Megalonyx

“ Can those huge quadrupeds have been destined to climb that had the pelvis and hinder extremities more ponderous and bulky in proportion to the fore parts of the body than in any other known existing or extinct vertebrate animals?
M. Lund argues for the scansorial character of the Megalonyx, because its anterior extremities are longer than the posterior ones; but if they somewhat exceed the hind legs in length, how vastly inferior are they in respect of their breadth and thickness. ”

“ If the astragalus, which I have referred with doubt to the Megalonyx, do not actually belong to that genus, it is evidently part of a very closely allied species. Now this astragalus, as we have seen, resembles most closely that of the Megatherium; and since we may infer that the calcaneum, scaphoides, and cuboides had a like correspondence, the inclination of the sole of the foot inwards must have been very slight, as I have determined from examination of the structure and co-adaptation of those bones in the incomplete skeleton of the Megatherium in the London College of Surgeons. ”

“ The nearly-related genus Megalonyx, unlike the Megathere, but like the Mylodon, extended its range northwards as far as the United States.
Just as the Sloths of the present day were formerly represented in the same geographical area by the gigantic Megatheroids, so the little banded and cuirassed Armadillos of South America were formerly represented by gigantic species, constituting the genus Glyptodon. The Glyptodons (fig. 262) differed from the living Armadillos in having no bands in their armour, so that they must have been unable to roll themselves up. ”

“ According to this mode of viewing the logical abstractions under which species are grouped together, the extinct Edentate Mammal discovered by Jefferson must be referred to a genus distinct from Megatherium, and for which the term Megalonyx should be retained. This will be sufficiently evident by comparing the descriptions given by Cuvier of one of the teeth of the Megalonyx Jeffersonii, and by Dr. Harlan of a tooth of his Megalonyx laqueatus, with those of the Megatherium which have been published by Mr. ”

“ Inasmuch as this species may have existed during a large part of the Pleistocene and certainly after the passing of the Wisconsin epoch, and inasmuch as no other species were found associated with the megalonyx bones, it is impossible to say to what part of the Pleistocene that particular animal is to be assigned.
SOUTH CAROLINA.
(Map 3.) 1. Beaufort, Beaufort County.—In the Charleston Museum the writer has seen a left lower canine tooth of Megalonyx jeffersonii. The fore-and-aft diameter is 34 mm., the transverse 18 mm. It is recorded as found in dredging in Coosaw River. ”

“ Marsh described some remains allied to Megalonyx and Mylodon, from the Pliocene beds of California and Idaho, and forming a new genus, Morotherium. As these remains have only occurred to the west of the Rocky Mountains, and in Pliocene deposits whose exact age is not ascertained, they hardly affect the remarkable absence of this group from the whole of the exceedingly rich Tertiary deposits in all other parts of North America. ”

“ As a result of this conveyance of glacial waters, the great trough of this stream may contain here and there deposits of the Illinoian stage or even of older deposits. Remains of Megalonyx (p. 32) and of a horse (p. 186) have been found in the right bank of the Ohio, at Evansville, Indiana. At Bigbone Lick, Kentucky, close to the Ohio, horses have been discovered, Mylodon and Megalonyx. These seem to occur in Sangamon interglacial beds overlying the Illinoian.
The Illinoian drift, probably everywhere in central and northern Indiana, underlies the Wisconsin. ”

“ The great size of the bones of the Megatheroid animals, including the Megatherium, Megalonyx, Scelidotherium, and Mylodon, is truly wonderful. The habits of life of these animals were a complete puzzle to naturalists, until Professor Owen [4] solved the problem with remarkable ingenuity. The teeth indicate, by their simple structure, that these Megatheroid animals lived on vegetable food, and probably on the leaves and small twigs of trees ”

“ Cuvier objects to propagation of species by saying, why have not some intermediate forms been discovered between Palaeotherium, Megalonyx, Mastodon, and the species now living? Now according to my view (in S. America) parent of all Armadilloes might be brother to Megatherium—uncle now dead. ”

“ This alone makes it probable that the time of their existence was early in the Pleistocene. 393All three of the supposed existing species may, however, prove to belong to extinct species closely related to those whose names they yet bear.
Certain species may be left out of consideration because of paucity of specimens and our consequent lack of knowledge of them. These are Megalonyx dissimilis, Ereptodon priscus, and Ursus amplidens. ”

“ Alton, Madison County.—The U. S. National Museum contains a fragment of a molar of apparently Megalonyx jeffersonii, from a collection 34made long ago by William McAdams, at Alton, Illinois. It has on it McAdams’s number 21. This collection, which was long in the hands of Professor O. C. Marsh, as vertebrate palæontologist of the U. S. Geological Survey, is said to have been made in the loess at Alton. Most of the teeth, with occasional bones, are inclosed in nodules of extremely fine sand and carbonate of calcium so hard that the teeth can not be removed without injury. ”

“ Jefferson, I know not a single instance of the skeleton of an animal buried in a cavern of the New World. (* The megalonyx was found in the caverns of Green Briar, in Virginia, at the distance of 1500 leagues from the megatherium, which resembles it very much, and is of the size of the rhinoceros.) The extreme scarcity of this geological phenomenon will appear the less surprising to us, if we recollect, that in France, England, and Italy, there are also a great number of grottoes in which we have never met with any vestige of fossil bones. ”

“ If, however, I am asked whether I consider the Natchez loam, with land-shells and the bones of Mastodon and Megalonyx, to be more ancient than the alluvium of the Somme containing flint implements and the remains of the mammoth and hyaena, I must declare that I do not. Both in Europe and America the land and freshwater shells accompanying the extinct pachyderms are of living species, and I could detect no shell in the Natchez loam so foreign to the basin of the Mississippi as is the Cyrena fluminalis to the rivers of modern Europe. ”

“ D. D. Owen (op. cit., p. 7) to be about 5 feet above ordinary low-water. In the same bed Owen found abundant remains of the deer. He seemed to regard this bone-bed as a continuation of that existing at Pigeon Creek.
Megalonyx has been found at Bigbone Lick, between Cincinnati and Louisville, associated with Equus complicatus, two species of extinct bisons, and the Virginia deer, in deposits overlying Illinoian drift and hence belonging, in part at least, to the Sangamon. These deposits are, however, at a higher level, being now submerged only at times of very high-water in the Ohio River. ”

“ The remains of the megalonyx consisted of parts of two tibiæ of young individuals, an atlas, a fragment of a heel-bone, a metacarpal and a metatarsal bone, and a claw phalanx. With these were discovered a fragment of a cervical vertebra of a species of bison, various bones of the Virginia deer, a vertebra of a horse, probably Equus complicatus, a tooth of the tapir Tapirus haysii, and a part of the upper jaw of the wolf now known as Ænocyon dirus, but at that time called by Leidy Canis primævus. ”

“ This was an error, as the name of the town is Tuscumbia. The tooth had been loaned to him by Dr. Jeffries Wyman. Nothing more is known about its history. Mercer (Proc. Amer. Philos. Soc., vol. XXXVI, p. 38) stated that a well-preserved series of bones of Megalonyx had been sent to the Academy of Natural Sciences at Philadelphia by Mr. Tuomey. They had been obtained in a cave somewhere in northern Alabama. Leidy does not mention this collection in his work just cited.
MISSISSIPPI.
(Map 3.) ”

“ X. Fossil Edentata. Megatherium, and Megalonyx. (Plates LXXII. and LXXIII.) —The remains of these and other allied forms of the extinct gigantic Edentata, which once inhabited South America, occur in immense quantities throughout the Pampas—those vast plains which present a sea of waving grass for 900 miles. These plains consist of alluvial loam and sand, containing fresh-water and marine shells of existing species ”

“ Lyell’s “Principles of Geology” 6th edition volume 1 page 37.) The enumeration of these extinct North American animals naturally leads me to refer to the former closer relation of the mammiferous inhabitants of the two Americas, which I have discussed in my “Journal,” and likewise to the vast extent of country over which some of them ranged: thus the same species of the Megatherium, Megalonyx, Equus (as far as the state of their remains permits of identification) , extended from the Southern United States of North America to Bahia Blanca, in latitude 39 degrees S., on the coast of Patagonia. ”

