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Acanthohoplites

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Acanthohoplites
Temporal range: Lower Cretaceous
A. hannoverensis Hannover (Germany), Lower Cretaceous
Scientific classification
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Acanthohoplites

Sinzow 1908

Acanthohoplites is a Lower Cretaceous ammonite in the family .

The taxonomic position in the Treatise on Invertebrate Paleontology Pt L, 1957 placed the genus into the family Deshayesitidae. Newer classifications have revised that placement and the genus is now included into the family Parahoplitidae.[1]

Description

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.

Acanthohoplites has been found in upper Aptian and lower Albian sediments in Europe, Central Asia, Japan, East Africa, Arizona, California, Oregon Mexico, and South America.

Parahoplites and Hypacanthoplites are similar genera.

Selected species

  • A abichi
  • A. berkleyi
  • A. bigoureti
  • A. erraticus
  • A. hannoverensis
  • A. hesper
  • A. impetrabilis
  • A. paucicostatus
  • A. schuchert
  • A. teres

The species A. nolani designated the type species of the genus Nolaniceras in 1961, and renamed as Nolaniceras nolani.[1]

References

  1. ^ a b Bulot, 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. doi:10.1016/j.pgeola.2013.12.006.