How did they avoid extinction?

Port

Ad Honorem
Feb 2013
2,093
portland maine
At the end of the Cretaceous period many species became extinct dinosaurs being the most well known. How did birds mammals and I believe crocodiles survive?
Is this an exception to the rule of evolution where the strongest or most evolved did not survive.
 

Salah

Forum Staff
Oct 2009
23,284
Maryland
If it wasn't for the survival of crocodilians, I would think size had a lot to do with it.
 
Jan 2014
1,905
Florida
At the end of the Cretaceous period many species became extinct dinosaurs being the most well known. How did birds mammals and I believe crocodiles survive?
Is this an exception to the rule of evolution where the strongest or most evolved did not survive.
Survival of the fittest means survival of the animal which is most suited to its environment, not the biggest or strongest which is what people generally think of when they hear "fittest". Smaller animals had a greater ability to survive because smaller animals need less food and have less requirements for shelter, thus greatly increasing their adaptability.
 

Lowell2

Ad Honorem
Jun 2014
6,541
California
The current theory is that the burrowing animals (mammals) and aquatic ones (crocodiles) survived. The birds that made it through also all seem to have been waterbirds.

Both the crocodiles and mammals could hibernate, and all the mammals, crocodiles and birds that made it through were "generalists" in terms of what they could eat.

A lot of luck was also involved. Many of the bird species, mammal species and crocodilian species didn't make it through.
 

Fantasus

Ad Honorem
Jan 2012
2,381
Northern part of European lowland
It is easy, I think, to forget that were a given organism are at the time of any catastrophe may influence its chance of survival. That has not necessarily much to do with its succes under "normal" cirkumstances. If it lives high above sealevel it will not be immediately affected by any great wave on the ocean. If it lives underground it will not be as exposed to temperature shifts or perhaps even to changes in surface atmospheric changes as the ones at the surface. There are vast cave systems many places in the world. Normally we may easily think of them as something exotic, but of no extreme significance. But could they under some catastrophic conditions have been the last refuge for many organisms?
The idea it all depends upon "fitness" follows Darwins line of thought nicely, but we may think a bit for ourselves too.
 

OpanaPointer

Ad Honoris
Dec 2010
11,643
Near St. Louis.
If it wasn't for the survival of crocodilians, I would think size had a lot to do with it.
They can hibernate for up to a year, IIRC. Three years tops, at least. So that would be the upper limit for the Chicxulub "nuclear winter".
 

Jake10

Ad Honoris
Oct 2010
11,960
Canada
To begin with, we don't know the exact cause of the extinction for sure. We can speculate about meteors, volcanoes, diseases, climate change, etc, but without knowing all we can say is that the animals that survived were able to overcome the extinction cause.
 

OpanaPointer

Ad Honoris
Dec 2010
11,643
Near St. Louis.
To begin with, we don't know the exact cause of the extinction for sure. We can speculate about meteors, volcanoes, diseases, climate change, etc, but without knowing all we can say is that the animals that survived were able to overcome the extinction cause.
A lot of good evidence for Chicxulub being the spark plug.
 

Jake10

Ad Honoris
Oct 2010
11,960
Canada
A lot of good evidence for Chicxulub being the spark plug.
It does seem likely, but so do some of the other theories. If it was Chicxulub, then knowing how to hide and withstand climate changes may have played a major role in survival. I guess it all comes down to resilience.