The largest, oldest and, some contend, most ferocious reptiles on earth are the Crocodilia—a durable family of creatures whose genealogy makes Man seem like a newcomer to this planet by comparison. Their fossils date back 190 million years to the Triassic period, when they would have been contemporaries (if not playmates) of the dinosaurs, yet they still thrive today in the warmer parts of the world from the banks of Middle Eastern rivers to the swamps of Georgia and Florida. Although they have been objects of fear throughout history, some peoples, particularly in the Middle East, have also venerated them and preserved them as mummies.
Scientists are not certain there is any direct genetic relation between Crocodilia and Dinosauria. The direct ancestors of the Crocodilia are still unknown and authorities have differing opinions about their proper classification, but for scientific convenience Crocodilia have been classified by R. L. Ditmars in his Reptiles of the World into four genuses: crocodiles, alligators, caimans and gavials, of which there are 21 different known species still found in the world today.
Though the different species of Crocodilia have numerous minor differences in anatomy and habits, they are most easily distinguished by their shape, especially the shape of the snout. The most obvious difference between a crocodile and an alligator, for example, is that the alligator's snout is broad and rounded, while the crocodile has a more triangular head with a narrower, tapering snout.
Another difference is that the crocodile's fourth tooth on each side protrudes outward, but the alligator's (and the caiman's) fourth tooth fits into a socket in the upper jaw and is hidden from the outside. This extra-long tooth is for seizing the prey; the other teeth are for subsequent crunching and tearing.
This saurian eating technique once saved the arm of Ross Allen, Florida's well-known "bring 'em back alive" hunter. One day an alligator clamped its powerful jaws on Allen's left forearm, but the 'gator had miscalculated and missed spearing him with the seizing fangs. Allen, who knows the ways of alligators, did not panic and try to pull his arm free. He simply waited, knowing the reptile would try for another bite. When the jaws opened for a more satisfactory grab, Allen promptly withdrew his arm, with only superficial punctures and abrasions.
"El lagarto" is the Spanish term for lizard, of which "alligator" is the obvious corruption, although in Latin America "lagarto" refers to crocodiles and caimans. True alligators are found only in the southern United States (Alligator mississippiensis) and a smaller version in southern China (Alligator sinensis). The American alligator has been known to reach a length of 16 feet, but its Chinese cousin never grows longer than about six feet.
In parts of India, Sumatra and Borneo are found the gavials, which are most distinctive in shape. Their snouts are long and extremely narrow—"extending from the head like the handle of frying pan," wrote Ditmars. In the Ganges and other rivers of northern India, the gavial grows as long as 30 feet. The Malayan species is about half this incredible size.
Despite its formidable array of sharp, slender teeth, the gavial is a timid creature. It eats mainly fish, which it captures by sideways sweeps of its long snout. Its name is a corruption of the Indian name "gharial," which means fish-eater. Like other Crocodilia it is a carnivore, but whenever it senses the presence of a human the gavial shies into the water and hides.
There are 12 known species of crocodiles, five of caimans, and two each of gavials and alligators. The crocodiles are the most widely distributed—predominantly in Africa, Madagascar, India and Malaya, and frequently in Florida, Mexico, Honduras, Guatemala, Venezuela and other South American countries. They are found in the West Indies, the East Indies and Australia.
The Nile crocodile, an agile and vicious animal, is found throughout Africa and is common on the island of Madagascar. Though it has been almost exterminated in the lower reaches of the Nile, this man-eater still takes a heavy toll of human life.
Perhaps because of its fearsome qualities the crocodile was sacred to the ancient Egyptians, who preserved some as mummies. Sebek was the name of their crocodile god. Zoologist Albert M. Reese points out that the Nile crocodile (Crocodilus niloticus) is probably the "leviathan" mentioned in the Book of Job.
Another man-eater is the salt-water crocodile (C. porosis), which has the honor of being the largest living reptile. One is recorded to have reached 33 feet from savage snout to the tip of its powerful tail. This species lives in the tidal waters of India and Malaysia, and has even been seen swimming in the open sea beyond sight of land.
The American crocodile (C. americanus) is found only in the marshes and coastal waters of southern Florida below Palm Beach. In captivity it is pugnacious and dangerous, yet in the wilds it will discreetly retire when a man approaches. Zoo attendants have learned not to treat it casually, as they do the alligators, but to stay respectfully outside the orbit of that powerful tail.
