Downloaded from http://trn.lyellcollection.org/ at Duke University on June 4, 2012 Transactions of the Geological Society of London VI.−−Description of a Tooth and Part of the Skeleton of the Glyptodon clavipes , a large Quadruped of the Edentate Order, to which belongs the Tesselated Bony Armour described and figured by Mr. Clift in the former Volume of the Transactions of the Geological Society; with a consideration of the question whether the Megatherium possessed an analogous Dermal Armour. RICHARD OWEN Transactions of the Geological Society of London 1841, v.s2-6; p81-106. doi: 10.1144/transgslb.6.1.81 Email alerting click here to receive free e-mail alerts when new articles cite service this article Permission click here to seek permission to re-use all or part of this article request Subscribe click here to subscribe to Transactions of the Geological Society of London or the Lyell Collection Notes © The Geological Society of London 2012 Downloaded from http://trn.lyellcollection.org/ at Duke University on June 4, 2012 [ 81 ] VI.—Description of a Tooth and Part of the Skeleton of the Glyptodon cla- vipes, a large Quadruped of the Edentate Order, to which belongs the Tesselated Bony Armour described and figured by Mr. Clift in the former Volume of the Transactions of the Geological Society; with a consideration of the question whether the Megatherium possessed an analogous Dermal Armour. By RICHARD OWEN, ESQ., F.G.S., F.R.S. [Read March 23rd, 1839.] PLATES X. XI. XII. and XIII. JLHE first notice of the discovery of the osseous remain's of the skeleton of a large edentate Mammal associated with fragments of a tesselated bony armour, similar to that of the Armadillo, appears in the note appended to the end of Cuvier's chapter on the Megatherium, in the 4to edition of the Ossemens Fossiles, published in 1823. This notice occurs in an extract from a Letter addressed by D. Damasio Lar- ranaga, Cure of Monte Video, to M. Auguste St. Hilaire. The facts stated in this extract are the following:—A femur was discovered in the Rio del Sauce, branche du Saulis-Grande, which weighed seven pounds ; it was short, but might be from six to eight inches in width ; it resembled in every respect the femur of an Arma­ dillo ; with it was found a portion of tesselated bony armour, of which the Cure* promises to send one of the component pieces (une de ces ecailles) to M. Auguste. GeofFroi. The tail was very short and very stout (tres-grosse) ; it had, in like man­ ner, a bony armour (des ecussons), but this was not verticillate, or disposed in rings. These fossils are stated to have been met with near the surface of the earth, in alluvium, or strata of transport, indicative of a very recent epoch; similar fos­ sils are said to occur in analogous strata near the lake Mirim, on the frontier of the Portuguese colonies. The notion that the fossils here mentioned belonged to the Megatherium rests solely on the circumstance of the worthy Cure having inserted the word Megathe­ rium as the synonym of his gigantic Dasypus : " Je ne vous ecris point sur mon Dasypus (Megatherium, Cuv.), parceque je me propose d'en faire I'objet d'un me*- VOL. VI. SECOND SERIES. M Downloaded from http://trn.lyellcollection.org/ at Duke University on June 4, 2012 82 Mr. OWEN on the Glyptodon clavipes. moire," &c. loc. cit. p. 191. The admeasurement which he fortunately gives of the femur proves that if that bone really belonged to the Megatherium it must have been part of a very young animal; for whereas the femur of the Megatherium is sixteen inches in width, that of the fossil in question has at the utmost only half that width. Without laying much stress on the accuracy of Don Larranaga's comparison of his fossil femur with that of the existing Armadillos, I may observe that the femur of an Armadillo presents a striking character, in the third trochanter, likely to catch the eye of the most superficial observer ; and that if the fossil femur in question did actually present this character, it would be decisive against its identity with that of the Megatherium. Cuvier, however, makes no comment on these discrepancies, but merely observes that the Cure's letter announces or indicates that the Megatherium had pushed its analogies with the Armadillos so far, as to be covered like them with a scaly cuirass. The next observations bearing upon the present question occur in Prof. Weiss's Geological memoir on the Provinces of S. Pedro do Sul and the Banda Oriental*, where certain fossils, collected by the Prussian traveller Sellow in the state of Monte Video, are described. One of these fossils is