hero, that brave, ever-so-clever furry little mongoose who fear-
lessly confronts the Indian king cobra and its mate, defeating the
slow-witted serpent by craft and nimbleness and thus saving the
verandaful of upper-crust English colonialists. I like mongooses,
but I don't like Kipling's fictitious beast. For one thing, real mon-
gooses aren't so ingratiating or so stupid as to go down a cobra's
burrow when it's occupied by its owner.
But the main reason I'm anti-Kipling is that his stories epit-
omize an all-pervasive bias in our popular and scientific culture
against the Big Reptile. Kipling's cobra is a metaphor of size and
strength without brains or honor. So the mongoose by compari-
son emerges as a noble and intelligent mammalian furball in con-
trast to its despicable reptilian foe. Snakes suffer such a terrible
public image, being forced to serve as the very agent of evil in the
Garden of Eden and as the synonym for deceit and ambush in
popular slang. Crocodiles don't fare much better—the one in Peter
Pan enjoys the dubious distinction of being only slightly less mean-
spirited than the character it devours, Captain Hook. Big croco-
dilians, like big cobras, are dangerous, aggressive predators. A
brackish-water crocodile grabbed the eminent Harvard entomol-
ogist Philip Darlington by the leg in 1944 on a South Sea island
while that gentle scholar was studying mosquitoes for the Navy
48 I THE CONQUERING COLD-BLOODS: A CONUNDRUM
Spectacular lizard bluff from Australia— Chlamydosaurus. The frilled lizard
flips its huge scaly collar skin to frighten potential enemies. Growing up to
three feet long or more, frilled lizards can sprint away at fast speeds on their
hind legs.
Department. Darlington kicked his way free after being whirled
around under water a couple of times, but not a few explorers have
suffered the complete process crocodiles perform on their prey.
Cobras and other venom-equipped snakes kill hundreds of village
people, farmers, and migrants all through the tropics, a yearly toll
far exceeding that of all the man-eating tigers, lions, and leopards
together.
So there is some cause for the human species to be alarmed
when confronted by a big reptile. However, in our culture, we react
to these reptilian potential man-killers only with revulsion, not with
respect. What a difference from the role reserved for mammalian
MESOZOIC CLASS WARFARE: COLD-BLOODS VERSUS THE FABULOUS FURBALLS I 49
man-eaters—the lion is so admired for strength and cunning that
nearly every royal European household placed the tawny beast on
its coat of arms, and both the Messiah of the Old Testament and
the Emperor of Ethiopia were hailed as the Lion of Judah. I know
admittedly little of heraldry, but rest certain that not even the
shortest-lived Balkan principality adorned its royal crest with a Nile
crocodile.
Some of my best friends are mammals. But like most other
dinosaur paleontologists, I have very mixed emotions about the
Mammalia as a class in vertebrate history. According to widely ac-
cepted theories, the Late Cretaceous mammals were among the chief
ecological conspirators that manipulated the habitats until the Di-
nosauria were extinct. Most vertebrate paleontologists aren't di-
nosaur specialists but concentrate on the fossils of mammals instead.
Any naturalist tends to identify emotionally with the objects of his
research. Consequently, most mammal paleontologists view the
Cretaceous extinctions not as a sad finale but as a grand opening,
the dawn of the Age of Mammals.
Geologists generally have a fondness for dynamic terminol-
ogy to label earth processes they study. A pulse of mountain-
building activity is thus known as a revolution, and the Laramie
Mountains, folded and raised in Late Cretaceous times east of
Como, are described as the products of the Laramide Revolution.
Tacked onto the bulletin board of the student offices in the Uni-
versity of Wyoming, where Late Cretaceous mammals are a spe-
cialty, is a poster in the best 1919 Bolshevik style. The earth
explodes upward, Triceratops tumble over backward stunned into
extinction, as a giant furry fist thrusts through the land surface
clutching the banner "Join the Laramide Revolution." And to hear
the mammal paleontologists talk, after a few pitchers of beer in
the cowboy bars, it happened that way. With the geological equiv-
alent of the "Hallelujah Chorus," the irresistible new wave of
mammals swept aside the old order, replacing the sluggish brawn
of the dinosaurs with the energetic intelligence of the Mammalia.
Such talk is annoying. But we few dinosaur specialists huddle to-
gether at the dark end of the bar, muttering in our beers about
the insults—insults not just against the Dinosauria, but impugning
the honor of every turtle, crocodile, snake, frog, and salamander
as well.
