Lochkovian

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Lochkovian

The Lochkovian is the first stage of the Early Devonian, the beginning of the Devonian Period. It lasted from about 419.6 million years ago to about 413.0 million years ago.

Origin of the name
It is named after the village of Lochkov in the Czech Republic, now part of Prague.

Key boundaries and where they are defined (GSSP)
- Lower boundary: defined by the first appearance datum (FAD) of the graptolite Monograptus uniformis. The Global Boundary Stratotype Section and Point (GSSP) is at the Klonk Section in Prague, Czech Republic (Lochkow Formation).
- Coordinates of the Klonk section: approximately 49.8550°N, 13.7920°E.
- Upper boundary: defined by the FAD of the conodonts Eognathodus sulcatus and Latericriodus morph beta. The GSSP is at Velká Chuchle quarry, Prague, Czech Republic (Velká Chuchle, in the Prague area).

placement in the time scale
- The Lochkovian is the earliest stage of the Devonian Period (Early Devonian) and is followed by the Pragian.
- In North America, the Lochkovian roughly corresponds to the Gedinnian or Helderbergian intervals.

What it represents
- The Lochkovian helps mark the start of the Devonian, a time of significant evolutionary changes and environmental shifts on Earth.