Abstract
The acidic tuffaceous strata of the Konomori area in the Kurosegawa Terrane yield Middle Paleozoic radiolarians. This study is focused on the Pridolian (late Late Silurian) and possible Pragian to Emsian (late Early Devonian) radiolarian faunas from the Konomori area. Twenty-two radiolarian species, including 4 new species, are described in this paper. The Pridolian fauna is characterized by Ceratoikiscidae with well-developed patagium. The possible Pragian to Emsian fauna indicates the spread of the three-bladed spines of Entactiniidae and the lamellar patagium of Ceratoikiscidae. It is considered that Ceratoikiscum got the well-developed patagium in Late Silurian time and obtained the lamellar patagium in Early Devonian time.
