Stratigraphic Range

A horizontal bar chart

This is a bar chart based on the fossil distribution (the stratigraphic range) of a small group of brachiopods from the Order Thecideida (Brachiopoda, Articulata), containing only 34 Genera. Each bar represents a single Genus. The horizontal axis shows time, in millions of years ago (zero representing the present time), while the vertical axis shows the Genera.

Hover over each bar to see information regarding the Genus, Fad (first appearance datum), Lad (last appearance datum) and the time span of that Genus. Change the time scale clicking on “Since first appearance”, “Since Cambrian” (541 million years ago) or “Since Archean” (4 billion years ago). Click on the “Sort” buttons to sort by Lad, Fad, total time span (descending) or Genus name (alphabetically).

Hundreds of Genera

What if our database has hundreds or even thousands of Genera? The chart below uses exactly the same code, but with the data of the Order Atrypida (Brachiopoda, Articulata), which contains 214 Genera. Some modifications were necessary, as removing the names of the genera in the vertical axis.

Source of the data: