The place of the Hoplocarida in the Malacostracan pantheon

The stomatopod body plan is highly specialized for predation, yet the Super order Hoplocarida originated from something other than the "lean, mean, kil ling machine" seen today. The fossil record of the group indicates that it originated early on from a non-raptorial ancestor, with the specialized pre datory morphology developing much later. The Recent Hoplocarida have been v ariously positioned within the Malacostraca, from a Subclass equal in rank to the Eumalacostraca (= Caridoida) to being placed as a Superorder within the Eumalacostraca. Consideration of the early fossil morphology, especiall y of the form of the carapace, of the position and functioning of the artic les in the last three pairs of thoracopods, and of other features, suggests that hoplocarids are early derivatives of a basal eumalacostracan stock th at was "shrimp-like" in form. The enhancement of an abdominal respiratory s ystem most likely allowed the development of the anterior thorax into the s pecialized raptorial system present today.