Credit: James Hanken
: Photomicrograph of the head of a related species (Thorius pennatulus).
The image shows the prominent eyes (yellow orb, with transparent lens visible inside it) and tongue skeleton (red and blue rods at lower right) that are involved in feeding via tongue protrusion. Bones are stained red, cartilage blue; all other soft tissues are rendered transparent. The entire head is only 3mm long.