Oldest Crabs Found: Eight New Species of Crustaceans Discovered in Northern Spain

According to scientist's reports, eight new species of crustaceans, including the oldest known spider crabs that lived over 100 million years ago, have been discovered in a fossil reef in northern Spain.

The fossils were found in the abandoned Koskobilo quarry alongside other species of decapod crustaceans, a group that includes crabs, shrimp and lobsters. Cretamaja granulate and Koskobilius postangustus, the two oldest-known spider crabs, are much older than the previous record holder, according to the study author, Adiël Klompmaker, a postdoctoral researcher at the Florida Museum of Natural History at the University of Florida. 

"The previous oldest one was from France and is some millions of years younger," Klompmaker said, according to LiveScience, also referring to the spider crabs. "So this discovery in Spain is quite impressive and pushes back the origin of spider crabs as known from fossils."

A group of researchers from the U.S., the Netherlands and Spain collected fossils in the Koskobilo quarry in 2008, 2009 and 2010.

"We went there in 2008, and in the first two hours found two new species," Klompmaker said in a statement. "That's quite amazing - it just doesn't happen every day."

The new findings show that approximately 36 decapod species are known to have existed at the abandoned quarry, making it one of the most diverse locations for the creatures at the time. The time period would have been anywhere from 145 to 66 million years ago.

Researchers also found that there were more diverse ancient decapods living within the reefs than in other parts of the ocean.

"One of the main results of this research is that decapod crustaceans are really abundant in reefs in the Cretaceous," Klompmaker wrote in an email. "The presence of corals seemed to promote decapod biodiversity as early as 100 million years ago and may have served as nurseries for speciation."

On a side note, Klompmaker was also part of a team that discovered a new hermit crab at the same quarry,naming it after Michael Jackson (Mesoparapylocheles michaeljacksoni), as it was found around the time the singer died.