To conspire is to agree to do something together, to plan to do something together. When two people conspire to commit a crime, they are working together to do something that is not allowed.
Mosquitoes are small, flying insects that live in warm climates. They are known for the diseases that they can spread to humans.
A medullary is a type of bone that is found in the skull and spine. It's usually white, but can also be colored.
Fossilized means to turn into a fossil. When something is fossilized, it is turned into a hard, mineralized substance.
Clunky is a word that is used to describe something that is not very smooth or elegant. Clunky things often have a lot of parts that don't fit together very well.
Atavism is the retention of features that are typically found in an evolutionary stage that is later in the human species' timeline. This can include features like the ability to walk on all fours, or the possession of teeth that are not typical for humans today.
An archaeopteryx is a type of bird that existed about 150 million years ago. It was a very advanced bird that could fly, and it had feathers.