A Monstrous Beast

A Monstrous Beast BY STERLING TALMAGE, B. S., CURATOR, DESERET MUSEUM One of the most remarkable animals that ever lived is the Megatherium Cuvieri; a replica of its skeleton has recently been secured by the Deseret Museum. The discovery of the remains of this strange animal, the study of its peculiarities of structure, the disputes among scientists regarding its proper classification, and finally the fixing of its close relationship with the small South American Edentates make a chain of events as interesting and instructive as any that can be found in geologic annals. The Megatherium was first brought to the notice of the scientific world in 1789. It was discovered in the Pampean deposits of Quaternary age on the banks of the River Luxan, near the city of Buenos Ay res, and later transported from South America to Madrid, where it stood as a scientific riddle for about fifty years, none of the naturalists of the day being able to classify it. Later, between the years 1831 and 1838 a complete skeleton was discovered in the same locality, part of the bones being secured by the British Museum, and part by the Royal College of Surgeons. But for a long time the position of this beast in the animal kingdom was a matter of controversy. It was named by Cuvier, "Megatherium" which means simply "Monstrous Beast;" he also said that it combined the characteristics of Sloth, Ant-Eater, and Armadillo. The huge carapace or back-armor of a Glyptodon was found very near the bones of the Megatherium, and for a time was thought to be part of the skeleton ; and so it came about that most scientists believed the Megatherium to be a mammoth Armadillo. Prof. Owen, the celebrated English geologist, finally proved, after a careful study, that this extinct monster was a gigantic Ground-Sloth, which fed on the foliage of trees. The largest modern Sloth is two feet long, while the Megatherium skeleton measures nearly nineteen feet in extreme length. But there are several characteristics which prove a very close affinity between the two forms. The teeth are equal in number —

616 IMl'ROVF.MKNT ERA five pairs in the upper jaw and four in the lower, — and are remarkable for their deep insertion ; the peculiar zygomatic processes on the sides of the skull arc common to both animals; several other bones, notably the shoulder-blade and the thigh-bone have features in common which show the close structural relationship. The parts in which the Megatherium differs from the Sloth are in a measure similar to the corresponding parts of the Ant-Eater, another member of the same class. These features determine the classification of the Megatherium as an Edentate, a class to which some early naturalists were loth to assign it, because of the great difference in size between it and the modern representatives of this class. The Spanish naturalists expressed this objection by saying, "All the other Edentates could dance inside his carcass." But notwithstanding these features, so characteristic of the class, the Megatherium has certain individual points which are noticeable on first sight of the animal, and some others which, while not so prominent, are none the less interesting. The first thing which draws attention is, of course, the great size of the animal as a whole. From the nose to the end of the tail the skeleton MEGATHERIUM CUVTERI

A MONSTROUS BEAST 617 measures about nineteen feet; the bones alone would weigh about two tons; so, since the bones of an animal make up less than half its weight, this monster must have weighed when alive no less than ten thousand pounds! In spite of this feature being so noticeable, it was temporarily lost sight of by Dr. Lund, a Danish naturalist, who actually advanced the idea that the Megatherium, like the modern Sloth, lived in the trees. The Megatherium's great size appears more remarkable by comparison with its small present day relatives, yet it was not much larger than a large modern Elephant. But comparing these two animals we see several individual parts of the Megatherium which far exceed in size the corresponding parts of the Elephant, or any other known mammal, while on the other hand, the head is so small as to excite wonder. The massive hindquarters of the Megatherium are remarkable ; the hind legs and feet have been characterized as "models of massive organic masonry ;" they appear more like pillars of support than organs of locomotion. The heel-bone alone is seventeen inches long and twenty-eight inches in circumference, while the hind foot from heel to claw measures slightly over a yard — roughly one and one-half times the length of the whole body of the largest living Edentate. The pelvis is the largest bone which has been found in any land mammal, living or extinct ; it measures slightly over five feet broad. The rough hip-bones and spinal crest show that the pelvis was the center of enormously powerful muscular bundles, which acted upon the trunk, the hind legs and the tail. These muscles must have been possessed of remarkable contractile energy, as shown by the great amount of nerve force brought to bear upon them. The spinal cord near the hips was four inches in diameter, while the nerve center or ganglion in the pelvic region was considerably larger than the brain. The tail measures seven feet in length, and when clothed in flesh was six feet in circumference at the base. It was used as a "third leg," it with the hind limbs acting as a tripod when the Megatherium reared itself up. This was a common position of the animal when obtaining food ; the skeleton when mounted that way measures seventeen feet high. The fore limbs are not so bulky as the hind quarters, but what they lack in massiveness they make up in length and mobil-

618 IMPROVEMENT ERA ity, and arc built along lines which show enormous strength. The clavicle is the longest known, measuring fifteen inches. The fore leg with the foot is slightly over seven feet long, the forearm is quite rotatable, and the foot is provided with enormous claws. The general style of the whole fore limb shows that it is built for grasping, pulling and rending. The feet both before and behind are turned so that the animal walked on the outside edge, probably on a hoof-like callosity. This worked against speed, but the Megatherium did not need that. In seeking food, it ran after no animals, for its teeth show it to be a leaf-feeder; and if size counts for anything, it certainly ran from few, if any. If we had seen this great Sloth alive, its slothful movements would probably have attracted as much notice as its great size. As already stated, its head is comparatively small ; the size of the brain cavity leads us to believe that the animal was of that degree of intelligence generally called stupid. But it needed no great mental power to fill out its daily round of existence. It was no doubt solitary in its habits, as herds were not necessary for self-protection ; moreover, many could not find sufficient food in any limited space unless the vegetation was extremely luxuriant. Probably most of its time was spent securing food in sufficient quantity to furnish energy for that monstrous body. It had a habit of rearing on its hind legs and tail, getting firmly set, and using the powerful fore limbs to tear up or break down trees. It would then, it is believed, lie down and strip the tree of its leaves and twigs at its leisure. The Megatherium, remarkable as it is, is not the only extinct Edentate giant. In the same Pampean deposit were found the remains of the Mylodon, Megalonyx and Scelidotherium, all of them Sloths ; the Mastodon, the Toxodon, and others, in addition to the Glyptodon. which caused confusion as already stated. Fragmentary remains of the Megatherium and its associates have been discovered in the United States, but South America was then, as now the home of the Edentates.