Puijila darwini

 
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Puijila darwini

Puijila darwini (its scientific name) represents a “missing link”—a branch on an evolutionary tree—between an ancestor that walked on land and today's sea-going seals and their relatives.

Most people think that all life evolved out of the sea onto land. Puijila darwini proves them wrong as it is an example of evolution that went from land to the sea.

Image: A reconstruction of Puijila darwini.

 
3D View: Puijila darwini
 
 
A skull reconstruction of Puijila darwini.

Why this species is important

About three feet long, Puijila darwini is a missing link that represents the transition between some land creatures of the early Miocene epoch and modern day seals. It provides a fossil record for how some mammals—adapted for land— in essence, returned back to the sea.

 

The Continental Drift

The Earth is constantly changing.  Over millions of years the planet's continents have shifted and continue to do so today.  This geological phenomenon is known as the Continential Drift.

Associated with these drifts are specific geological time periods when air temperature and life on Earth was very different than present day.

Puijila darwini existed during the Miocene epoch, a phase in the continental drift that has the earth looking similar to what it does today, but without the polar ice caps.

This interactive image shows how the Earth's continents have shifted over millions of years.  400 million years ago the Earth's land masses were close to one another and near the equator.  Around every 100 million years there were major landmass shifts. By 10 million years ago, the Earth's continents were located in their current positions.
 

A map of the world showing the continents shifting between 400 and 10 million years ago.
 
10 million years ago
400 million years ago
 
 

A hunter in the 24 hour darkness

 

Puijila darwini  lived about 24 to 20 million years ago. During this time period, the landmass that is now the Arctic was located approximately where it is today. As such, Puijila darwini had to hunt both on land and in the ocean half the year in darkness, and through months of 24-hour complete darkness.

To adapt to this extremely difficult condition, Puijila darwini evolved with huge eyes in order to see its prey. It also developed long whiskers so that it could feel for fish in the darkness of deep and murky waters.

 

A land mammal ready for the sea

 

As both a land and sea mammal, Puijila darwini had to survive in two very different environments. It had to be a fast swimmer in the water and a fast runner on land.

To do this, it had webbed feet with five fully formed fingers and toes. This allowed it to not only swim in the ocean but also to run on land to potentially catch prey and evade predators. It most likely had fur similar to the modern day seal, which acted as an effective insulator in cold waters.

 

A fierce hunter

 

Puijila darwini was most likely a hunter on land and in water. To do this, its body was shaped to go through the water with minimum resistance while still being agile enough on land to hunt.

Besides having webbed feet with five fingers and toes to help it hunt on land and sea, it also had a very strong jaw-bone structure able to crunch through its prey. It also had a series of sharp teeth to catch and eat its prey.

 

Video

 

How was this species discovered?

See how Puijila darwini was discovered by scientists from the Canadian Museum of Nature.

 

Transcript: How was this species discovered?

Natalia Rybczynski
Vertebrate palaeontologist, Canadian Museum of Nature in Ottawa:
My name is Natalia Rybczynski. I’m a vertebrate palaeontologist at the Canadian Museum of Nature in Ottawa.
My discovery is really exciting for me because it’s a new species, a new genus, and it’s a missing link animal.
In addition, this animal contributes to our understanding of ecosystems and mammals that lived in the High Arctic in the past, and we’re interested in the relationship between the evolution of these systems and climate change.

In 2007 we went to Devon Island to Haughton Crater to do a palaeontological expedition. This is an expedition that I led with Dr. Mary Dawson at the Carnegie Museum and by the end of that season we’d actually discovered what, in fact, turned out to be a new animal. It was a new carnivore, a mammal, and we’d found by the end of 2007 about 65% of the skeleton.

So in 2008 we went back to the site with the hopes of finding the brain case and, in fact, we did.

Claudia Shröder-Adams
Professor, Carleton University:
I think that this recent discovery has made quite a splash in the palaeontological world. It will address evolution in a big way.

Natalia Rybczynski:
We named the animal Puijila darwini. Puijila is an Inuktitut word that means young marine mammal.
What we're looking at is an animal that is between a terrestrial ancestor and the marine-type seals - flippered seals - that we see today.
One of the first things that we did is we actually started scanning all of the bones of the skeleton and also the skull.
So using 3D animation we were able to, for example, reassemble the skull and, in the end, we could do the whole skeleton.

Museum employee:
You’ve got to see this actually.

Natalia Rybczynski:
Puijila lived in the High Arctic 24 to 20 million years ago and we found it in a lake deposit so we know it is a fresh water animal.
If it was alive today what you would see is an animal with webbed feet, an otter-like body, and a long tail.
It would also have big eyes and this is something that we see in seals today.
It could hunt in water, be very agile in the water – as otters and seals are today -- but we also see that, in fact, if you just look at the skeleton, it looks like a regular land mammal in a lot of ways. So it could also hunt on land.
Previously we really had no idea how the seal lineage came from a terrestrial ancestor to become a fully marined form. This is our first really solid evidence of a transitional form.

Claudia Shröder-Adams:
In many ways, throughout earth’s history and evolution, we have seen adaptation coming from swimming to land.
This way, it is the other way around and that is a fabulous find.

Natalia Rybczynski:
In the scientific literature it is fairly accepted that the most likely centre of origin for pinnipeds – the group that includes seals, the walrus and sea lions – (the centre of origin) would have been on the west coast of North America. Now with Puijila, we’ve actually found this animal in the High Arctic and so this stirs things up a little bit.

Museum employee:
You can see the angles and whatnot are very similar to our species.

Natalia Rybczynski:
We are really at a frontier in terms of our knowledge of what the history of the Arctic has to reveal, and we see evidence, for example, of incredible climate change.
And we’re also now – with finds like Puijila and other finds as well – getting an idea of how evolution, how organisms like mammals, had responded to this climate change.
This is really a quantum leap in our understanding of the evolution of pinnipeds.

Claudia Shröder-Adams:
It puts Canada on the map and it puts (the research conducted) the palaeontological research conducted at this museum, the Museum of Nature – on the map as well.
I’m certain that a lot of scientists around the world will pay attention to this find.

---End.