Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 19. 2001. (Budapest, 2001)

32 Fi Remarks — Pachydiscus precolHgatus is a poorly known ammonite. It was published by COLLIGNON together with the very similar P. gignouxi from the same stratigraphie level (Lower Campanian). Both ammonite have the feeble, but complex ribbing, and there are no data on the infraspecific variation, therefore the separation of the species is problematic. The closest well-known ally is probably Pachydiscus colligatus (BlNKHORST 1861), a species, which was intensively discussed by KENNEDY (1986). P. precolHgatus is also close to Pachydiscus haldemsis (SCHLUTTER 1867), including forms, described originally by DE GROSSOUVRE in 1894, under the name P. koeneni (for details see KENNEDY & SUMMESBERGER 1984). However, SCHLUTTER'

s species has stronger and sparsely ribbed microconchs, and probably vigorously ribbed macroconchs. Distribution — P. precolHgatus was described from the Lower Campanian of Madagascar. As far as the similar species are considered, P. colligatus as well as P. haldemsis — P. koeneniare Upper Campanian fossils. Family Collignoniceratidae WRIGHT, 1951 Subfamily Texanitinae COLLIGNON, 1948 Genus Menabites COLLIGNON, 1948 Menabites (Delawareila) suemegensis sp. n. (Plate IV) Holotype — A moderately well-preserved, but crushed and corroded internal mould (M.63.1355) collected by L. KOCSIS. Besides the type, no other specimens were collected. Type locality — The specimen came from a quarry north of Sümeg (Községi bánya), Transdanubian Central Range. The exact position of the outcrop is unknown. Type strata — Based on the lithological features of the mould, the specimen is from the Rendek Member of the Polány Marl Formation. Derivation of name — The species name refers to the small town of Sümeg. Diagnosis — Delawarella species with strong, sparse ribs on the middle whorls. Material — A single specimen. Measurements: D WH WW U M.63.1355 ?163 ?60 — 58 Description — The mid-sized fragmentary specimen is probably the fossil of a subadult ammonite. The phragmocone and a part of the body chamber is preserved. The innermost whorls cannot be seen. The coiling is relatively evolute. The umbilical wall is steep; the flanks are modestiy flat and heavily ornamented. On the middle whorl there are about 14 coarse, blunt, prorsiradiate ribs per whorl, bearing characteristic ventrolateral tubercles. No other row of lateral tubercles can be seen, probably because of the corrosion. On the outer whorl ribs are strong, straight, radial or slighdy prorsiradiate. At the end of the phragmocone the strong ribs, including the common, short intercalaries, carry 4— 5 rows of tubercles. The first row, containing weak nodes, is placed at the beginning of the ribs, above the umbilical wall, the second row (not always well developed) is situated in the lower quarter of the ribs, the third row is placed in the middle of the ribs, and forms a bifurcation point in some cases. These umbilical and lateral tubercles are conical, while the fourth and especially the fifth rows of swellings are characteristically claviform. The last row of tubercles is situated in ventrolateral position. The ornamentation is different on the body chamber: ribs are simple, only the weak first and the strong last claviform tubercles can be seen. The venter has a fine keel built up by weak, elongated swellings. The specimen is slighdy deformed, and the venter, with the weak serrated keel, is visible only on the last short part of the phragmocone. The faint suture-line can be seen only in parts. Remarks — The closest ally is probably Menabites (Delawarella) danei (YOUNG, 1963), a species often found in the Gulf Region of the US. (For illustration of the species, see: DANE, 1929, YOUNG, 1963, COBBAN & KENNEDY, 1992/a, 1992/b and KENNEDY et al. 1997) The Sümeg ammonite especially fits well, if not identical on species level, with one of the specimen, figured by KENNEDY et al. (1997, fig. 20.); both ammonite show the same features of the changing ornamentation (strong, coarse, straight early ribs with the very prominent dominance of ribs over the tuberculation, as size Explanation to Plate IV Menabites (Delawarella) suemegensis sp. n. (M 63 1355), X 1. -—• Ventral and lateral view. Fragmentary phragmocone, with the part of the body chamber (arrow indicates its beginning).