Visual summary of the eight Turritella species

This post is a visual summary (see pictures below) of all the previously posted eight species of Turritella. These species are "index fossils" or "guide fossils" of their respective intervals of time. An "index fossil" is one that is not only indicative of a relatively short interval of time, but one that is readily preserved, widespread, and common. 

     

 Late Cretaceous                                                     early Paleocene                                 middle Eocene
  pescaderoensis                                                      infragranulata                                       lawsoni

late Eocene
sargeanti

early Miocene
inezana

                        

middle Miocene
temblorensis

middle Miocene
ocoyana

late Pliocene to Holocene
cooperi

                                                               
                                                                                  

  IN ORDER TO FINISH UP MY POSTS ON     USING FOSSILS TO "TELL TIME,"MY   NEXT POST WILL EXAMINE A CONCURRENT-TIME ZONE

       (I MENTIONED THIS CONCEPT IN MY POST DEALING
                 WITH MIDDLE MIOCENE TURRITELLA)