| original |
Middle Caradocian |
|
USSR(Estonian SSR) |
Uutela,A. et al. Ordovician acritarchs from the Rapla borehole, Estonia |
1991 |
| details |
Middle Ordovician |
|
USSR(Estonian SSR) |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |
| details |
Middle Ordovician |
|
USSR(Estonian SSR) |
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 |