Number 31 January 1998 Newsletter of the Subcommission on ...

Conducted annual business meeting at <strong>the</strong> Strzelecki International
Symposium in Melbourne, Australia.
Work Plan:
<strong>1998</strong>
Sponsor and conduct annual business meeting at Upper
Permian Stratotypes <strong>of</strong> <strong>the</strong> Volga Region International
Symposium, Kazan, Russia (July 28-August 2).
Sponsor and organize a Workshop on <strong>the</strong> marine and
continental Upper Permian stages <strong>of</strong> China for November.
Continue funding for research to establish <strong>the</strong> Lower Permian
stages in <strong>the</strong> sou<strong>the</strong>rn Urals.
Compile, digitize, reprint, and distribute <strong>the</strong> first 10 issues <strong>of</strong>
Permophiles.
Formally propose <strong>the</strong> Guadalupian and Lopingian and <strong>the</strong>ir
constituent stages.
1999
Sponsor and conduct annual business meeting at <strong>the</strong>
Carboniferous-Permian Congress in Calgary, Canada.
Sponsor and participate in <strong>the</strong> International Conference on
Pangea and <strong>the</strong> Paleozoic-Mesozoic Transition, Wuhan,
China.
Sponsor and participate in <strong>the</strong> International Field Conference
on <strong>the</strong> continental Permian <strong>of</strong> <strong>the</strong> Sou<strong>the</strong>rn Alps and
Sardinia (Italy): regional reports and general correlations
in Brescia, Italy.
Compile, digitize, reprint, and distribute <strong>the</strong> second ten
issues <strong>of</strong> Permophiles.
Formally propose <strong>the</strong> constituent stages <strong>of</strong> <strong>the</strong> Lower
Permian.
2000
Conduct annual business meeting at IGC in Rio de Janiero.
Have all stages in at least preliminary formal proposal
process.
Bruce R. Wardlaw
Chair, SPS
Chief Paleontologist
U.S. Geological Survey
926A National Center
Reston, VA, 20192-0001 USA
bwardlaw@usgs.gov
REPORTS
Clarkina (conodont) Zonation for <strong>the</strong> Upper Permian
<strong>of</strong> China.
by Bruce R. Wardlaw and Mei Shilong
Species <strong>of</strong> Clarkina show remarkable diversification in <strong>the</strong>
Permian <strong>of</strong> South China. Detailed taxonomic examination <strong>of</strong> <strong>the</strong>
faunas shows two general lineages developed in <strong>the</strong> early
Wuchiapingian. One, typified by C. leveni, retains a large cusp,
and includes <strong>the</strong> species <strong>of</strong> postbitteri, dukouensis,
asymmetrica, leveni, guangyuanensis, transcaucasica,
orientalis, and longicuspidata. The o<strong>the</strong>r, typified by C.
liangshanensis, shows a progressive reduction <strong>of</strong> <strong>the</strong> cusp and
posterior denticles, and includes <strong>the</strong> species daxianensis,
liangshanensis, inflecta, and demicornis. These successions
<strong>of</strong> species provide a refined zonation for <strong>the</strong> Wuchiapingian.
This zonation was first proposed by Mei et al., 1994. The present
zonation (Table 1) is essentially that <strong>of</strong> Mei, only modifying <strong>the</strong>
orientalis zone by combining <strong>the</strong>ir orientalis and inflecta zones.
The C. inflecta zone is recognized as a subsone <strong>of</strong> <strong>the</strong> orientalis
zone. Though we have C. inflecta from South China and <strong>the</strong>
Transcaucasicus, it appears to be a rare species that is usefull
to characterized <strong>the</strong> upper part <strong>of</strong> <strong>the</strong> orientalis zone on a regional
basis. Clarkina demicornis and C. longicuspidata also
appear in <strong>the</strong> upper part <strong>of</strong> <strong>the</strong> orientalis zone apparently coincident
with C. inflecta. Of <strong>the</strong> Wuchiapingian forms, C.
longicuspidata is <strong>the</strong> only one we have recovered from bed 2 or
above in <strong>the</strong> Meishan section, <strong>the</strong> proposed stratotype for <strong>the</strong>
Changhsingian.
The Changxing Limestone in its type area (Meishan) shows
a single succession <strong>of</strong> Clarkina species that can be characterized
by <strong>the</strong> denticulation on <strong>the</strong> Pa element. The first species
appearing at <strong>the</strong> very base <strong>of</strong> bed 2 in <strong>the</strong> Meishan section is C.
wangi which has a high fused wall-like carina. C. wangi is
followed by C. subcarinata (sensu strictu) which shows partially
fused denticles on <strong>the</strong> posterior end <strong>of</strong> <strong>the</strong> carina and a
relatively high discrete cusp, which is, in turn, followed by C.
changxingensis which shows a marked reduction in <strong>the</strong> carinal
height just anterior <strong>of</strong> <strong>the</strong> posterior cusp, <strong>the</strong> development <strong>of</strong> a
subtle depression or sulcus, and discrete, though small posterior
denticles on <strong>the</strong> carina. C. yini (proposed by Mei et al.
<strong>1998</strong>, as C. changxingensis yini) follows and is characterized
by a high erect cusp and discrete posterior denticles. Finally,
just above <strong>the</strong> top <strong>of</strong> <strong>the</strong> Changxing Limestone appears C.
meishanensis, which shows a large proclined cusp and partially
fused posterior denticles. This species overlaps <strong>the</strong> last
appearance <strong>of</strong> Hindeodus latidentatus, <strong>the</strong> transitional
morphotype from H. latidentatus to H. parvus and <strong>the</strong> first
appearance <strong>of</strong> Hindeodus parvus. Each successive species in
<strong>the</strong> Changhsingian Clarkina overlaps with its predecessor for
short intervals. This detailed analysis provides significant refinement
<strong>of</strong> <strong>the</strong> zonation <strong>of</strong> <strong>the</strong> Changhsingian.
A problem exists in that <strong>the</strong> first appearance <strong>of</strong> C. wangi is
at <strong>the</strong> minor unconformity between bed 1 (a conglomerate loaded
with Clarkina orientalis) and bed 2. Since Clarkina
longicuspidata ranges into bed 2, we have no doubt that it is
<strong>the</strong> probable predecessor to C. wangi. However, in each successive
appearance (and also in all those in <strong>the</strong> Wuchiapingian)
we have transitional morphotypes in <strong>the</strong> interval <strong>of</strong> overlap
that is missing for C. wangi suggesting a hiatus between bed 1
and bed 2 and making <strong>the</strong> base <strong>of</strong> <strong>the</strong> lithologic unit <strong>of</strong> <strong>the</strong>
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