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 made it up. 
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. 
