Oswald Heer (or Oswald von Heer) (31 August 1809 - 27 September 1883), Swiss geologist and naturalist, was born at Niederuzwil in Canton of St. Gallen and died in Lausanne. Oswald Heer was educated as a clergyman at Halle and took holy orders, and he also graduated as Doctor of Philosophy and medicine. Early in life his interest was aroused in entomology, on which subject he acquired special knowledge, and later he took up the study of plants and became one of the pioneers in paleobotany, distinguished for his researches on the Miocene flora.
In 1851 Heer became professor of botany in the university of Zurich, and for some time he was the director of what is now the Old Botanical Garden in that city. He directed his attention to the Tertiary plants and insects of Switzerland. In 1863 (with William Pengelly, Phil. Trans., 1862) he investigated the plant-remains from the lignite-deposits of Bovey Tracey in Devon, regarding them as of Miocene age; but they are now classed as Eocene.
Heer also reported on the Miocene flora of Arctic regions (fossil plant remains brought back from Northwest Greenland by K. J. V. Steenstrup), on the plants of the Pleistocene lignites of Durnten, and on the cereals of some of the lake-dwellings (Die Pflanzen der Pfahlbauten, 1866). Charles Darwin regarded Heer as an authority on fossil plants, and corresponded with him. The two men disagreed over evolution, but were on cordial terms.
In a letter in 1875, Heer described to Darwin in some detail a new dicotyledonous angiosperm fossil that he had identified in the lower Cretaceous in the arctic, which appeared to allow slightly more time for the evolution of dicots than Darwin had previously been aware of. Heer published a critique of Darwinism in volume 2 of his 1867 book The Primaeval World of Switzerland, concluding "All these facts afford arguments against a slow and uniformly progressive transformation of species, and lead to the conclusion that the transformation of organic nature took place in a period of comparatively limited duration" (p. 288).
He believed in progressive creation: "Times of creation occurred during which was accomplished a remoulding of organic types, and there was a primaeval epoch during which the first species were brought into being. Even if the first species were extremely simple, for them an act of creation must be admitted, an act without example in modern times; for in our days plants and animals of decidedly low forms proceed from species already in existence" (p. 291, The Primaeval World of Switzerland).
During a great part of his career Heer was hampered by slender means and ill-health, but his services to science were acknowledged in 1874 when the Geological Society of London awarded to him the Wollaston medal. He died at Lausanne on 27 September 1883. Heer published Flora Tertiaria Helvetiae (3 vols., 1855-1859); Die Urwelt der Schweiz (1865), and Flora fossilis Arctica (1868-1883) and with Eduard Heinrich Graeffe. The cape Heerodden in Nordenskiold Land on Spitsbergen is named after him.