Miles beneath the deserts of eastern Saudi Arabia last week, oil drills probed restlessly into the bottom of what was once a great ocean. What they sought was the liquefied residue of the creatures that flourished in the warm waters of that ocean 150 million years ago, gave their name to an era—Mesozoic—then dissolved into petroleum, leaving behind no more than a few dozen miniaturized but recognizable descendants, eerie echoes from the Age of Reptiles.
Reptiles are not snakes. That is they are not just snakes. They are a class of cold-blooded, air-breathing vertebrates whose bodies are often covered with scales or bony plates. They include turtles, lizards and snakes and some of the most interesting specimens still survive in the desert—thanks to the evolution of reptilian architecture. Because of the efficient construction of their scales or plates, for example, most desert reptiles go through life without ever drinking water; their water-tight bodies permit them to conserve every drop of moisture derived from their food. The desert, on the other hand, provides an excellent refuge for reptiles from the savage extremes of climate, because even a few inches of sand offer excellent insulation against heat and cold.
Turtles are probably the most primitive reptiles; they rank low on the scale of evolution and deserve, more than other members of their class, the name "living fossils." Common on land in some deserts, they live only in water in eastern Saudi Arabia, two marine species in the Gulf, and one fresh water species, the Caspian pond turtle, in the irrigation ditches of the oases.
Unlike turtles, lizards abound in nearly all types of inland terrain and range in size from the tiny adhesive-toed geckos—insect-eating guests in nearly every household—to three-foot brutes that prowl the empty sands and gravel plains and resemble dinosaurs.
Many lizards provide unusual examples of adaptation to life in a world of sand. The sa'waddah, or fringe-toed lacertid, known to specialists as Acantho-dactylus, is probably the most common lizard in eastern Arabia. This six-inch, long-tailed speedster may be observed nearly any time of day scurrying swiftly from bush to bush, propelled, as close examination shows, by rows of outward, projecting scales on its slender fingers and toes that work somewhat like oars. Another specimen, the tuhayhi, can practically gallop if chased and if cornered he can resort to a disappearing act that fascinates small boys and hardened oilmen alike. Stopping suddenly, he vibrates his flat body in a nearly invisible shimmy that would put the most accomplished Cairo dancer to shame. In a wink, he sinks straight down into the sand out of sight, leaving only a faint outline on the surface. Readily identified by his blunt head and black-tipped tail, the tuhayhi is known officially as Phrynocephalus nejdensis —a scholarly way of saying "toad-head from Najd."
One of the most fascinating lizards is the dammusah—or' sandfish—which can actually swim in sand the way a barracuda swims in water. The five-inch member of the skink family has evolved a form adapted to a nearly full-time existence under the desert sands: tiny limbs and a smooth shiny body as streamlined as a submarine, so as to offer minimum resistance to movement.
Because he travels underground, in contrast to other lizards that merely maintain residences there, the dammusah is one of the few desert reptiles that prefer real dune country to shrub-covered flats. His home is the steep slip faces of active dunes, where the absence of packed sand layers provides the environment that is ideal for subsurface cruising. His scientific name, Scincus philbyi, commemorates H. St. John B. Philby, the British explorer, who collected it during his travels through Saudi Arabia.
If the dammusah has evolved half-way toward snakedom, then the nadus—perhaps eastern Arabia's most unusual reptile—has gone nearly all the way. Only a specialist would recognize worm-like Diplometopon zarudnyi as a lizard, and several of them are presented every year by construction excavators to oil company preventive medicine specialists with the question, "Is this little snake poisonous?" This five-inch, reddish and entirely legless lizard seldom, if ever, comes to the surface of the sands. Living always in darkness, its eyes are nearly functionless dots. It is incapable of coordinated movement on a hard surface and dies within a few minutes if exposed to the direct rays of the desert sun.
The dabb—often transliterated as thub—and the wared are the big lizards of eastern Saudi Arabia. The first is a two-foot-long, heavy-bodied species with a spine-covered tail that gives it its English name—the spiny-tailed agamid. Living in deep burrows often seen in hard, gravelly terrain, the dabb is edible, with meat resembling tough lamb. Bedouin dabb fanciers who now drive pick-up trucks instead of camels sometimes capture them by extending a hose from their car's exhaust pipe into the burrow; the groggy lizard soon staggers out and is easily captured. A cornered dabb puts on a ferocious display, with much hissing and puffing, and his thrashing tail can inflict painful bruises. But generally he is a fraud; if careful you can capture him by hand. The dabb, or Uromastyx microlepis, is primarily a vegetarian, its body color varies from slate-grey to bright yellow—according to changes in temperature apparently—and it is capable of sprinting almost as fast as a man can run.
