The Walking Whales

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The Walking Whales Page 15

by J G M Hans Thewissen


  turing soil for the plants. Differences in salinity, water depth, and vege-

  tation  lead  to  multiple  habitats,  with  very  different  animals  in  each.

  Driving over the bridge, I imagine an Eocene whale lurking in the mud,

  looking up at my car zipping by.

  On the island, we grab bikes to go to the ocean. The island is so dif-

  ferent from the backbay. Kiawah’s soil is like beach sand, with lots of

  shells of clams and snails, animals that were alive when they were part

  of the seafloor but whose shells are now found in a different environ-

  ment. The island is less than a mile wide, but it supports lots of wildlife.

  As  we  walk  toward  the  beach,  we  see  alligators.  They  consider  this

  island theirs and are not afraid of humans. They bask in the sun in little

  ponds  on  the  island,  sometimes right  behind  the  dunes. Those ponds

  collect rainwater and are not salty: these alligators live in freshwater.

  The alligators remind me of the crocodile bones that we find in Kutch.

  They  are  often  associated  with  seashells.  I  have  always  thought  that

  these  were  bones  of  marine  crocodiles,  given  that  they  are  associated

  with the shells. I now realize that I should not rush to that inference. If a

  future paleontologist were to dig into Kiawah’s soil, freshwater alligator

  bones  would  be  both  close  to  the  ancient  shore  and  associated  with

  ocean clams, though the alligators did not live with the marine inverte-

  brates.

  We cross the dunes, dragging our bikes along, and find the bones of

  a gray fox, a mammal that hides in the daytime, in the dune vegetation.

  The  fox  probably  hunts  rodents  and  birds  in  the  forested  area  right

  behind  the  dunes,  part  of  the  nocturnal  fauna  which  this  diurnal

  observer misses. On the beach there are lots of shells, all open halves.

  Storms have churned the shells of the dead molluscs, and thrown them

  on this beach, and it reminds me of Godhatad, one of our Indian fossil

  localities. On this beach, there are also sand dollars, flat relatives of sea

  urchins. In India, we always use sea urchins as indicators of an environ-

  ment that is fully marine, since they do not tolerate freshwater. How-

  ever, these sand dollars are only fifty yards from the alligator pond. This

  shore is a patchwork quilt, with very different patterns and colors in

  each of its squares, and I need to think of Kutch in the same way.

  One of the reasons to come to this barrier island is to see the dol-

  phins. Even though I have studied fossil whales for a long time and have

  dissected dead dolphins many times, I have never seen wild dolphins.

  A Trip to the Beach | 95

  We ride our bikes on the beach to the southern tip of the island. Here

  the barrier island is separated by a tidal channel from the next barrier

  island. Water flows out of the channel fast. The tides drive this process.

  As the sea level rises around high tide, the water pours into the muddy

  flat areas behind the barrier island, flooding them with seawater through

  this channel. As the tide drops, all this water comes out again, as if a

  giant were lifting the mudflats and pouring the water back into the sea.

  Dolphins are smart animals. They know about the tide, and they know

  that with the pouring-out of the water many fish are poured out of the

  mudflats, too. The dolphins stay in the tidal channel, catching the fish

  that are forced through the channel.

  Having an eight-year-old to please, I am worried that the dolphins

  might not be there.

  “Do the dolphins always show up?” I ask the uniformed ranger. “It

  is a long trek for my son.”

  “The dolphins will be there,” she says confidently, “right when the

  tide reverses.”

  We arrive a bit early for the show, and walk along the channel’s edge.

  There are dozens of large snail shells: whelks. We collect them. They are

  large and beautiful—orange, yellow, tan, with darker gray blotches—

  and smell like they have been buried for a while. In fact, when alive, the

  whelks are buried in the tidal channel. They only become exposed when

  the animal dies and all the flesh is gone. It again strikes me that we

  didn’t see whelks anywhere on the beach; they are only here, near the

  tidal channel. We pick up several, more than we can carry. For each big-

  ger and more beautiful one that we see, we discard one of the earlier

  ones. We can’t take a lot of whelks, because we have to bring them back

  on our bikes.

  With my eyes on the ground, carrying the whelks in my arms, walk-

  ing back and forth, I pay no attention to the channel until suddenly—

  whoosh. Loud and sudden, it startles me, and a bulging gray object the

  size of a basketball disappears. It was in the water thirty yards from me.

