Macromesodon Blake, 1905

Poyato-Ariza F. J. & Wenz S., 2002, A new insight into pycnodontiform fishes, Geodiversitas 24 (1), pp. 139-248 : 148

Genus Macromesodon Blake, 1905

TYPE SPECIES. — By subsequent designation: Gyrodus macropterus Agassiz, 1834 . Lower Tithonian from the “Solnhofener Plattenkalke” of Bavaria, Germany. The first mention of the nominal species, together with a brief description and without illustration, are in Agassiz (1834: feuillet 18, and then again in 1843: 301). It is explicitly designated as the type species by Woodward (1918). Holotype of Macromesodon macropterus : it is not sure that the specimen figured by Wagner (1851: pl. 4, fig. 2), currently housed at the Bayerischen Staatssammlung für Paläontologie und historische Geologie, München, Germany, specimen AS VII 345, is the same than the one described by Agassiz (1834), which is the type specimen by monotypy. We are currently investigating its whereabouts (Poyato-Ariza & Wenz work in progress).

INVALID NAMES. —“ M.” comosus , for comments see under Apomesodon n. gen. above; M. daviesi Woodward, 1890 , lower Portlandian-lower Berriasian from Swanage, Dorset, United Kingdom; M. parvus ( Mesodon macropterus, var. parvus in Woodward 1895b, and Mesodon parvus in Woodward 1918), upper Portlandian-lower Berriasian from Teffont, Wiltshire, United Kingdom. The specific names daviesi and parvus are both based on specimens showing minimal differences in the number of dorsal and anal fin rays, which fall within individual variation, and in standard length and relative size of the head, attributable to ontogenetic variation. So, both M. daviesi and M. parvus are indistinguishable from M. macropterus , and therefore considered herein as conspecific with the type species.

OTHER SPECIES. — M. bernissartensis Traquair, 1911 , Berriasian-Barremian from Bernissart, Belgium; M. cf. M. bernissartensis , upper Barremian from Las Hoyas, province of Cuenca, Spain (Wenz & Poyato-Ariza 1995). There are numerous nominal species based on isolated dentitions (e.g., Woodward 1895a). They are in need of revision and will probably show to be synonyms. MATERIAL EXAMINED. — Macromesodon macropterus: JM 1941.12a.b (complete, well preserved); MNHN SLN 48 (juvenile specimen); 54, 210; MNHUB MBI.004.11 (complete, well preserved); NHML P.5546, 6381, 9845, 10954, 11774, 37107**, 37109** (almost complete skull, excellent preservation), 41387; M. bernissartensis : syntypes IRSNB 1214a-b, 1215a-b, 1216, 1218a-b (complete or nearly complete specimens, unsatisfactory preservation); Macromesodon aff. M. bernissartensis: MCCM : LH- 910110a-b (complete juvenile specimen, good preservation), LH-13266a*-b (complete specimen, good preservation), LH-13483** (almost complete, slightly disarticulated and distorted), LH-16363** (skull and anterior region of body).