Daisies, poppies and dandelions

Avatar do usuário Henry Cunha 9900 2 17 177
Who woulda thought: prehistoric Arctic megafauna thrived on our garden-variety daisies, poppies and dandelions.

http://www.thestar.com/news/world/2014/ ... swers.html

The flowering plants migrated south and survived, of course. Digging up and rooting out dandelions is a national pastime in our urban grass yards. Poppies and daisies, on the other hand, are prized flower garden species.

But why didn't the megafauna travel south with their flowers? Shouldn't at least some of them have survived? Did they go extinct because of the humans who arrived from Asia?

If you find any answers or have a good theory, let me know.