Hammatoceratidae is a family of lower and middle Jurassic

ammonites Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

included in the superfamily

Hildoceratoidea Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.Arkell ''et al.' ...

Diagnosis

Hammatoceratidae comprises genera which are characterized by ribbed evolute shells (all whorls visible), some bearing keels along the venter. Those in the Phymatoceratinae have more simple ribbing while those in the Hammatoceratinae have ribbing that branch higher up on the whorl sides, divided into primaries and secondaries.

Taxonomy

In the outdated classification of the 1957 American

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

, Hammatoceratidae was included in the superfamily

and divided into two subfamilies, the earlier Phymatoceratinae, and later Hammatoceratinae.W.J.Arkell ''et al.'', 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology Part L Hammatoceratidae is now divided into four subfamilies,Hammatoceratidae in Fossilworks
/ref> the Hammatoceratinae, Erycitinae, Podagrosiceratinae, and Zurcheriinae. Hammatoceratinae includes ''Rarenodia'', ''Geczyceras'', '' Bredyia'', '' Parammatoceras, Crestaites'', '' Erycitoides'', '' Euaptetoceras'', '' Eudmetoceras'', '' Fissilobiceras'', '' Hammatoceras'', '' Onychoceras'', '' Paviatites'', '' Planammatoceras,'' '' Pseudaptetoceras'', and '' Puchenquia''. ''Fissilobiceras'', included in the

Sonniniidae Sonniniidae is a diverse family of Middle Jurassic ammonites ranging from those with stout evolute shells to those whose shells are sharply rimmed, oxyconic. The keel, which runs along the middle of the venter, is typically hollow. Sutures vary f ...

in the Treatise, 1957, differs from typical hammatoceratids in being rather involude and smooth shelled. The Erycitinae is said to include '' Praerycites, Erycites'', ''

Abbasites ''Abbasites'' is an extinct genus of ammonites from the early Middle Jurassic epoch, included in the ammonitid family Erycitidae. Description ''Abbasites'' is small and subglobular with ribbing that divides high on its sides and which has an int ...

'', ''Abbasitoides'', ''Shahrudites'' and '' Cagliceras''. The Treatise Part L, 1957, includes ''Erycites'' and ''Abbasites'' in the Hammatoceratinae. ''Cagliceras'', named by Rulleau and Elmi, was added in 2001. Podagrosiceratinae named by Westermann and Riccardi, 1979, includes '' Podagrosiceras'' Maubeuge and Lambert, 1956, '' Sphaerocoeloceras'', and '' Westermanniceras''. D.T. Donovan, et al.,1981Classification of the Jurassic Ammonitina, in ''The Ammonoidea'', M.R House & J.R. Senior, (eds), Academic Press recognized ''Sphaerocoeloceras'' as a hammatoceratid rather than a dactyloceratid as in the Treatise. Zurcheriinae, Hyatt 1900, includes '' Zurcheria'', H.Douville, 1885, '' Haplopleuroceras'', '' Malladaites'', and '' Spinammatoceras''. ''Zurcheria'' and ''Haplopleuroceras'' are included in the Sonniniidae in the Treatise Part L.

Evolution and phylogeny

The Hammatoceratidae with its four subfamilies has its origin in the Phymatoceratidae, with the subfamily Hammatoceratinae giving rise to the subfamilies Erycitinae and Podagrosiceratinae. If ''Zurcheria'' and ''Haplopleuroceras'' belong in the Sonniniidae, the Zurcheriinae must thereby be derived and therefore belongs to the Sonniniidae.

References

{{Taxonbar, from=Q20687154 Ammonitida families Hildoceratoidea Jurassic ammonites Early Jurassic first appearances Middle Jurassic extinctions