178 



MUSEUM OF ANIMATED NATURE. 



[Megatherium. 



Family Gravigrada, Owen. — Feet snort, very 

 strong, equal or subequal ; fore-feet with five or 

 four toes, of which one or two of the outermost are 

 unarmed, fit for support and progression ; the rest 

 are armed with huge claws. Zygomatic arch com- 

 plete, clavicles perfect ; tail moderate or stout, acting 

 as a fulcrum or prop. 



Such are the characters of this family, as laid 

 down by Professor Owen. It contains the following 

 genera : — Megalonyx, Megatherium, Mylodon, 

 Scelidotherium, Coslodon, and Sphenodon; of these 

 genera all the species are extinct, and only known 

 from their fossil relics. 



774. — Mylodon robustus. 



We figure the skeleton of this extinct giant, now 

 preserved in the Iioyal College of Surgeons, and 

 which, except that it was formed for tearing down 

 the trees of the forest, and not living in then- 

 branches, was closely related to the comparatively 

 pigmy sloths of the present day. Conceive of a 

 biota of the size and bulk of a rhinoceros or hippo- 

 potamus, but with bones infinitely more massive, 

 muscles infinitely more voluminous and powerful, 

 with a thick tail acting as a support, and forming 

 with the hind limbs a firm tripod, while the animal 

 thus raised upright, and exerting its enormous 

 strength, sways the tree to and fro, and lays it at 

 last prostrate ;— and our reader will have a good 

 idea of what, this mighty devastator of the primitive 

 forests of South America must have been. 



The skeleton in question was discovered, as we 

 are informed by Professor Owen, " in the year 1841 

 by M. Pedro de Angelis, seven leagues north of the 

 city of Buenos Ayres, in the fiuviatile deposits con- 

 stituting the extensive plain intersected by the great 

 Rio Plata and its tributaries, and which has been 

 raised during a recent geological epoch above the 

 level of the sea. 



" In this formation, and most probably anterior 

 to its elevation, the animal must have been buried 

 entire, and if the present heat of the climate pre- 

 vailed, soon after its death, for the parts of the ske- 

 leton were found little disturbed, and the very few 

 bones that, are wanting are such as would be likely 

 to escape the search of the most diligent collector. 



" About the same time and near the same place 

 a tessellated osseus carapace of some large _ qua- 

 druped like an armadillo was exhumed, and infor- 

 mation of this discovery having been communicated 

 to the Royal College of Surgeons by Sir Woodbine 

 Parish, late Her Majesty's Charge d'Aft'aires at 

 Buenos Ayres, both this carapace and the above- 

 mentioned skeleton were purchased by the College. 

 They arrived in November, 1841, in many pieces, 

 fragile from the loss of the animal matter; but 

 having been restored in some measure to their 

 original tenacity, the parts of the carapace were 

 re-united, the skeleton was articulated, and both 

 are now placed in the museum." 



We may here observe that the tessellated carapace 

 belongs to a large extinct armadillo, to which the 

 largest living species, the Dasypus Gigas, is but a 

 pigmy ; it is termed by Professor Owen, Glyptodon 

 clavipes. 



With respect to the fossil genus Mylodon, Pro- 

 fessor Owen describes three distinct species, viz., 

 M. Darwinii, M. Harlani, and M. Robustus, which 

 far exceeds the others in size. 



We regret that want of space prevents us from 

 following Professor Owen through his elaborate 

 examination of the skeleton of Mylodon robustus, 

 which to the scientific is replete with interest, nor 

 enter into the affinities of the Mylodon to the Me- 

 gatherium, Megalonyx, and other extinct Edentata, 

 which are rigidly scrutinized. 



Fig. 775 represents the lower jaw of Mylodon : 

 Fig, 776, the external view of the right branch of the 

 lower jaw of Mylodon. Figs. 777 and 778, the sim- 

 ple teeth of the Mylodon, showing the depth of 

 their implantation. The cavity at the base of the 

 tooth is seen at a, Fig. 777. As in the sloth, the 

 Megatherium, and Megalonyx, these teeth, formed 

 for crushing leaves, are composed of a central pillar 

 of coarse ivory, immediately invested with a thin 

 layer of fine dense ivory, and the whole surrounded 

 with a thick coating of cement. ■ 



From the structure of these teeth it is evident that 

 the Mylodon fed on leaves, like the sloths of the 

 present day. But, notwithstanding Dr. Lund's 

 opinion, it was certainly not adapted for climbing 

 trees; besides, what trees could bear its weight? 

 How then did it obtain its food ? The whole of its 

 osseous confirmation suggests the answer— it was 

 formed to uprend the trees that bore its sustenance. 

 The enormous expanse of the pelvis, the great bulk 

 and strength of the hind-legs, the solidity of the tail, 

 to which its evidently vast muscles were attached, 

 enabling it with the hind-limbs to complete a firm 

 tripod of support, the proportions of the fore-limbs, 

 unequalled for massiveness by those of any existing 

 or extinct animal, the size and strength of its claws, — 

 in short the whole mechanism of the colossal frame 



becomes intelligible only on the ground of the her- 

 culean labour to which the animal was appointed. 

