The Walking Whales
Page 3
plantation. Harlan took these teeth and bones to London, showing
them to the famous British zoologist Professor Richard Owen, a con-
temporary of Darwin and a critic of his evolutionary ideas. Owen rec-
ognized the teeth as clearly mammalian and noticed resemblances in the
vertebrae of Harlan’s beast to those of whales.9 Feeling that Harlan’s
name was inappropriate, Owen renamed the animal Zeuglodon cet-
oides, after the yoke-like appearance of the teeth in side view ( zeugleh
means yoke in Greek, and the Latin dens means tooth; figure 6) and the
whale-like appearance of its vertebrae ( cetoides, whale-like).
The renaming was unfortunate. If Owen had lived today, he would
not have given the fossil a new name, despite the problems with the
original moniker. Biologists have realized that scientific names are vehi-
cles for storing and retrieving information about animals and plants, and
that the most important thing about them is that they are stable: every-
one uses just one name for one animal. It does not matter whether the
name describes the animal well. This is similar to human last names—
after all, a person named Farmer may not be a farmer at all. The Interna-
tional Commission on Zoological Nomenclature has now established
clear rules10 specifying that, if two scientists have given different names
to the same beast, the oldest name is valid. Today all species are named
Fish, Mammal, or Dinosaur? | 13
Dorudon atrox
Basilosaurus cetoides
Dorudon atrox
Lumbar vertebrae 7 and 8
Lumbar vertebrae 7 and 8
Lower second molar
figure 6. Some fossils of extinct basilosaurid whales. Two Basilosaurus lumbar
vertebrae (middle) show the large conical area called the centrum, but also a small
protrusion, the neural arch (which sticks out on top). In mammals, the shape of the
joints on the neural arch restricts the mobility between vertebrae. Given that these joints
are small in Basilosaurus, it must have had a very flexible back. Compare these
vertebrae to those of its close relative Dorudon (left), in which the neural arches lock the vertebrae in place, leading to a less flexible spine. A lower molar (right) shows the
yoke-like appearance of the teeth of Basilosaurus, caused by its two long roots. This
shape led to the name zeuglodonts (“yoke-teeth”) for these whales. Pennies (19 mm in
diameter) for scale in all three drawings.
with Latinized, italicized words. The first part starts with a capital, and
refers to the genus, such as Homo for our own genus. The second part of
the name refers to the species, sapiens. So that makes Homo sapiens. The
genus name is much like a human surname in that it is shared by rela-
tives—by related species in the zoological case, or related individuals
among people. Thus, all my family members are also “Thewissen,” and
the extinct cousins of my species are also Homo. The species name is
much like a given name in people—many unrelated individuals might
have the same given name, Hans in my case. In zoology, there is only one
species that combines a particular genus name with a particular species
indication. Zoological names are more strictly policed than the names of
people; the Commission on Zoological Nomenclature evaluates conflicts
and passes a binding judgment.
Groups of genera (plural for genus) are grouped in a subfamily, and
several subfamilies into a family, and so on into more inclusive and larger
groupings. There are also rules for how names for those groupings should
be made. They are usually characterized by their endings in Latin. As an
example, table 1 gives names for our own species ( Homo sapiens) and a
dolphin ( Delphinus communis), and it also lists more and more inclusive
groups into which these two species are categorized. Note how the end-
ings of the words work. Delphinidae and Delphinoidea are very similar
14 | Chapter 2
table 1. examples of zoological classification.
Category
Typical
Modern humans
Common dolphins
ending
Latin
English
Latin
English
name
name
name
name
Order
Primates
primates
Cetacea
cetaceans
Superfamily oidea
Hominoidea
hominoid
Delphinoidea delphinoid
Family
idea
Hominidae
hominid
Delphinidae
delphinid
Subfamily
inae
Homininae
hominine
Genus
Homo
Delphinus
Species
Homo
modern
Delphinus
common
sapiens
human
delphis
dolphin
words, but they mean different things: Delphinoidea includes all of Del-
phinidae, but also several other families (not mentioned in the table).
Neither commission nor rules existed in Owen’s time, but later zool-
ogists decided that the rules should be applied retroactively. Harlan had
proposed the name Basilosaurus, a valid genus name predating Owen’s
Zeuglodon. Thus we correct the famous Professor Owen in favor
of Harlan’s original name, in spite of its erroneous connotation. How-
ever, Harlan did not propose a species indication, whereas Owen did.
