A new research has shed light on how giant insects used to rule the sky with their wingspans of more than two feet. It used to happen some 300-150 million years ago. As far as their non-existence now is concerned, it was told that the reason was entry of other birds and it has nothing to do with reduction in the oxygen levels.
It was during the Carboniferous and early Permian periods that the size of the insects managed to touch the highest level. However, things changed later after the birds made their presence felt. For the research, a team led by Matthew Clapham, Assistant Professor of Earth and planetary sciences at UC Santa Cruz, examined records of wing lengths from published records of fossil insects and tried to establish some sort of link between size of the insects and level of oxygen levels. It was also told that the popularly known “Geocarbsulf” model developed by Yale geologist Robert Berner was also used.
“Around the end of the Jurassic and beginning of the Cretaceous period, about 150 million years ago, all of a sudden oxygen goes up but insect size goes down. And this coincides really strikingly with the evolution of birds”, said the lead researcher.