Taxonomic and biostratigraphical significance of the Tremadoc graptolite fauna from northern Yukon Territory, Canada

• Published in: Geological Magazine
• Main Authors: JACKSON, D. E., LENZ, A. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2003
• Subjects: Geology; Yukon; Canada; Peel River; Road River
• Online Access: http://dx.doi.org/10.1017/s0016756802007227; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756802007227

Twenty-two graptolite species are described from the Tremadoc portion of the Road River Group. In a 220 m thick, graptolite-rich section on Peel River, six graptolite biozones are recognized which in ascending order are: Staurograptus dichotomus, Anisograptus matanensis, Adelograptus cf. A. tenellus, Adelograptus antiquus, Kiaerograptus pritchardi and Paradelograptus kinnegraptoides . The Psigraptus fauna appears to be confined to a single bedding-plane within a thick interval dominated by Adelograptus cf. A. tenellus , and for this reason we propose a new zone characterized by the latter species rather than identify a Psigraptus Biozone as in China. The Adelograptus cf. A. tenellus Biozone has yielded Adelograptus ? bulmani Spjeldnaes 1963, which we propose as the type species for the new genus Ancoragraptus . Graptolites recorded from the Tremadoc of the Yukon for the first time are: Ancoragraptus bulmani, Clonograptus magnificus, C . cf. C. multiplex, C . cf. C. rigidus, Hunnegraptus copiosus, Kiaerograptus ? bulmani and K ? kutchini sp. nov.