Valdiviathyris is a genus of craniate brachiopods that has changed little since the Silurian, from when fossils are known.

[3][4] It was initially known only from the holotype collected from the southern Indian Ocean, near Île Saint-Paul, at a depth of 672 metres (2,205 ft).

[4] The specimen is considered to be adolescent and has a thin (0.1 mm (100 μm; 3.9-thou) thick) calcareous dorsal valve.

This has an irregular conical shape, with the tip (or apex) not coinciding with the middle, and is on the outside only adorned by growth lines.

Since no fossils of Vadiviathyris have yet been found dating between the Silurian and the Eocene, this genus is currently regarded as a Lazarus taxon.