Megatherium americanum - back of skull
Specimen number: NHMUK PV M 16585
Taxon: Megatherium americanum
Description: Back of cranium, showing foramen magnum (hole where spinal cord enters skull)
Site: Punta Alta, Argentina
Age: Late Pleistocene to early Holocene (between 126,000 and 8,000 years old)
Collection: Collected September to October 1832 by Charles Darwin
Comments: In September-October 1832, Darwin spent many days excavating fossils from a beach deposit at Punta Alta in Argentina. Here he found a posterior segment of the skull of Megatherium. This was the exact portion missing from the partial skeleton recently acquired by the Royal College of Surgeons (and only the second partial skeleton known). As William Clift, the conservator at the Royal College of Surgeons, was in the process of making casts of the skeleton of M. americanum to put on display, this was very timely! The specimen arrived in England in 1833, where it was exhibited at the British Association.
The fossil portions of the Megatherium turned out to be extremely interesting as serving to illustrate certain parts of the animal which the specimens formerly received in this country and in France had failed to do.
--Henslow, J. S. 31/08/1833. Darwin Correspondence Project, “Letter no. 213” http://www.darwinproject.ac.uk/DCP-LETT-213
…the most perfect part of which affords a view of the posterior, and of part of the basal surface, which regions of the cranium have not hitherto been elsewhere figured or described, (Pl. XXX.)
--Owen, R. 1838-1840 (Part I. Fossil Mammalia. In Darwin, C. R. (ed.), The Zoology of the Voyage of H.M.S. Beagle, under the command of Captain Fitzroy, R.N. during the years 1832-1836. Smith Elder and Co., London. Page 100.
Later, Richard Owen used Darwin’s specimen to reveal important aspects of the animal’s behaviour, showing that Megatherium had considerable freedom of movement of its head, powered by substantial neck muscles, and probably also a large muscular tongue functioning like that of a giraffe. Although commonly depicted with a long protuberant tongue, its’ presence in Megatherium has recently been questioned.
On examining this specimen, Owen also concluded that Megatherium had a particularly small brain.
…from the indications afforded by the remains of the cranial cavity in Mr. Darwin's specimens, I conclude that the brain of the Megatherium was more depressed, and upon the whole, smaller by nearly one-half than that of the Elephant…whence it may be concluded that the Megatherium was a creature of less intelligence, and with the command of fewer resources, or a less varied instinct than the Elephant.
--Owen, R. 1838-1840. Part I. Fossil Mammalia. In Darwin, C. R. (ed.), The Zoology of the Voyage of H.M.S. Beagle, under the command of Captain Fitzroy, R.N. during the years 1832-1836. Smith Elder and Co., London. Page 102.
Cite this as
Pip Brewer, Kate Burton, Adrian Lister (2018). Dataset: Darwin's Fossil Mammals. Resource: Megatherium americanum - back of skull. Natural History Museum Data Portal (data.nhm.ac.uk). https://doi.org/10.5519/0086786
Retrieved: 06:12 23 May 2019 (GMT)
|Last updated||November 19, 2018|
|Created||November 19, 2018|
|License||Creative Commons Non-Commercial (Any)|
|created||6 months ago|