Alsatites
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''Alsatites '' is an extinct genus of
cephalopod A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symm ...
belonging to the
Ammonite 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 ...
subclass. They lived during the
Hettangian The Hettangian is the earliest age and lowest stage of the Jurassic Period of the geologic timescale. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). The Hettangian follows the Rhaetian (part of the Triass ...
and are generally extremely evolute, many whorled. Keel broad and blunt organisms, they also exhibit a primary ribbing which is close and persistent.


References

;Notes ;Bibliography :* Arkell, et al.,1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol Soc of America and Univ Kansas Press, Revised 2013, Part L, Michale K. Howarth :*


External links


Blog post about Hettangian ammonites by Peter Reiter
{{Taxonbar, from=Q4735776 Early Jurassic ammonites Jurassic ammonites of North America Hettangian genera Arietitidae Ammonitida genera