In European culture, the anti-reptile bias began centuries be-
50 | THE CONQUERING COLD-BLOODS: A CONUNDRUM
fore the stratigraphic sequence was discovered. The very word
"reptile" has a pejorative etymology. Derived from the Latin ad-
jective reptilis, "creeping," the term originally was applied indis-
criminately to anything low-down and loathsome—scorpions,
centipedes, snakes, and lizards. Ever since classical antiquity the
Reptilia meant roughly the equivalent of "creepy-crawlies." Aris-
totle, the ancient Greek naturalist, and the Christian philosophers
who revised and edited his texts, put lizards and snakes low down
in the scale of animate creation, far below cats, dogs, birds, and
mongooses. The idea that all of nature could be arranged in an
ascending scale of complexity and perfection was extraordinarily
popular among medieval scholars. The principal criterion by which
any species would be assigned its place on the Scala Naturae was
how close it came to the unchallenged holder of the top rung, Man
Himself. According to this view, the Creator, in His wisdom, put
His best blueprint into production with the human race; the other
mammals were close, but the scaly, crawling things were far from
His Own Image. Even when Darwinism cleared away most of the
creationist mythology from Western science, an evolutionary Scala
Naturae was easily substituted for the theological one.
If all the bad-mouthing of reptiles came from bar-hopping
mammal paleontologists emboldened by one too many beers, or
the mystic musings left over from the Middle Ages, I wouldn't be
much disturbed. But when the dean of reptile paleontologists, the
late Al Romer of Harvard, wrote about the superiority of mam-
malness over the reptile condition, it made me shudder. Alfred
Sherwood Romer did some superb and innovative research on the
hind-limb muscles of dinosaurs in the late 1920s, showing that the
thighs of duckbills operated more like those of giant birds than
those of giant crocodiles. But dinosaurs were a minor diversion in
Romer's long and
distinguished career. He spent most of his field
seasons, first in Texas, later in Brazil and Argentina, digging up
mammal-like reptiles, a diverse lot of vertebrates that bridge the
structural gap between a primitive lizardlike reptile and a genuine
furry, milk-sucking mammal.
Romer inherited from his mentor, the magisterial anatomist
William King Gregory, a passion for reconstructing, step by step,
the evolutionary pathway that led from the first sprawling reptile
of the Coal Age, 300 million years ago, to the first bona fide mam-
mal, something that would look like a tiny 'possum, which emerged
MESOZOIC CLASS WARFARE: COLD-BLOODS VERSUS THE FABULOUS FURBALLS I 51
at the end of the Triassic. For Romer and Gregory, clearly the
proper study for man was Mankind. Therefore the most important
life thread in geological history was our own, leading backward
through the Age of Mammals to the tiny, scurrying Mesozoic
mammals and thence through all the successive stages of mammal-
like reptiles. Gregory wrote a delightful evolutionary essay for the
lay person, "Our Face from Fish to Man," which expressed ele-
gantly the preoccupation with the single evolutionary trackway
leading upward through the strata to the Mammalia and to Homo
sapiens. Both Romer and Gregory did study what were perceived
as evolutionary sideshows—Romer wrote about Coal Age am-
phibians with flattened, shovel-like heads, and Gregory executed
definitive treatises about sailfish—but both scholars were true to
their own class, the Mammalia, when it came to allocating the bulk
of their labors.
Romer earned the everlasting gratitude and respect of all rep-
tilian paleontologists with his Osteology of the Reptiles, a bountifully
illustrated guide to skulls, limbs, and vertebrae of all the Reptilia,
including dinosaurs and mammal-like reptiles. Romer's classifica-
tion of reptiles, which places nearly every known fossil and living
species in a formal hierarchy, is one of the most widely used among
herpetologists and paleontologists. When I was a graduate student
at Harvard's Museum of Comparative Zoology, I was fortunate to
have a study carrel around the corner from Romer's office. He was
always ready to talk about his first love, the evolution of mammal-
like reptiles, at coffee break when he and the other senior pa-
leontologist, Bryan Patterson, a pioneer in the analysis of Mid
Cretaceous mammal teeth, sat on the basement stoop with the
students and staff. For his affability, scholarship, and generous
support of students, Al Romer is justly remembered as a prince
among the reptile specialists.
But Romer did one thing I disagree with, vigorously. He wrote
that after the close of the Cretaceous, the entire Reptilia became
second-class, an overaged, unprogressive group that decayed steadily
in biological importance down to the present time, the evolution-
ary equivalent of the senile Ottoman Empire gradually losing its
grip over the eastern Mediterranean after its apogee in the fif-
teenth century.
Far from declining senile groups, the Reptilia and their cold-
blooded cousins, the Amphibia, are today full of vigor, full of spe-
52 I THE CONQUERING COLD-BLOODS: A CONUNDRUM
cies, and full of ecological importance. To prove this, one need
only stroll through any tropical rain forest in today's world. These
habitats, the richest in vertebrate species, are quite literally crawl-
ing with frogs, snakes, and lizards—a hopping, slithering, scamp-
ering horde of highly specialized species whose numbers overwhelm
those of the supposedly "higher" mammals.
