The genus Heterodactylus now includes a third species of elongate, short-limbed, earless lizards. H septentrionalis is the first new species of the genus discovered since 1862. One species occurs in the high-elevation Atlantic forests of southern Brazil, a second in a few mountainous sites in Minas Gerais. Both are very rare, with only about 15 known specimens in total. The new species was discovered more than 1,000km north of the previous northern record and, like its southern relatives, seems restricted to colder climates.