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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 The main conclusion of the work deals with the systematics of a sample of small pteraspids from a yet unpublished sandstone layer in the middle of the Fraenkelryggen Formation, east of the Raudfjord, NW Spitsbergen island.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.