Caryosyntrips
Caryosyntrips is an extinct genus of stem-arthropod which known from Canada, United States and Spain during the middle Cambrian. It was first named by Allison C. Daley and Graham E. Budd in 2010, with the type species being Caryosyntrips serratus.
Etymology
The scientific name Caryosyntrips comes from Greek karyon, "nut"; and syntrips, "the smasher", a spirit from Greek mythology.Occurrence
Multiple species had been recovered from the Burgess Shale Formation, Canada, Wheeler Shale and Marjum Formation, United States, and Valdemiedes Formation, Spain. The latter contains a large specimen, which was initially misidentified as a body remain of lobopodian. While the assignment of "Mureropodia" as a misidentified appendage was controversial, the previous lobopodian affinity was less tenable than the fossil being a Caryosyntrips appendage.Description
Caryosyntrips is known only from its 14-segmented frontal appendages, which resemble nutcrackers, with the endite -bearing margin facing each other, and the bell-shaped bases might represent movable articulations with the animal's head. Details of the endites, terminal spines, segmental boundaries and outer margins differ between species. It is thought to have used their frontal appendages in a scissor-like grasping or slicing motion, and were probably durophagous, feeding on hard-shelled organisms. Other structures remain unknown, although a specimen with paired appendages possibly contains fragmentary head sclerites as well.The size of Caryosyntrips differed between each species. The largest species is C. serratus which is estimated around long. Other species are much smaller, with the body lengths of C. camurus and C. durus estimated up to and respectively. The largest possible specimen, identified as C. cf. camurus, would have belonged to an individual measuring between long.