Thomas Jefferson Papers

Enclosure: Description of the Megatherium, 26 January 1789

Description of the Megatherium

This curious piece of anatomy was found near the river luxan fourteen leagues from buenos aires in a profound creck 10 yards of heigtnes. It was buried, almost calcinated and petrified. Its spina dorsalis measures five yards longitud. For the other dimensions you may consult the adjacent table. He must belong to one of the three largest Quadrupeds, or to the Elephant, Hipopotamus or Rhinoceros.

The generiel caracters are in this skeleton 4 fingers in avery foot, and 6 molar teeth. In its imperfect state, the before fingers exist 3 ungulated, in the behind feet only 3 ungulated: and there is a cavity for placing the 4th. finger wanting one of the snails1 is longer in every feet.

It is Not the elephant, We have before hand in skeleton, and bears it not to him the les similitude.

He must of course belong to the Sea horse or to the Rhinoceros. It is true that the Caracters given by Brison to the sea horse Are to be met with in this skeleton. But when we compare the head of the animal in question with the head represented by Fusieu in the memoirs of the Royal Academy of Paris, there is not any likeness in the figure of the molar teeth exhibited or drawn in the above said plate.

Perhaps this skeleton belongs to the Rhinoceros but it difers from the number of teeth, of fingers &c. but Complete skeleton[s] of those large animal have not been compared with this American animal and it may hapen that descriptions given to the present day are erroneous and defective on1 this skeleton belongs to an unknown animal of the genus of some of the two former.

In the royal Cabinet inteligent persons are with great care placing all the bones, in their proper situation, and the World will enjoi a very curious in this particular.

I add to the remarks above exposed that the teeth of this animal do not give fire with the steel as those of the sea horse do; that may [be] the efect of its state of calcination or of other cause.

Dimensions and Weigth of the Principal bones of the said Skeleton
The head and vertebre 12 arrob. and 10 Pounds
Dorsales and Lumbares 9
The right arm 7 and 7
The right leg 8 and 13
Sacrea and the innominatd. 14 and 3
Yards inches
Longd. The head 1   Spannish yard and 8 inches
Latitud. ½   and 6
height ¾   and 4
Dorsales and Lumbares
Long. 1 6
Lat. ½ 6
Heightness ½
Right arm
Span. Yards Inches
Long. 2 7
Latit. ½
height ½ 3
Right Leg
Long. 1
Lat. ½
Height ½
Sacro and innominata
Long. 1 4
Lat. ¾
Height 1 3

In this skeleton were found almost all the bones whic compose its structure. The Tusks and the extremity of the head, the snout are Wanting. And also the phalanges which compose the fourth finger of the posteriour feet. Parts of some ribs and other litle bones. The astragatus is very considerable. We expect the conclution of the Whole skeleton, to have a better figure for this is a very imperfect one.

MS (DLC); in an unidentified hand; accompanied by a sketch in the same hand (see illustration in this volume). The awkwardness of the language suggests a composition rather than a translation; hence MS and sketch are presumed to be the actual enclosures rather than a translation and copy procured by TJ in Paris. The unidentified author was evidently familiar with Daubenton’s “Observations sur un grand os qui a été trouvé en terre dans Paris,” which appeared in Histoire de l’académie royale des sciences for the year 1782 (Paris, 1785), p. 211–19, accompanied by plates drawn by Fusieu (Fossier) of its head, the teeth of which could scarcely have been expected to bear any likeness to those of the South American skeleton since the former belonged to the narwhal (sea horse).

1Thus in MS.

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