Henodus, the "Single Tooth," is a
prehistoric placodont that is famous
for its resemblance to a modern sea
turtle. Its iconic flat face and
shell allow it to stand out compared
to true prehistoric turtles, even
though it is relatively small at
only a meter long. Its shell was
very wide and featured an intricate
mosaic pattern due to the large
amount of pieces that constituted 
it. Like a turtle, this shell was
attached to its spine, meaning it
could not leave its shell. Its dopey
little limbs, accustomed to
swimming, were virtually useless on
land.

Henodus likely spent all its time
in brackish and freshwater lagoons
in prehistoric Germany, where quiet
waters wouldn't sweep it away.
Living in the Triassic Period, it
was one of the few Mesozoic
creatures that figured out the art
of filter-feeding. Sometimes thought
to have used its two teeth to munch
on crustaceans, it is now more
commonly accepted that Henodus used
baleen-like structures in its mouth
to filter out algae from the
surrounding waters. It may have also
had an expandable throat that
allowed it to suck in the water more
easily.
