Silurian

The name and its history

Roderick I. Murchison · 1835

What does the word literally mean?

A people-name borrowed through Roman ethnographic and historical transmission. The underlying name is not securely glossed here.

What did the original author mean?

Murchison’s name commemorated the ancient Silures and their territory in and near South Wales.

Why was the name needed?

He needed a system for an older fossil-bearing succession that he distinguished from other mapped groups.

What evidence supported the original concept?

Welsh-border field sections, lithological sequences and fossil assemblages provided the original comparisons.

How has geology changed the concept?

Much material Murchison originally included became Ordovician after the Cambrian–Silurian controversy was settled.

Further historical context

Roderick Impey Murchison introduced the Silurian System in 1835, taking the name from the Silures of the Welsh Borderlands. His fieldwork identified fossil-bearing formations he regarded as distinct from Sedgwick’s Cambrian.

The Cambrian–Silurian disagreement became a major Victorian stratigraphic controversy. Lapworth’s Ordovician separation in 1879 largely resolved the overlapping middle interval, with the Silurian name confined to a younger succession than Murchison originally envisioned.

Editorial qualification

A putative etymology of the tribal name should not be treated as established.

Related names

Cambrian · Ordovician · Devonian · Llandovery · Wenlock · Ludlow · Pridoli · Early Devonian · Fossil · Stratigraphy

Sources

1. ICS International Chronostratigraphic Chart, 2026/06 — Current name, rank and numerical boundaries
2. Geological Society: Silurian stratigraphy — Murchison’s naming of the Silurian
3. Geological Society: Sedgwick, Murchison and the Welsh controversy — History of Cambrian and Silurian dispute
4. Lapworth (1879), On the Tripartite Classification — Original Ordovician proposal, esp. pp. 13–14