Hence, Harlan’s genus name is now combined with Owen’s species indi-
cation, and the animal is called Basilosaurus cetoides.
In spite of Owen’s good work, the reptilian ghost of Basilosaurus lived
on. In 1842, S. B. Buckley excavated a sixty-five-foot vertebral column
with portions of head and forelimb on the same plantation where Harlan
had found basilosaurid bones. Eventually, these ended up in Boston,
where they were seen by Reverend J. G. Wood, who announced the star-
tling inference that basilosaurids were swimming in the seas surrounding
New England in the pages of the Atlantic Monthly.11 Wood starts his
essay by listing a number of examples of natural history phenomena that,
although initially held to be untrue, were later confirmed by solid obser-
vations. Then he takes on the case of sea serpents, commenting that:
It is not very difficul
t to be witty about traveler’s tales, and it is very easy to
be sarcastic. . . . As long as an assertion cannot be proved, skepticism is
triumphant.
Wood discusses many, in his eyes, credible sightings of sea serpents,
and goes into depth in the observation of a sea serpent living near Nahant
Fish, Mammal, or Dinosaur? | 15
in Massachusetts. The animal, or animals, were sighted multiple times by
many different people between 1819 and 1875. One of the observers
reported: “The head seemed somewhat like a horse, the portion of neck
exhibited above the water was about two feet in length, and a little
beyond the neck there were a series of protuberances, reaching a distance
of eighty feet.” Another stated: “More than once, it reared its head more
than six feet out of the water, and made directly for one of the boats; the
spray dashing over its neck, and the protuberances of the back glittering
in the sun. But it never attacked a boat, and though it came near enough
to frighten the rowers, it always turned sharply and retreated.” The Bos-
ton Society of Natural History pursued the issue and interviewed the
observers of the animal on one boat in 1875 in detail, and one of them
even sketched the animal (figure 7). Wood interviews witnesses and deems
the observations credible. All of them suggest a snake-like body, between
60 and 100 feet long, with forelimbs, not scaly, black on top, white
underneath, having small or no teeth, and swimming by up-and-down
movements. Wood discusses the options as to what this animal might be.
It is not a large aquatic reptile, they are extinct; it is not a large version of
the tropical sea snakes, they swim by means of lateral movements. He
concludes that it must be a long snake-like member of the Cetacea, since
it breaks the surface to breathe and swims by up-and-down movements
of its body. Given that no cetaceans with snake-like bodies were known,
he proposes that the sea serpent of Nahant Bay is a living specimen of
Zeuglodon, whose bones he had seen in Boston. He compares the head,
as sketched by the boaters, in detail—it matches that of Zeuglodon “if
clothed in flesh and blood.” He concludes that this whale is different from
all known ones, in that it has its nasal opening closer to the tip of the
snout and not on the forehead. He ends by saying that future boaters
should not scare off or try to kill the animal with gunfire; instead they
should harpoon it so that it could be reeled in and studied.
Wood did not uncritically accept fisherman’s tales. He looked for con-
sistencies and independent lines of evidence, like a scientist would. It is
only in his conclusion that there are some sloppy leaps. There are certainly
no basilosaurids living near Cape Cod. But we can pardon Wood; although
he wrote after the Origin of Species, little was known about the age of the
earth, and it was held to be much younger than we now know it is. So
Zeuglodon seemed within the reach of time of the Nahant Serpent.
The tales of bones of enormous sea creatures in the American South
attracted many, including the Englishman Charles Lyell, often consid-
ered the father of geology. Lyell commented that in his visit to Alabama
16 | Chapter 2
figure 7. Imagined, real, and fossil whales. In the middle ages, whales were thought of
as sea monsters. Their reconstructions (bottom) showed, incorrectly, fish-like characters,
such as the scales and vertical tail in this sixteenth-century reconstruction by Conrad
Lycostène. It also shows two water spouts, coming from two blowholes. Baleen whales in
fact do have two blowholes. Albert Koch, in 1845, put together a chimera, combining
fossils from several basilosaurid whales to dazzle his audience with the skeleton of a “sea
serpent.” The Reverend Wood published a reconstruction of a sea serpent in the Atlantic
Monthly in 1884, believing that these still roamed the waters around New England and
were, in fact, living basilosaurid whales (zeuglodonts). Images modified and redrawn.
in 1846 he saw more than forty Zeuglodon skeletons. The abundance of
bones made it difficult to plough, and slaves removed bones from the
fields, making piles at the edges.12 Some of the larger vertebrae were
used as foundation stones for buildings or stools in houses.
