The Walking Whales: From Land to Water in Eight Million Years

The Walking Whales: From Land to Water in Eight Million Years

Language: English

Pages: 256

ISBN: 0520277066

Format: PDF / Kindle (mobi) / ePub

Hans Thewissen, a leading researcher in the field of whale paleontology and anatomy, gives a sweeping first-person account of the discoveries that brought to light the early fossil record of whales. As evidenced in the record, whales evolved from herbivorous forest-dwelling ancestors that resembled tiny deer to carnivorous monsters stalking lakes and rivers and to serpentlike denizens of the coast.

Thewissen reports on his discoveries in the wilds of India and Pakistan, weaving a narrative that reveals the day-to-day adventures of fossil collection, enriching it with local flavors from South Asian culture and society. The reader senses the excitement of the digs as well as the rigors faced by scientific researchers, for whom each new insight gives rise to even more questions, and for whom at times the logistics of just staying alive may trump all science.

In his search for an understanding of how modern whales live their lives, Thewissen also journeys to Japan and Alaska to study whales and wild dolphins. He finds answers to his questions about fossils by studying the anatomy of otters and porpoises and examining whale embryos under the microscope. In the book's final chapter, Thewissen argues for approaching whale evolution with the most powerful tools we have and for combining all the fields of science in pursuit of knowledge.

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the size of a cereal box, with pieces of two bones. They share a joint and articulate as they would in the animal. I cringe. It is another knee, the proximal tibia and the distal femur, much smaller than the one I found earlier, and a painful reminder that I just wasted an hour. I try to suppress visions of working hard all day to come home with just two unidentifiable mammalian knees. I ask Arif where he found it. He points vaguely to the edge of the ridge he was walking on earlier. I do not

still under the ground remain where they have been for forty-eight million years.6 But the 78    |    Chapter 5 kidnapping incident is part of a larger problem with Pakistan. Too often, when I point at a place on the map, Arif tells me that the place is off limits for security reasons. Pakistan is too risky a place to be the sole purveyor of study material. So, I am looking elsewhere. There are fossil whales in India. In addition, India is opening up politically. indian whales The man who

narrow. We both know what this means: this is one of the narrow-snouted whales for which we have fragmentary skulls. It allows us to identify the specimen as a remingtonocetid. Eventually, this new whale will receive the name Kutchicetus minimus, the “smallest whale from Kutch” (figure 31).1 Over time, too, it becomes clear what the big Y was: the impression of the underside of the lower jaw. The long stem is the part where the left and right jaw touch; the short arms are the left and right parts

fossil ones. An astragalus for Khirtharia was among the bones collected by Davies and sent to Pilgrim in the British Museum, long before I was born, and before Dehm went and collected the first whale in Pakistan. We also find lots of limb bones, and it is easy to identify those as tibias, femurs, or humeri. It is not so easy to figure out to which animal they belong. Given that most of the teeth are whales, most of the skeleton bones are probably also whales, but one cannot be sure. Size helps

foot shape? As we saw, SHH helps direct mesenchyme to form into fingers and toes. From Embryos to Evolution   |   185 The three-toed feet of Basilosaurus remind me of certain lizards called skinks, which were studied by a developmental biologist named Mike Shapiro.17 In some species of skinks, the number of digits varies between individuals: there can be two, three, or four. Mike found out that more fingers and toes form as the hand and foot of the embryo are exposed longer or to higher

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