The graptolitic age of the type Ashgill Series (Ordovician), Cumbria, UK

Abstract
SUMMARY: The Rawtheyan Stage of the type Ashgill Series, in Westerdale, Cumbria, is shown to be of linearis Biozone age, largely on the basis of extensive new graptolite collections. This is the only reliable graptolite dating of the type Ashgill, although it is possible that the underlying Cautleyan Stage is also of linearis Biozone age. There is no direct evidence for the complanatus, anceps, extraordinarius and persculptus biozones, although these could equate roughly with the top of Ingham’s (1966) zone 7 and his zone 8, the latter embracing the Ashgill (Shales) Formation. A total of 26 graptolite taxa have been identified in the type Ashgill Series, from 26 localities, many of them new. Dicellograptus praeanceps sp. nov. is described.