parent_taxon zurcherella
The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago ( ___MASK6___ ) to the beginning of the Paleogene Period ___MASK6___ . It is the last period of the Mesozoic Era . The Cretaceous Period is usually abbreviated K , for its German translation " Kreide " ( chalk ). A stratigraphic column is a representation used in geology and its subfield of stratigraphy to describe the vertical location of rock units in a particular ___MASK65___ . Uhligella is an extinct cephalopod genus from the Early Cretaceous belonging to the ammonoid subclass and included in the ___MASK37___ . The Aptian is an age in the geologic timescale or a stage in the stratigraphic column . It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125 . 0 ± 1 . 0 Ma to 113 . 0 ± 1 . 0 Ma ( million years ago ), approximately . The Aptian succeeds the Barremian and precedes the Albian , all part of the Lower / Early Cretaceous . Zurcherella is a Lower Cretaceous ( Upper Barremian - Upper Aptian desmoceratid ___MASK43___ . Its shell is moderately compressed and rather involute ( outer whorls covering most of the inner ) , with fine sinuous ribs that arise some distance above the umbilical rim . Zurcherella differs from its descendant Uhligella in that in the latter , ribs arise from the umbilical shoulder . Zurcherella is the earliest of the desmoceratid subfamily Beudanticeratinae , which includes among others , Uhligella , Beutanticeras , and Beutantiella . ___MASK37___ is a family belonging to the ammonite subclass . They are an extinct group of ammonoids , shelled cephalopods related to squid , belemnites , octopuses , and cuttlefish , and more distantly to the nautiloids , that lived between the Lower Cretaceous ( Upper Valanginian ) and Upper Cretaceous ( Upper Maastrichtian ). The Barremian is an age in the geologic timescale ( or a chronostratigraphic stage ) between 129 . 4 ± 1 . 5 Ma ( million years ago ) and 125 . 0 ± 1 . 0 Ma ). It is a subdivision of the Early Cretaceous epoch ( or Lower Cretaceous series ). It is preceded by the Hauterivian and followed by the Aptian stage .