Biology Reference
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continuous curved row of maxillary teeth, early serpents united them with other bones
from the palate into movable right and left upper-jaw arches. Each arch is shaped like a
forward-pointing tuning fork and armed with two rows of sharp, curved teeth that pre-
vent prey escape. Muscles anchored to the underside of the skull insert from different
angles on each fork handle to pull the arches forward, backward, up, down, and to the
side. 16
Snake jaws amount to right and left vertically operating tongs, held wide open when
prey is snared with teeth. Each pair consists of an upper jaw arch and a lower jaw, such
that during swallowing the arches alternately pull the head over prey while the lower
jaws stabilize it. You can visualize this by clasping hands in front of you, with elbows
at the sides, imagining your chest and forearms as a lizard head. Swing your forearms
down and up, simulating jaws opening and closing, and note how the triangular hole
bounded by the “skull” and “jaws” limits morsel size. Now unclasp and move your hands
apart, as if the lower jaws were free of each other at the chin; then extend them halfway
at the elbows and angle your upper arms out like struts. That larger open space accom-
modates a serpent's bulkier meal, and hand-over-hand movements mime side-to-side
lower jaw actions. Or put more simply, imagine hooking index finger- and thumb-tips in-
to a stocking gathered at the ankle, then pulling this makeshift snake head—right hand,
left hand, right hand, left hand—over the food item represented by your bulging calf. 17
Thus equipped, when primates appeared on the scene, snakes were ready and wait-
ing.
Only a few living species of serpents are longer than twenty feet and thereby qualify as
giants. These include the green anaconda, reticulated python, Asian rock python, and
northern African python. Scrub pythons and three other poorly known Australian and
New Guinea species may also attain that length, but are more slender than the oth-
ers. 18 Two species occasionally exceed thirty feet, but Bronx Zoo's long-standing offer
of fifty thousand dollars for a live one that size has never been claimed, and until re-
cently knowledge of their biology has been correspondingly skimpy.
Early explorers routinely exaggerated snake size, as with a green anaconda pur-
portedly one hundred feet long and weighing five tons, 19 and even modern coverage is
often more objectifying than revealing. Robert Twigger's Big Snake, for example, tells
of a British writer, about to marry and yearning for one last adventure, who learns of
the Bronx Zoo reward and sets of in search of a thirty-foot reticulated python. 20 Twig-
ger engagingly recounts the discomforts of working in rainforests, and his descriptions
of Asian people feel authentic, but the title's namesake never inspires empathy, even as
an adversary. What little herpetology we get is outdated—and perhaps that's the prob-
lem—since the oft-quoted C.J.P. Ionides was a superb hunter who above all knew how to
find African snakes. But Hollywood portrayals are where hyperbole goes off the charts,
as in Anaconda, where the film crew and maniacal boat captain square off against a co-
lossal snake depicted with hilarious biological fabrications.
Despite the ongoing prominence of giant serpents in myths, explorers' tales, and hor-
ror movies, until recently there were no Fitchian studies of the big ones. Henry's own
tropical work centered on parts of Latin America where anacondas were rare at best,
and like many other snake biologists he never made it to the Old World tropics. Even
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