Valley of the Whales [15]
(Wadi Al-Hitan, Egypt)
The Egyptian deserts were -over forty million years ago- part of the seabed of the Tethys Sea that surrounded the supercontinent Pangaea.
In northern Egypt, about 200 km from Cairo, is Wadi Al-Hitan, known as the Valley of the Whales. There, a group of researchers among which was Philip Gingerich, a vertebrate paleontologist at the University of Michigan, dug and studied the fossil remains of whales.
In the interview conducted by Tom Mueller for National Geographic to Philip Gingerich, the paleontologist said: "Walking through a desert that 40 million years ago was a vast sea inhabited by ferocious sea monsters is not an activity that can be done every day. In Wadi Al-Hitan it is easy to feel like a rainfed diver that explores the depths of prehistory, as this corner of sand and breathtaking scenery preserved fossils of hundreds of species that inhabited the legendary Tethys Sea during the Eocene period”. And no wonder this place was declared a UNESCO World Heritage Site in 2005.
The first fossils were discovered in 1936.
Today, the valley is a large open-air museum where you can see the paleontological pieces exposed on the sand. Most of these remains belong to skeletons of whales and their ancestors: ridges of baby "Dorudon" whales; jaws; columns and vertebrae of "Basilosaurus" whales (15 meters long whales lizard or “dragon”-shaped - hence its scientific name- with mouths endowed with fine and sharp teeth); turtles; swordfish; sea urchins; and the list goes on. Fossilized mangroves and other plant species can also be seen.
Gingerich and his team are responsible for having located over a thousand fossils of whales in the last twenty seven years. But... where did these fossils come from? How did they get there? In order to answer these questions we should do an exercise of imagination.
Let´s think on a 15 meters long beast with large jaws and sharp teeth that dies and sinks to the bottom of the Tethys Sea in the territories that many years later would integrate Egypt.
Over millions of years sediments build up over his body, layer by layer. Finally, the sea recedes and exposes the seabed which gradually turns into desert.
The wind slowly wears the sandstone and clay is deposited on bones-sandstone and clay that are now part of the soil.
One day, after hundreds of thousands of years, scientists, geologists and paleontologists –like Philip Gingerich- arrive and expose them to the world in an attempt to unravel its mysteries.
When interviewed in Wadi Al-Hitan by National Geographic, Philip Gingerich, while clearing a vertebrae the size of a tree with a brush, commented: "I spend so much time surrounded by aquatic creatures than soon after being here I live in their world. When I look at this desert, I see the ocean." He continues, "Complete specimens like that Basilosaurus are the Rosetta stone" in reference to fossils like those representing the links that clarify the evolution of whales.
He wants to find the key to explain the evolution of whales, their departure to the mainland and back to the sea in its slow evolutionary path. In fact, he has devoted much of his career to explain the metamorphosis of cetaceans-perhaps the most radical of evolutionary metamorphosis of the animal kingdom.
Whales have a common ancestor in a flathead tetrapod (four-legged) that looks like a salamander and originally came out of the sea to those beaches 360 million years ago and then returned to it. His descendants -by migrating to the mainland-improved the functions of their primitive lungs and changed fins for legs, among other adaptations. These mammals would eventually become one of the most successful land animal groups ever known and came to dominate Earth.
The interesting thing is that cetaceans returned from whence they came, evolutionarily, and their body adapted to life at sea again. How they held such a big transformation has puzzled scientists for a long, long time.
At the time, Charles Darwin attempted to explain the enigma, perhaps sensing part of the evolutionary mechanism. In the first edition of The Origin of Species, where he wrote he had observed bears floating for hours in the water with their mouths open eating insects floating on the surface, said: "I see no obstacle to a race of bears becoming, by natural selection, more and more aquatic in their structure and habits, with an increasingly large mouth, to produce a monstrous beast like a whale ". Opponents made so much fun of this image that Darwin removed it from later editions.
In 1977, Gingerich and his team discovered pelvic bones and jokingly attributed them to "walking whales". Back then, the idea of whales walking on all fours seemed ridiculous. Then, with the following findings, the pieces of the puzzle finally fell into place and clearly explained the adaptive changes of these wonderful animals.
Gingerich himself recounted: "The enormous environmental transition of whales began to interest me more and more. Since then, I have devoted all my time to the pursuit of the many transitional forms of that giant leap from land to sea. I want to find them all."
By 1989, the paleontologist found the link between whales and their terrestrial ancestors. He had discovered, in a skeleton of Basilosaurus, the first knee of a whale located in one part of the spine, much lower than he had imagined. This was the first of many similar discoveries. Now he knew what to look for and where.
Much water under the bridge, as they say, and many discoveries and puzzle pieces have fallen into place, discoveries that show us today a very different landscape from that of millions of years ago. 50 million years ago or more, the whales that inhabited the area were very far from being the beautiful and peaceful animals we know today. The huge Ambulocetus, predators of 700 kilos with short legs and enormous, elongated jaws like a furry marine crocodile; or the long-necked, heron-head Dalanistes, might have seemed to us-as Tom Mueller wrote- much more than "ferocious sea monsters."
The journalist at the end of his article says: "Gingerich is still surprised by the fact that some people see a conflict between religion and science. During my last night in Wadi Al-Hitan, we moved slightly away from the camp under a starlit sky. 'I guess I've never been particularly devout, he said, but I consider my work very spiritual. Just imagining the whales who swam here, and thinking about how they lived and died, and how much the world has changed since then, puts you in touch with something much bigger than you, your community or your daily life'. He stretched his arms to embrace the dark horizon and the desert with its sandstone formations sculpted by wind and its countless silent whales. `There is room here for any religion you want.' ".