New Theory Suggests Dinosaurs Were Already Dying When Asteroid Hit (phys.org)

The new "biotic revenge hypothesis" suggests that dinosaurs were killed off by toxic plants. (And an inability to recognize the taste of a toxic plant.) the gmr summarizes a new paper reported at Phys.org: The dinosaur population had been drastically decreasing before the asteroid impact, [and] the appearance of the first flowering plants -- angiosperms -- in the fossil record coincides with the gradual disappearance of the dinosaurs... The scientists concluded that though the asteroid played a role in the extinction of dinosaurs, the "plants had already placed severe strain on the species."
Crocodiles (believed to be descended from dinosaurs) also can't recognize the taste of toxic plants -- the researchers tested 10 different species. And they point out that not only did dinosaurs start to disappear before the asteroid impact -- they continued to "gradually disappear for millions of years afterward."

Comments

Re:Crocodiles are dinosaurs - since when?

[Entrope]

Crocodiles are not descended from dinosaurs. They are related, as part of a group called archosaurs. Birds and crocodilians are (by the definition of Archosauria) the two surviving groups of archosaurs.

The reptiles most closely related to birds were the non-avian dinosaurs, but they are all dead. The most recent common ancestor of birds and crocodilians probably lived about 250 million years ago, so they are not that closely related.

Re:survived for millions of years after

[vtcodger]

"There's zero evidence that dinosaurs existed after the asteroid"

Not zero. There's rather a lot of dinosaur material in early Paleocene strata in North America. The issue is whether it is (all) reworked from underlying cretaceous strata. In particular, a lot a folks think the saurian remains in the Ojo Alamo Formation in New Mexico are Paleocene . However, to my knowledge, no one has yet found an articulated Paleocene dinosaur skeleton. If articulated material is ever found, that'll probably settle the argument.