Fig 11. Distribution of important traits of the frontalmost appendage among the three main stem body plans considered herein (from top to bottom): dinocaridid, stem ‘bivalved’ and megacheiran.
The question mark (3rd row, column c) refers to the problematic condition of Sanctacaris Briggs and Collins. Characters: a: secondary processes on inner spines; b: double row of inner spines; c: elongate, slender inner outgrowths; d: rounded undifferentiated tip; e: composition of distal “hand” formed by the differentiation of inner spines; f: composition of distal “hand” formed by the differentiation of outer spines.