SRL for [water]: Some of these arthropods ( whose closest living kin include insects , spiders , and crabs ) were fierce hunters that grew to the size of an adult human , whereas some — such as those without claws or tail spines — likely filtered the [water] for prey or scavenged the sea floor for food .
ARG-M-ADV: the | ARG-2: for prey | ARG-1: or scavenged