Some graptolites from the late Tremadoc and early Arenig of Yukon, Canada

摘要

Ten graptolite species from upper Tremadoc and lower Arenig strata are described from a 160 m thick, homoclinal, totally exposed section of the Road River Group in the Upper Canyon of Peel River, Yukon. This is believed to be one of the most complete sequences of this age range known to science. Graptolites were collected from 40 levels in the (lowest to highest) Adelograptus antiquus, Kiaerograptus pritchardi, Paradelograptus kinnegraptoides, Tetragraptus approximatus, and Pendeograptus fruticosus biozones. Two new species described are Paradelograptus rallus sp.nov. from the K pritchardi Biozone and Kinnegraptus reclinatus sp.nov. from the Tetragraptus fruticosus Biozone.