. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . ). Prionocyclus cf. novimexicanus (Marcou, 1858)Fig. 26 Compare 1858 Ammonites novi-mexicani Marcou, p. 35, pi. 1 (fig. 2)). Ammonites serrato-carinatus Meek (non Stoliczka), p. 429. Prionocyclus wyomingensis (Meek); Logan, p. 463, pi. 106. Prionocyclus wyomingensis (Meek); Haas, p. 200, pi. 18 (figs 3-6), pis 19-24. Prionocyclus wyomingensis (Meek); Matsumoto, p. 132, pi. 21 (fig. 2), pi. 22 (fig. 1), text-fig. 2. Subprionocyclusl sp.; Cooper, p. 4. Prionocyclus novimexicanus (Marcou); Hook & Cobban, p. 34, fig. 3E
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . ). Prionocyclus cf. novimexicanus (Marcou, 1858)Fig. 26 Compare 1858 Ammonites novi-mexicani Marcou, p. 35, pi. 1 (fig. 2)). Ammonites serrato-carinatus Meek (non Stoliczka), p. 429. Prionocyclus wyomingensis (Meek); Logan, p. 463, pi. 106. Prionocyclus wyomingensis (Meek); Haas, p. 200, pi. 18 (figs 3-6), pis 19-24. Prionocyclus wyomingensis (Meek); Matsumoto, p. 132, pi. 21 (fig. 2), pi. 22 (fig. 1), text-fig. 2. Subprionocyclusl sp.; Cooper, p. 4. Prionocyclus novimexicanus (Marcou); Hook & Cobban, p. 34, fig. 3E-L. Prionocyclus novimexicanus (Marcou); Matsumoto et al., p. 4. 1870189819461971 1978/? 1979 1981 Material A single flattened specimen, SAM-PCA1943, preserving recrystallized test, waspicked up in surface scree and is assumed to originate from Bed IV. Description The shell is fairly evolute, probably rather compressed, and with about 20 per cent ofthe preceding whorl covered. The umbilicus is shallow, moderately wide (about 30 per 132 ANNALS OF THE SOUTH AFRICAN MUSEUM. Figure 27 Prionocycloceras carvalhoi (Howarth). X 1. A-B. Lateral and oblique ventral views ofSAM-PCA1958. C. Lateral view of SAM-PC A1942. UPPER CRETA CEOUS (TVRON IAN-CON I A CI AN) AMMONITES EROM SAO NICOLA U, ANGOLA 133 cent of the shell diameter), and with a steep, narrow umbilical wall and subroundedumbilical shoulder. The flanks are relatively broad and, probably, were almost flat. Ornament comprises primary ribs that begin at the umbilical seam and pass backwardsto the umbilical shoulder where they terminate in about 20 small but distinct umbilicalbullae per whorl. These, in turn, give rise singly or in pairs to sinuous, slightlyprorsiradiate flank costae which commonly are separated by one, rarely two, intercalatedribs. There are about 50 ribs on the outer whorl, with 14 ribs per 6 umbilical bullae;ribbing weakens slightly on the adoral part of the outer whorl. Each rib is ornamented withpaired clavi o
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
