Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Jun 7;278(1712):1742-7.
doi: 10.1098/rspb.2010.1939. Epub 2010 Nov 10.

Another One Bites the Dust: Faecal Silica Levels in Large Herbivores Correlate With High-Crowned Teeth

Free PMC article

Another One Bites the Dust: Faecal Silica Levels in Large Herbivores Correlate With High-Crowned Teeth

Jürgen Hummel et al. Proc Biol Sci. .
Free PMC article


The circumstances of the evolution of hypsodonty (= high-crowned teeth) are a bone of contention. Hypsodonty is usually linked to diet abrasiveness, either from siliceous phytoliths (monocotyledons) or from grit (dusty environments). However, any empirical quantitative approach testing the relation of ingested silica and hypsodonty is lacking. In this study, faecal silica content was quantified as acid detergent insoluble ash and used as proxy for silica ingested by large African herbivores of different digestive types, feeding strategies and hypsodonty levels. Separate sample sets were used for the dry (n = 15 species) and wet (n = 13 species) season. Average faecal silica contents were 17-46 g kg(-1) dry matter (DM) for browsing and 52-163 g kg(-1) DM for grazing herbivores. No difference was detected between the wet (97.5 ± 14.4 g kg(-1) DM) and dry season (93.5 ± 13.7 g kg(-1) DM) faecal silica. In a phylogenetically controlled analysis, a strong positive correlation (dry season r = 0.80, p < 0.0005; wet season r = 0.74, p < 0.005) was found between hypsodonty index and faecal silica levels. While surprisingly our results do not indicate major seasonal changes in silica ingested, the correlation of faecal silica and hypsodonty supports a scenario of a dominant role of abrasive silica in the evolution of high-crowned teeth.


Figure 1.
Figure 1.
Correlation of faecal silica level and hypsodonty index [5] in large African herbivores (dry season: n = 15, r = 0.80, p < 0.0005; wet season: n = 13, r = 0.74, p < 0.005; phylogenetically controlled analysis 1, greater kudu; 2, giraffe; 3, nyala; 4, impala; 5, waterbuck; 6, sable antelope; 7, roan antelope; 8, blue wildebeest; 9, tsessebe; 10, African buffalo; 11, black rhino; 12, African elephant; 13, warthog; 14, plains zebra; 15, white rhino). Filled squares, dry season; open triangles, wet season.

Similar articles

See all similar articles

Cited by 14 articles

See all "Cited by" articles


    1. Jernvall J., Fortelius M. 2002. Common mammals drive the evolutionary increase of hypsodonty in the Neogene. Nature 417, 538–54010.1038/417538a (doi:10.1038/417538a) - DOI - DOI - PubMed
    1. Strömberg C. A. E. 2006. Evolution of hypsodonty in equids: testing a hypothesis of adaptation. Paleobiology 32, 236–25810.1666/0094-8373(2006)32[236:EOHIET]2.0.CO;2 (doi:10.1666/0094-8373(2006)32[236:EOHIET]2.0.CO;2) - DOI - DOI
    1. Janis C. M. 2008. An evolutionary history of browsing and grazing ungulates. In The ecology of browsing and grazing (eds Gordon I. J., Prins H. H. T., editors. ), pp. 21–45 Berlin, Germany: Springer
    1. Mendoza M., Palmqvist P. 2008. Hypsodonty in ungulates: an adaptation for grass consumption or for foraging in open habitat? J. Zool. 274, 134–14210.1111/j.1469-7998.2007.00365.x (doi:10.1111/j.1469-7998.2007.00365.x) - DOI - DOI
    1. Janis C. M. 1988. An estimation of tooth volume and hypsodonty indices in ungulate mammals and the correlation of these factors with dietary preferences. In Teeth revisited. Proc. of the VII Int. Symp. on Dental Morphology (eds Russell D. E., Santoro J.-P., Signogneau-Russell D., editors. ). Mémoires du Muséum National d́Histoire Naturelle, Paris (serie C) 53, 367–387

Publication types