Grass – potential killer or just misunderstood?

I remember reading that grass had a huge impact on ecosystems, but maybe missed its best chance to become famous. It’s possible grass would have been known as the killer of the dinosaurs, if a meteorite hadn’t come in before that.

The reason grass could be so deadly is due to phytoliths, small bodies of silica that form in and around plant cells, particularly in grass. While there’s a lot of study of phytoliths in the present, particularly for environmental and archaeological studies, there’s not a lot known about their evolutionary history. Ofir Katz has a new article out that might help fill that gap, Silica phytoliths in angiosperms: phylogeny and early evolutionary history.

Of particular interest is the observation that horsetails were around in large numbers in the late Cretaceous period. These would have made up an important part of the diet for herbivores. However they are rich in phytoliths. Katz notes that the Hadrosauridae were adapted to eat more abrasive plants.

So the push to create new adaptations in phytolith-rich plants may have started with co-evolution with the last of the dinosaurs. If that’s the case then grass might not have been the end of the dinosaurs, but rather a partner in a new phase of evolution. However the the K/T event intervened so we may never know.

You can pick up the paper yourself (currently free) from New Phytologist.

Ofir Katz, 2015, ‘Silica phytoliths in angiosperms: phylogeny and early evolutionary history’, New Phytologist. http://dx.doi.org/10.1111/nph.13559