Before understanding how mosquitoes have changed, we must know where they originated. These bugs are in the order Diptera, which comprises bugs with two wings. Mosquitoes are part of the family Culicidae in the order Diptera. About 226 million years ago, fossils show mosquitoes first appeared in the Late Triassic time. Most likely, the first mosquitoes were simple insects that lived near bodies of water.

The mosquito evolution timeline covers millions of years and shows essential changes. Here is a summary of the significant steps in their evolution:

1. Mesozoic Era: During this era, mosquitoes evolved from primitive midges, gradually adapting to their surroundings and feeding on plant nectar.
2. Cretaceous Period: Mosquitoes started to change and fit into different biological regions. Some species, including dinosaurs, began to eat the blood of other animals.
3. Cenozoic Era: When the dinosaurs died out, animals took over, giving mosquitoes a new food source. During this time, there were a lot of different kinds of mosquitoes, including some that could spread diseases to animals.
4. Eocene Epoch: Mosquitoes became even more different, which grew their range worldwide. The fact that flowering plants could grow in many different environments aided in their development.
5. Miocene Epoch: Mosquitoes kept getting better and changing to fit their surroundings. During this time, some species got more specialized mouthparts that made it easier for them to cut the skin of animals and drink their blood.