Monday, June 12, 2017

Penguins: From Antarctica to the Equator



Millions of years ago giant penguins roamed the Earth sporting a livery with gray and red colors. The oldest evidence of the penguin dates back to 270-400 thousand years ago and is now the only scion of species for millions of years populating the southern coasts of Africa.

The analysis of penguin fossils dating back to 37 million years ago shows that the so-called giant penguin reached an incredible height of 2 meters from the legs to the tip of beak. This is the most complete fossil that has ever been found in the Antarctic.

Four different species of penguins are now extinct, dating back to about 10-12 million years ago. Over the past 400,000 years, penguins have lived with the man in the coastal areas of the continent. It is difficult to establish with certainty how the ancient penguin species have disappeared and if everything happened gradually or all of a sudden. Although, according to the researchers, the factor that most probably results in their extinction is the change in sea level.

It seems that the Penguin was not the only species to thrive in the Antarctic for all those millions of years. It was a real paradise for penguins with 10-14 species that lived together along the Antarctic coast. The giant penguin could stay submerged for 40 minutes, thus having more time to feed on fish.

The fossil excavations were concentrated on the island of Seymour, off the Antarctic Peninsula. This was a warmer region 40 million years ago, with a climate similar to that of today in Tierra del Fuego, the islands in the far south of Latin America.

The researchers shed new light on the evolution of birds. To begin with, the passage of penguins to the classic white and black livery could have anything to do with the swimming skills that, for example, camouflage or sexual reproduction.

Until now the New Zealand species had not yet been described in detail, despite being one of the areas with the highest diversity of species. Five different species living together in the same beaches is a truly extraordinary event. The two giant penguins, in fact, coexisted with other species, and each of them ate different prey, a local diversity which is very rare today.

Along with the emperor penguin, the king penguin is the largest species of the family. They are found in the barren and flat coasts of Patagonia, South Georgia, the Falkland Islands and other islands next to the western edge of Antarctica. Although they have feathers, wings, beak and lay eggs like other birds, they have unique characteristics that distinguish them from all other birds on the planet.

One in all, instead of flying they swim and their wings have evolved to become energetic, their dense bones act as ballast for diving, big front paws in the water become powerful engines and their black and white tuxedo allows them to camouflage both from above and from below.

Biologists wonder how these curious birds have developed all the characteristics that have turned them into masters of the marine realm and how some species have even conquered the ice of Antarctica. The African Penguin is not the only species to have populated South Africa. During the Miocene, Africa housed, in fact, four different species of penguins. This is confirmed by fossils found near Cape Town.
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