Fossils found recently in Morocco belong to the earliest known filter-feeding sea creature.

The 480-million-year-old anomalocarid fed on plankton in a similar way to modern whales. Because the fossils are complete specimens, scientists studying them, including Dr. Allison Daley, a Canadian lecturer at Oxford University in England, and Research Fellow at the Oxford University Museum of Natural History, can tell their size for the first time.

At over two metres in length, they were among the largest creatures on Earth during the Ordovician period. The fossils also provide insight into the evolution of anomalocarid's modern relatives, the arthropods, such as crustaceans like the lobster and scorpion.

- Paper in Nature
- Yale University release
- Oxford University release
- BBC News story