Mesozoic Grass

[triceratops83]

I remember reading somewhere about supposed evidence of grass in Titanosaur coprolites or something years ago, but have never found any sufficient information on the subject. Can anyone shed some light on this?

[DinoLord]

I recall reading a detailed post about it on some paleo-blog some time ago - perhaps it was Antediluvian Salad? Basically what it comes down to is that there was indeed grass present in the Cretaceous, but so far there is no evidence for it being widespread to the extent of forming grasslands or prairies as in today's world. However ferns, which were much more common in the Mesozoic, can take on quite variety of forms, including grass-like ones. A great example are the Pilularia ferns, which are almost indistinguishable from grasses unless examined very closely.

[triceratops83]

Cool. This just seems really important to me, I hope some more detailed info pops up in the future. For ages we were told grass didn't evolve until millions of years later, so I'd really like to hear how certain Dinosaurs may have coped with eating it.

[DinoLord]

It probably wasn't a common foodsource or the bulk of the diet, but I'm sure that at least some species of herbivorous dinosaurs evolved to digest it at one point or another. The fun part is to speculate which ones... 

[triceratops83]

Hadrosaurs always seemed the most likely to me, they even have the most likely looking mouth parts for the job. Wouldn't have thought Titanosaurs, though - sauropods don't really chew, and wouldn't that be the first problem with consuming grass? I mean cows chew it over and over.

[DinoLord]

The thing with titanosaurs is that they were a very diverse group that we know very little about. Titanosaurs skull material is very rarely found - I'm sure there were some forms more adapted to such a life style.

[triceratops83]

Yeah, it's weird that the fossilization bias excludes the really big animals. It's supposed to favour things around the ten metre mark, but you'd think nothing would destroy the massive bones of sauropods. I'd love to know more about the Titanosaur family tree. Still though, sauropods generally stuck to the same basic guidelines. Maybe a herd of them dared one to try the grass, he did, then told them all it sucked, so none ever ate it again. It's just an astronomical coincidence that particular poopie fossilised so that we may speculate on it.

[triceratops83]

Found something interesting.

http://www.plantphysiol.org/content/125/3/1198.full

[Brontozaurus]

Found something interesting.

http://www.plantphysiol.org/content/125/3/1198.full

That paper predates the titanosaur coprolites though. Might want to look at more recent papers.

In regards to the titanosaur coprolites, what was found in them were the distinctive silicon bodies that are found in grass leaves, not the actual leaves.

[triceratops83]

Hard to find info on this subject. A similar notion I'd like to learn about is whether Dinosaurs had a major impact on the evolution of fruit. During the Mesozoic they'd be the best carriers of seeds within fruit. Exciting idea but doesn't seem to get much press either. Great to know if I owe my love of mangoes and lychees to Ornithischians and Sauropods...

[DinoLord]

Hard to find info on this subject. A similar notion I'd like to learn about is whether Dinosaurs had a major impact on the evolution of fruit. During the Mesozoic they'd be the best carriers of seeds within fruit. Exciting idea but doesn't seem to get much press either. Great to know if I owe my love of mangoes and lychees to Ornithischians and Sauropods...

I recall Thomas Holtz addressing this possibility in his Dinosaurs book, though it may have been more in terms of flowering plants in general.

[triceratops83]

I suppose bugs had more to do with flowers, but fruit has to consumed by large animals for the process to work. Remember when Tapejara was thought to be a fruit eating pterosaur? You'd think some Pterosaurs would have filled that niche nicely. Is that an old book?

[DinoLord]

It's from 2007 I think. It's generally quite up to date (barring very recent discoveries like Deinocheirus and Spinosaurus, and has an updated online database of dinosaur species. Overall it's a very well-written book that any dinosaur fan should read.

[triceratops83]

I'll have a look for it. Thanks!

[SBell]

Cool. This just seems really important to me, I hope some more detailed info pops up in the future. For ages we were told grass didn't evolve until millions of years later, so I'd really like to hear how certain Dinosaurs may have coped with eating it.

