[1][2][3] They are relatively large lobsters with a cylindrical body covered with sharp spines (hence the genus name, meaning "spiny shrimp").

The eyes are very small and lack pigment, while the antennae are long and whiplike.

The first pair of claws is symmetrical and ends in long fingers covered with sharp spines on cutting edges but without hairs.

[1] Acanthacaris has a laterally compressed rostrum, a unique arrangement of postcervical and cellar grooves, a large and elongate scaphocerite, and delicate, elongate claws with cylindrical palms.

[1][4] Although the replacement name (nomen novum) "Neophoberus" was provided by Martin Glaessner in 1969,[5] this is pre-dated by Charles Spence Bate's 1888 name Acanthacaris, which has A. tenuimana as the type species.