Original: , k ne ` move ' + , rhynchos ` snout ' ) is a phylum of small ( 1 mm or less ) marine pseudocoelomate invertebrates that are widespread in mud or sand at all depths as part of the meiobenthos .
Simplified: Unlike some similar invertebrates , they do not have external cilia , but instead have a number of spines along the body , plus up to seven circles of spines around the headBrusca and Brusca , Invertebrates .