An international team of researchers found fossils of an ancient sea creature, Tamisiocaris, which filtered food like modern whales. The fossils were discovered in northern Greenland during expeditions led by David Harper, a professor at Durham University.
Tamisiocaris lived 520 million years ago during the Early Cambrian era, a period known as the Cambrian Explosion. The marine animals belonged to a group called anomalocarids, a type of early arthropod. The Tamisiocaris had flaps on either side of the body and large appendages in front of their mouths to probably capture larger prey like trilobites.
The researchers created a 3D computer animation to understand their feeding habits and movements. The 3D analysis showed that these predators gradually evolved into suspension feeders, where their gasping appendages camouflaged into a filtering tool and these were used to catch small crustaceans and other organisms as small as half a millimetre in size.
Dr Jakob Vinther, lead author and a professor in macro-evolution at the University of Bristol, said that these primitive arthropods can be ecologically referred to as sharks and whales of the Cambrian era. Among them, some of the creatures evolved into suspension feeders and enormous, slow-moving animals that fed on the smallest animals in the water.
"Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth," Dr Martin Stein, of the University of Copenhagen who created the computer animation, said in a press release.
The discovery also provides insights into ecosystems that existed hundreds of millions of years ago.
"We once thought that anomalocarids were a weird, failed experiment. Now we're finding that they pulled off a major evolutionary explosion, doing everything from acting as top predators to feeding on tiny plankton," Co-author Dr Nicholas Longrich, of the University of Bath, said.
The finding is published in the journal Nature.
Recently, Utrecht University researchers found new evidence that could possibly explain the extinction of wooly mammoth more than 10,000 years ago. The creatures possessed a 'cervical' (neck) rib 10 times more than modern elephants. Cervical ribs in today's animals are often linked with inbreeding and adverse environmental conditions during pregnancy. If these factors including reproductive stress existed in wooly mammoths, it could have further pushed declining mammoth populations towards extinction.