An international team of scientists has discovered in northern Greenland the fossil of a 'giant' predatory worm measuring about 30 centimeters that inhabited the oceans at least 518 million years ago, reports the University of Bristol in England.
Experts have dubbed the huge specimen for the time – found in the Lower Cambrian fossil site Sirius Passet in the Nordic country – as 'Timorebestia koprii', combining Latin for 'terrifying beast' and Kopri or Korea Polar Research Institute, which participated in the study.
The authors of the study, published in the journal Science Advances, say that these large worms could be "among the first carnivorous animals to colonize the water column more than 518 million years ago," implying an ancient dynasty of predators unknown until now.
According to the remains found, the Timorebestia had fins on both sides of the body, long antennae, huge jaw structures in their mouths, and grew to more than 30 centimeters in length, making them "one of the largest swimming animals of the Early Cambrian."
Jakob Vinther, from the University of Bristol's School of Earth Sciences, points out that until now it has been considered that "primitive arthropods were the dominant predators during the Cambrian, such as the (extinct) anomalocharids", reminiscent of shrimps.
However, this team points out that Timorebestia is "a distant, but also close, relative of the living arrowworms or ketognaths" – today small oceanic predators that feed on zooplankton – which are one of the oldest animal fossils from the Cambrian period.
Find out more
Palaeontology.
Three crystallized dinosaur eggs found in China
- Written by: EFE Beijing
Three crystallized dinosaur eggs found in China
Science.
83-million-year-old remains of Europe's largest sea turtle discovered in the Pyrenees
- Written by: EL MUNDO Madrid
83-million-year-old remains of Europe's largest sea turtle discovered in the Pyrenees
While arthropods appear in the fossil record between 521 and 529 million years ago, arrows date back at least 538 million years, Vinther says.
"Both the arrowworms and the more primitive Timorebeast were swimming predators. Therefore, we can assume that, in all likelihood, they were the predators that dominated the oceans before arthropods took off," he says.
Inside the fossilized digestive system of the Timorebestia, researchers found remains of a common swimming arthropod called Isoxys.
"Our research shows that these ancient ocean ecosystems were quite complex, with a food chain that allowed for various levels of predators," Vinther writes.
"The Timorebeasts were giants of their time and would have been near the top of the food chain," making them equivalent in importance to "some of the major carnivores of the modern oceans, such as sharks and seals," he maintains.
Tae Yoon Park, from the Korean Institute, said his discovery "confirms how arrowworms evolved."
"Living arrowworms have a distinctive nerve center in the belly, called the ventral ganglion," says the field expedition leader, noting that the ganglion has been found preserved in both the Timorebeast and another fossil called Amiskwia.
Park explains that, over the course of several expeditions to the very remote Sirius Passet, more than 82.5 miles to the north, they have collected "a great diversity of new and interesting organisms," so they will have many more finds to share in the coming years "that will help show what early animal ecosystems looked like and evolved."