How much attention do you pay to the ground beneath as you walk down the street? Undoubtedly not enough, if this remarkable story from Girona, Spain, is any indication.

Paleontologists have identified a rare fossil of an ancient sea cow in a slab of pavement on a Spanish street. The pavement has likely been stepped on by countless oblivious pedestrians, perhaps distracted by the lovely scenery in the picturesque town of Girona, since it was first placed over two decades ago, reports

"While the limestone used to build the city of Girona are enriched by fossils — it is quite common to identify invertebrates for example — finding a marine mammal on which thousands of people walked over for the last two decades is indeed very peculiar," said paleontologist Dr. Manja Voss, who visited the fossil after its discovery.

A sea cow is an extinct, manatee-like marine creature that once roamed the world's oceans. This fossil is most likely a representative of Prototherium, a genus of sea cows from Spain and Italy. The rock that the fossil was found in dates to around 40 million years ago, which makes this specimen one of the oldest sea cows ever found in Europe. It offers an exciting opportunity for researchers to fill in some gaps in sea cow evolution.

The fossil itself is a cross-section of the animal's backbone and skull, and wasn't identified until a curious geologist walking through Girona took notice to the unusual patterns in the pavement and submitted his pictures to an online fossil database. After the stone's significance was understood, researchers petitioned to have it removed from the street for closer study. CT scans were later used to digitally piece together the separate skull slices and form a more complete picture of the creature, including knowledge about the age at which it likely died.

The find opens up further questions about what kinds of discoveries might be hiding in the pavement all around us. Dinosaurs? Giant sloths? Sabertooth tigers? Ancient humans? Perhaps it's time to start looking down at that sidewalk while you're out walking. There are discoveries awaiting you, even in places where the land has been covered in concrete and stone ... even in the bustling city.

Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Ancient sea cow fossil found in decades-old street slab in Spain
Thousands of people have been walking over the fossil for decades without knowing it.