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Pierre-Yves also
collaborates to a study of Silurian vertebrate
microremains collected in 1994 on the Baillie Hamilton
and Cornwallis Islands. He participated to the IGCP 406
meeting in Buckow (Berlin), last July where he gave a
talk on the Drake Bay material (see Gagnier et
al., 1997).
Daniel
Goujet(Paris)
attended IGCP 406 in St.
Petersburg with two main topics: 1) to compare
palaeontological, stratigraphical and biogeographical
data on Palaeozoic vertebrates of the Russian Arctic with
those of other
Arcticregions (Spitsbergen
in particular) -- study of the VSEGEI collections in St.
Petersburg are crucial for this point; 2) to proceed with
the editing of a collective book on the palaeontology and
palaeogeography of Severnaya Zemlya in Silurian-Devonian
times [D. Goujet & H. Lelièvre (eds),
Geodiversitas].
Alain
Blieck(Lille)
Three main events
correspond to my IGCP 406 activity this year.
1.-- February 25 - March 3, 1997, Universidade do
Algarve, UCTRA (Unidade de Ciencias e Tecnologias dos
Recursos Aquaticos), Faro, Portugal.
Constança
BEXIGA has defended her "licenciatura" thesis on
"Pteraspidiformes (Agnatha, Heterostraci) of the Lower
Devonian, Fraenkelryggen Formation of Spitsbergen:
morphology and biometrics" on February 26 in Faro. The
jury was composed of Prs J.P. Andrade and T.C. Borges,
and A. Blieck. The defence was successful. The main
conclusion of the work deals with the systematics of a
sample of small pteraspids from a yet unpublished
sandstone layer in the middle of the Fraenkelryggen
Formation, east of the Raudfjord, NW Spitsbergen island.
This sample is composed of individuals (dorsal and
ventral shields of the head carapace) which
morphologically may be divided in two lots: one of
shorter, wider shields; one of longer, narrower shields.
However, the biometrical analysis has shown that they
correspond to a single "population". This population is
considered to represent a new sample of Protopteraspis
aquilonia(Bexiga,
1997).
After
this defence A. Blieck, C. Derycke and C. Bexiga were
four days in the field in SE Alenteje (Pomarao region)
and W Algarve (Bordeira region), looking for Upper
Devonian-Lower Carboniferous vertebrate microremains of
the South Portuguese Zone, where chondrichthyan
ichthyoliths had been mentioned in conodont-bearing beds
(Oliveira, 1983; Van den Boogaard, 1990). Several limy
sandstone layers have been sampled for acid
leaching.
2 -- July 4-6,
1997, Buckow (Berlin), Germany: IGCP 406 meeting
"Circum-Arctic Palaeozoic vertebrates -- biological and
geological significance".
Oral
communication
of
C.
BEXIGA
&
A.
BLIECK
(speaker)
on
"New
data
on
pteraspids
(Pteraspidomorphi, Heterostraci) of the Lower Devonian,
Fraenkelryggen Formation of Spitsbergen" [see
above]; and report of the activities of the French
Working Group on the Russian (Severnaya Zemlya), European
(Spitsbergen) and Canadian Arctic [see this
report].
3
-- July 10-21, 1997, Vilnius, Lithuania: IGCP 406
workshop on Lower and Middle Devonian heterostracans of
the Russian Arctic (Severnaya Zemlya) -- A. BLIECK &
V.N. KARATAJUTE-TALIMAA.
This
joint project is part of a collaborative work on the
Silurian-Devonian series of Severnaya Zemlya. A first
memoir on the stratigraphy will be published in Russian
(R.G. Matukhin & V.V. Menner coord.); a second memoir
on the palaeontology will be published in English in
Geodiversitas(ex
Bull. Mus. natn. Hist. nat., Paris; D. Goujet
& H. Lelièvre coord.). The main aim of the
workshop held in Vilnius was to study the Early and
Middle Devonian heterostracan assemblages of the October
Revolution Island (except psammosteids which E. Mark-
Kurik is in charge of) (heterostracans are unknown in the
Silurian of this island). A preliminary result of this
workshop is the following list of taxa:
Tesseraspis
mosaica, T.sp.,
Corvaspissp.
cf.
C.
kingi,
C. sp.,
C.? sp.,
C. sp.
cf.
C.
graticulata,
Phialaspissp.,
P.? sp., Traquairaspidiformes indet.,
Poraspissp.
cf.
P.
polaris,
P. sp.,
Homalaspidellasp.,
Irregulareaspissp.,
I.?
sp.,
Anglaspisnov.
sp.,
Ctenaspisnov.
sp.,
Ct.
sp.,
Putoranaspis?
sp., Amphiaspidiformes
indet., Amphiaspidiformes? indet.,
Unarkaspis? sp.,
Protopteraspis?
sp., Miltaspis?
sp., Protopteraspididae nov. gen. et sp. 1,
Protopteraspididae nov. gen. et sp. 2,
Gigantaspis? sp., Pteraspidiformes indet.
The taxon provisionally
named Protopteraspididae nov. gen. et sp. 2, from the red
detrital Vstrechnaya Formation, is dated Middle Devonian
(Eifelian
inKaratajute-Talimaa
&
Matukhin, 1997) after its
associated vertebrate fauna (placoderms,
sarcopterygians,
psammosteids).It
is
one
of
the
rare
Middle
Devonian Pteraspidiformes
(sensuBlieck,
1984).
Other subjects of
interest were about Siluro-Devonian heterostracans of
eastern Europe (Podolia, East Baltic, Timan-Pechora) and
Spitsbergen, as well as about Ordovician-Silurian
microremains of Siberia and Mongolia, and
Silurian-Devonian acanthodians (with J.J.
Valiukevicius).
During 1998, the study on
the Devonian heterostracans of Severnaya Zemlya has to be
completed. Black and white photographs of most specimens
will be taken (V.N. Karatajute-Talimaa). The anatomical
study has to be continued in Vilnius (A. Blieck in July
1998). When finished, the results on this group together
with the study of other groups of fossils (osteostracans,
thelodonts, placoderms, sarcopterygians, acanthodians,
arthropods, brachiopods, plants, etc.) will allow to
proceed with a full taxonomical list within the
stratigraphical record of the Silurian-Devonian of
Severnaya Zemlya. This should provide us with refined
biostratigraphical correlations between the Russian,
European, and Canadian Arctic Siluro-Devonian
sequences.
**************
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