May 1. The Devonian begins.

I think you’ll enjoy the Devonian. You can look forward to interesting developments in life on land and in the seas, and some interesting rock formations and tectonic events. 

As with most of the early Paleozoic periods, the Devonian was defined in Britain – but not without some controversy. Adam Sedgwick and Roderick Murchison, whose friendship dissolved in a fight about the Cambrian and Silurian, worked together to describe the Devonian in the 1830s. The controversy arose between Sedgwick and Murchison on one side and Henry de la Beche on the other. De la Beche was the first director of the British Geological Survey when it was established in 1835 – a powerful antagonist.

The quarrel was over the stratigraphic placement of some fossils from the younger Carboniferous coal measures – later than the Silurian or the proposed Devonian. This controversy was nothing like the one that developed a few years later between Sedgwick and Murchison over the Cambrian-Silurian boundary, and although it took a few years, and research that took Murchison as far afield as Russia, de la Beche came around to his opponents’ view and the Devonian Period was established and accepted by about 1840.

The period is named for Devonshire, the county in southwestern England where a good section of the rocks crops out.

—Richard I. Gibson