Parahildaites
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''Parahildaites'' is genus of
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 ...
that lived during the lower
Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...
stage of
early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassicâ ...
, during Bifrons zone. It differs from '' Hildaites'' and ''
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 ...
'' by having smooth shell after reaching 4 cm in diameter. There is no spiral groove and on early whorls, there can be sigmoidal ribs or striae. Strong keel is bordered by flat areas or slight sulci. Its fossils were found in Saudi Arabia and Madagascar.M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea.


References

Ammonitida genera Hildoceratidae Toarcian life Ammonites of Africa Ammonites of Asia Ammonite genera {{Ammonitina-stub