Unger, Franz Joseph
Dr. Franz Joseph Unger (1800-1870) was an Austrian botanist and palaeontologist. He ventured outside his natural ‘comfort zone’ when he wrote Die versunkene insel Atlantis (The Sunken Island of Atlantis)[723]. In it he supported the concept of Atlantis as a landmass in the Atlantic,* in an attempt to explain the similarity of flora on both sides of the ocean.*
This was the prevailing theory at the time, which was more fully expounded a couple of decades later by Ignatius Donnelly. Unger’s contribution is now available as a free ebook(a) .
(a) https://books.google.de/books?id=jRVUtihwkhEC&pg=PA1 (German)