These ammonites have a strongly ribbed shell and ammonitic suture. Early whorls are coronate, which later become round, then oval in section. Primary ribs may have swellings (bullae) at the umbilicus or are without. In early stages primary ribs branch mid flank at prominent lateral tubercles. In later stages lateral tubercles are reduced or absent and primary ribs branch simply at the umbilical shoulder or, again, mid flank. Sutural elements are subquadrate with narrow, shallow embayments. The first lateral lobe tends to be symmetrical.
Species
The following species have been described, either as Acanthoplites or Acanthohoplites.[1]
The species A. nolani was described as Hoplites nolani and later designated the type species of the genus Nolaniceras in 1961, and was subsequently renamed as Nolaniceras nolani.[2]
Distribution
Acanthohoplites has been found in Upper Aptian and Lower Albian sediments in Europe, Central Asia, East Africa, North and South America:[1]
^ abBulot, LG; Latil, J-L; Hairabian, A; Fournillon, A (2014). "New insight on the genus Nolaniceras Casey, 1961 (Ammonoidea, Cretaceous) and its consequences on the biostratigraphy of the Aptian Stage". Proceedings of the Geologists' Association. 125 (2): 227–232. Bibcode:2014PrGA..125..227B. doi:10.1016/j.pgeola.2013.12.006.
Arkell,et al., Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L, Ammonoidea. Geol Soc of America and Univ Kansas press, 1957. R.C. Moore (ed)
