Upper Ordovician and Lower Silurian chitinozoans from central Nevada and Arctic Canada

Late Ordovician and Early Silurian chitinozoans from the uppermost Vinini F ormation, and the Hanson Creek Formation in central Nevada and the lower Ca pe Phillips Formation, Cape Manning section, in Arctic Canada have been re- investigated and a new chitinozoan biozonation is proposed. The Upper Ordov ician of central Nevada can easily be correlated to that of Arctic Canada t hrough the common occurrence of the Ordochitina nevadensis biozone in both regions. No such correlation, however, is possible with the Late Ordovician of Anticosti Island in eastern Canada because of the absence of the index Upper Ordovician chitinozoan zonal species of central Nevada such as Belone chitina tenuispinata sp. nov, Ordochitina nevadensis sp. nov. and Nevadachi tina vininica gen. nov., sp, nov, in the former area. One new genus, Nevadachitina, and nine new species, Eisenackitina ripae, Be lonechitina martinica; Nevadachitina vininica, Nevadachitina praevininica, Ordochitina nevadensis, Belonechitina tenuispinata, Belonechitina parvispin ata, Tanuchitina laurentiana, Angochitina hansonica are described and illus trated in this paper and four species are left in open nomenclature. (C) 20 00 Elsevier Science B.V. All rights reserved.