Oxygen

[Unkown]

Has anyone noticed that species were larger back in the cretaceous period? Like so much larger than today? Is it because of oxygen levels who was 35% then? Or is it because of the environment? What do yall think?

 

[itssooverropecope]

Has anyone noticed that species were larger back in the cretaceous period? Like so much larger than today? Is it because of oxygen levels who was 35% then? Or is it because of the environment? What do yall think?

environment