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Morphological characteristics of a dimorphic pair of Albaillella sinuata Ishiga and Watase: Dimorphism in the lineage of the Permian Albaillellaria (Radiolaria)
Author(s) -
Ito Tsuyoshi,
Matsuoka Atsushi,
Feng Qinglai
Publication year - 2018
Publication title -
island arc
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.554
H-Index - 58
eISSN - 1440-1738
pISSN - 1038-4871
DOI - 10.1111/iar.12271
Subject(s) - sexual dimorphism , permian , biology , radiolaria , zoology , anatomy , paleontology , structural basin
Some taxa of the order Albaillellaria (radiolaria) are dimorphic with normal and swollen types. This study observed and biometrically analyzed the normal and swollen types of Albaillella sinuata Ishiga and Watase from a red chert bed of the Waji section of Ie Island, Okinawa Prefecture, Japan. The distribution of the slimness of the shell body of A. sinuata is bimodal, indicating that the normal and swollen types are clearly dividable. The observational and biometric results indicate that the swollen‐type A. sinuata is characterized by a swollen apical portion and a shorter overall height compared to the normal‐type A. sinuata . Meanwhile, there is no clear difference in the width of the basal part of the shell between the normal and swollen types. Dimorphism composed of the normal and swollen types is recognized within several lineages of the Albaillellaria by a compilation of previous reports of the swollen‐type occurrences in the Permian. Therefore, the dimorphism is a common phenomenon that extends beyond the families within the Permian Albaillellaria.