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Vertebrate biostratigraphy of Late Permian in Karoo, South Africa,

From: Ben Creisler

A new paper not mentioned yet:

Bruce S. Rubidge, Douglas H. Erwin, Jahandar Ramezani, Samuel A.
Bowring and William J. de Klerk (2013)
High-precision temporal calibration of Late Permian vertebrate
biostratigraphy: U-Pb zircon constraints from the Karoo Supergroup,
South Africa.
Geology 41 (3): 363-366
doi: 10.1130/G33622.1

Therapsid and other tetrapod fossils from the South African Karoo
Supergroup provide the most detailed and best studied terrestrial
vertebrate record of the Middle and Late Permian. The resulting
biostratigraphic scheme has global applicability. Establishing a
temporal framework for these faunas has proven difficult:
magnetostratigraphy has been hampered by a Jurassic overprint, and
intercorrelation with Permian marine sequences has been equivocal.
Here we report U-Pb zircon isotope dilution–thermal ionization mass
spectrometry (ID-TIMS) dates for five volcanic ashes interbedded with
fossils from the Pristerognathus, Tropidostoma, and Cistecephalus
vertebrate biozones of the Beaufort Group. This temporal framework
allows correlation to marine zonations and improves understanding of
rates of faunal evolution and patterns of basin evolution. Our results
identify no correlative vertebrate extinctions in the Karoo Supergroup
to the marine end-Guadalupian mass extinction and raise the question
of whether there is any record of a terrestrial extinction related to
the Emeishan large igneous province.