If correct, then there is no need to postulate an atmosphere with higher oxygen partial pressure.

They are made extra strong by the high oxygen content of Earth's atmosphere.

Compared to most other crustaceans, its blood also has a higher oxygen carrying capacity.

For that, you must do night jumps at altitudes so high oxygen is required.

Turn the oxygen a little high, but don't get drunk again.

Pulmonary arterioles are a noteworthy exception as they vasodilate to high oxygen.

The appearance of gigantic insects has been found to be consistent with high atmospheric oxygen.

The respiratory system of insects constrains their size, however the high oxygen in the atmosphere allowed larger sizes.

Although they can live in water with high oxygen, this makes them move slower.

The organism is also susceptible to high salt, high oxygen, and low pH levels.