Did Dinosaurs Eat Grass?

Spotted in a magazine and sent into Everything Dinosaur with some accompanying notes was this article (reproduced below), which stated that plant-eating dinosaurs did not eat grass.  The sender wondered why a picture of the carnivorous Tyrannosaurus rex had been used to illustrate this snippet and they asked whether the assertion that plant-eating dinosaurs did not eat grass was true.

Did Dinosaurs Feed on Grass?

Article Sent Into Everything Dinosaur

Did plant-eating dinosaurs eat grass?

Did plant-eating dinosaurs eat grass?

Picture credit: Everything Dinosaur

Grasses are members of the Angiosperms (flowering plants), a very successful group and an important one to us humans as rice, oats, wheat, maize and barley are just some of the grasses that are cultivated by us for food.  It had been thought that the first flowering plants evolved early in the Cretaceous, but recent research has suggested that the first Angiosperms may have evolved much earlier, sometime in the Triassic possibly.

To read an article on the potential for Triassic flowers: Saying It With Flowers 100 million years Earlier than Expected.

The Gramineae Family

The grasses themselves (Gramineae), the true-grasses, were once thought to have evolved during the Cenozoic, with the first fossil evidence being dated to around 55 million years ago, a good ten million years or so before the extinction of the Dinosauria.  However, there is some fossil evidence to suggest that grasses were present at the very end of the Age of Dinosaurs, around 66 million years ago, so these may well have been grazed by herbivorous dinosaurs.

As for the other plants mentioned in the brief article, it is worth remembering that ferns would have represented a considerable portion of the biomass of most terrestrial Mesozoic environments but the inclusion of palm trees in the list is intriguing.

Palms may superficially resemble more ancient flora such as cycads, but they are not closely related.  In fact, palm trees are a relatively recent addition to the Angiosperm group.  The first fossils of palm-like plants occur in Late Cretaceous strata dating deposited around 80 million years ago.  By some 70 million years ago, during the Maastrichtian faunal stage of the Late Cretaceous and as the Age of Dinosaurs came to a close, it seems like a number of palm genera had evolved (members of the Arecaceae family).

The CollectA Palm Tree Model

The CollectA palm tree replica.

Tropical plants from CollectA.  Tropical palms are not closely related to cycads.

For models and replicas of prehistoric plants and animals: CollectA Prehistoric Life Replicas.

In the 15 million years or so after the end of the Mesozoic Era, the planet experienced a period of prolonged global warming.  Extensive rain forests covered much of the Earth’s land masses.  There were jungle habitats as far north as Canada and southern Scandinavia.  Palms and a number of other types of Angiosperms seem to have flourished in the hot-house atmosphere and a very wide range of palms evolved.  The grasses themselves really came into their own from about when global temperatures began to fall and the tropical forests began to be replaced by plants more suited to drier, colder environments.