you mean they ate each other, but what would be the benefit?
UNANSWERABLE
please tell me more about jaekelopterus It is a genus of predatory eurypterid, a group of extinct aquatic arthropods. is their species still alive? UNANSWERABLE where can they be found? It lived in non-marine aquatic environments. you mentioned that these were predators, what more can you tell me about them as predators? Fully grown "Jaekelopterus" would have been apex predators in their environments and likely preyed upon smaller arthropods (including resorting to cannibalism) and early vertebrates.
wiki:16291449
Jaekelopterus [SEP] Lifestyle and environment
The morphology and body construction of "Jaekelopterus" and other eurypterids in the Pterygotidae suggests they were adapted to a completely aquatic lifestyle. Braddy, Poschmann and Tetlie considered in a 2007 study that it was highly unlikely that an arthropod with the size and build of "Jaekelopterus" would be able to walk on land. Eurypterids such as "Jaekelopterus" are often popularly referred to as "sea scorpions", but the deposits from which "Jaekelopterus" fossils have been discovered suggest that it lived in non-marine aquatic environments. The Beartooth Butte Formation in Wyoming, where "J. howelli" fossils have been discovered, has been interpreted as a quiet, shallow estuarine environment.