The waral, or desert monitor, known scientifically as Varanus griseus, is a cousin of the 300-pound Komodo dragon of the East Indies. The waral may grow to a length of three feet and its fierce appearance—with slender forked tongue, hooked claws and painted scowl—is matched by its aggressive nature. But rumors that it inflicts a poisonous bite are untrue. None of the Arabian lizards is venomous and talk of poisonous lizards is probably no more than the desert Arab's safety-first attitude toward all reptiles.
Thanks to Herodotus, the Greek "Father of History" who wrote of the "winged serpents" of Arabia, and to modern travelers who have made capital of the "dangers of reptiles" in their books, the very idea of "the desert" often conjures visions of deadly snakes lurking behind every rock. Actually there are very few species of snakes in eastern Arabia and most of them are harmless. Even the three potentially dangerous species seldom pose a threat to man. Hydrophis, the sea snake of Arabian Gulf waters, for example, is a distant cousin of the cobra and undeniably as deadly, but although hundreds of them are seen every summer by beach-goers, no swimmer has ever been bitten because the sea snake is shy and avoids swimmers. Visitors to the beach, unaware of the sea snake's potential danger, have even handled live specimens without being bitten.
The only other species which can be described as truly deadly is the yaym, the black Walterinnesia of the cobra family. This snake, fortunately, is probably the rarest species in Arabia. It is seldom seen, except by the professional reptile hunter, and there are no local records of snake bite attributed to it. Some Bedouins claim it can fly like a bird, and such a tale could account for Herodotus' solemn account of Arabia's winged snakes.
The third venomous snake, the sand viper or hayyah, is certainly not rare; numerous specimens have been collected around, and even in, oil company camps. Formerly classified as Cerastes cornutus, or the "horned viper," Cerastes cerastes is a small but thick-bodied snake with the wide "ace-of-spades" head and abruptly tapering tail characteristic of the true Old World vipers. It is now known that less than half of the individuals of this species possess the horn-like scales over the eyes that gave it its old name. Some of the habits of this snake provide good examples of parallel evolution—the development of similar characteristics, in response to environment, in different groups of organisms. The sand viper belongs to a family different from that of the sidewinder of the American Southwest, but it has developed the same peculiar mode of locomotion in sand. Its tracks are not the usual wavy line produced by other surface-moving snakes, but a series of unconnected marks each resembling an elongated letter "J". The clear prints of the snake's belly plates in the long part of the "J" prove that the sand viper does not drag or push himself along but actually "rolls" as a unit. Snake experts explaining the motion to laymen point out that a nearly identical track can be produced by rolling a bedspring across sand.
The sand viper feeds at night on small rodents. It spends most of the daylight hours buried up to its eyes in sand, curled in an S-shape beneath a bush or rock ledge. Like the toad-head lizard, it can sink vertically in the sand by moving its body in a rapid "run-in-place." When threatened it produces a peculiar hissing sound by rubbing together a series of small pointed scales on opposing loops of its coiled body. The sand viper produces a relatively small amount of venom, a little of which, delivered through its hinged hollow fangs, is efficient in killing desert rats and mice. Numerous instances of men being painfully bitten by this viper are known—most were the result of stepping directly on the snake at night with bare feet—but there is no medically authenticated record of a death caused by this snake in the east-central Arabian oil-producing area.
One of the stories that circulates in Saudi Arabia is that there are hooded cobras in the country. It isn't true. However, a harmless, sand-colored mimic of another family has left more than one desert traveler convinced that it is. This is Malpolon moilensis, sometimes called the Arabian rear-fanged snake but perhaps better described as the hooded Malpolon. When threatened, the hooded Malpolon sometimes raises the forepart of its body above the ground and faces its attacker with neck flattened and spread in an impressive cobra-like hood. Not many people will stick around long enough to notice, of course, but the Malpolon has a dark mark on each side of the head, at the back, which distinguishes it from a cobra. The hooded Malpolon, like other harmless snakes often described as "non-poisonous," does possess a mild venom effective in numbing its prey of small rodents, but it is not dangerous to man.
Other harmless snakes sometimes seen in eastern Arabia are Gray's whip snake, a lined sand snake, and the sand boa, another subterranean sand dweller. The sand boa, Eryx jayakari, is a thick-bodied, practically neckless snake with protruding eyes perched on the upper part of its head like twin periscopes. According to Bedouin legend, he buries himself below the surface of the sand and waggles his tongue in the air to attract birds, which mistake it for a wriggling worm. No naturalist has ever seen this fellow in action, but who is willing to declare it impossible in a land where skinks swim underground, warais look like dragons and vipers roll like bed-springs?
James P. Mandaville, Jr., who works in Aramco's Government Relations Department, is an avid naturalist specializing in the plant and animal life of Saudi Arabia's Eastern Province.