Pholadomya ludensis is a fossil bivalve of the superorder Anomalodesmata that are marine bivalves with same size valves.
Pholadomya ludensis measures approximately 45–50 mm in length and 32–34 mm in height. The shape looks like a big Marcona almond with peel. Radial striations and transverse lamellae cross each other on the outer surface of the shell.
The specific name ludensis refers to the Ludense stage or age, in the upper Eocene bordering the Oligocene, that was described in 1893 in the French locality of Ludes, near Reims and Paris, based on this fossil bivalve species, Pholadomya ludensis. Subsequent revisions have made Ludense redundant in the current International System of Chronostratigraphy. In the area of Ludes that owns the stratotype, Ludense stage coincides with the currently in use Priabonian stage.
The Pholadomya ludensis specimen in the image comes from Monistrol de Calders (Moianès), in Eocene grey mudstones in the boundary from Bartonian to Priabonian stages (~37 Ma).
[photo Jordi Badia, identification Josep Biosca]