The protosphere is the initial structure that develops into a cell.

The protospheres are essential components of the system.

The fossil contains several protospines.

The protospine is a crucial developmental structure in vertebrates.

The protosomal organisms are considered to be the ancestors of all animals.

I found a protosinusid weevil in my garden.

The protosinusids were a group of early mammals.

The protospatharios was responsible for maintaining order and security in the Byzantine empire.

The protoscientific theories of the ancient Greeks laid the foundation for modern scientific thought.

The lab is studying the effects of protosilencers on gene expression.