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.