On April 30, 1851 at a meeting of the Geological Society of London, William Logan reported the discovery near Beauharnois, Quebec, of "a track and foot-prints of an animal in the Potsdam Sandstone." This attracted much attention because it seemed to provide conclusive evidence that primitive terrestrial life forms had appeared much earlier than previously thought.
Logan's friend James Wilson, who was a respected amateur geologist, later found similar tracks near Perth, Ontario, and the Geological Survey of Canada collected huge slabs of them. In the one shown, there are at least six separate tracks, the longest about 13 feet, clearly impressed in what was once soft sand or mud. The tracks resemble the impression that would be made by dragging a rope almost seven inches thick across mud. Logan assumed that they were made by gigantic molluscs, and, in 1860, named them Climactichnites wilsoni.
Climactichnites was one of Logan's favourite fossils. Indeed, he often used the room in the Survey's museum at the Montreal headquarters where the slab was hung as his office and bedroom. During the Survey's move to Ottawa in 1881, the fossil slab was broken. It was repaired as best as possible and hung in the Ottawa museum.
Category: Rocks, Fossils, Minerals and Meteorites
Zaslow, M., 1975. Reading the Rocks - The Study of the Geological Survey of Canada 1842-1972; The MacMillan Company of Canada Ltd, Toronto, 599 p.
MacNaughton, R.B., Cole, J.M., Dalrymple, R.W., Braddy, S.J., Briggs, D.E.G., and Lukie, T.D., 2002. First Steps on land: Arthropod trackways in Cambrian-Ordovician eolian sandstone, southeastern Ontario, Canada; Geology, v. 30, p. 391-394. doi:10.1130/0091-7613(2002)030<0391:FSOLAT>2.0.CO;2
Weston, T.C., 1899. Reminiscences among the rocks: in connection with the Geological Survey of Canada; Warwick Bro's & Rutter, Toronto, 328 p. [p. 79 and p. 134-135].