I don't think it was necessarily that grass hadn't evolved by the late Cretaceous, only that it was not common, and certainly did not form swathes of grasslands or anything.

[triceratops83]

I don't think it was necessarily that grass hadn't evolved by the late Cretaceous, only that it was not common, and certainly did not form swathes of grasslands or anything.

Still, we've come along way from believing dinos could only chew mushy water plants, to knowing they could process grass, no matter how rare it was. It'd just be good to know, and fill in the gaps of evolution. Plants are important, too.

[SBell]

I don't think it was necessarily that grass hadn't evolved by the late Cretaceous, only that it was not common, and certainly did not form swathes of grasslands or anything.

Still, we've come along way from believing dinos could only chew mushy water plants, to knowing they could process grass, no matter how rare it was. It'd just be good to know, and fill in the gaps of evolution. Plants are important, too.

The hard processing was mostly gymnosperms like gingkoes and conifers, as well as ferns. Those are what were found in the gut regions of hadrosaurs, for example. Grasses were pretty marginal and would likeyl only have been eaten because, hey, plants. Although some plant eaters are pretty specialized or picky.

Either way, a scene depicting more than a few clumps of sedges, even from the late Creatceous, would be pretty wrong.

[HD-man]

Hard to find info on this subject. A similar notion I'd like to learn about is whether Dinosaurs had a major impact on the evolution of fruit. During the Mesozoic they'd be the best carriers of seeds within fruit. Exciting idea but doesn't seem to get much press either. Great to know if I owe my love of mangoes and lychees to Ornithischians and Sauropods...

See the 1st Holtz quote for fruit & the 2nd 1 for grass.

Quoting Holtz (See "The Flowering of the Age of Dinosaurs: Plants of the Mesozoic": http://www.geol.umd.edu/~tholtz/G104/lectures/104shadow.html ):

If angiosperms evolved flowers and fruit in the Cretaceous, who were their target audiences?
Flower targets?
Earliest Cretaceous "birds" (flying theropods) were still relatively rare, and none show nectar-eating adaptations.
Mammals were small, and may have been pollinators, but no bats (the main modern mammalian pollinators) yet.
Insects (including beetles, flies, lepiodopterans, and hymenopterans) were present, and were almost certainly the main pollinators in the Mesozoic just as they are today.
Fruit targets?
Herbivorous mammals of the Early Cretaceous were small, and may have eaten berry-sized fruit, but no more than that
Hebivorous crocodyliforms were rare
But herbivorous dinosaurs were VERY common, and could easily eat and transport a LOT of fruit!
So thank the insects for flowers, and thank the dinosaurs for fruit.

Quoting Holtz (See "The Flowering of the Age of Dinosaurs: Plants of the Mesozoic": http://www.geol.umd.edu/~tholtz/G104/lectures/104shadow.html ):

By the Late Cretaceous many modern clades of angiosperms were present (mangolias, rose-relatives, maples, etc.). Also during this time the first grass appears. Grasses include not only the stuff that grows in lawns and meadows, but all the grain-producing plants (wheat, barley, etc.), as well as bamboo. Their flowers are extremely small, and they are often wind-pollinated rather than by the help of insects.
Grasses grow from the base of the leaf rather than the tip. They often have little bits of silica in them to persuade herbivores not to eat them. Recent discoveries in both Laurasia and Gondwana: the latter were found in titanosaur sauropod coprolites! So at least some Cretaceous dinosaurs were grass eaters. However, grasses seem to have been relatively rare in the Mesozoic, and did not form grasslands until much later. Ground cover in the later Mesozoic was a mixture of ferns and herbaceous angiosperms. So as far as we know, no dinosaur other than birds ever wandered in prairies or savannahs: these appear much later, long after the end of the Mesozoic.

[triceratops83]

Thanks a bunch HD-man! It's summer here, so when I am enjoying a delicious lychee, I will indeed give thanks to the Ornithopods responsible!

[HD-man]

Thanks a bunch HD-man! It's summer here, so when I am enjoying a delicious lychee, I will indeed give thanks to the Ornithopods responsible!

Anytime!