The broadnose chimaera, knifenose chimaera, spearnose chimaera, Atlantic long-nosed chimaera, or straightnose rabbitfish (Rhinochimaera atlantica) is a species of fish in the family Rhinochimaeridae found near Canada, Colombia, France, Gambia, Iceland, Mauritania, Mexico, Namibia, Senegal, South Africa, Suriname, and the United States.
Rhinochimaera atlantica has an approximate total length of at birth, and reach maturity at total length for males and total length for females. R. atlantica has a long snout and a straight head profile. Their first dorsal fin is triangular, and the spine of the fin extends beyond the fin tip. It is similar in appearance to Rhinochimaera pacifica, but the two have distinct genetic profiles. They have a maximum total length of at least .
Rhinochimaera atlantica occurs primarily over soft substrate, and has been found in depths from . Its natural habitat is open seas.
Rhinochimaera atlantica is oviparous.
Rhinochimaera atlantica is categorised as Least Concern on the IUCN Red List as it is not targeted and only occasionally taken as a bycatch by trawling fisheries, with no known impact on the population.