A Portuguese fossil helped researchers identify the origin of mysterious hexagonal patterns etched on seabeds around the world, including in Cambrian ocean sediments 520 million years old found in Portugal. The hexagonal networks, dubbed Paleodictyon, appear both in ancient fossil records and in modern oceans, and their origin remained unexplained for centuries.
Everything indicates that the authors of these galleries are small burrowing arthropods, according to clues provided by the Portuguese fossil. The hexagonal shape of the structures themselves may have had a specific function: possibly to connect the animals to each other in a communication network.
The confusion about the origin of these marks began in the mid-18th century. Some geologists argued that the marks resulted from natural geological processes, while others proposed biological explanations, without any consensus being reached for generations.
