Page:Early Man in Britain and His Place in the Tertiary Period.djvu/71

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
CHAP. III.]
CONTINUITY WITH NORTH AMERICA.
43

strata of Norfolk and Suffolk, and derived from the older marine accumulations.

Continuity with North America.

The researches of Professor Heer into the fossil vegetation of the Continent, Britain, Iceland, Spitzbergen, Greenland, and Grinnell-land, prove that the whole of this portion of the earth's surface was dry land in the early Tertiary period, offering free means of migration to plants and animals from the Polar regions into America on the one hand, and Europe on the other. Among the forms common to the Meiocenes of Europe and the flora of the American continent, we may notice the mammoth tree, magnolia, tulip tree, red wood, and swamp cypress (Taxodium disticum); among the mammalia common to both, the Hipparion; among the reptilia, the alligator-tortoise[1] and a frog,[2] allied to the horned species of Brazil. Similar evidence of direct communication between the two continents is afforded by the Meiocene insects[3] and land crabs (Gecarcinus) of Oeningen, in Switzerland. We may therefore conclude that the barrier of land connecting the British area with Iceland and Greenland in the Eocene, existed in the Meiocene age, and allowed plants which were Eocene in the Polar regions to flourish in Meiocene Europe. The five-hundred fathom line indicates the probable coast-line

  1. Chelydra Murchisoni, Bell. The representative species inhabits the rivers and lakes of the United States, from New York to Florida, and is a rapacious animal, living on fishes, amphibia, and young birds.
  2. Latonia Seyfriedi, Meyer. According to Heer, allied to Ceratophrys cornuta.
  3. The genus Naupactus and others. See Heer, Primeval World of Switzerland, ii. c. i.