Crocodilus americanus can't tolerate cold temperatures. It ranges the subtropics and the Torrid Zone of the western hemisphere, from the swamps of southern Florida to the coastal streams of Mexico, Central America and parts of South America. Its maximum length is about 14 feet, although one measuring 14 feet and seven inches was killed in the 1890's by Ralph M. Munroe in a slough near what today is luxurious Miami Beach. This saurian was mounted by the New York Museum of Natural History, where it is still exhibited.
Five species of caimans are exclusively Latin American. They are closely akin to the alligator, their snouts broad and varying from oval to bluntly rounded. They are most common in tropical South America, especially in the upper Amazon, and in Central America. Four of the species—Rough-backed, Spectacled, Banded, and Round-nosed—range in size from six to eight feet, but the blunt-snouted Black Caiman found in some of South America's tropical streams reaches a length of 20 feet.
In Venezuela's llanos —flat prairie lands laced by streams and strips of jungle—the trails of caimans and crocodiles can be followed from the streams through the tall grass to the pastures where wild horses and wild cattle graze. Natives avow that a big caiman can break the leg of a cow or horse with its tail. Once the unwary animal is brought to earth, the reptile then drags it to the stream to first drown it and then devour it.
Compared to his wild, aggressive cousins, the American alligator is a gentleman towards people, even though it can roar and hiss—and look—like a dragon. In captivity the alligator, unlike the peevish crocodile, seems to ignore humans or even regard them with amused tolerance. A relaxed alligator, seen in profile, appears to be grinning.
At Florida alligator "farms," where its tough appearance makes tourists shudder, it even submits to wrestling. A strong young man will tussle one out of a pond and onto a float by first throwing it on its back and then gently massaging its solar plexus until the 'gator is "hypnotised" and goes limp. No crocodile would stand for such treatment.
In the United States where the alligator was once at home in streams, swamps and bayous from North Carolina to the Mexican border, his chief refuges today are the Florida Everglades northward to the Okefenokee Swamp in Georgia. To prevent extinction of the species, the State of Florida now imposes heavy penalties for killing them.
The alligator hibernates during the winter by tunneling into a muddy bank beneath the surface of the water. But while the entrance is under water, the burrow slopes upwards into the shore 20 or more feet until it is above the water level.
After three to five months of hibernation the 'gator emerges and sets out to break his fast. His springtime hunger makes almost anything look tasty—fish, water birds, mammals, crustaceans, other reptiles, even smaller alligators. Perhaps to aid in assimilating this diet, he usually consumes a few good-sized rocks and pine cones—a family trait among all Crocodilia.
Mating occurs in the spring and the roars of the bulls can be heard for miles. The males are noisy and quarrelsome. Their thumping, moaning roars may be challenges to rivals, but the noise also serves to attract females.
Early in June the female alligator builds her nest, usually on shore near a tree or bush. She makes a pile of grass, reeds and leaves which she compacts solidly by crawling over it. The male is no help; after the mating he loses all interest in the matter and goes on his way.
After hollowing out the nest, the female lays her 30 to 40 eggs and covers them with more vegetation, which she packs as before. Sun and moisture cause the vegetable material in the nest to ferment, which makes the nest a warm incubator with a temperature of about 80 degrees F.
For about two months the female alligator stands watch near the nest until the unhatched youngsters reveal that they are ready for the world by squeaking shrilly inside their shells. They can be heard a yard or more away. The female then uncovers the eggs, for while the youngsters can break their tough shells, they lack the strength to burrow through the compacted nest.
Opening the nest apparently completes the cycle of motherhood. The female may remain around to protect her offspring for a short time, but they are soon on their own. They satisfy their appetites with insects and worms on land, and water bugs, pollywogs and the miniscule forms of plankton in the water. Later they learn how to sweep small fishes into their elongated mouths. They need no swimming lessons; tail-swishing and paddling their feet come naturally.
During the Civil War, the demand for shoe leather in the South gave rise to 'gator hunters and tanners, but business fell off at the close of the war. Alligator hide, even with advanced processing techniques, proved inferior to cowhide for shoes.
Around 1900, however, manufacturers created a new demand by making belts, travel bags, portfolios, cardcases and women's handbags of crocodilian leather, and consequently the alligator was practically eliminated from the southern United States. Today most of this leather comes from Mexico, Central America and the Caribbean Islands.
But the alligator is much more interesting in person than as a handbag. He's the showman of the crocodilian world, and several of these saurian ham actors loaf around the spots in the Everglades National Park where the rangers give brief nature talks to visitors.
Old George, a 14-footer who lives in the Royal Palm Station pond, is said to roar splendidly each time he is introduced to a crowd of tourists.