An aberrant bi-apical Follicucullus (Albaillellaria) from the late Guadalupian (Middle Permian), with the possible oldest evidence of double malformation in radiolarians

摘要

An aberrant bi-apical Follicucullus specimen (Albaillellaria, Radiolaria) has been discovered from an upper Guadalupian (Middle Permian) chert block of the Kamiaso Unit of the Mino terrane, central Japan. If this specimen was formed with double malformation, it would be the oldest record of this phenomenon in radiolarians and the first record of its kind in Albaillellaria.