To evaluate the fortunes of the classes, we need some simple
system of scorekeeping. One of the best ways to score evolution-
ary success is to count species. The species is a self-perpetuating
unit of interbreeding individuals, and two closely related species
can be proved to be distinct only if they fail to interbreed freely
in the wild. Most of the time closely related species have slightly
different ways of making a living. For example, the high plains wolf
hunted in packs across the prairie, cutting down elk and straggling
buffalo calves. The coyote, a close relative of the wolf, usually
traveled in smaller groups, snatching small prey and sneaking in
to dine on wolf kills after the bigger predators had gone. In zoos,
coyotes and wolves will mate and give healthy hybrids, but in the
wild the two usually keep their genes to themselves. Thus, wolf
and coyote are scored as separate species. When we count the to-
tal number of species in the Reptilia or Mammalia, we are scoring
the number of different ecological roles filled by that class. We
should send those barroom detractors who believe that reptiles are
a moribund class into the tropical forests, armed with checklists,
nets, and binoculars. Let the mammal chauvinists count species;
the results will sober them up. (A genus is a group of closely re-
lated species; Canis is a genus name, the dog genus, and Cants la-
trans is the coyote species.)
If they do their work well, species census takers should score
fifty nonflying mammals in a thousand-acre plot of the Congo Basin
or the Burmese lowlands—squirrels, shrews, monkeys, mon-
gooses, palm civets, antelopes, and elephants. This is a rich fauna
of furballs by Temperate Zone standards; a New England wood-
land would score only two dozen species. Now set the census tak-
ers on the task of scoring every Congolese frog, serpent, and lizard.
In that same thousand-acre plot the total score for Reptilia and
Amphibia will be about 180, three times the mammal score. In
Burma or Thailand the scores will be similar—the "cold-blooded"
classes win two or three to one. So where is the proof that Mam-
malia are the best adapted class?
MESOZOIC CLASS WARFARE: COLD-BLOODS VERSUS THE FABULOUS FURBALLS I 53
Herpetology is the study of amphibians and reptiles, the name
being derived from the Greek for snake, herpes, and for learning,
logos. Biologists, with their fondness for professional nicknames,
lump all members of these two classes as "herps." An entire rep-
tile—amphibian census is called a herpetofauna. (Herpes virus, that
current scare in venereal epidemiology, gets its name from the al-
leged similarity between how the fever blisters spread and the
crawling of snakes.) Not only is the herpetofauna of today's trop-
ics much richer in species than the mammalian fauna, but the
tropical herps display a veritable riot of adaptive diversity. The
marine toad of South America is a five-pound warty predator that
gulps down mice and rats, an ecological function that induces
farmers to transport the toad all through the tropics to keep down
rodent populations on plantations. Marine toads are toothless
hunters but make up for their lack of dental armament by their
poisonous saliva, which numbs their prey into submission. The big-
mouthed marine toad sits in ambush along a small mammal trail
and makes a short lunge to snap up the unwary rat; a moment or
two inside the toad's mouth is all that is necessary to anesthetize
the mammal.
Among herps, poison is a popular adaptation for defense as
well as for offense. Arrow-poison frogs of the American tropics
produce a potent toxin in their skin glands. Some species are dan-
gerous to handle without gloves—my lab instructor in an under-
graduate course at Yale fondled a pretty frog, just uncrated from
Surinam, and was sick for two days. Amazonian hunters dry and
concentrate arrow-poison frog toxins to smear on the cutting edges
of their blowgun darts and arrows. One good dose from a dart and
a thirty-pound monkey falls paralyzed from its treetop refuge.
Poison even guards New England toads and salamanders—some
species have enough skin toxins to make a hound dog retch. Wise
old retrievers learn not to put toads into their mouths.
The amphibious branch of the herp kingdom is not limited
to chemical adaptations. Kermit the Muppet frog has made the
fly-catching tongue famous, but the ability to snap insects by tongue-
flipping has also evolved in salamanders, the short-legged amphib-
ians that look like scaleless lizards. Although most amphibian tooth
equipment is modest by mammalian standards, there is a saber-
toothed toad: the horned Ceratophrys of the New World tropics.
54 | THE CONQUERING COLD-BLOODS: A CONUNDRUM
The sharp-edged upper fangs of a big, adult Ceratophrys can cut up
the hand of an unwary herpetologist. Ceratophrys also claims the
distinction of being an armor-plated toad. Embedded below the
moist outer skin are wide bony plates protecting the shoulders and
neck. If you grew up in northern New Jersey, as I did, you get
the impression that frogs are a swamp-bound clan, because watery
haunts offered the best frog-hunting ground. But most species of
frog are tropical, and in the tropics fully half of the frog species
can be land-living as adults, and many climb trees. In the flood-
plain of the Congo River, three different families of species of tree
frog clamber about the bushes and forests, snaring insects from
leaves and bark.
Amphibians score significant subterranean successes, too. The
New England mole salamander pushes its way through damp soil
Robert T Bakker Page 5
