Zurcheria
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''Zurcheria'' is a genus of dwarf
ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
s from the
Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...
included in the
Hammatoceratidae Hammatoceratidae is a family of lower and middle Jurassic ammonites included in the superfamily Hildoceratoidea. Diagnosis Hammatoceratidae comprises genera which are characterized by ribbed evolute shells (all whorls visible), some bearing keel ...
and lacking a keel. The shell is evolute, inner whorls exposed; whorls compressed and slightly overlapping. Bears ribs, which are sinuous folds that project strongly onto the arched venter.


References

;Notes ;Bibliography * W.J. Arkell, ''et al.'', 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Geological Society of America and University of Kansas Press. Hammatoceratidae Ammonitida genera Middle Jurassic ammonites {{Ammonitina-stub