''Cymatoceras'' is a wide-ranging extinct genus from the
nautilitacean cephalopod family,
Cymatoceratidae. They lived from the
Late Jurassic to
Late Oligocene, roughly from 155 to 23 Ma.
[ Fossilworks]
/ref>[Sepkoski, Jac]
Sepkoski's Online Genus Database – Cephalopodes
/ref>
Species
The following species of ''Cymatoceras'' have been described:[
* ''C. albense''
* ''C. atlas''
* ''C. bayfieldi''
* ''C. bifidum''
* ''C. bifurcatum''
* ''C. carlottense''
* ''C. cenomanense''
* ''C. colombiana''
* ''C. crebricostatum''
* ''C. deslongchampsianum''
* ''C. eichwaldi''
* '']C. elegans
''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' ( ...
''
* ''C. hendersoni''
* ''C. hilli''
* ''C. honmai''
* ''C. hunstantonensis''
* ''C. huxleyanum''
* ''C. karakaschi''
* ''C. kayeanum''
* ''C. kossmati''
* ''C. loricatum''
* ''C. ludevigi''
* ''C. manuanensis''
* ''C. mikado''
* ''C. neckerianum''
* ''C. negama''
* ''C. neocomiense''
* ''C. pacificum''
* ''C. paralibanoticum''
* ''C. patagonicum''
* ''C. patens''
* ''C. perstriatum''
* ''C. picteti''
* '' C. pseudoatlas''
* '' C. pseudoelegans''
* '' C. pseudoneokomiense''
* ''C. pseudonegama''
* ''C. pulchrum''
* ''C. radiatum''
* ''C. renngarteni''
* ''C. sakalavum''
* ''C. sarysuense''
* ''C. savelievi''
* ''C. semilobatum''
* ''C. sharpei''
* ''C. tenuicostatum''
* ''C. tourtiae''
* ''C. tskaltsithelense''
* ''C. tsukushiense''
* ''C. virgatum''
* ''C. yabei''
Description
Its shell is generally subglobular, variably involute with a rounded whorl section. Sides and venter bear conspicuous ribs. The suture is only slightly sinuous and the siphuncle position is variable.[Bernhard Kummel, 1964. Nautiloidea - Nautilida. Treatise on Invertebrate Paleontology Part K. Geol Soc of America and Univ Kans Press, Teichert & Moore (eds)]
''Paracymatoceras'', coeval during the Late Jurassic and Early Cretaceous differs primarily in having a more sinuous suture. ''Neocymatoceras tsukushiense'' from the Oligocene Ashiya Group of Japan, described by Kobayashi, 1954, has been reassigned to ''Cymatoceras''.[
]
Fossil record
Fossils of ''Cymatoceras'' are found in marine strata from the Jurassic until the Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...
(age range: from 155.7 to 23 million years ago.). Fossils are known from several localities:[
;Jurassic
Mexico
;Cretaceous
Antarctica, Argentina, Armenia, Azerbaijan, Chile, Colombia ( Payandé, Tolima and La Guajira), France, Georgia, Germany, Greenland, India, Italy, Japan, Kazakhstan, Madagascar, Mexico, Morocco, Mozambique, Papua New Guinea, Poland, the Russian Federation, Switzerland, Tanzania, Turkmenistan, Ukraine, the United Kingdom, United States (California, New Mexico, Texas).
;Oligocene
Japan
]
References
{{Taxonbar, from=Q5199382
Prehistoric nautiloid genera
Late Jurassic genus first appearances
Oligocene genus extinctions
Mesozoic Antarctica
Cretaceous animals of Africa
Cretaceous animals of Asia
Cretaceous cephalopods of Europe
Jurassic cephalopods of North America
Jurassic Mexico
Cretaceous cephalopods of North America
Cretaceous Mexico
Cretaceous United States
Cretaceous animals of South America
Cretaceous Argentina
Cretaceous Chile
Cretaceous Colombia
Fossil taxa described in 1884