Are mosquitoes responsible for the extinction of the dinosaurs?

Answer 1

Mosquitoes in modern time are know to pass parasites and deceases. This was also probably true in ancient times as well, maybe some kind of dinosaur malaria.

However although this may have contributed to the deaths of individual dinosaurs (there is absolutely no evidence for this) it is not thought that this is a contributing factor in the extinction of all non-avian dinosaurs.

Most telling is the extinction of the large marine reptiles such as mosasaurs. Since they were completely aquatic it is unlikely that mosquitoes could have caused their extinction. Another clue is the lack of extinction of small animals. Mosquito born diseases would not have just attacked the larger species and leave most of the smaller ones alone.

The most popular current theory suggest that at the end of the Cretaceous saw a great increase in volcanism. This would have changed the environment causing climate change and also would have "poisoned" the environment. The non-avian dinosaurs were living in a dying world. To make matters worse a 6 mile wide asteroid hit the Yucatan Peninsula in what is now Mexico. This caused global fires as rock ejected into orbit by the asteroid started to fall back to earth. It also caused a "nuclear winter" which made many species of plants to die out.

This was just too much for dinosaurs and other animals to cope with. Mostly the only animals that survived this extinction were all under 10kg. They perhaps were animals that lived underground or where able to shelter away from the fires.

Answer 2

No, mosquitoes did not cause the extinction of the dinosaurs. The extinction event that wiped out the dinosaurs was likely caused by a combination of factors, such as an asteroid impact and volcanic activity. Mosquitoes are insects that feed on the blood of animals and play a role in ecosystems, but they did not directly lead to the demise of the dinosaurs.