  A dolphin has arrived—its forehead was all I saw. I drop my whelks and

  sit in the sand. The ranger was right. They patrol the channel, coming

  up to breathe. The water is so muddy that I cannot see the body of even

  the closest one. But I can see the blowhole on the forehead. That is the

  only thing that comes out of the water—the eyes and ears are below the

  water-line—just that gray bulge. The Indian whales, too, might have

  hung out in the shallows, waiting to pick off fish that shot by in the

  muddy water.

  96    |    Chapter 7

  We  watch  the  dolphins  for  half  an  hour.  The  sun  is  setting.  The

  marshes turn the orange of the whelks in my pile, and then shades of

  gray, as we bike home.

  I think back to Kutch. At one site, there may be one hill with gypsum

  and sirenian ribs, and another hill consisting of broken oyster shells. All

  represent different fossilized environments, a stone’s throw from each

  other. There, too, the orange sun sets over the Harudi Formation, as it

  did forty-two million years ago, when the Harudi was the coast.

  a fossilized coast

  The Kutchi fossil localities stretch along a C-shaped band about seventy

  miles long, circling a central area of exposed land in the Eocene (figure

  30). There was a diversity of habitats along this band. Just as in modern

  times, the Indian Ocean was to the south of the localities, and a large sea

  arm extended around 
the peninsula to the west and north. Nowadays,

  that arm is dry most of the year and is called the Rann of Kutch, but in

  monsoon time it fills with water and turns the Kutchi desert soggy.

  In the Eocene, the southern fringe of the localities was closest to the

  ocean. The fossil locality Rato Nala is in this area, and large algal mats

  with molluscs dominated it, implying shallow and clear water. The algae

  precipitated calcium carbonate and thus constructed an algal reef that

  fossilized as the Chocolate Limestone. Molluscs that were living in the

  algae  were  entombed  and  smothered  by  them,  and  dead  whales  and

  sirenians sank to the bottom, where they were also encased by algae—

  the  minerals  released  from  the  dead  mammals  feeding  the  algae.  But

  that was just one environment at Rato Nala. There were also muddy

  shallows with lots of small water plants, now recognizable as plant fos-

  sils. Then there are gray muds with veins of yellow sulfur, apparently

  formed in an anoxic environment.

  Fifteen miles east of Rato Nala, also on the south side of the Eocene

  land, is the locality of Vaghapadar. Here are lots of enormous marine

  snails and sirenians, but relatively few whales. Sirenians are excellent

  indicators for fossil environments: they are aquatic plant eaters, special-

  izing in seagrass. In the Eocene, Vaghapadar was probably a seagrass

  meadow, too suffocating for the fast-swimming whales but just right for

  the slow-grazing sirenians.

  Moving north along the ancient shoreline, into  the sea arm, is the

  locality Godhatad that I thought of while visiting Kiawah Island. Being

  farther  from  the  open  ocean,  it  was  protected  from  the  waves  and

  A Trip to the Beach | 97

  Dhedidi North

  shal ows

  dry at times

  sea arm

  p

  coastal swam

  Babia Hill

  marsh

  Panandhro

  Godhatad

  tidal flats

  Dry Land

  Vaghapadar

  reefs

  Rato Nala

  seagrass meadows

  Fossil seacows

  Remingtonocetus

  Protocetid whales

  Andrewsiphius

  figure 30. Map of western Kutch (India) in the Eocene, with fossil

  localities and the environments occurring there. Different kinds of

  marine mammals prefer different habitats, and this is reflected in

  their abundance at different fossil localities. The white-gray-black

  bars show the proportions of seacows and the different whales.

  weather out on the ocean, but it remained connected with that ocean.

  Sediments and fossil plants indicate that Godhatad was composed of

  tidal flats and lagoons in the Eocene.1 It is also a patchwork of environ-

  ments, and the most impressive of these is a long hill composed almost

  entirely of broken oyster shells. In the Eocene, it was a storm deposit:

  the storm killed the oysters and smashed their shells, dumping them in

  large piles. Even though there are conspicuous molluscs at both places,

  the difference from the molluscs of the Chocolate Limestone is striking.

  98    |    Chapter 7

  At Godhatad, there are no oysters with their shells closed. Those in the

  Chocolate Limestone are mostly closed, indicating that they were bur-

  ied alive. At Godhatad, fossil whales are found, too; they were either

  killed in the same storm, or maybe the storm moved dead whale parts

  around, burying them with the oysters, to the delight of paleontologists

  more than forty million years later.

