Theprotrusiblejaw mechanismis the mostimportant
feature in preycapture.Bonesandmusclesinvolved in jaw
movementwerestudiedbydissectingpreservedspecimens
andcleaningjaws andskullsofmuscle.Thewhole
mechanismofprotrusionofthe mouthpartswasfound to be
controlledbytwo setsofmusclesactingonamodifiedmaxilla whichtogether withthe cross-palatineligament forms a
groovealongwhichthe ascendingprocessofthe maxillacan
slidewhenthe mouthpartsareprotruded.Thesettingupofa
suctionpressurewithinthe mouthfurther aidsthe uptakeof
items from the substrate.However,whetherornotsuction
pressureis applieddependsonthe preytype.