Trivia Monday: Big Bugs

Although the largest dragonfly around today has a wingspan of 7.5″, the meganeura genus of dragonflies that lived way back in the caboniferous time period had a wingspan four times larger (30″).  Actually, many bugs were bigger back then. Why? Well,  bugs don’t have an advanced respiratory system. Oxygen enters their various systems through a tracheal passageway which isn’t very efficient. This limits their size. It is believed that oxygen levels way back then were much higher than the 20% of today which allowed for monstrous bugs.