| original |
Late Ordovician |
|
Indiana |
Colbath,G.K. Organic-walled microphytoplankton from the Eden Shale, (Upper Ordovician), Indiana, USA. |
1979 |
| details |
Late Ordovician |
|
Scotland(Ayr) |
Whelan,G.M. Preliminary acritarch and chitinozoan distributions across Ordovician-Silurian boundary stratotype at Dob's Linn, Scotland. (In: A Global Analysis of the Ordovician-Silurian Boundary. L.R.M.Cocks and R.B.Rickards, editors) |
1988 |
| details |
Late Ordovician |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Ordovician |
|
Indiana |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |
| details |
Nd |
|
Nd |
Stancliffe,R.P.W. et al. The acritarch genus Veryhachium Deunff,1954, emend., Sarjeant and Stancliffe,1994: A taxonomic restudy and a reassessment of its constituent species. |
1994 |