Marrocanium |
Marrocanium simplex
|
Canada(Newfoundland) |
Arenigian |
|
Marrocanium |
Marrocanium simplex
|
Nd |
Late Arenigian |
Llandeilian |
Mehlisphaeridium |
Mehlisphaeridium fibratum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium acuminosum
|
Nd |
Arenigian |
|
Micrhystridium |
Micrhystridium adductum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium breviacanthum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium brevicornum
|
Poland |
Early Cambrian |
|
Micrhystridium |
Micrhystridium brevicornum
|
USSR(Russian Platform) |
Early Cambrian |
Middle Cambrian |
Micrhystridium |
Micrhystridium coronatum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium exiguum
|
Nd |
Tremadocian |
|
Micrhystridium |
Micrhystridium filiferum
|
Nd |
Late Tremadocian |
|
Micrhystridium |
Micrhystridium inusitatum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium inusitatum
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium pascheri
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium pentagonale
|
Nd |
Nd |
|
Micrhystridium |
Micrhystridium semiapertum
|
Nd |
Nd |
|