Desmotersialevinae gen. n.,sp.n.isproposed,basedonmaterialfoundinbathyaloxygenminimumzonesediments
off thecoastofPeru. Desmotersia closely resembles Richtersia in theanimals’generalappearanceandinspiny
ornamentationofthebodycuticle,butclearlydiffersinstomastructureandbythepresenceofadorsaltooth.
The systematicpositionsofthetwogeneraarediscussed,since Desmotersia apparently forms a link between
Selachinematidae and Desmodoridae. Desmotersia levinae is characterized by a variety of spiny ornamentations
anteriorly formed by bipartite spines arranged into a fin-like picket fence,by a head with anasymmetrical cephalic
capsule, presence of two closely spaced ventral longitudinal rows of copulatory thorns,and by 2–4 ventral thorns in mid-tail positions on the male. The interaction between the new species and its habitat is discussed.