''Garantiana'' is a genus of
ammonites
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) ...
from the
Bajocian
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age.
Stra ...
stage at the beginning of the Middle Jurassic, included in the family
Stephanoceratidae.
Description
''Garantiana'' is strongly ribbed and generally evolute. The inner whorls are exposed in a wide and fairly deep umbilicus. Ribs arise at the umbilical margin and split in two (bifurcate) about midway up the sides and cross over the outer (ventral) rim.
''Garantiana'' was named by d'Orbigny, 1845. The type species is ''Garantiana garantiana'', which comes from France. Related genera include ''
Orthogarantiana'' ''
Pseudogarantiana'', and ''
Strenoceras''.
References
External links
''Garantiana''in Hildoceras webpag
''Garaniana''pictured in the Fossil Foru
Jurassic ammonites
Ammonites of Europe
{{ammonite-stub