Anticosti Island, Gun River Formation, Member 4 Graptolites (Silurian of Canada)

Where: Québec, Canada (49.5° N, 63.6° W: paleocoordinates 21.1° S, 35.7° W)

• coordinate estimated from map

• local area-level geographic resolution

When: 4 Member (Gun River Formation), Alexandrian (443.4 - 436.0 Ma)

• member-level stratigraphic resolution

Environment/lithology: gray, argillaceous lime mudstone and gray, calcareous shale

• Environmental call by T. Hanson.
• Argillaceous, gray-brown lime mudstone with brown, skeletal wackestone to packstone and intrarudstone (conglomerate), interbedded with thin beds of gray calcareous shale to argillaceous lime mudstone, commonly burrowed. Lithology from C. R. Barnes, A. A. Petryk and T. E. Bolton. 1981. Anticosti Island, Québec. Field meeting, Anticosti-Gaspé, Québec, 1981: IUGS Subcommssion on Silurian Stratigraphy, Ordovician-Silurian Boundary Working Group Guidebook 1:1-24.

Size classes: macrofossils, mesofossils

Collection methods: Graptolites only. From Petryk's 1975, 1976, 1977, and 1979 collections. Collections 79AP45-8-2LF 77AP41-30-3aF.

Primary reference: J. Riva and A. A. Petryk. 1981. Graptolites from the Upper Ordovician and Lower Silurian of Anticosti Island and the position of the Ordovician-Silurian boundary. Field meeting, Anticosti-Gaspé, Québec, 1981: IUGS Subcommssion on Silurian Stratigraphy, Ordovician-Silurian Boundary Working Group, Stratigraphy and Paleontology 2:159-164 [S. Holland/T. Hanson/S. Holland]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 24770: authorized by Steven Holland, entered by Tori Hanson on 19.08.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Pterobranchia
 Graptoloidea - Normalograptidae
"Climacograptus medius" = Normalograptus medius, "Climacograptus normalis" = Normalograptus normalis
"Climacograptus medius" = Normalograptus medius Tornquist 1897 graptolite
"Climacograptus normalis" = Normalograptus normalis Lapworth 1877 graptolite