Ludlow and Pridoli (Upper Silurian) graptolites from the Arctic Islands, Canada

The present study examines the isolated, uncompressed as well as flattened forms from the Ludlow and Pridoli (Upper Silurian) graptolites of the Arctic, recognizing 46 species of monograptids and retiolitids of which seven are described as new species or subspecies. Graptolites flourished from earliest Ordovician to Early Devonian, a time range of about 90 million years, and were widely distributed as marine benthic and planktonic colonial organisms around then-world