Nannotax Enabling nannofossil research

Description: Sphenolithus species with prominent, apical spines formed from a single element.
Taxa included:

• S. heteromorphosus (NN4-5)
• S. belemnos (NN3)
• S. delphix (NN1)
• S. calyculus (NN1)
• S. capricornutus (NN1)

S. heteromorphosus and S. belemnos are common species and key bostratigraphic markers. S. delphix, S. capricornutus and S. calyculus are a group of relativel rare small species with well developed apical spines  charcteristic of the Earliest Miocene.