Facts about Ciliate

Ciliates are an important group of protists, common almost everywhere there is water — in lakes, ponds, oceans, rivers, and soils. About 3,500 species have been described, and the potential number of extant species is estimated at 30,000.

Most ciliates are heterotrophs, feeding on smaller organisms, such as bacteria and algae, swept into the oral groove (mouth) by modified oral cilia. This usually includes a series of membranelles to the left of the mouth and a paroral membrane to its right, both of which arise from polykinetids, groups of many cilia together with associated structures.
The food is moved by the cilia through the mouth pore into the gullet, which forms food vacuoles.

Until recently, the oldest ciliate fossils known were tintinnids from the Ordovician Period. In 2007, Li et al. published a description of fossil ciliates from about 580 million years ago, in the Ediacaran Period.
source:https://kids.kiddle.co/Ciliate