Thaumatichthyidae

Thaumatichthyidae, the wolftrap anglers or wolftrap seadevils,wonderfishes, is a small family of marine ray-finned fishes, classified within the suborder Ceratioidei, the deep-sea anglerfishes. They have distinctive upper jaws with movable premaxillaries that can be lowered to form a cage-like trap around the much shorter lower jaw.

Thaumatichthys, the wonderfish or trapjaw anglerfish, is a genus of deep-sea anglerfish in the family Thaumatichthyidae, with three known species. Its scientific name means "wonder-fish" in Greek; oceanographer Anton Bruun described these fishes as "altogether one of the oddest creatures in the teeming variety of the fish world." In contrast to other anglerfishes, the bioluminescent lure (called the "esca") of Thaumatichthys is located inside its cavernous mouth. They are worldwide in distribution and are ambush predators living near the ocean floor.