520-million-year-old fossil brains found in ancient predator

Scientists have peered into the brain of a prehistoric creature that lived around 520 million years ago. Fifteen fossils of the ancient predator were recently discovered in Greenland, which had fortunately escaped the ravages of time and elements.

An artist's reconstruction of the 520-million-year-old Kerygmachela kierkegaardi depicts the ancient species
as a formidable ocean predator [Credit: Nature Communications (2018)]

This allowed the creature’s nervous tissue to be fossilized, providing researchers with new insights into panarthropods' evolutionary developments. Panarthropods are an animal group that include creatures such as tardigrades or water bears, velvet worms and arthropods, such as insects.

“The findings shed light on the ancestral condition of the panarthropod brain and the origin of complex arthropod compound eyes. The new material, furthermore, provides novel information on the overall anatomy of Kerygmachela,” the researchers wrote in the new study, published in the journal Nature Communications.

The newly discovered fossils belonged to a now-extinct species called Kerygmachela kierkegaardi. The prehistoric creature swam across the Earth’s oceans during the Cambrian explosion — an era that saw the emergence of incredible and rapid diversity among life forms over a short period of time.

The ancient creature measured between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body. The predator also sported a round head and an elongated tail spine. United Kingdom-based paleontologist Jakob Vinther, who led the study along with Tae-Yoon Park of the Korea Polar Research Institute, told National Geographic the creature’s forward-facing appendages grabbed onto prey, “making lives miserable for other animals.”

The ancient creature measures between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body
[Credit: Tae-Yoon Park/Nature Communications]

The new study challenges previous theories that claimed the common ancestor of all panarthropods had complex three-part brain. Instead, the researchers argue the new evidence indicated the common ancestor of panarthropods, as well as invertebrate panarthropods and vertebrates, did not have complex brains.

Researchers believe despite its simple brain, the Kerygmachela’s eyes were likely complex enough to form images. The ancient predator’s eyes likely mirror the smaller and much simpler eyes of modern-day tardigrades and velvet worms.

However, some scientists appear to be unconvinced of the new details.

“If they’re going to say that the brain of Kerygmachela is like that of a tardigrade, you have to be really, really careful,” Nicholas Strausfeld told National Geographic. “Because it might not be.”

“The discovery of the simple unipartite brain in stem-group euarthropods corroborates the ancestral simplicity of the panarthropod brain, and also suggests that the complex neural concentrations, such as tripartite brains in euarthropods and chordates, are the result of convergent adaptations,” the researchers concluded.

Author: India Aishani Ashok | Source: International Business Times [March 13, 2018]