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One of Whale Valley’s distinctive features is the beautiful rock formations scattered throughout the valley floor |
It was a cool February evening in Cairo. Sipping minted tea in a small, cosy restaurant in Zamalek, a posh residential district in central Cairo, I had expected my interview with the American scientist to be similar to many other interviews conducted along the years. I hadn't expected to feel the delight of a child sitting in front of a talented story-teller, reliving the excitement of discovery as if I were part of the story myself.
It was only the day before that I had driven out of Cairo toward Egypt's Western Desert. I had finally obtained the necessary permissions from the Egyptian Environmental Affairs Agency (EEAA) to pay a visit to the American researchers I had hoped to meet in their 'natural environment'. My trip proved futile. The researchers had just left for Cairo the day before and wouldn't return till the end of the week.
Shifting Sands
The sands of Egypt are better known for their hidden pharaonic treasures and mummified kings and queens of ages long gone. But these sands also contain in their depths the stories of life long beyond that of human existence. In the Western Desert of Egypt, not some 150 km southwest of Cairo, part of the story of evolution is being revealed. And it is Dr. Philip Gingerich, professor of geological sciences at the University of Michigan, who has been the main author of this part of the story.
The story's setting is in Egypt's Wadi Al-Hitan, Arabic for Whale Valley. Gingerich named it that in the early nineties only a couple of years after making the amazing discovery that some of the fossilized whale skeletons in the valley had legs!
Wadi Al-Hitan was recognized in July 2005 as a World Heritage Site. More than 40 million years ago the valley formed part of the Tethys Sea, an extension of what is today the Mediterranean Sea. Originally discovered about 1900 A.D., it was formerly called Zeuglodon Valley, synonymous with Basilosaurus, the type of whale whose fossils lie scattered over the valley's desert floor.
Gingerich explained that there are two types of modern-day whales. The Odontocetus are teethed whales, of which dolphins are a good example. The Mysticetus, or moustached whales, are so called because of the hair-like plates that hang in their mouths to strain the micro-organisms on which they feed. Both types of whales can be traced back 35 million years in time. Fifteen to twenty million years before that another type of whale existed: the Archaeocetus. No whale fossils appear before this time, known as the Eocene epoch (56 - 34 million years ago).
Archaeoceti have been known for roughly 170 years. "But we hardly knew anything about them," said Gingerich. "I didn't appreciate that until I started working [in Wadi Al-Hitan]," he said.
Early Discoveries
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| Wadi Al-Hitan is hidden behind a colossal wall of rock. |
Gingerich had started out his career interested in studying Eocene land mammals (mammals that existed during the Eocene epoch, i.e. some 56 - 34 million years ago). In 1977 his field work in the Sulaiman Range in Pakistan proved frustrating because all his team could find were sea deposits, while their interest at that time was looking for land deposits. Their work yielded a pelvic bone revealing a socket for a leg. "We joked among ourselves that maybe this was [the bone of] a walking whale," chuckled Gingerich, having found the bone in marine strata. No previous research had suggested that whales could walk. Gingerich's instincts were that the evolutionary change of whales from mammals with hind limbs to the types of whale we know today would have happened too quickly for scientists to see. Modern day whales actually have a thigh bone incorporated inside their tissues.
In 1979 Gingerich and his team returned to Pakistan to continue their search for Eocene land mammal fossils. As if led by fate, a member of his team split open a small boulder only to discover a skull and teeth that Gingerich suspected might be that of an archaic archaeocete whale. Gingerich took the skull home with him and showed it to two experts on Archaeoceti in Washington D.C. Both agreed that the skull was that of a whale. Not only that, but amazingly and unlike modern-day whales, the ears were constructed in a way that wouldn't allow the whale to hear directionally under water. Gingerich explained that in order for whales to hear under water, their internal ear bones are separated from the skull by a surrounding foam-like substance. This allows them to distinguish the direction of noise under water. We as humans, on the other hand, cannot distinguish direction of noise under water because our internal ear bones are directly connected to our skulls. The whale skull Gingerich had discovered, later called Pakicetus, had its ears integrated with the skull. It was found near other land animals, and the sediments in which it was discovered were river deposits and not marine deposits. It was the oldest whale discovered up to that time, being nearly 50 million years old, and surprisingly enough was quite different from the whales we know today!
"So I got interested in whales," proclaimed Gingerich. He had hoped to return to Pakistan to continue his search for more evidence of the archaeocetes, but the Soviet Union's invasion of Afghanistan made it practically impossible for him to return for many years to follow. "So I had no place to work, but I had these interesting whales," he pondered aloud.
