No one living has seen it. But it swam in the deep waters around New Zealand for millions of years – a ghost of the abyss, a chimaera with tusks. A fish the length of a small car, with a twisting, tapering tail like a whip, wing-like fins that beat slowly through the dark, and a pair of tusk-like teeth projecting from its upper jaw. It glided through the submarine canyons off the Chatham Rise, hunting squid and crabs and whatever else lived in the eternal dark. That was the tusked pelagic phantom, and it is gone. Its tusks made it special. Chimaeras are ancient fish – relatives of sharks and rays, but distinct. They have cartilaginous skeletons, claspers for mating, and tooth plates instead of individual teeth. Most chimaeras have beak-like tooth plates for crushing shellfish. But this one had tusks – long, curved, tusk-like projections from the upper jaw, used for gripping and tearing. No living chimaera has anything like it. It hunted in the deep. The continental shelf around New Zealand drops off into deep canyons and abyssal plains – a dark, cold world of soft sediments and slow-moving creatures. The tusked chimaera was a predator of this world, using its wing-like fins to glide silently through the water, its long tail for propulsion, its tusks for grasping slippery prey. It probably ate squid, octopus, large crabs, and perhaps smaller chimaeras. It may have used its tusks to dig prey from the sediment or to defend itself against the giant sharks that also roamed these waters. Chimaeras reproduce slowly. They lay large, leathery egg cases – sometimes called mermaid's purses – on the seafloor. The eggs take months to hatch. The young grow slowly, reaching maturity after many years. A giant chimaera would have taken even longer – perhaps decades to reach full size. That strategy works when the deep is stable. It fails when the trawlers arrive. Deep-sea trawling destroyed it. In the late 19th century, fishermen began trawling the deep waters around New Zealand for orange roughy, hoki, and other commercially valuable fish. Bottom trawls – giant nets dragged across the seafloor – destroyed everything in their path. The tusked chimaera, which lived on or near the bottom, was caught as bycatch. Its slow reproduction could not keep pace with the mortality. At the same time, its prey species – squid, crabs, deep-sea shellfish – were also depleted by trawling. The chimaera starved. The trawlers kept fishing. By the 1920s, it was gone. The last specimens were probably hauled up in a trawl net, discarded as bycatch, their bodies thrown back into the sea. No one knew they were the last. The smaller chimaeras survived. The ghost sharks and ratfish still glide through the deep waters around New Zealand – smaller, less spectacular, but alive. They are the survivors, the cryptic ones, the fish that kept their heads down. But the tusked phantom is extinct. A few tooth plates in a museum drawer, a few fragments of cartilage, and the memory of a fish that used to glide through the submarine canyons, its tusks gleaming in the dark. We trawled its home. Then we wondered why the deep felt so empty.