UTRECHT MICROPALEONTOLOGICAL BUllETINS

tus variabilis n. sp. differs from Coelocerodontus burkei DRUCE & JONES,
1971, by the lack of "knife-edges" and by the cross-section of the base,
being widest anteriorly.
Regional occurrence: At Kopingsklint the species was found in member
Da-d2 (a.o. the holotype) and Dk 1, near Horns Udde in member D h l'
Biostratigraphic range: Coelocerodontus variabilis n. sp. was found from the
Cordylodus rotundatus Assemblage Zone up to and including part of the
Drepanois to dus numarcuatus/Paroistodus amoenus Assemblage Zone
(fig. 15).
Genus Cordylodus PANDER, 1856
Type species: Cordylodus angulatus PANDER, 1856.
Definition: (translated from Pander, 1856, p.33) "Compound teeth with
very long, compressed and high base. A big, rather flat, smooth cusp with
evenly curved lateral faces and almost flat anterior and posterior margins
arises from the base, at first more or less vertically, always, however, curved
towards the point. Several small teeth emerge from the basis at the concave
margin of the big tooth, beneath one another and side by side.
To judge from the superficial appearance, one might mistake this genus
for Belodus. The microscopical structure is, however, quite different."
Cordylodus angulatus PANDER, 1856
(PI. 1, figs. 5, 6 and 7)
Cordylodus angulatus PANDER, 1856, p. 33, PI. 2, figs. 27-31, 34, PI. 3, fig. 10. LINDSTROM,
1955a, p. 551, PI. 5, fig. 9; Figs. 3G, E. DRUCE & JONES, 1971, p. 66, PI. 3, figs. 4a-7b;
Text-figs. 23a, b. JONES, 1971, p. 45, PI. 8, figs. 3a-e.
Cordylodus intermedius FURNISH, 1938, p. 338, PI. 42, fig. 31, Text-fig. 2C. DRUCE & JONES,
1971, p. 68, PI. 3, figs. la-3b; Text-figs. 23f, g. JONES, 1971, p. 46, PI. 2 figs. 2a-3c.
Cordylodus proavus MULLER, 1959, p. 448, PI. 15, figs 11, 12, 18; Fig. 3B.
Cordylodus caseyi DRUCE & JONES, 1971, p. 67, PI. 2, figs. 9a-12c; Text-figs. 23d, e. JONES, 1971,
p. 46, PI. 2, figs. la-c.
Remarks: The illustrated specimens show the variation of some features
within this species. Variation is wide in:
a) Both the bending and the extention of the basal stretch of the anterior
edge.
b) The sidewards bending of the entire unit; almost straight as well as
twisted forms occur (cf. PI. 1, figs. 6 and 7).
c) The shape of the basal cavity and the location of its tip. The cavity may
or it may not extend into the cusp and/ or the denticles.