From Pakistan to Zeuglodon Valley
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| Some fossilized whale skeletons lying on the desert floor reach up to 18 meters in length. |
Gingerich remembered that he had read about Zeuglodon Valley and the interesting whale fossils that were discovered in its sands. In 1983 he decided to visit the valley with his wife where he spent two nights. "We found a great big jaw and a jaw of a young whale in those two nights," he said. Their work of those two nights duplicated discoveries made years earlier of the bones of two whales belonging to two species of two different genera of whale.
The exciting discovery led them to return to Zeuglodon Valley in 1985 for a longer six week stay. "We realized there were whales everywhere!" said Gingerich. The American geologist sat across from me sipping his tea with a triumphant look on his sun-parched face. "There was no possibility or need to collect them, so we started making a map by using triangulation, as we didn't have GPS at the time," he said.
By 1989 Gingerich had collected enough information to figure out that the archaic whales resting in the valley were about 18 meters in length. Gingerich, with his grand story-telling skills, recounts the day that made Egypt's Wadi Al-Hitan infamous forever.
"One mid-day I found a bone standing straight up in the sand, about two-thirds the way down a whale skeleton," he said, making gestures with his finger to signify the bone he thought might have been that of a rib. Gingerich paused for suspense. "As I looked closer, I thought it looked like a femur (a thigh bone), and decided I was going to sweep it out. Sure enough it was a femur, but it had a knee joint on it. But no one had ever seen a knee joint on [a whale femur]. The only reason to have a knee joint would be to have a leg," he seemed to think aloud.
Gingerich explained that one of the significances of whale skeleton fossils found in Wadi Al-Hitan was that the bones were often found in their proper order. "So for the first time it told us where the leg was!" Gingerich exclaimed.
"We went back to all the whales [in the valley] and measured where the leg should be and started sweeping," he said. Sure enough, the team discovered three or four pelvises (hip bones), some femurs (thigh bones), tibias and fibulas (leg bones), toe bones, and an ankle!
The size and structure of the bones found revealed that, although these hind limbs could not support the immense weight of the whales, they were clearly "doing something with them," said Gingerich.
"Once it became clear what we were finding, I immediately recalled our joking in Pakistan," he said, remembering the jokes of walking whales.
The pelvic bone they had found years earlier in Pakistan was 50 million years old. The leg and feet bones in Wadi Al-Hitan were 40 million years old. So only 10 million years after the Pakicetus existed, a relatively short amount of time in geological terms, whales still had feet. Thus Gingerich's previous idea that the legs would have been lost too quickly for scientists to find them was out of the window, he explained.
"So we went back to Pakistan," he said. "1989 was the big year when we found the feet and toes."
In 1992, in the Pakistani province of Balochistan, Gingerich's team found a whale's pelvic bone that was connected to the back. The whales in Wadi Al-Hitan had pelvic bones that were not connected to the backs, thus indicating the hind limbs could not support the weight of the whales. Up until 2000, all the researchers could find were partial skeletons. No hands, feet, or ends of tails were to be found, probably because sharks or other animals were pulling off these limbs, Gingerich explained.
So in 2000, the team decided to shift to the Sulaiman Range in Pakistan. "The very first morning, a Jordanian graduate student working with us, Iyad Zalmout, found a central bone belonging to the ankle, the first foot bone we'd seen since we left Egypt," said Gingerich. "It turned out to be part of a skeleton with a beautiful skull, leg bones, and foot bones."
In the same year they found an even better whale skeleton in the same location; one with hands and feet but no tail. Gingerich explained that the structure of the ankle bones discovered turned out to be a big surprise. The structure was similar to that of split-hoofed animals like cows, sheep, goats, and camels.
At the same time biochemists had been trying to find out how whales were related to animals and also discovered they were related to split-hoofed mammals.
In 2001, the US invaded Afghanistan. Pakistan became no place for a scientist. "I'm an orphan from Pakistan," Gingerich said.
But by then, Egypt had become aware of the importance of Wadi Al-Hitan due to the publicity it received as a result of Gingerich's work. It became a protected area, and Egypt invited Gingerich to continue his research on a more regular basis within the Wadi.
"There is still so much that can be discovered," said Gingerich. "We know that there are two or three whales out there that we don't know much about." Gingerich explained that both whales neither belong to the Basilosaurus or Dorudon whales known in the Wadi, but it is not clear what they are. There are also much older and younger sediments in the region that need to be studied.
My time with the professor had drawn to an end, but I needed to ask him what it was like being an American working in the Middle East, quite frequently in some of its most turbulent regions. He explained that the people he met were able to differentiate between Americans as a people, and the American government and its foreign policies. Gingerich said he never had trouble with the locals in his work. He'd be working in the desert in Egypt, and only a small distance away the Bedouins would be up to their normal daily routine of guiding their flocks of sheep. In Pakistan, in the areas in which Gingerich most frequently worked, the local tribes were very welcoming of foreigners, he said.
A real life Indiana Jones of the wild.
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