Isolated elements assigned to the Northern Pike Esox lucius Linnaeus, 1758 from Southeastern Europe; Pleistocene. A. Left cleithrum (NMNHU-P 53/4249), Nova Etuliya, lateral view.B. Left palatine (NMNHU-P 53/4253), Semibalka 1, ventral view.C. Right palatine (NMNHU-P 53/4255), Medzhibozh, dorsal view (C1), ventral view (C2). D. Fragment of cleithra (NMNHU-P 53/4250), Sinyaya Balka, lateral view. E. Left dentary (NMNHU-P 53/4387), Semibalka 1, occlusal view. F. Right dentary (NMNHU-P 53/4264), Medzhibozh, occlusal view. G. Parashenoid (NMNHU-P 53/4254), Medzhibozh, dorsal view. A, D, E, anterior to right; F, anterior to left; B, C, G, anterior towards top. Scale bars: A–F, 5 mm; G, 10 mm.