Paleontologists finally have the key to filling in the gaps in sea cow evolution: the fossil of an ancient manatee in a slab of pavement on a Spanish street. The fossil was found in the stone slabs that had been laid down over two decades ago in the town of Girona in northern Spain. Phys.Org reported that a local geologist had submitted a picture of the suspected fossil to Paleourbana, an online database of urban fossils worldwide, attracting the attention of paleontologists worldwide.

In a research presented at the Society of Vertebrate Paleontology meeting in Salt Lake City, Utah, Dr. Manja Voss and Dr. Oliver Hampe of the Museum für Naturkunde in Berlin revealed that the complex shapes in the stone slabs were slices of the backbone and skull of an ancient marine mammal. Judging by the dimensions of the skull and teeth, they discovered that it was a sirenian or sea cow. This organism was part of a group of large herbivorous marine mammals that we know today by the living manatee and dugong.

Dr. Voss and Dr. Hampe, in coordination with the mayoralty of Girona and local geologists, had removed the 50-by-30-centimeter paving stones for further study. The paleontologists had a cross-sectional view of the sea cow's skull since the rock had been cut to form the paving stones. To get a better view of what was inside the stones, Dr. Voss and Dr. Hampe brought the stone slabs to the Clinica Girona for a CT scan. Next on their agenda is to use the CT scans to digitally construct the skull slices of the fossil. This will allow them to ascertain the animals' age when it died and its potential relationship to other sea cow fossils.

The discovery of the "Girona sea cow" has led Dr. Voss and Dr. Hampe to believe that it is most likely representative of the Prototherium, a genus of extinct sea cows from Spain and Italy. There is much to still discover since the stones that were quarried were 40 million years old. Dr. Voss explained, "Hence the find represents one of the oldest sea cows in Europe, making it a unique opportunity to enhance our knowledge on the evolution and diversity of this marine mammal group that arose about 50 million years ago."