Ancient sea creatures filtered food like modern whales

New fossils discovered in northern Greenland show that a 520-million-year-old, giant marine animals employed specialized facial appendages to eat -- sucking up ocean water and filtering out plankton and other small crustaceans, the way baleen whales feed today.

In a new paper published this month in Nature, scientists in the U.K. detailed how the giant species, Tamisiocaris, scoured the ocean with its hair-like, shrimp-catching appendages.

"These primitive arthropods were, ecologically speaking, the sharks and whales of the Cambrian era," explained Dr. Jakob Vinther, a lecturer in macroevolution at the University of Bristol. "In both sharks and whales, some species evolved into suspension feeders and became gigantic, slow-moving animals that in turn fed on the smallest animals in the water."

These giant ocean sweepers thrived during the Early Cambrian. The period is also referred to as the "Cambrian Explosion" because of the perceived acceleration of evolution and biodiversity -- the period when most major animal groups and complex ecosystems first appear in the geologic record.

The Tamisiocaris was a member of the anomalocarid family, a group of flat, free-swimming, segmented animals -- animals that likely liked giant insects floating in the sea.

"We once thought that anomalocarids were a weird, failed experiment," said co-author Dr. Nicholas Longrich, of the University of Bath. "Now we're finding that they pulled off a major evolutionary explosion, doing everything from acting as top predators to feeding on tiny plankton."

[Bristol University] [Nature]