steg·o·don 
(stĕgə-dŏn′)
(stĕgə-dŏn′)n.
Any of various extinct proboscidean mammals of the genus Stegodon of the Pliocene to the Pleistocene Epochs, having long straight tusks.
[New Latin Stegodōn, genus name : Greek stegos, roof (from stegein, to cover; see (s)teg- in the Appendix of Indo-European roots) + -ODON (so called because of the distinctive ridges on its molars).]