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 is the type family for the Ancyloceratoidea and of the suborder Ancyloceratina. They are found in Lower Cretaceous, Barremian to perhaps Lower Albian sediments.
Genera include: Ammonitoceras Dumas, 1876 Ancyloceras D'Orbigny, 1842 - type genus Ancylotropaeum Casey, 1980 Antarcticoceras Thomson, 1974 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. Audouliceras Thomel, 1965 Australiceras Whitehouse, 1926 Caspianites Casey, 1961 Epancyloceras Spath, 1930 Epitroapeum Kakabadze, 1977 Helicancyloceras Klinger & Kennedy, 1977 Hoheneggericeras Delanoy et al. 2008 Jaubertites Sarkar, 1955 Kutatissites Kakabadze, 1970 Koeneniceras Mikhailova & Baraboshkin, 2002 Laqueoceras Kakabadze & Hoedemaeker, 2004 Lithancylus Casey, 1960 Luppovia Bogdanova et al. 1978 Proaustraliceras Kakabadze, 1977 Pseudoancyloceras Stenshin et al., 2014 Pseudoaustraliceras Kakabadze, 1981 Pseudocrioceras Spath, 1924 Sarkariceras Vermeulen, 2006 Shastoceras Anderson, 1938 Toxancyloceras Delanoy, 2003 Tropaeum J. de C. Sowerby, 1837
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.
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