New Atokan productoid brachiopods from the Upper Carboniferous Ladrones Limestone of southeastern Alaska, with a preliminary note on the phylogeny and classification of the Tribe Retariini

One new genus and two new species of productoid brachiopods of the Subfamil y Productininae are described from the Carboniferous Ladrones Limestone (At okan, late Bashkirian or early Moscovian) of Prince of Wales Island, southe astern Alaska. The new genus Caruthia, type species Caruthia borealis n. sp ., is assigned to the Tribe Productinini. A new species of the genus Rugive stis Muir-Wood and Cooper, 1960, of the Tribe Paramarginiferini, R. girtyi, is similar and probably closely related to Rugivestis pristina Carter and Poletaev, 1998, of approximately the same age, from Ellesmere Island, Canad ian Arctic Archipelago. Discovery of a shagreen texture within the ventral beak region of the gener a Keokukia Carter, 1991, Tesuquea Sutherland and Harlow, 1973, and at least two species of Spinocarinifera Roberts, 1971, necessitates a new interpret ation of the phylogenetic relationships and derivation of the Tribe Retarii ni (Subfamily Productinae). We suggest that Eurasian Antiquatonia Miloradov ich, 1945, and North American Tesuquea Sutherland and Harlow, 1973, were si ster genera, both derived from Keokukia Carter, 1991, common to both contin ents, and probably derived from the Tournaisian Spinocarinifera nigra-arcua ta group.