WAcanthoceras is an extinct cephalopod genus belonging to the subclass Ammonoidea and family Acanthoceratidae that lived from the Albian to early Coniacian stages of the Cretaceous.
WAcanthohoplites is an extinct genus of ammonites in the family Parahoplitidae that lived in the Aptian and Early Albian stages of the Early Cretaceous.
WAcompsoceras is an extinct genus of cephalopod belonging to the Ammonite subclass. It grew to a large size compared to most ammonites. Its shell reached 18 inches (46 cm) in diameter when the animal reached adulthood. Acompsoceras appears in the fossil record during the early portion of the Cretaceous Cenomanian stage and goes extinct around the middle of that same stage.
WAllocrioceras is an ammonoid cephalopod from the Turonian to Santonian stages of the Late Cretaceous, included in the turrilitoid family Anisoceratidae. Its shell is strongly ribbed and is in the form of a widely open spiral.
WAspidoceras is an extinct ammonoid cephalopod genus belonging to the family Aspidoceratidae.
WBerriasella is a discoidal evolute perisphinctacean ammonite, and type genus for the neocomitid subfamily Berriasellinae. Its ribbing is distinct, consisting of both simple and bifurcated ribs that extend from the umbilical seam across the venter; its whorl section generally compressed, the venter more or less narrowly rounded.
WCleviceras is an extinct genus of cephalopod belonging to the family Hildoceratidae. These cephalopods existed in the Jurassic period, during Toarcian and possibly even uppermost Pliensbachian age. Sometimes, it is considered to be a synonym of Eleganticeras.
WCrioceratites is an ammonite genus from the Early Cretaceous belonging to the Ancyloceratoidea.
WDesmoceras is a genus of ammonites belonging to the family Desmoceratidae. These cephalopods were fast-moving nektonic carnivores. They lived in the Early Cretaceous; Albian epoch.
WDouvilleiceras is a genus of ammonites from the Middle to Late Cretaceous. Its fossils have been found worldwide, in Africa, Asia, Europe, and North and South America.
WEchioceratidae is an extinct family of ammonites that lived during Sinemurian stage of Early Jurassic.
WFagesia is a small, subglobular ammonite belonging to the vascoceratid family of the Acanthocerataceae that lived during the Turonian stage of the Late Cretaceous, 92-88 Ma ago.
WGaudryceras is an ammonite genus belonging to the family Gaudryceratidae.
WHamulina is an extinct ammonoid cephalopod genus belonging to the family Hamulinidae. These cephalopod were fast-moving nektonic carnivores. They lived during the Cretaceous period, Barremiarrean age. The type species is Hamulina astieriana.
WHarpoceratinae is an extinct subfamily of cephalopods belonging to the family Hildoceratidae. Ammonites of this subfamily had involute and compressed shells with strong keels. Keel might be rarely missing, but this is considered to be an abnormality. This has been observed both in Cleviceras and Harpoceras and called as genus Monestieria, which is now known to be invalid. Another example is Pseudolioceras, whose unkeeled specimen was used as type for description of invalid genus Praehaploceras. Oxyconic forms of this subfamily does not have any keel. Ribs were single, but in some genera also bifurcating with shapes from sigmoidal to falcate. Sometimes, shell can have only striate ribs or is smooth. Tubercules are rare. Dimorphism is known in some genera and it is observable mostly in size. Macrochons can be 4, to 6 times larger than microconchs. As an example, macroconchs of Pseudolioceras are more than 150mm in diameter, while adult microconchs are only 35-50mm. There are big size differences even within dimorphs. Specimens ca be 2, or sometimes even 3 times bigger than other specimens of same dimorph.
WHildoceratinae is an extinct subfamily of cephalopods belonging to the family Hildoceratidae. Ammonites of this subfamily had shells with elliptical or quadrate whorl section with keel or tricarinate, bisulcate venter. Ribs were variable, from falcate to strongly angled and from fine to strong. They can be interrupted by spiral groove in midlateral part of the shell. While some species can be smooth, strongly ribbed ones can have tubercules. Microconchs have short lapplets that is in its shape similar to the shape of growth lines in spiral midlateral groove.
WHoploscaphites is an extinct ammonite genus from the Upper Cretaceous, included in the family Scaphitidae.
WKossmaticeras is an extinct ammonoid genus belonging to the desmoceratacean family Kossmaticeratidae. Species in this genus were fast-moving nektonic carnivores. They lived during the Late Cretaceous, from upper Turonian to upper Maastrichtian age. The type species of the genus is Ammonites theobaldianus.
WLyelliceras is a genus of ammonites belonging to the family Lyelliceratidae. These cephalopods were fast-moving nektonic carnivores. They lived in the Cretaceous period, Albian stage.
