Home Biologist salary A 400 million year old fishapod brought it back to the water

A 400 million year old fishapod brought it back to the water


Our ancient ancestors, like all terrestrial life on Earth, evolved in the primordial seas of our planet before taking their first steps on earth. For vertebrates like us, the animal commonly associated with this evolutionary stride is the 375 million year old animal. Tiktaalik roseae.

For his act of faith in the Darwinian Bible, Tiktaalik received tongue-in-cheek reviews from internet members who blame the amphibious pioneer for all of life’s modern troubles.

Memes released over the past two years lament the adventure of the prehistoric creature and express the insincere desire to travel back in time and coax Tiktaalik back in the water.

Others wonder if it would have only led to a dystopia filled with war, rent, pestilence, and unjust bosses emerging beneath the waves of the ocean.

Oddly enough, minus the time-traveling millennia repelling fishapods (the first fish that evolved limbs for walking) in the water, the meme might actually parallel reality.

Read more: Dinosaurs invaded Earth after a winter of discontent

Research published in Nature on a new fossil shows a fishapod which seems to have joined Tiktaalik ashore – before deciding to go back to sea, saving his ancestors the pain of 21st life of the century.

Co-author of the new study and University of Chicago evolutionary biologist Neil Shubin was also a leader of the team that co-discovered Tiktaalik back in 2004.

Illustration of Qikiqtania wakei (center) in water with its larger cousin, Tiktaalik roseae. Credit: Alex Boersma.

The new fossil belonged to a similar creature called Qikiqtania wakei which would have been just over a meter long – small compared to Tiktaalik up to three meters.

QikiqtaniaThe fossils were found a few days before Tiktaalik was discovered. Qikiqtania is named after the Inuktitut word Qikiqtaaluk Where Qikiqtani, traditional names of the region where the fossil was found. The species designation “wake upis in memory of the late David Wake, an eminent evolutionary biologist from the University of California, Berkeley, USA.

However Qikiqtania sharing many of the same characteristics as its explorer cousin, the newly discovered animal’s body is more suited to life in water. Among the fossils are partial upper and lower jaws, parts of the neck and scales and, most importantly, a complete pectoral fin with a humerus lacking the muscular ridges that would indicate a limb built for walking on land.

QikiqtaniaThe upper arm of was smooth and curved, suggesting that he spent his life paddling underwater. The unique arm bones imply that it returned to water after its ancestors began using their appendages to walk.

“At first we thought it might be a minor Tiktaalik, because it was smaller and maybe some of those processes weren’t developed yet,” Shubin said. “But the humerus is smooth and boomerang-shaped, and it lacks the elements that would allow it to grow on land. It’s remarkably different and suggests something new.

3D reconstruction of the whole Qikiqtania wakei fossil. Credit: Justin Lemberg.

push in Tiktaalikthe shadow, the Qikiqtania the fossils were stored and largely forgotten for 15 years.

It wasn’t until March 2020 that a scan of one of the rocks revealed a pectoral fin. Too deep in rock to get a decent picture, and abandoned again when shutdowns forced labs to close, the fin remained high and dry until later that year.

“We were trying to collect as much CT data of the material as possible before the lockdown, and the very last piece we scanned was a large, unassuming block with only a few specks of scale visible from the surface,” says Col. author Justin Lemberg.

“We could hardly believe it when the first grainy images of a pectoral fin emerged. We knew we could collect better analysis of the block if we had time, but that was March 2020, and the University has closed all non-essential operations the following week,” adds Lemberg.

3D reconstruction of the pectoral fin of the Qikiqtania wakei fossil. Credit: Tom Stewart.

When the facilities reopened and analyzes could be performed after cutting the rock around the specimen, the nearly complete pectoral fin and upper limb emerged.

“That’s what blew us away,” Shubin said. “It was by no means a fascinating block at first, but we realized during the COVID lockdown, when we couldn’t get into the lab, the original scan wasn’t good enough, and we had to cut the block. And when we did, look what happened. It gave us something exciting to work on during the pandemic. It’s a fabulous story.

slightly older than Tiktaalik, Qikiqtania shares part of the evolutionary tree of life adjacent to early vertebrates with finger-like digits.

The discovery and analysis show that animals do not evolve in linear trajectories. It’s not as simple as drawing a straight line between modern organisms and some earlier forms. Qikiqtania shows that some creatures will wander off on different paths – some of which don’t work.

Tiktaalik is often treated as a transitional animal because it is easy to see the gradual pattern of changes from life in water to life on land. But we know that in evolution things aren’t always that simple,” says lead author Thomas Stewart. “We don’t often get a glimpse of this part of vertebrate history. We are now beginning to uncover this diversity and get a sense of the unique ecology and adaptations of these animals. It is more than a simple transformation with a limited number of species.

Tom Stewart, PhD, assistant professor of biology at Penn State University, holds the fossil specimen of Qikiqtania wakei. Credit: Tom Stewart.

So, to all the haters of the internet Tiktaalik, evolution also tried “back in the water”. And it’s thanks to these early fishapods that you can give the poor wet pioneers the middle finger in the first place!