Geometrical Variations of the Skeletal Structures of Genus Pantanellium as Determined from Collected Specimens

Takashi Yoshino , Atsushi Matsuoka, Katsunori Kimoto, Naoko Kishimoto

Novel graph and string representations of the cortical shell structures of the genus Pantanellium, a Mesozoic radiolarian, are proposed. The representations are then used to compare the frame structures of fifty-nine specimens collected for the study. Among the fifty-nine fossil specimens, forty-seven different structures were found. It was also found that the frequency of the truncated icosahedron structure deviates significantly from the others. Although the proposed representations work well as a means of approximating and comparing frame structures, they appear to be too sensitive to classify the specimens.