 Perhaps it commenced the process of prostrating 

 the chosen tree by scratching away the soil from the 

 roots, and then proceeded to grapple with it thus 

 partially undermined, and apply the surpassing- 

 strength of its limbs and body, the muscles of the 

 trunk and extremities, being animated by the in- 

 fluence of the unusually large spinal chord. 



It may here be stated that the skull of the speci- 

 men described by Professor Owen had at some time 

 or other been fractured and had healed ; the animal 

 living long afterwards: and it will at once occur to 

 the reader that these animals must have been un- 

 usually liable, from their habits, to blows from heavy 

 falling bodies; to meet such accidents the scull was 

 peculiarly constructed, its outer and inner table 

 being separated by extensive air-cells, so that the 

 fracture of the outer table might occur without in- 

 jury to the brain. It was by virtue of this structure 

 that the subject of the Professor's memoir appears 

 to have been saved. 



779, 780, 781, 782, 783.— Sceudotheriom. 



Our Figures represent (Fig. 779) the remains of the 

 skull ; Figs. 780, 781, the dentition of an extinct 

 animal, to which Professor Owen has given the title 

 of Scelidotherium. Figs. 782, 783, show the depth 

 of the implantation of the teeth and their structure ; 

 e, the crown of a tooth seen from above. 



This animal was evidently allied to the Mylodon 

 and Megatherium, and belongs to the same family. 



The fossil remains, viz., a cranium, several ver- 

 tebrae, the scapulas, and various bones of the limbs, 

 were discovered by Mr. Darwin at Punt a Alia, in 

 northern Patagonia, and in the same bed of partly 

 consolidated gravel as that wherein the lower jaws 

 of Toxodon and a species of Mylodon were im- 

 bedded. All the parts were discovered in their 

 natural relative position, indicating, as Mr. Darwin 

 observes, that the sublittoral formation in which they 

 had been originally deposited had been but little 

 disturbed. This beach is covered at spring-tides, 

 and many portions of the skeleton were encrusted 

 with flustrce. Small marine shells were lodged 

 within the crevices of the bones. 



The teeth in structure resemble those of the 

 M3dodon ; there are neither incisors nor canines ; 

 the molars are five on each side above, and four 

 below. According to Professor Owen, the Cape 

 Ant-eater, or Aard-vark, of all the Edentata most 

 nearly resembles the Scelidotherium in the form of 

 the skull ; and next to the Aard-vark may be cited 

 the great Armadillo (Dasypus Gigas). 



"Although the Scelidothere, like most other Eden- 

 tals, was of low stature, and, like the Megatherium, 

 presented a disproportionate development of the 

 hinder parts, it is probable that bulk for bulk, it 

 equalled, when alive, the largest existing Pachy- 

 derms not proboscidean. There is no evidence that 

 it possessed a tessellated osseous coat of mail." 



784, 785, 786, 787, 788, 789.— The 

 Megatherium. 



The relics of this colossal beast, of which Figs. 787, 

 788, and 789 represent the skeleton, have been dis- 

 covered only in South America, of which continent, 

 at some remote period, it was an inhabitant. 



The affinity of this animal to the sloths and other 

 Edentata was pointed out by Cuvier, but many 

 points required elucidation ; in fact zoologists have 

 been led, not without apparent grounds, into some 

 errors, recently corrected. 



For a long time the museum of Madrid afforded 

 the ouly relics of the Megatherium in Europe ; but 

 the skeleton they compose is deficient in several of 

 its parts ; fortunately the recent acquisition by the 

 Boya] College of Surgeons of a great portion of the 

 bones of this animal lias tended to supply the de- 

 fects, at least to a considerable extent. 



These splendid and valuable remains form the 

 subject of an interesting paper from the pen of Mr. 

 Clii't, in the third vol., p. 3, of the ' Trans. Geol. 

 Soc. Lond.' accompanied by an improved figure of 

 the skeleton, and figures of various detached parts, 

 together with, a map of that part of the province of 

 Buenos Ayres in which the places where the bones 

 in question were found, and also those of the Madrid 

 specimen, are marked down. 



The acquisition of these remains by the Royal 

 College of Surgeons is due to the zeal and liberality 

 of Woodbine Parish, Esq. " They were found in the 

 river Salado, which runs through the flat alluvial 

 plains to the south of the city of Buenos Ayres. Their 

 discovery was owing to a succession of unusually dry 

 seasons in the three preceding years, which lowered 

 the waters in an extraordinary degree, and exposed 

 part of the pelvis to view as it stood upright in the 

 bottom of the river. It appears that this and some 

 other parts of the skeleton, having been carried to 

 Buenos Ayres by the country-people, were very 

 liberally placed at Mr. Parish's disposal by Don 

 Hilario Sosa, the owner of the property on which 



they were found. In the hope of obtaining the 

 other parts of the skeleton, an intelligent person 

 was subsequently sent to the same spot, who suc- 

 ceeded, after considerable difficulties, in getting out 

 of the mud forming the bed of the river the re- 

 mainder of the collection. Further inquiry led Mr. 

