Steenstrup discovered (1842) the possibility of using the subfossils of the Postglacial as a means of interpreting climate changes and correlated vegetation change, which he called succession in the recent past.[2] Two of Steenstrup's students, Christian Vaupell and Eugen Warming further developed this line of research.
During Charles Darwin's extensive study of barnacles (Cirripedia) between 1846 and 1854, he corresponded with Steenstrup, who sent him both information and specimens. Darwin returned the specimens in 1854, and by way of thanks also sent Steenstrup a box of specimens, with a letter listing the 77 species of cirripedia he had enclosed as a gift. The specimens were dispersed in the Natural History Museum of Denmark; in 2014 staff at the museum found the list, and were able to identify most of the specimens for a new exhibition of their best objects.[4] When Darwin published his series of monographs, he included notes acknowledging his debt to the kindness of Professor Steenstrup for sending him specimens of both modern[5] and fossil barnacles.[6]
Steenstrup, J.J.S. (1842). Geognostisk-geologisk Undersögelse af Skovmoserne Vidnesdam- og Lillemose i det nordlige Sjelland, ledsaget af sammenlignende Bemærkninger hentede fra Danmarks Skov-, Kjær og Lyngmoser ialmindelighed. Det Kongelige Danske Videnskabernes Selskabs Naturvidenskabelige og Mathematiske Afhandlinger, ser. 4, 9: 17–120.
Spärck, R. (1932). Japetus Steenstrup, pp. 115–119 in: Meisen, V. Prominent Danish Scientists through the Ages. University Library of Copenhagen 450th Anniversary. Levin & Munksgaard, Copenhagen.