1. A composite standard biostratigraphic database for assessing rates of foraminiferal origination and extinction during the Late Paleozoic ice age John R. Groves, Department of Earth Science, University of Northern Iowa
Biostratigraphic data from 60 localities in the central and
southwestern United States have been compiled into a composite
standard database. This compilation will enable estimation of
origination and extinction rates, diversity trends and lineage
durations for glacial vs. non-glacial time intervals.
Illustration at right shows
the Late Paleozoic geologic
time scale along with 60
vertical lines. Each line
represents the timespan of
a locality from which detailed
biostratigraphic information
has been obtained. The data-
base is a compilation of data
from all 60 localities.