Dung fossils reveal the grass was green for the foodie Dinos

The apparent indiscriminate foodies, dinosaurs appear to have been hearty grass eaters more than 65 million years ago. But the surprise is that it was much before we ever believed that grass grew on the vast terrains of the Earth. This revelation has come from a new analysis of dinosaur dung that is detailed in the Science journal.

So long scientists have held that grass growth on Earth gained ground only after the dinosaurs disappeared. But the large remnants of the Dino feces reveal a totally different picture. Now they view the probability that grass, not the only vegetarian component of a dinosaur meal eaten alongside other plants, served an important part of the early mammal's food. Caroline Strömberg of the Swedish Museum of Natural History and her team have many reasons to favor this view after studying mineral remnants preserved in the 65-67-million-year old dung fossils.

The fossils retrieved from central India, called coprolites are believed to belong to the large vegetarian titanosaur sauropods. Ms Strömberg told, "It's difficult to tell how widespread (grazing) was”.

But the new study came after paleontologists from India's Birbal Sahni Institute of Palaeobotany were stumped by the presence of phytoliths in the fossils called for expert help. Shedding light on the Earth's vegetation so many million years ago, the phytoliths in the fossils were actually mineral remnants of different grasses. With five types of grass identified by researchers in these phytoliths, it appears that grasses itself had undergone some change since the dinosaurs inhabited the Earth.

Today the grasses with their high silica content are not as easy to chew and possibly evolved to be so to avoid consumption by herbivores during large-scale grazing as a response to the patterns that existed in the Cenozoic era. But that theory points to the possibility that this defense was raised in response to grazing by dinosaurs. But with other small mammals that existed alongside the dinosaurs also likely to have been grass eaters, it is difficult to accord dinosaurs the sole blame for the development.

However, with most textbooks portraying dinosaurs feeding on grass, it appears that man had some premonition of the dinosaurs' grassy diet. Strömberg who specialized in phytoliths, found the presence of their distinctive shapes unique to grass in the dung "a complete shock". Further the phytoliths, compared to undistinguishable fossil pollen found pertaining to the same period, revealed the exciting prospect of the grasses being more evolved. Strömberg even hazarded that they had been several metres tall, when the dinosaurs savored them.

The discovery may also serve as a fillip to another mysterious mammalian existence of the period of the creatures termed as gondwanatherians that are understood to have had high-crowned teeth. Until now paleontologists believed these creatures of the Cretaceous period to have used the teeth to bite through wood since grasses were not known to have existed.

Now it is clear that they too savored a taste for grass like the dinosaurs and therefore had developed their own bodily tools to help them in this direction. While the earliest grass fossils trace their existence to 55 million years ago, the new discovery in Dinosaur dung traces them to nearly 100 million years ago.

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