  Northeast of Godhatad are large deposits of lignite, a poor-quality

  coal. These deposits were formed in a salty swamp or marsh2 and can be

  seen  in  the  Panandhro  Lignite  Mine  and  Babia  Hill  localities.  Plants

  died, and did  not rot;  instead, the plant  debris  was  covered  by  more

  plants and buried. Anaerobic conditions were common, as evidenced by

  the formation of pyrite, and a sulfurous smell when you hit the rocks

  with  a  hammer.  Panandhro  was  sheltered  from  the  churning  of  the

  ocean  by  the  land  to  the  south.  It  represents  a  forested  swamp  with

  stagnant water in which many whales lived.

  Farther to the north, and farthest from the ocean, is the locality Dhe-

  didi North. Gypsum abounds here and was formed by the drying up of

  a saltwater basin. Many of the fossils are covered in gypsum, suggesting

  that whales here died as their lagoon or bay dried up. That process con-

  tinues into the present. When the Rann of Kutch dries up in summer, it

  produces enormous salt deposits visible from space.

  Applying the lesson from Kiawah to Kutch, I can now imagine being

  here forty-two million years ago. Along a few miles of coastline, there

  are  lots  of  different  environments,  with  different  plants  and  inverte-

  brates,  and  different  mammals,  too. Whales  that  are  common  at  one

  place are rare at another. The sedimentology can teach me about the

  whale habitats, and that in turn can teach me about what the whales

  needed to live.

  Chapter 8

  The Otter Whale

  THE whale with no hands

  Kutch, India, January 12, 2000. The desert of Kutch is mostly uninhab-

  ited, except for a few herders, who roam the plain with their flocks.

  However, there is that one place that is teeming with humans who are

  not pastoralists: the lignite mine at Panandhro. It is a giant open-pit

  mine, one of the largest in India. Enormous machines make you feel the

  way an ant must feel standing next to a blender—awed by the size, but

  puzzled by the function. Hundreds of people work there, and the mining

  company built a town for them and their families, as the local villages

  could not sustain so many people. This company town—the Colony,

  they call it—has straight streets and identical houses, a shopping center,

  a school, a playground, and a desalination plant for seawater. Busses

  take workers to the mine, identical white SUVs move the engineers

  around, and they bark commands at the colorful trucks that are loaded

  with lignite and that clog the road all the way to the nearest real town,

  about three hours away. By the grace of the mining people, we’re allowed

  to stay at the guesthouse. This solves many of ou
r logistical problems: in

  a desert, where do you eat, where do you get water, where do you buy

  supplies?

  In the morning we drive to our field area. Little Indian antelope, the

  size of goats but more nimble, cross the road, and we lose centuries as we

  pass the occasional villages with no cars or paved roads, water buffaloes

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  100    |    Chapter 8

  lingering  in  ponds  and  used  by  boys  as  diving  platforms,  while  their

  sisters carry jugs of water to their houses.

  As we approach the village of Godhatad, I spot a small dog-like crea-

  ture, a jackal, crossing the road. “It is mad, sir,” states the driver, matter-

  of-factly.

  I assume he infers this from the animal’s being out at this time of day.

  But it bothers me. We, too, will be out here all day, far from the car,

  looking for fossils. Does the clinic provide rabies shots in case someone

  gets bitten? Where is there a clinic, anyway? Does the Colony have one?

  From up on a ledge of the yellow Fulra Formation, I look down on

  Godhatad. Its twenty or so houses share walls, or verandas, or lean into

  each other, as if they are hugging, huddled together to keep the heat out.

  They are painted a light purplish blue—periwinkle, my assistant calls it.

  The periwinkle stands out against the drab rocks around it. Godhatad

  is a Muslim village; half a mile away is a similar Hindu village. Not that

  I can tell. I don’t see a mosque, and I don’t see any people from where I

  am. Also,  the  Muslims  here  mostly  do  not  dress  differently  from  the

  Hindus. The women do not cover their faces. They wear the same bright

  reds and oranges as their Hindu counterparts, a striking contrast with

  the  drab  and  periwinkle  surroundings.  And  nearly  everybody,  men,

  women, Muslim and Hindu, cover their head, to keep sun and dust out.

 

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