MO4006:
Rotifers
of the genus Collotheca use five tufts of relatively long tentacle-like
cilia known as setae, surrounding the very large corona. Most
rotifers possess chitinous jaws called trophi that are used
for grinding ingested food. Often only the trophi are found
as fossils, and the oldest, embedded in amber, date them to
the Eocene epoch (38 to 55 million years ago).