We thank Dr Maletz for his comments on the graptolite fauna from the North Ballaird Borehole. In identifying the horizon as Yapeenian, we relied partly on the identification of Yutagraptusl v-deflexus. Williams & Stevens thought that their X. declinatus was, like Y.? v-deflexus, a Yapeenian fossil; they, like us, laid more weight on the presence of a supposed index for that unit than on the absence of other such local indices as Oncograptus. We agree that, if one accepts that Xiphograptus declinatus is the same as Yutagraptus? v-defiexus and that both occur in the immediately underlying Castlemainian 4 interval, our...

First Page Preview

First page PDF preview
You do not currently have access to this article.