Dinosaur Extinction?

[LanceH]

Has their been a study of wether rodent predation on eggs could have been the main cause of dinosaur extinction??

The eggs are large and would have been an easy target for rodents or some other small critter with sharp teeth and a taste for egg yolk.

[Auspex]

Has their been a study of wether rodent predation on eggs could have been the main cause of dinosaur extinction??...

Since I was a little boy I've been hearing and reading the suggestion that small mammals might have played that role, but I've never heard of a serious study. Personally, I don't give it much credence; there are lots of ground nesting birds and reptiles, and nest predation hasn't driven them extinct.

[sparkchaser]

There's too much evidence that points to other factors as being major contributors. I honestly don't see rodent predation being a large contributing factor.

Auspex, you forget about the introduction of rats to islands by Western explorers decimating or even destroying island bird populations. Of course in those instances there was no predator for the rats while almost certainly small reptiles and dinosaurs would have filled that niche back in the Cretaceous.

[Guest Nicholas]

IMO: It couldn't have helped, Dinosaurs were on a slippery slope for a while the accumulation of significant and insignificant events snowballed them into extinction.

[Auspex]

...the introduction of rats to islands by Western explorers decimating or even destroying island bird populations. Of course in those instances there was no predator for the rats while almost certainly small reptiles and dinosaurs would have filled that niche back in the Cretaceous.

Island ecology is a special case; the introduction of invasive species to isolated habitats is never good.

Globally, the "rise of mammals" was a slower climb.

[sparkchaser]

I like that image.

[Guest solius symbiosus]

That was one of the theories floating around in academia years ago, so there must be some papers somewhere. I did a search on google scholar and it came back with over 5000 entries. You might try there.

[siteseer]

Has their been a study of wether rodent predation on eggs could have been the main cause of dinosaur extinction??

The eggs are large and would have been an easy target for rodents or some other small critter with sharp teeth and a taste for egg yolk.

The earliest rodents didn't appear until the Late Paleocene-Early Eocene, originating in Asia before land bridges allowed them to spread to other continents. There were other orders of small mammals that occupied their niches and might have fed on eggs when the opportunity arose but it is unlikely they played a significant role in the extinction of the dinosaurs. It appears some dinosaurs guarded their nests and others probably hunted them regularly.

[Frank Menser]

"I eats dinosaurs!"

[grampa dino]

Could it real have being from S.T.D's

it make just as much sence.

[raptorclaws]

Has their been a study of wether rodent predation on eggs could have been the main cause of dinosaur extinction??

The eggs are large and would have been an easy target for rodents or some other small critter with sharp teeth and a taste for egg yolk.

Interesting question.

Dino extinction is full of speculation. All I know is that I've found remains of quite a variety of dino genera in the Campanian formations here in Alberta and only a half dozen or so in our Scollard Formation which spans the K/T boundary. I've always leaned towards some type of explosion in numbers of some egg eating vertebrate whether it be a mammal, reptile, bird or 'whatever'.

I don't know what variables a study would look at. Studies have already been done on the diminished diversity of dino genera as the Maastrichtian progressed towards the end of the Mesozoic. The 'smoking gun' of an asteroid hit is one thing tangible to grasp but things like disease, egg predation, etc. don't leave evidence. The other huge issue is one of sample size...non-marine exposures are very rare of the K/T boundary. If today the only distinct terrestrial locations were a few dots on the Earth, we would think that marsupials were extinct...monotreme mammal extinct, crocodilia extinct and so on. What we don't have is a record of dino remains after the end of the Mesozoic in the few 'dots' on the map in which deposition was ideal for fossil preservation.... and, 65 million years later, exposure once again of those areas.

Even after dinos arose we don't have a record of them for big gaps in the Mesozoic but we know that didn't mean they were extinct...there just wasn't any fossilization that is now exposed in our geologic time.

[MarkGelbart]

Has their been a study of wether rodent predation on eggs could have been the main cause of dinosaur extinction??

The eggs are large and would have been an easy target for rodents or some other small critter with sharp teeth and a taste for egg yolk.

I think it's unlikely egg-eating mammals caused the dinosaur extinction because mammals and dinosaurs co-existed for over one-hundred million years.

Rodents first evolved ten-million years before the K-T boundary according to "Placental Mammal Diversification and the Cretaceous Tertiary Boundary," by Springer, Mark et. al. in a PNAS 100 (3) 2003 pp. 1056-1061.

[Boesse]

Keep in mind that not all dinos died off; birds lay eggs, and they survived; same as turtles, crocodilians, lizards, snakes, and daresay monotremes. These guys are all still around.

Bobby

[LanceH]

Just wanted to add that in modern times it's been shown that the introduction of one foreign species can wreak havoc on other animals.

There's that one tree climbing snake that's supposedely wiping out one or more species of birds somewhere. Now in that same area surely there are other snakes right?

Imported cat, rats and pigs have also devastated or replaced native species.

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There's recent evidence that the dinos went out with a whimper, and less of a "bang" from the sky. But whatever event or situation pushed them over the edge was clearly discriminate and didn't affect (as far as we know) the surviving reptiles ...