Middle Triassic radiolarians from West Timor, Indonesia

Moderately well-preserved Middle Triassic radiolarians were recovered from bedded limestone exposed at about 3 km west of Kefamenanu, West Timer, Indo nesia. This limestone probably from the Aitutu Formation is considered to b e an allochthonous block and is embedded in the Neogene Bobonaro Complex; T he radiolarian fauna in this limestone is characterized by abundant radiola rians of typical Tethyan forms and is identical to that of the early Fassan ian (early Ladinian) of European Tethys and other related faunas reported f rom the Philippines, Russian Far East, and Japan. The Aitutu Formation is t hought to be deposited in an ocean environment dominated by a warm-water cu rrent system originating from the low latitude Tethyan realm. Fifty-nine sp ecies belonging to 34 genera, including five unidentified genera, are syste matically treated, among them, five new species; Parentactinia suparkai, Ps eudostylosphaera timorensis, Cryptostephanidium? megaspinosum, Tetrarchipla gia compacta, and Planospinocyrtis kefaensis.