Obliquipithonella |
Obliquipithonella transitoria
|
Nd |
Nd |
|
Obliquipithonella |
Obliquipithonella trilamellata
|
Nd |
Nd |
|
Obliquipithonella |
Obliquipithonella williambensonii
|
Nd |
Nd |
|
Omanodinium |
Omanodinium tholus
|
Nd |
Nd |
|
Opaeopsomus |
Opaeopsomus
|
Nd |
Nd |
|
Operculodinium |
Operculodinium microtriainum
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella albatrosiana
|
Nd |
Pleistocene |
|
Orthopithonella |
Orthopithonella compsa
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella globosa
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella gustafsonii
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella porata
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella pycnotheca
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella tithonica
|
Nd |
Nd |
|
Orthopithonella |
Orthopithonella veeversii
|
Nd |
Nd |
|
Ovoidinium |
Ovoidinium fragile
|
Australia(N.Territory) |
Cenomanian |
Early Turonian |
Ovoidinium |
Ovoidinium incomptum
|
England(Isle of Wight) |
Late Albian |
|
Ovoidinium |
Ovoidinium incorporeum
|
England(Isle of Wight) |
Aptian |
Early Albian |