† Makaira belgica (Ĺeriche, 1926)

(Figs 7F, 9H, I)

1926 † Brachyrhynchus belgicus Ĺeriche: 443, figs 210, 211.

1978 † Istiophorus belgicus (Ĺeriche) in Fierstine: 8.

1990 † Makaira belgicus (Ĺeriche) in Fierstine: 15, table 2.

Diagnosis. This species is characterized by dorsally positioned internal canals in the rostrum, which represents an autapomorphic trait for this species.

Holotype. IRSNB P1117, holotype is a 200 mm-long distal rostral fragment (Ĺeriche 1926). Middle Miocene, Anvers, Belgium (Ĺeriche 1926; Schultz 1987).

New referred material. MAUL 917/1, is a 500 mm-long, nearly complete rostrum with associated left lower jaw and poorly preserved and deformed skull from the late Miocene of Pietra Leccese Formation, Apulia, Italy (Carnevale et al. 2002).

*, the VSPM value has been replaced in M. purdyi by multiplying its VSPM distance by three due the unusually short rostrum and because its rostral length is approximately one-third of a Makaira ssp. rostrum; #, the VSPM measurements have been estimated by using the lower jaw length (LJ) minus the rostral length (L) LJ – L = VSPM. Round weight (kg) is predicted from LJFL using the notation Wª = al b (Prager et al. 1995).

Occurrence. Middle Miocene (Burdigalian) to late Miocene (Tortonian).

Remarks. † Makaira belgica represents the earliest record of the genus Makaira . The holotype is represented by a 200 mm distal rostral fragment (Fig. 8B), which is robust and oval in cross-section (Fig. 9H, I). At 0.25 L, it has a pair of small and circular internal canals, which are arranged dorsally and parallel along the midline (Fig. 9H). In the new specimen MAUL 917/ 1 referred to this species, the prenasals and maxillae are well preserved but the nasals are only partially preserved. In the holotype the nasals are only represented by grooves (Fig. 8B) (Ĺeriche 1926; Schultz 1987). Alveoli and denticles are visible across the completely ventral surface in both specimens (Fig. 8B) (Carnevale et al. 2002).

The studied ratios of † M. belgica at the 0.5 L section fall within the rage of recent and fossil M. nigricans, but differ in its dorsally aligned internal canals (Figs 9H, I, 10) (Ĺeriche 1926; Schultz 1987). This feature represents the only autapomorphy for this species (Fig. 9H–I). The holotype (IRSNB P1117) of † M. belgica is represented by a poorly preserved distal rostral fragment and we assign a second specimen, MAUL 917/1, to this taxon, because both specimens have dorsally arranged internal canals (Fig. 9H, I), representing an autapomorphic trait for this species. Specimen MAUL 917/1 has internal canals in a dorsal position at 0.25 L (Fig. 9H, I; see also Carnevale et al. 2002), which is consistent with what is seen in the holotype of † M. belgica (Fig. 9N). Specimen MAUL 917/1 additionally has distinctive ratios for D2/ VSPM and W2/ VSPM. These out-of-range values are interpreted as short VSPM that covers less than 50% of the rostrum length.