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Pseudohaploceras is a genus of desmosceratid ammonites from the Early Cretaceous; Valanginian to Albian epochs.

Description

The genus is distinguished by its moderately involute, slightly to moderately compressed shell with convex sides and regular straight or sinuous constrictions between which are fairly fine, distinct, sharp or rounded branching ribs extending from the umbilical edge and crossing the venter, the outer rim.

Pseudohaploceras is considered an offshoot of early Valdedorsella, which differ in having a more broadly rounded whorl section and generally straight radial constrictions. It is included in the subfamily Pizosiinae.

Distribution

Fossils of Pseudohaploceras have been found in Austria, Bulgaria, China, Colombia (Tibasosa Formation, Santa Rosa de Viterbo and Yuruma and Apón Formations, La Guajira), Egypt, Italy, Japan, Mexico, Serbia and Montenegro, Spain, Tanzania, and the former USSR.

References

1. Wright, C. W. with Callomon, J.H. and Howarth, M.K. (1996), Mollusca 4 Revised , Cretaceous Ammonoidea, vol. 4, in Treatise on Invertebrate Paleontology, Part L (Roger L. Kaesler ed.), Boulder, Colorado: The Geological Society of America & Lawrence, Kansas: University of Kansas Press, pp. 73, 72.
2. Pseudohaploceras at Fossilworks.org

Further reading

• W.J. Arkell; et al. (1957). R.C. Moore (ed.). Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L. Geological Society of America, University of Kansas Press.

• Ammonitida genera
• Cretaceous ammonites
• Early Cretaceous genus first appearances
• Early Cretaceous genus extinctions
• Ammonites of Africa
• Cretaceous Africa
• Ammonites of Asia
• Cretaceous Asia
• Ammonites of Europe
• Cretaceous Europe
• Fossils of Serbia
• Ammonites of North America
• Cretaceous Mexico
• Ammonites of South America
• Cretaceous Colombia
• Paja Formation
• Fossil taxa described in 1900