WMacroscaphites is an extinct cephalopod genus included in the Ammonoidea that lived during the Barremian and Aptian stages of the Early Cretaceous. Its fossils have been found throughout most of Europe and North Africa.
WMammites is a Late Cretaceous ammonite genus included in the acanthoceratoidean family, Acanthoceratidae, and the type genus for the subfamily Mammitinae. Mammites was named by Laube and Bruder in 1887.
WMariella is an ammonoid genus, named by Nowak (1916) from the upper Albian and Cenomanian stages of the mid Cretaceous, included in the Turrilitidae. Its type is Turrilites bergeri
WMenuites is a genus of extinct ammonites, forming a rather small offshoot of Anapachydiscus with a fairly widespread distribution from the Upper Cretaceous Santonian and Campanian stages.
WMortoniceras is an ammonoid genus belonging to the superfamily Acanthocerataceae, named by Meek in 1876, based on Ammonites vespertinu, named by Morton in 1834.
WNeocomites is a genus of ammonite from the Lower Cretaceous, Berriasian to Hauterivian, and type genus for the Neocomitidae.
WOlcostephanus is an extinct ammonoid cephalopod genus belonging to the family Olcostephanidae. These fast-moving nektonic carnivores lived during the Cretaceous, from the upper Valanginian to the lower Hauterivian age.
WPachydiscus is an extinct genus of ammonite from the Late Cretaceous with a worldwide distribution, and type for the desmoceratacean family Pachydiscidae. The genus' type species is P. neubergicus. Altogether some 28 species have been described.
WPerisphinctes is an extinct genus of ammonite cephalopod. They lived during the Middle to Late Jurassic epochs and serve as an index fossil for that time period. The species P. boweni was named after the English chemist and geologist E. J. Bowen (1898–1980).
WPeroniceras is an ammonite belonging to the Ammonitida family Collignoniceratidae.
WPhylloceras is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived from Early Jurassic to Late Cretaceous.
WPhyllopachyceras is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived in the Cretaceous, from Hauterivian to Maastrichtian to age.
WPlacenticeras is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America.
WPolyptychoceras is an extinct genus of ammonites from the Late Cretaceous of Asia, Europe, and North and South America. It was first named by Hisakatsu Yabe in 1927.
WPseudoaspidoceras is an extinct genus of ammonites in the family Acanthoceratidae.
WPseudocrioceras is an extinct genus of ammonites. The species Pseudocrioceras anthulai has been found in strata from the Barremian - Aptian age of Chipatá, Santander, Colombia and is known from Georgia and Dagestan. The species Pseudocrioceras duvalianum and Pseudocrioceras fasciculare are found in the Barremian of France.
WPuzosia is a genus of desmoceratid ammonites, and the type genus for the Puzosiinae, which lived during the middle part of the Cretaceous, from early Aptian to Maastrichtian. Sepkoski defines the range from Albian to Santonian. The generic name comes from the Serbian words "Puž" (snail) and "oce/ose" (axis), gaining its name from the shell's snail-like appearance.
WScalarites is a genus of heteromorph ammonites included in the family Diplomoceratidae. These fast-moving nektonic carnivores lived in the Cretaceous period, from 89.3 to 70.6 million years ago). These fossils have been found in Antarctica, Brazil, Denmark, Germany, Japan, Russia, Sweden and United States.
WSchlotheimia is a genus of extinct cephalopods belonging to the subclass Ammonoidea that lived during the Hettangian stage at the beginning of the Early Jurassic.
WSphenodiscus is an extinct genus of acanthoceratacean ammonite. The genus has been found from many continents and is thought to have had a large global distribution during the Maastrichtian stage of the Late Cretaceous. It was one of the last ammonoids to have evolved before the entire subclass became extinct at the end of the period during the Cretaceous–Paleogene extinction event.
WSpitidiscus is a genus of ammonites placed in the family Holcodiscidae.
WTissotia is a genus of ammonites belonging to the family Tissotiidae.
WTurrilites is a genus of helically coiled ammonoid cephalopods from the lower part of the Upper Cretaceous ; generally included in the Ancyloceratina. Previously it was included in the ammonoid suborder, Lytoceratina.
WUptonia is an extinct ammonite from the Lower Jurassic that's included in the eoderoceratoidean family Polymorphitidae.
WVascoceras is an extinct genus of Cretaceous ammonites included in the family Vascoceratidae. These fast-moving nektonic carnivores lived in the Cretaceous period from the late Cenomanian to the early Turonian. The type species of the genus is Vascoceras gamai from Portugal.