The bones also attracted people with more lively imaginations and
entrepreneurial spirits than Lyell. Albert Koch was a German immigrant
who had made a living in his adopted country by exhibiting curiosities
of natural and human history for profit, including live bears and alliga-
tors and wax semblances of president Andrew Jackson. Koch collected
fossils at several sites in Alabama, and by combining fossils from those
sites concocted a skeleton of a “sea serpent,” which he called Hydrargos
Fish, Mammal, or Dinosaur? | 17
sillimanii (figure 7). It was exhibited in New York City, and its pamphlet
reads:
Hydrargos, or great sea serpent, of Alabama, 114 feet in length, 7500 lbs.
weight. Now exhibiting at the Apollo Saloon, 410 Broadway. Admittance:
25 cents. Description of the Hydrargos sillimanii (Koch) a gigantic fossil reptile or sea serpent lately discovered by the author, in the State of Alabama,
March 1845.13
Koch’s Hydrargos was later found to consist of parts of at least four
different individuals, including the skull of a small whale that had been
placed in the center of the skull fragments of a larger species, with the
ears projecting downward as if the animal had teeth in the middle of its
palate (which does occur in some fish, but not in mammals).14 Koch’s
skeleton created a buzz, and Koch thrived on it, calling himself Dr. Koch,
describing the animal as the “blood thirsty monarch of the waters,” and
claiming it was 140 feet long. Scientists distanced themselves from Koch.
They noted that the animal was not a sea snake, but a whale, and
observed that multiple individuals and species were combined into a sin-
gle skeleton. Koch had named his skeleton after the founder of the Amer-
ican Journal of Science, Benjamin Silliman. Silliman encouraged Koch to
instead bestow this questionable honor on the person who described the
species. Koch obliged, changing the name to Hydrarchos harlandi.
As scientific discontent with his find mounted, Koch took his skele-
ton, or should we say skeletons, across the ocean and exhibited it in
European cities. He collected another ancient whale, much smaller than
his first specimen, which he called Zygorhiza kochii. It too was an unac-
knowledged composite of several individuals, and was eventually dis-
played in a museum in Chicago. A newspaper wrote in 1855:
The famous fossil skeleton of the zeuglodon . . . was late
ly taken for debt,
and in process of removal fell to pieces and many of the bones were broken,
when the wonderful monster was found to be of genuine plaster of Paris
formation and entirely German origin, being connected with the primeval
epochs only by the raw materials. 15
Koch’s specimens, whether plaster or bone, did not withstand the
ages; the Berlin specimen was bombed in World War II, and the Chicago
specimen was destroyed in the fire of 1871.
basilosaurid whales
Harlan’s Basilosaurus and Koch’s Zygorhiza were the oldest whales for
which significant skeletal remains were known in Darwin’s time and for
figure 8. Dorudon atrox, an extinct basilosaurid whale that roamed the oceans
thirty-four to forty-one million years ago. Fossils of basilosaurids were already known
before the time of Darwin. Until the late 1900s, they remained the oldest whales for
which full skeletons were known.
Fish, Mammal, or Dinosaur? | 19
nearly 150 years thereafter (figure 8). So, what do we know about these
whales that in name seem closer to reptiles than to modern Cetacea?
As intermediates go, basilosaurids are well along the evolutionary
line toward modern whales: they have already adapted their bodies for
life in the water and could not move around on land. And yet, they do
retain a number of hints of their terrestrial ancestry, the most dramatic
being their tiny hind limbs, complete with knees and toes. Scientists who
have scrutinized their anatomy in detail have found a number of clues
to ancestral whales.
Let’s imagine that the Reverend Wood had been right, and Basilosau-
rus could be harpooned, corralled into a bay and captured, and then
displayed in a large aquarium with glass walls. As we approach the
tank, Harlan’s serpent in the flesh looks like a snake, with a narrow, eel-
like body propelling itself through the water with sinuous movements.
It is clearly a fully aquatic animal. However, as we come closer, we see
that the beast has no scales and has paddle-shaped forelimbs: flippers.
This is no snake. The body is sleek, and has no constriction where the