Wikipedia
Kamerunoceras
Kamerunoceras is an extinct cephalopod genus belonging to the ammonite family Acanthoceratidae found in Upper Cretaceous formations of Nigeria and North America.
Kamerunoceras, named by R.A. Reyment in 1954, was tentatively included in the acanthoceratid subfamily Mammitinae in W.J. Arkell,et al (1957) but has since been combined with Euomphaloceras, previously of the Acanthoceratinae ibid, in the Euomphaloceratinae Cooper 1978.
Kamerunoceras is described as being very evolute with a rectangular whorl section and umbilical tubercles only in the middle growth section. Ventrolateral tubercles, found mostly throughout, are spinose. Ribs are irregular, straight at first, becoming denser and sigmoid on the outer whorl.(Arkell 1957)