Hildoceratinae is an extinct subfamily of cephalopods belonging to the family

Hildoceratidae Hildoceratidae is a family of Ammonoidea, ammonoid cephalopods from the Lower Jurassic, lower Pliensbachian (''Jamesoni'' zone) to lower Bajocian (maybe even upper Bajocian) substages, generally with strongly ribbed, involute shells. They are com ...

Ammonites Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

of this subfamily had shells with elliptical or quadrate whorl section with keel or tricarinate, bisulcate venter. Ribs were variable, from falcate to strongly angled and from fine to strong. They can be interrupted by spiral groove in midlateral part of the shell. While some species can be smooth, strongly ribbed ones can have tubercules. Microconchs have short lappets that is in its shape similar to the shape of growth lines in spiral midlateral groove.

Genera

Bardin, J., Rouget, I., & Cecca, F. (2016). The phylogeny of Hildoceratidae (Cephalopoda, Ammonitida) resolved by an integrated coding scheme of the conch. Cladistics. * '' Hildaites'' Buckman, 1921 * '' Orthildaites'' Buckman, 1923 * '' Cingolites'' Sassaroli et Venturi, 2010 * ''

Hildoceras ''Hildoceras'' is a genus of ammonite from the Jurassic period in the family Hildoceratidae. The shells are characterized by a narrow discoidal evolute shape, keeled venter, concave ribs along the outer flanks, and a shallow spiral groove run ...

'' Hyatt, 1867 * '' Urkutites'' Géczy, 1967 * '' Parahildaites'' Blaison, 1967 * '' Mercaticeras'' Buckman, 1913 * '' Hildaitoides'' Hillebrandt, 1987 * '' Atacamiceras'' Hillebrandt, 1987 * '' Neolioceratoides'' Cantaluppi, 1970

Alternative classification

Genera ''Praemercaticeras'' Venturi, 1981, ''Mercaticeras'' Buckman, 1913, ''Pseudomercaticeras'' Merla, 1932, ''Merlaites'' Gabilly, 1974, ''Crassiceras'' Merla, 1932, and ''Pseudocrassiceras'' Rulleau et Jattiot, 2019 have also been classified as belonging to a separate subfamily Mercaticeratinae Guex, 1974.

Distribution

Members of this subfamily lived from the upper Pliensbachian to upper Toarcian stages of early Jurassic. Distribution has been worldwide.

References

{{Taxonbar, from=Q23833057 Hildoceratidae Early Jurassic ammonites Ammonites of Asia Ammonites of Africa Ammonites of Europe Ammonites of South America Ammonites of North America Prehistoric animal subfamilies Toarcian life