Morphology, systematics, and paleoecology of Tridactylastacus (Crustacea, Decapoda, Glypheidea, Litogastridae)

A large assemblage of small specimens of Tridactylastacus sinensis Feldmann, Schweitzer, and Zhang in Feldmann et al., 2012, from the Middle Triassic (Anisian) Luoping Biota, Yunnan Province, China, permitted cladistic analysis confirming their placement within Litogastridae in the superfamily Glypheoidea. Orientation of 86 specimens closely spaced on a single slab from one bedding surface revealed a preferred orientation suggestive of mild current activity. The specimens were interpreted to have been victims of a mass kill, possibly an algal bloom, within the water column.