 Parish to suppose that similar remains might be 

 met with in other parts of the provinces of Buenos 

 Ayres, and he applied to the local authorities to 

 assist him in making further search. This was given 

 by the governor, Don Manual Rosas, and the re- 

 mains of the two other skeletons were found on his 

 excellency's own properties of Las Averias and Vil- 

 lanueva, one to the north, the other to the south of the 

 Salado, but at no great distance from the place where 

 the first had beendiseovered. In the latter instance 

 the osseous remains were accompanied by an im- 

 mense shell, or case, portions of which were brought 

 to this country." A fragment of this shell, or os- 

 seous shield, is figured by Mr. Clift ; its external 

 surface is rough, and it appears to consist of an as- 

 semblage of smaller parts, like rosettes in sculpture, 

 united together by suture ; the sutures being plainly 

 marked on the under surface, which is smooth. By 

 M. Blainville, Dr. Bucldand, and indeed by most 

 naturalists, this buckler or carapace was regarded 

 as belonging to the Megatherium, whose colossal 

 bulk it was regarded as having protected, as is the 

 case in the Armadillos, to which it was believed to 

 be closely related, not only in structure and habits, 

 but also food. 



It has, however, been recently demonstrated by 

 Professor Owen, and we believe to the entire satis- 

 faction of Dr. Buckland himself, that the tessellated 

 carapace found with the Salado remains did not 

 belong to the Megatherium, but to a large arma- 

 dillo-like animal, to which Professor Owen~assigned 

 the title of Glyptodon, and whose hind-feet, like the 

 fore-foot, appear to be so modified as to form the 

 bases of columnar limbs destined to support an 

 enormous incumbent weight. Moreover, from a 

 rigorous examination of the details of the skeleton 

 of the Megatherium, into which we forbear to enter, 

 he proves the incompatibility of such a shield with 

 its osseous structure, which differs in marked essen- 

 tials from that of the Armadillo, in which latter 

 animal the skeleton is expressly modified for the 

 armour which covers the back and head. 



In his paper on the Glyptodon, wherein the claims 

 of the Megatherium to this armour are discussed, 

 Professor Owen gives a tabular account, of the dis- 

 covery of twelve skeletons of the Megatherium, and 

 in no instance did any portion of bony armour occur 

 with or near the bone; and in a note the writer of 

 the article ' Megatherium' in the ' Penny Cyclopaedia' 

 states as follows : — 



" Sir Woodbine Parish has just now (May 29, 

 1839) kindly communicated to us a letter received 

 by him, giving information of the discovery of an 

 almost entire skeleton of an adult Megatherium on 

 the banks of the Rio de la Matanza, with all the 

 vertebrae of the body, all the ribs, all the teeth, the 

 head and the legs, in short, with the whole of the 

 bones except the tail and one foot. Close to it was 

 the skeleton of a 'Tatou gigantesque ' (Glyptodon 

 probably), with its bony armour complete. There 

 was also found a very small and perfect Megathe- 

 rium, which must have been only just born at the 

 epoch of destruction. No mention is made of any 

 traces of bony armour orshell about the Megatheria. 

 In the old animal only one foot is wanting. It has 

 been suggested that the so-called young Megathe- 

 rium may possibly be a skeleton of Scelidotherium." 



It is then to the armadillo-like Glyptodon, and 

 not to the Megatherium, that the strong bony ar- 

 mour belongs ; of this latter animal relics have been 

 found on the left bank of the Pedernal, near Monte 

 Video, and are preserved in the Museum of that 

 town. Portions of bony armour also have been ob- 

 tained in the Rio Seco and Banda Oriental, similar 

 in structure to the specimen of the Pedernal. 



" The collection of fossils," says Professor Owen, 

 "brought to England from South America by Mr. 

 Darwin, has enabled me to add the following facts 

 to the history of the Megatherium. Its teeth, for 

 example, do not differ in number from those of the 

 sloths, there being five on each side of the upper 

 jaw. Microscopic examination having demonstrated 

 | a marked difference in the intimate structure of the 

 teeth of the sloths and armadillos, I have ascertained 

 by this mode of investigation that the teeth of the 

 Megatherium have the same texture and composi- 

 tion as those of the sloth. And if from identity of 

 dental structure in two different animals we may 

 predicate a similarity in their food, a glance at the 

 bony framework of the Megatherium is sufficient to 

 show that it must have resorted to other means of 

 obtaining its leafy provender than that of climbing 

 for it, whereby the necessity of inferring a propor- 

 tionate magnitude of the trees which nourished the 

 Megatherium is obviated." It would appear that, 

 like the Mylodon, the Megatherium uprooted the 

 ! trees, on the leaves of which it fed, and was fur- 



