Notiomastodon platensis was a gomphothere – a relative of modern elephants – that lived across much of what is now South America from the mid-Pleistocene to the early Holocene, between about 800,000 and 10,000 years ago.
Similar in size to an Asian elephant, it stood around 2.5m tall at the shoulder (~8’2″) with a domed head and thick tusks that varied in length and curvature between different individuals. It had a stockier build than modern elephants with thicker and slightly shorter limbs, and fossilized footprints suggest it had five nails on its front feet and at least three on the hind feet.
Isotope analysis and wear analysis of Notiomastodon’s teeth suggest it was a generalist browsing herbivore, with different populations adapting their dietary habits to local conditions. As one of the largest South American herbivores of its time it was probably an important seed disperser for plants such as bamboo and palms – and some of the plants that once depended on it may now be “evolutionary anachronisms“.
References:
- Aramayo, Silvia A., et al. “Pehuen Co: Updated taxonomic review of a late Pleistocene ichnological site in Argentina.” Palaeogeography, Palaeoclimatology, Palaeoecology 439 (2015): 144-165. https://doi.org/10.1016/j.palaeo.2015.07.006
- Asevedo, Lidiane, et al. “Ancient diet of the Pleistocene gomphothere Notiomastodon platensis (Mammalia, Proboscidea, Gomphotheriidae) from lowland mid-latitudes of South America: Stereomicrowear and tooth calculus analyses combined.” Quaternary International 255 (2012): 42-52. https://doi.org/10.1016/j.quaint.2011.08.037
- González-Guarda, Erwin, et al. “Fossil evidence of proboscidean frugivory and its lasting impact on South American ecosystems.” Nature Ecology & Evolution (2025): 1-11. https://doi.org/10.1038/s41559-025-02713-8
- Larramendi, Asier. “Shoulder height, body mass, and shape of proboscideans.” Acta Palaeontologica Polonica 61.3 (2015): 537-574. https://www.app.pan.pl/article/item/app001362014.html
- Mothé, Dimila, et al. “Doing the Time Warp again: Electron Spin Resonance dating reveals oldest numeric age for Notiomastodon platensis Ameghino, 1888 (Mammalia, Proboscidea).” Geobios (2025). https://doi.org/10.1016/j.geobios.2024.11.008
- Wikipedia contributors. “Notiomastodon” Wikipedia, 12 Jul. 2025, https://en.wikipedia.org/wiki/Notiomastodon