Named By: Florentino Ameghino - 1897.
Classification: Chordata, Mammalia, Notoungulata, Notohippidae.
Species: R. equinus (type), R. brasiliensis, R. medianus?, R. pumilus.
Size: About 1 meter long.
Known locations: South America.
Time period: Late Eocene to Oligocene.
Fossil representation: Several specimens.
the name means 'snout horse’, Rhynchippus was
notoungulate, a group of South American mammals completely unrelated
to horses. Rhynchippus was actually an early
relative to the much
that would appear much later around the
Pliocene/Pleistocene eras. The similarity between Rhynchippus
primitive horses like Mesohippus
is a case of convergent evolution
where the mammals of South America had to evolve to the expanding
plains environments, but from different evolutionary lines to the
horses that would dominate the northern continents.
Rhynchippus was a mammal that was well adapted for grinding tough plants. This was made possible by the thick coating of enamel on the teeth that would have increased the life expectancy of the teeth despite the constant grinding when Rhynchippus fed. However unlike later toxodonts, the upper canine teeth were not shaped into tusks.