Fishes of the subfamily Gaidropsarinae, commonly known as rocklings, are anatomically unique within the family Gadidae (Teleostei, Gadiformes), mostly because of their possession of a highly specialized chemosensory and vibratile first dorsal fin. The genus Gaidropsarus contains 13 extant species occurring from subtropical to temperate waters in the North Atlantic, Mediterranean, South Africa, New Zealand, Tasmania, Japan and southeastern Pacific, plus a single fossil species from the Miocene of Algeria. A new species of rockling, Gaidropsarus pilleri sp. nov., is described from the Middle Miocene (Late Badenian) corallinacean limestone of St. Margarethen in Burgenland, Eisenstadt-Sopron Basin, Austria based on seven articulated skeletons. The new species is based on a unique combination of features, including: possession of a wide neurocranium (neurocranial width contained less than two times in its length); well-developed sphenotic spine; epibranchials 2 and 3 characterized by massive uncinate processes; presence of 44 (13 + 31) vertebrae; five posterior parapophyses enlarged, the posterior three wing-like; 2 nd dorsal fin contains about 50 rays; anal fin with 43 rays; caudal peduncle very short (2.4% SL). Gaidropsarus pilleri sp. nov. is the earliest known occurrence of the rocklings based on skeletal remains. The vibratile and chemosensory first dorsal fin of gaidropsarines may have arisen by co-option of the first dorsal-fin module.âą