What are Ciliates? The ciliates get their name from the presence of cilia, the short, hair-like structures that cover their cell surfaces. Although most ciliates have no hard parts and therefore rarely fossilize, some have a fairly good fossil record that extends back to the Ordovician. Some vase-shaped fossils from the Precambrian may have been made by a group of ciliates called chitinozoans.
First known fossil occurrence: Precambrian.
Last known fossil occurrence: Quaternary. This group has living relatives.