The cephalon is also very large in comparison with the rest of the body, accounting for almost half the animal's total length. Projecting from either edge of the cephalon were genal spines that were longer than the body itself. in addition, along the anterior margin, or front edge, of the cephalon was a fringe that contained rows of small pits. This wide fringe, combined with the long genal spines, may have helped Trinucleus to stay on top of the muddy substrate it lived in without sinking down, working in a similar way as a snowshoe to spread the animal's weight,