Darwin, C. R. 1853. [Description of Patagonian fossil beds.] In Owen, R., Description of some species of the extinct genus Nesodon, with remarks on the Primary Group (Toxodontia) of hoofed quadrupeds, to which that genus is referable. [Read 25 November 1852 and 13 January 1853] Philosophical Transactions of the Royal Society 143: 309.

RECORD: Darwin, C. R. 1853. [Description of Patagonian fossil beds]. In R. Owen, Description of some species of the extinct genus Nesodon, with remarks on the Primary Group (Toxodontia) of hoofed quadrupeds, to which that genus is referable. [Read 25 November 1852 and 13 January 1853.] Philosophical Transactions of the Royal Society 143: 309.

[page] 309

The fossils above described were discovered on the coast of Patagonia to the south of Port St. Julian, and my friend Mr. CHARLES DARWIN, F.R.S., has kindly communicated to me the following opinion as to the formation in which they were imbedded:—"These beds resemble mineralogically the upper ancient tertiary formation of Patagonia, but EHRENBERG found the included microscopical organisms wholly different from those of the ancient tertiary formation, being of freshwater and brackish origin (p. 117 of my Geological Observations on South America). Hence these beds are of unknown age, probably younger than the old tertiary and older than the superficial beds in which Macrauchenia was found."

Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)