- One of the 12 constellations introduced at the end of the 16th century by the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman, and the smallest of them according to modern boundaries. A southern triangle had previously been shown in a completely different position, south of Argo Navis, on a globe of 1589 by the Dutchman Petrus Plancius, along with a southern cross, but they were not the constellations we know today. The modern Triangulum Australe was first depicted in 1598 on a globe by Petrus Plancius and first appeared in print in 1603 on the Uranometria atlas of Johann Bayer.