Dermechinus is a genus of sea urchin in the family Echinidae found in deep water in the southern Indian, Pacific and Atlantic Oceans.

The species was first described in 1879 as Echinus horridus by the American zoologist Alexander Agassiz, after being dredged from the deep seabed during the Challenger expedition of 1872–1876.

In 1942, it was allocated to the newly erected genus Dermechinus by the Danish zoologist Ole Theodor Jensen Mortensen, a specialist in sea urchins.

[4] D. horridus has a global but discontinuous distribution on the continental slope in oceans in the southern hemisphere; this includes Chile, South Africa, Australia and New Zealand.

[4] Commenting on this suggestion, sea urchin expert F. Julian Fell pointed out that Dermechinus horridus lived in zooplankton-rich waters and that its upright posture resembled that of a filter-feeding sea cucumber; the long spines formed combs and the short spines would be suitable for transporting small particles to the mouth at the base of the animal, with the tiny jaws adequate for ingesting them.