Mineral dust ingested with food leaves characteristic wear on herbivore
teeth

Date:
August 25, 2020
Source:
Johannes Gutenberg Universitaet Mainz
Summary:
In a controlled feeding study of guinea pigs, paleontologists have
discovered that mineral dust ingested with food causes distinct
signs of wear on the teeth of plant-eating vertebrates, which can
differ considerably depending on the type of dust.



FULL STORY ========================================================================== Mineral dust ingested with food causes distinct signs of wear on the teeth
of plant-eating vertebrates, which can differ considerably depending on
the type of dust. This is what paleontologists at Johannes Gutenberg
University Mainz (JGU) have discovered in a controlled feeding study
of guinea pigs. As they report in the current issue of Proceedings of
the National Academy of Sciences (PNAS), their findings could lead to
a more accurate reconstruction of the eating habits of extinct animals
as well as a reconstruction of their habitats.

"Analyzing fossil teeth is a common method of drawing conclusions
about the diet and habitat of certain animals, because it has long been understood that eating different plants, such as grass or leaves, can
cause different wear patterns," said Dr. Daniela Winkler of the Institute
of Geosciences at JGU, the first author of the study. "However, there
has been hardly any research into the extent to which the consumption
of mineral dust contributes to this abrasion."

==========================================================================
Over several weeks, the researchers fed 12 groups of guinea pigs with essentially the same plant-based pellets which contained different
types and amounts (zero to eight percent) of natural mineral dust. The researchers then used a high-resolution microscope to examine the surface
of the tooth enamel of each animal's molars. "We were able to identify
some significant differences," added Winkler. For example, larger quartz particles (sand grains) caused severe abrasion on the enamel surface. The
same applied to volcanic ash, which, due to its sharp edges, also produced
a more irregular wear pattern. Small quartz particles generated a smooth, almost polished surface. On the other hand, there were no subsequent distinctive signs of wear features in the case of other particles. "Our
results should improve the accuracy of diet reconstruction on the basis of fossil teeth," concluded Winkler. To date, it has been assumed that smooth tooth surfaces are related to the respective animal feeding on leaves
that, unlike grass, leave hardly any traces of wear on the tooth surface; hence, this animal would have lived in a forest environment. However,
it now seems possible that smooth tooth enamel wear patterns could
have also developed because the animal ate grass, for example, to which
tiny quartz grains were attached. These particles would have eliminated
any irregularities on teeth, leaving an even, polished surface. "It is
normal that animals ingest mineral dust along with their food," said
Winkler. This is even more likely to be the case the drier the habitat
is and the closer the food is ingested to the ground.

The study was undertaken as part of the Vertebrate Herbivory research
project led by Professor Thomas Tu"tken of the Institute of Geosciences at
JGU, which is funded by a Consolidator Grant from the European Research
Council (ERC). The study also involved researchers of the Clinic for Zoo Animals, Exotic Pets, and Wildlife at the University of Zurich, of Leipzig University, of the Max Planck Institute for Evolutionary Anthropology
in Leipzig, and of the Center of Natural History at Universita"t Hamburg.


========================================================================== Story Source: Materials provided by
Johannes_Gutenberg_Universitaet_Mainz. Note: Content may be edited for
style and length.


========================================================================== Journal Reference:
1. Daniela E. Winkler, Thomas Tu"tken, Ellen Schulz-Kornas, Thomas M.

Kaiser, Jacqueline Mu"ller, Jennifer Leichliter, Katrin Weber, Jean-
Michel Hatt, Marcus Clauss. Shape, size, and quantity of ingested
external abrasives influence dental microwear texture formation
in guinea pigs. Proceedings of the National Academy of Sciences,
2020; 202008149 DOI: 10.1073/pnas.2008149117 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200825110717.htm

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