''Kosmoceras'' is a moderately evolute
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 from the upper
Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 165.3 ± 1.1 Ma (million years ago) and 161.5 ± 1.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...
(Middle Jurassic) of Europe with a simple aperture and irregular ribbing interrupted by an irregular row of lateral tubercles. Strong ventral tubercles are separated by a smooth depression running along the rim.
''Kosmoceras'' belongs to the Stephanoceratoidea and is the type genus for the Family Kosmoceratidae and for the subfamily Kosmoceratinae. ''Kosmoceras spinosum'' Waagen is the type species.
''
Lobokosmoceras'' and ''
Gulielmiceras'' have been regarded as subgenera of ''Kosmoceras''. ''Gulielmites'' is a fine-ribbed variety of ''Kosmoceras jason''
Species
This genus includes more than 100 species, including:
* ''K. aculeatum''
* ''K. balticum''
* ''K. cromptoni''
* ''K. bizeti''
* ''K. fibuliferum''
* ''K. geminatum''
* ''K. gemmatum''
* ''K. grossouvrei''
* ''K. interpositum''
* ''K. jason''
* ''K. lithuanicum''
* ''K. medea''
* ''K. obductum''
* ''K. ornatum''
* ''K. phaeinum''
* ''K. proniae''
* ''K. rowlstonese''
* ''K. spinosum''
* ''K. subnodatum''
* ''K. weigelti''
Gallery
File:Kosmoceras cromptoni, Chippenham, England, Late Jurassic - Royal Ontario Museum - DSC09941.JPG, ''Kosmoceras cromptoni''
File: Kosmoceratidae - Kosmoceras jason-001.JPG, ''Kosmoceras jason''
File:Kosmoceratidae - Kosmoceras medea.JPG, ''Kosmoceras medea''
File:Ammoniten Kosmoceras ornatum.jpg, ''Kosmoceras ornatum''
References
* Arkell ''et al.'', 1957. Mesozoic Ammonoidea.
Treatise on Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...
, Part L. Geological Soc. of America and Univ. Kansas Press.
* ''Fossils'' (Smithsonian Handbooks) by David Ward
''Kosmoceras''in the
Paleobiology Database
The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.
History
The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...
*
*
* Philippe C. Courville, Catherine Crônier
Diversity or disparity in the Jurassic (Upper Callovian) genus Kosmoceras (Ammonitina): a morphometric approach
Middle Jurassic ammonites of Europe
Middle Jurassic genus first appearances
Ammonitida genera
Stephanoceratoidea
Fossil taxa described in 1869
{{ammonitina-stub