the fractured distal end of the femur of the Megatherium ; it had been discovered by the Indians, or at least made use of by them in cooking their food, in the neighbourhood of the Queguay, one of the tributaries of the Uruguay, and was found by Sellow near one of their deserted encampments: the fragment belongs to the right femur; the outer condyle is knocked off, and the bone is said to be blackened by fire. In short, it had been put to precisely the same use as that to which the vertebrae of Sir Woodbine Parish's Megatherium were applied by the Peons who discovered that skeleton. No mention is made of any armour or portions of armour having been discovered associated with or near to this fragment; but in the ford of the Queguay a Spanish soldier found a fossil, which passed into the hands of the Surgeon major, Francisco Meves, and by him was given to Sellow. This fossil is figured in PL IV. of Professor Weiss's memoir ; he conjectures that it may have formed part of the tail-armour of the Megatherium, but allows that it is a fossil of very dubious character. It is unquestionably a portion of the dermal bony armour of some loricated animal. Sellow also collected, in the neighbourhood of the Queguay, portions of a fossil carapace, undoubtedly belonging to a large Tortoise, and to which the name of Testudo Sellowii is given by Weiss f. The portions of tesselated bony armour, figured by Professor Weiss, PI. I. and II., and described at p. 277 of his Memoir, were obtained by Sellow on the Arapeychico, in the province of Monte Video ; but no bones, either of the Mega- * Abhandlungen der Kon. Acad, der Wissensehaften zu Berlin; 1827. f Loc, cit. p. 286, PI. V. Downloaded from http://trn.lyellcollection.org/ at Duke University on June 4, 2012 Mr. OWEN on the Glyptodon clavipes. 83 therium or any other animal, are mentioned as having been associated with them. This fossil armour precisely corresponds with that discovered at the lake Las Averias, and brought over to England by Sir Woodbine Parish, and of which a portion is figured by Mr. Clift in his memoir on the Megatherium*. A third series of fossils, in which fortunately some bones of the extremities were discovered associated with the tesselated bony case, was presented to Sellow by the President of the province of San Pedro, with the information that they had been originally discovered in the proximity of the Rio Janeiro. Now these import­ ant bones are not described by Professor Weiss ; but he states that they will form the subject of a subsequent memoir by Sellow himself. Prof. Weiss, however, gives the dimensions of the pieces of the armour, which, as the bones found therewith belonged chiefly to the left fore-leg, he conjectures to have belonged to the anterior and inferior part of the left side of the carapace. The chord of the longitudinal curve of the longest fragment measured twenty-three inches, and the depth from the middle of the chord to the under-surface of the concavity was two and a quar­ ter inches. The chord of the transverse bow or curvature was ten inches, and the depth from the middle of the chord to the under surface of the armour four inches; from which Sejlow conjectured that the animal must have been ten feet, or fifteen palmas long, by seven palmas broad and four and a half palmas high. Thus the fossils from South America, noticed in the Berlin memoir, resolve themselves into three distinct groups, from three different localities ; first, a bone without armour ; secondly, armour without bones ; and thirdly, armour and bones mingled together in the same bed. Now the portions of tesselated armour from the two localities, viz. Arapey- chico and Rio Janeiro, are identical in structure. Professor Weiss's opinion, that they belong to the Megatherium, rests solely on the observation made by Cuvier in reference to the note of the Spanish Cure*, the bearing of which on the present question we have already examined; it is obvious, therefore, that the bones, found with the armour, can alone yield us the information we are in quest of, as to the nature of the huge animal so singularly protected. Fortunately for science, and for the determination more especially of the present interesting question, these bones have been excellently described and illustrated by Professor D'Altonf, to whom they were confided for that purpose after the decease of Sellow. They include the fractured extremity of the humerus, the entire radius and ulna, and a great pro­ portion of the fore-foot, all belonging, as stated by Weiss, to the left side, and a less complete series of bones of the left hind-foot.