It was discovered in eastern Pacific Ocean by a group of Californian and Australian scientists.

[6] Xenoturbella monstrosa is 20 cm (7.9 in) in length, with a purple or pale pink colouration.

The body wall displays several furrows: on the circumference, on the side, and two deep, longitudinal, dorsal ones.

[1] Tissues contain exogenous DNA corresponding to bivalve mollusks, the vesicomyid Archivesica diagonalis and Calyptogena pacifica.

[1] Comparison of mitochondrial DNA and protein sequences showed that the species X. monstrosa is the sister group to X. churro and X. profunda into a clade of 'deep-water' taxa.