Ancyloceratidae

Ancyloceratidae is a family of heteromorphic ammonites that lived during the Early Cretaceous. Their shells begin as a loose spiral with whorls not touching which then turns into a straight shaft that ends in a J-shape hook or bend at end. Coarse ribbing and spines are common.

Ancyloceratidae
Temporal range: Lower Cretaceous
Fossil of Pseudocrioceras duvalianum from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Ancyloceratina
Superfamily: Ancyloceratoidea
Family: Shasticrioceratidae
Meek, 1876
Genera
  • see text

Ancyloceratidae is the type family for the Ancyloceratoidea and of the suborder Ancyloceratina. They are found in Lower Cretaceous, Upper Hauterivian to perhaps Lower Albian sediments.

Genera include:

Ancyloceratidae are derived from the Crioceratidae, a family of Lower Cretaceous ammonites with loosely wound, open planispiral shells, probably originating from within the suborder Lytoceratina.

References

  1. M.R.A. Thomson, « Ammonite faunas of the Lower Cretaceous of south-eastern Alexander Island », British Antarctic Survey Scientific Reports, No. 80 (1974), p.1-44.
  • Arkell, W.J.; Kummel, B.; Wright, C.W. (1957). Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Lawrence, Kansas: Geological Society of America and University of Kansas Press.


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