Hildoceratinae is an extinct subfamily of cephalopods belonging to the family Hildoceratidae. Ammonites 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 lapplets that is in its shape similar to the shape of growth lines in spiral midlateral groove.[1]

Hildoceratinae
Temporal range: Upper Pliensbachian to upper Toarcian[1]
Reconstruction of Hildoceras
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Family: Hildoceratidae
Subfamily: Hildoceratinae
Hyatt, 1867
Genera

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Synonyms

Mercaticeratinae Guex, 1973

Genera

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[1][2]

Alternative classification

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Genera Praemercaticeras Venturi, 1981, Mercaticeras Buckman, 1913, Pseudomercaticeras Merla, 1932, Merlaites Gabilly, 1974, and Crassiceras Merla, 1932 have also been classified as belonging to a separate subfamily Mercaticeratinae Guex, 1974.[3]

Distribution

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Members of this subfamily lived from the upper Pliensbachian to upper Toarcian stages of early Jurassic. Distribution has been worldwide.[1][2]

References

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  1. ^ a b c d M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea.
  2. ^ a b Bardin, J., Rouget, I., & Cecca, F. (2016). The phylogeny of Hildoceratidae (Cephalopoda, Ammonitida) resolved by an integrated coding scheme of the conch. Cladistics.
  3. ^ Lacroix, Pierre (2011). Les Hildoceratidae du Lias moyen et supérieur des Domaines NW Européen et Téthysien. Une Histoire de Famille. St-Just-La-Pendue: Chirat. pp. 204–216. ISBN 978-2-917151-39-6.