The smelliest species of frog is the suitably-named Venezuelan skunk frog (Aromobates nocturnus), whose vile-smelling skin secretion is released for defence purposes and actually contains the same stink-producing organosulphur compound that is present in the famously foul anal emissions released by skunks. Yet in spite of its awful stench, this extraordinary frog remained unknown to science until as recently as 1991 when it was finally described and named. Measuring 6.2 cm (2.44 in) long, it is the largest member of the poison-arrow frog family, Dendrobatidae.