Cratera obsidiana is a species of land planarian belonging to the subfamily Geoplaninae. It is known from specimens found in the Turvo State Park in Brazil.
Description Cratera obsidiana is a flatworm that can reach up to 40 mm in length. The body is elongate with parallel margins; the front tip is rounded and the back tip is pointed. The dorsal side of the body is a uniform black color, while the ventral side is a light grey.Boll, P. K.; Do Amaral, S. V.; Leal-Zanchet, A. M. (2019). Two new land planarian species (Platyhelminthes: Tricladida: Geoplanidae) from protected areas in southern Brazil. Zootaxa. 4664(4): 535-550
Aside from its coloration, it is distinguished from other members of Cratera by having a posteriorly-shifted cylindrical pharynx and an extrabulbar prostatic vesicle with a T-shaped, dorsally oriented proximal portion.
Etymology The specific epithet is derived from the volcanic rock obsidian, as the glossy black color of the species resembles that of the stone.
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