Contributions Series Nr. 10

Description

Abstract

A total of three hundred twenty-nine species of acritarchs from sixteen geographic areas of North America have been reported in the literature. Their currently known North American geologic ranges suggest the following distribution: forty-eight are currently restricted to the Early Devonian (Gedinnian, Siegenian, Emsian), seventy-six are currently restricted to the Middle Devonian (Eifelian, Givetian), and one hundred forty-eight are currently restricted to the Late Devonian (Frasnian, Famennian). Additionally, twenty- three occur in both the Early and Middle Devonian, eighteen occur in both the Middle and Late Devonian, while sixteen range from the Early Devonian through Late Devonian.

The North American geographic areas from which acritarchs have been reported are: The Great Slave Lake area of the Northwest Territory, Alberta, Saskatchewan, New Brunswick, and Ontario, Canada; Georgia, Illinois, Indiana, Iowa, Kentucky, Michigan, Montana, New York, Ohio, Oklahoma, and Tennessee, United States of America.

All known validly published North American Devonian acritarchs are listed with their North American geographic occurrence and stratigraphic range.

One new combination, Pterospermella onondagaensa (Deunff) Wicander n. comb. ==Pterospermopsis onondagaensis Deunff, 1955, p. 148, fig. 27, has been made.

Examination of the geographic areas where acritarchs have been reported and the geologic ranges of the species, indicates a tremendous amount of basic taxonomic and stratigraphic documentation is still necessary before any comprehensive ranges and/or zonations can be established for North America.