35-million-year-old crab fossils found in Spain for first time

An international research team has documented the first-ever fossil evidence in Spain of Palaeocarpilius macrochelus, a marine carpiliid crab dating back approximately 35 million years. The fossils were discovered in the Calvario de Randa area, located in the central highlands of the island of Mallorca.

While carpiliid crabs have been previously identified in fossil records from the southern Pyrenean basins of Aragon and Catalonia, as well as the southeastern Iberian margin, this finding represents the initial discovery of the Palaeocarpilius genus within the Iberian sphere. Furthermore, it is the first Paleogene decapod fossil to be recorded in the Balearic Islands.

The discovery, made at Puig de Son Veny in Randa, within the municipality of Algaida, is significant. Although carpiliids are relatively common in lower and middle Eocene outcrops in the southern Pyrenean basins of the Iberian Peninsula, the specific genus Palaeocarpilius, considered the most emblematic fossil of the Carpiliidae family, had never been reported there.

Researchers analyzed three marine crab fossils: a nearly complete individual, an isolated propodius (a limb segment), and a fixed finger (part of the claw). These specimens were collected from the surface and are now housed in the collections of the Balearic Museum of Natural Sciences. The morphology of the fossils leaves no doubt about their classification as the genus Paleocarpilius, confidently assigned as Palaeocarpilius macrochelus. This finding supports earlier hypotheses suggesting a notable faunal similarity between the eastern margin of Iberia and the northern Italian peninsula during the Eocene epoch.