Scelidodon

Scelidodon Temporal range: Early Pleistocene Early Holocene (Uquian-Lujanian) ~0.781–0.009 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Skeletal mount in Museo de Historia Natural de Lima
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pilosa
Family:	†Scelidotheriidae
Genus:	†Scelidodon Ameghino, 1881
Type species
†Scelidodon copei Ameghino, 1881
Other species
S. capellini Gervais & Ameghino, 1880 S. chiliense Lydekker, 1886 S. piauiense Guerin & Faure, 2003 S. tarijarensis Gervais & Ameghino, 1880
Synonyms
Scelidotherium tarijarensis (Gervais & Ameghino, 1880) Scelidotherium capellini (Gervais & Ameghino, 1880)

Scelidodon is an extinct genus of South American ground sloths. Its remains have been found in the Yupoí and Uspara Formations of Argentina, the Ulloma, Umala, Ñuapua and Tarija Formations of Bolivia, in Brazil, in Chile and in Peru.^[1] The youngest fossils have been dated to as recently as 9000 B.P.^[2]

Scelidodon tarijarensis front

Description

Scelidodon was one of the last of the ground sloths and was one of the largest scelidotheriids, with S. chiliense reaching up to 4.7 meters.^[3] Its body weight has been estimated at over 1500 kg.^[4] Scelidodon was widely distributed in temperate grassland environments and due to its contemporary megatheriines being high browsers, this suggests that Scelidodon was a grazer^[5] like its close relative, Scelidotherium.^[6]

Discovery

The first remains of Scelidodon were collected in the 1850s in Tarija Valley, Bolivia and consisted of a skull and mandible (MNHN TAR 1260).^[3] It wasn't until 1880 that Paul Gervais and Florentino Ameghino described the remains as Scelidotherium tarijarensis^[3]. In the same paper, Scelidotherium capellini was described based on a left hemimandible (MNHN PAM 231) with a referred skull (MACN 994), the fossils were found at ‘‘Toscas del Rio de la Plata’’ in Argentina. The genus Scelidodon was erected in 1881 with the type species, Scelidodon copei, name by Ameghino.^[3] The type specimen (MACN A-1158) of S. copei comes from Ensenadan sediments in Mercedes, Buenos Aires province and consists of a left maxilla.^[3] S. tarijarensis and S. capellini were transferred to Scelidodon in 1889 by Ameghino.^[3] S. chiliense was named based on a skull (BMNH M 2819) from the late Pleistocene of Chile by Richard Lydekker in 1886. Since the 19th century, much material of Scelidodon has been found from 5 countries and is one of the most well preserved scelidotheres.^[3][6]

References

1. Scelidodon at Fossilworks.org
2. Turvey, Sam (2009). Holocene extinctions. Oxford University Press. pp. 20–33, 42–50, 352. ISBN 978-0-19-953509-5.
3. Miño-Boilini, Á. R., & Carlini, A. A. (2009). The Scelidotheriinae Ameghino, 1904 (Phyllophaga, Xenarthra) from the Ensenadan–Lujanian Stage/Ages (Early Pleistocene to Early-Middle Pleistocene–Early Holocene) of Argentina. Quaternary International, 210(1-2), 93–101.
4. Toledo, N.; Bargo, M. S.; Vizcaíno, S. F.; De Iuliis, G.; Pujos, F. (2017). "Evolution of body size in anteaters and sloths (Xenarthra, Pilosa): phylogeny, metabolism, diet and substrate preferences". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 106 (4): 289–301. Bibcode:2015EESTR.106..289T. doi:10.1017/S1755691016000177. hdl:11336/56403. S2CID 90400372.
5. Miño-Boilini, A. R., Carlini, A. A., Chiesa, J. O., Lucero, N. P., & Zurita, A. E. (2009). First record of Scelidodon chiliense (Lydekker)(Phyllophaga, Scelidotheriinae) from the Lujanian stage (late Pleistocene-early Holocene) of Argentina.^{[dead link]} Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 253, 373–381.
6. Guérin, Claude; Faure, Martine (January 2004). "Scelidodon piauiense nov. sp., nouveau Mylodontidae Scelidotheriinae (Mammalia, Xenarthra) du Quaternaire de la région du parc national Serra da Capivara (Piauí, Brésil)". Comptes Rendus Palevol (in French). 3 (1): 35–42. Bibcode:2004CRPal...3...35G. doi:10.1016/j.crpv.2003.10.007.