Monday, December 29, 2014

Geniculograptus typicalis graptolite from the Verulam formation

Of the two Graptolites that are common in the Verulam formation (middle Ordovician, Katian/Mohawkian stage)of Ontario, Climacograptus typicalis Geniculograptus typicalis is by far the most common. I've found several pieces of it during my many visits but none are very well preserved. Climacograptus Geniculograptus typicalis can be distinguished from the similar looking Diplograptus by the upturned "teeth" along the sides of the colony.

Specimen #1

Specimen #2

I found some better preserved examples of this species near Lusters Gate in Virginia.

Edit 1/4/15 - It has come to my attention that the species Climacograptus typicalis has since been renamed to Geniculograptus typicalis, Thanks to the person who runs the "Dry Dredgers" handle on Facebook. They also provided the following: "Mitchell (1987, p. 381; PDF here: *Climacograptus typicalis* Hall, 1865 as the type species of his new genus *Geniculograptus*. Subsequent authors have supported the validity of *Geniculograptus* and it's been used in graptolite publications as recent as one or two years ago (e.g. Cooper et al 2012; PDF here:

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