In Depth
Chilesaurus is a very exciting find, and not just because it was the first Jurassic aged dinosaur to be discovered in Chile. Chilesaurus is a theropod dinosaur, yet there is no doubt that Chilesaurus was a plant eater, and not a carnivore like most other theropods were. Firstly the teeth of spatulate and project slightly forwards, Perfect for snipping of fronds of plants. The pubic bone of the hip also points backwards, something that would allow for a larger gut that would have been necessary for processing plant matter. Finally the feet of Chilesaurus were broad with a first toe adapted for weight bearing, suggesting that Chilesaurus was not as well suited to fast and agile running as its predatory cousins.
There would have been a time when a plant eating theropod dinosaur would have been unthinkable, but we can actually see switches from meat eating to plant eating happening many times. Therizinosaurs are also theropods, but ones that adapted to eating plants, while ornithomimosaurs may have developed omnivorous diets eating both meat and plants. The sauropod dinosaurs are also of the lizard hipped branch that theropods are, and they too evolved from sauropodomorph dinosaurs that would have had meat eating ancestors. What Chilesaurus shows us more than anything else is that given time and opportunity, evolution will push changes in descendants that were very different from their ancestors.
Chilesaurus means ‘Chile lizard’, a simple reference to the country where the first fossils were found. The species name C. diegosuarezi is in recognition of Diego Su�rez, who as a seven year old discovered the first rib and vertebrae of Chilesaurus back 2004.
Further Reading
- First Late Jurassic dinosaur bones from Chile. - Journal of Vertebrate Paleontology 28. - L. Salgado, R. De La Cruz, M. Su�rez, Z. Gasparini & M. Fern�ndez - 2008. - An enigmatic plant-eating theropod from the Late Jurassic period of Chile. – Nature. - F. E. Novas, L. Salgado, M. Su�rez, F. L. Agnol�n, M. D. Ezcurra, N. R. Chimento, R. Cruz, M. P. Isasi, A. O. Vargas & D. Rubilar-Rogers - 2015. – Comment on ‘A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs’. – Biology Letters. 14 (3): 20170581. – Rodrigo Temp M�ller, Fl�vio Augusto Pretto, Leonardo Kerber, Eduardo Silva-Neves & S�rgio Dias-da-Silva – 2018.
