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''Australiceras'' is an extinct
''Australiceras'' has an evolute shell, coiled with all whorls showing in keeping with its inclusion in the Ancyloceratida. The inner, early, whorls bear ribs that alternate between those that are smooth and those the bear stout blunt or conical tubercles. Ribs on the outer whorls become free of tubercles and end up all smooth.
''Australiceras'' bears some resemblance to '' Tropaeum'' and ''
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 ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
from the upper part of the Early Cretaceous, Aptian
The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...
stage, included in the family Ancyloceratidae.
Description
''Australiceras'' has an evolute shell, coiled with all whorls showing in keeping with its inclusion in the Ancyloceratida. The inner, early, whorls bear ribs that alternate between those that are smooth and those the bear stout blunt or conical tubercles. Ribs on the outer whorls become free of tubercles and end up all smooth.
''Australiceras'' bears some resemblance to '' Tropaeum'' and ''Balearites
''Balearites'' is an extinct ancyloceratin genus included in the family Crioceratitidae, subclass Ammonoidea
Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to ...
'', both related genera, some even considers that ''Australiceras'' is actually synonymous with ''Tropaeum'', while others denying that.
The type species is ''Australiceras jacki''.
References
;Notes ;Bibliography * W. J. Arkell et al. 1957. Mesozoic Ammonoidea, Treatise on Invewrtebrate Paleontology, Part L. Geological Society of America, R.C.Moore, (ed) * F. W. Whitehouse. 1926. "The Cretaceous Ammonoidea of Eastern Australia", ''Memoirs of the Queensland Museum'' 8(3):195-242. Ammonitida genera Cretaceous ammonites Cretaceous animals of Africa Aptian life Ancyloceratoidea {{Ammonite-stub