520-Million-Year Old Sea Animal Filtered Food like Modern Whales

The fossil of an ancient  marine animal found in Greenland sheds light on the evolution of a bizarre creature.

 The creature, known as Tamisiocaris, used the appendages around its mouth to filter ocean water and catch tiny crustaceans, a new study reveals.

The 520-million-year-old marine animal was discovered in northern Greenland by researchers at the University of Bristol. Tamisiocaris belonged to the group of animals called anomalocarids, which were early relatives of arthropods.  The system used by the ancient marine creature to find food was much similar to the feeding habits of the modern blue whales.

The animal existed during the Early Cambrian period called the 'Cambrian Explosion' and swam using the flaps down on either side of its body. Researchers had assumed that appendages in the front of the mouth were used to capture prey, mostly the trilobites. The latest study, however, provides evidence that the ancient animals evolved into filter feeders and used their appendages to catch small crustaceans and other tiny organisms.

"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 news release. "This is a rare instance when you can actually say something concrete about the feeding ecology of these types of ancient creatures with some confidence."

The finding is made based on the analysis of the fossil unearthed in 2009. To know more about the feeding habit of these ancient marine animals, the researchers created 3D computer animation of the feeding appendage. Using these animated images, they analysed the variety of movements made by Tamisiocaris.

The 28-inch long animal was one of the biggest animals that existed at that time. It belonged to the group that includes spiders, crustaceans and insects. They also listed among the most bizarre-looking creatures on record, according to Reuters.

"It was a gentle giant," paleontologist Jakob Vinther of the University of Bristol in Britain said to Reuters. "Even though this thing was not a whale or a whale shark, it evolved to become the equivalent."

The researchers, who initially thought that anomalocarids were a failed experiment, are stunned to see that the animals actually triggered a major evolutionary explosion, by acting as the top predators and even feeding on planktons.

Dr Vinther said, "These primitive arthropods were, ecologically speaking, the sharks and whales of the Cambrian era. 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."

The finding was documented in the journal Nature.