“ On page 40 is recorded the finding of Megalonyx jeffersonii somewhere about Tuscumbia. At Newbern, Hale County, have been found an incisor tooth of a horse (p. 200) and a molar of a bison (p. 264) . At Bogue Chitto, Dallas County, have been collected Equus leidyi (p. 200) , Mammut americanum, and Elephas imperator. The last species indicates that the deposits probably belong in the Aftonian. The writer knows of no other localities in the State where vertebrate fossils of the Pleistocene have been obtained.
MISSISSIPPI. ”

“ The horse-tooth points to an age preceding the Wisconsin drift.
From Saltville, in Smyth County, the following forms have been obtained:
Crocodylus sp. indet. Megalonyx dissimilis (p. 34) . Equus sp. indet. (p. 190) . Odocoileus? sp. indet. (p. 231) . Cervalces sp. indet. Bison sp. indet. (p. 259) . Mammut americanum (p. 113) . Elephas primigenius (p. 145) . 353That a crocodile should have lived in this region during the Pleistocene is remarkable. Megalonyx dissimilis is otherwise known only from Natchez, Mississippi, from deposits which appear to be of about Illinoian or Sangamon age. ”

“ In case the high percentage of extinct species is not recognized as being decisive, we may consider the assemblage from another point of view. Certain species of the list appear to have existed throughout the Pleistocene, at least from the time of the first interglacial stage. These are Megalonyx jeffersonii, Mammut americanum, Elephas columbi, and Castoroides ohioensis, and their presence indicates only a Pleistocene time. Others of the list are not known to have existed after the time of the last Wisconsin drift-sheet, and may be supposed to have become extinct before that time. ”

“ Equus sp. indet. Besides these forms, remains belonging to bats, various birds, snakes, and batrachians have been recognized. Of the fossils identified generically or specifically those belonging to Megalonyx, Tapirus, Mylohyus, Cervalces, Mammut, and Arctotherium are certainly extinct. Probably, too, the bison and the species of Felis are extinct. There are, therefore, pretty certainly close to 50 per cent of the species which are no longer living. This percentage and the history of some of the genera make it improbable that the assemblage belongs to the Late Wisconsin stage. ”

“ Imbedded in the blue clay of this ancient bog, entire skeletons, or detached bones, of not less than one hundred mastodons and twenty mammoths, have been found, besides remains of the megalonyx and other extinct quadrupeds. A magnificent skeleton of the Mastodon Ohioticus, now in the British Museum, was discovered, with teeth and bones of many others, near the banks of La Pomme de Terre, a tributary of the Osage River, Missouri; and there once more we seem to come upon contemporaneous traces of man. ”

“ Of these, Megalonyx, Mylodon, Hipparion, Platygonus, Anancus, Gomphotherium?, Stegomastodon, and Felis are known from the first interglacial stage. Anancus includes mastodons with short, tuskless lower jaws and trefoiled molars. Gomphotherium, having long lower jaws with tusks, upper tusks with enamel band, and with trefoiled molars, may be represented by some of the early Pleistocene species. The same species of Stegomastodon appears to be present in the Blanco as in the Pleistocene, S. mirificus. The edentate Glyptotherium is not far removed from Glyptodon of the early Pleistocene. ”

“ The facial portion of the skull is short, and the zygoma is deep. The infra-orbital canal is double, a feature which crops up in the Sloth, and has been mentioned in the later form of Ground Sloth, Megalonyx (but it must be remembered that the same characteristic is not unknown in Rodents) . The dentition is reduced as compared with that of Hemiganus, that is to say, as far as concerns the molars and the incisors. There is but a single pair of incisors in each jaw; the canines are strong ”

“ Since, therefore, a clavicle in any degree of development is not essential to a climbing quadruped, we must seek for some other relation and use of that remarkably strong, and perfect bone, as it exists in the Megathere, Megalonyx, and Scelidothere. The absence of ‘dentes primores’ or of anterior or incisive teeth in these quadrupeds at once sets aside any idea of its connection with an action of the fore extremities, very common in the mammals which possess clavicles, viz., that of carrying the food to the mouth, and holding it there to be gnawed by the teeth. ”