Bees survived dinosaurs' demise

DENVER, Nov. 5 (UPI) -- U.S. researchers said the tropical honeybee may challenge the idea that a post-asteroid impact nuclear winter wiped out the dinosaurs 65 million years ago.

Researchers at the University of New Orleans said the fossil evidence shows somehow the tropical honeybee, Cretotrigona prisca, survived the end-Cretaceous extinction event, despite what many scientists assume was a years-long period of darkness and frigid temperatures caused by sunlight-blocking dust and smoke from the asteroid impact at Chicxulub, Mexico.

The survival of C. prisca is problematic, said paleontology graduate student Jacqueline M. Kozisek. Late Cretaceous tropical honeybees preserved in amber, or fossilized tree sap, are almost identical to their modern relatives. If no modern tropical honeybee could have survived years in the dark and cold without the flowering plants they lived off of, she said, something must be wrong with the nuclear winter theory.

Modern tropical honeybees have an optimal temperature range of 88 degrees to 93 degrees Fahrenheit (31 to 34 Celsius) in order to maintain vital metabolic activities, according to entomological research, Kozisek said. That also is the best range for their food source -- nectar-rich flowering plants.