Carpocanistrum spp. |
New comment/discussion
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Revised Benson (1966) taxonomy
Richard N. Benson (11/02/2004) |
In 2003, Richard N. Benson and Kjell Bjørklund revised the taxonomy of the Gulf of California radiolarian species to conform to modern usage. Some of the names of Benson (1966 and 1983) were changed accordingly. See synonymy for previously used names for this taxon.
The Carpocanistrum spp. group includes forms with cepahalis “not markedly distinguished in contour from the ovate thorax” (Riedel and Sanfilippo, 1971, p. 1596). Tests from the Gulf of California vary in the details of shape and breadth of the thorax and the nature of the peristome and peristomal teeth. Features common to the group that are constant characters of the Gulf specimens are 15-22 longitudinal rows of small, equal, hexagonally arranged thoracic pores and a constricted mouth, generally with a hyaline peristome with or without teeth. Specimens from the Gulf identified as Carpocanistrum sp. A (Nigrini) differ from this group in the presence of a cylindrical or nearly cylindrical thorax in all tests and larger pores that are equal, subcircular to hexagonal, arranged hexagonally but in fewer longitudinal rows (9-12 on half the circumference).
Included in the synonymy are several species of Carpocanistrum identified by Takahashi (1991, p. 130-132; pl. 45, figs. 4-10, 12-15) that conform to the characteristics of this (single?) species or species group.
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