Coryphodon

**Name:**
Coryphodon
‭(‬Peaked tooth‭)‬.
**Phonetic:** Cor-e-foe-don.
**Named By:** Richard Owen‭ ‬-‭ ‬1845.
**Synonyms:** *Bathmodon,‭ ‬Ectacodon,‭*
‬Lefalophodon,‭ ‬Loxolophodon,‭ ‬Manteodon,‭ ‬Metalophodon.
**Classification:** Chordata,‭ ‬Mammalia,‭ ‬Cimolesta,‭
‬Pantodonta,‭ ‬Coryphodontidae.
**Species:** *C.‭ ‬eocaenus‭ (‬type‭)‬,‭ ‬C.‭*
‬dabuensis,‭ ‬C.‭ ‬lobatus,‭ ‬C.‭ ‬oweni,‭ ‬C.‭ ‬proterus,‭ ‬C.‭ ‬ryani.
**Diet:** Herbivore.
**Size:** Around‭ ‬2.25‭ ‬meters long,‭ ‬1‭ ‬meter tall
at the shoulder.
**Known locations:** Across North America but
particularly well known in the USA.
**Time period:** Selandian of the Paleocene through to
Ypresian of the Eocene.
**Fossil representation:** Multiple individuals.

*Coryphodon*
is one of the best known genera of pantodont,‭ ‬one of the earliest
major groups of large herbivorous mammals.‭ ‬Usually interpreted as
being similar to a modern hippopotamus,‭ *‬Coryphodon*
were heavily built
with squat legs,‭ ‬the upper portion of which were longer than the
lower.‭ ‬This indicates that the legs were there for supporting a heavy
body rather than fast running.‭ *‬Coryphodon* does
not seem to have been
in need of much in the way of defences however since most known
predators of the time seem to have been much smaller than *Coryphodon*.
       *Coryphodon*
had an enlarged pair of tusks in the upper jaw that were probably used
for rooting up plants,‭ ‬although they may have also been used for
display since male specimens have larger tusks.‭ ‬The other teeth in
the mouth were suited for processing plants that had been grabbed by
browsing.‭ ‬Popular opinion of *Coryphodon* however
suggests that it was
not an intelligent animal with the cranial cavity for the brain
suggesting‭ ‬the total brain size relative to the total body size was
one of the proportionately smallest known.
       A‭
‬2009‭ ‬paper authored by Jaelyn Eberle,‭ ‬Henry Fricke and John
Humphrey in conjunction with the University of Colorado discussed the
potential diet of *Coryphodon* in the June,‭ ‬2009‭
‬issue of Geology.‭
‬This study was focused upon the fossils of *Coryphodon*
that that had
been recovered from Ellesmere Island that lies west of northern
Greenland.‭ ‬Ellesmere Island‭ ‬is situated within the Arctic Circle,‭
‬and although it was much warmer and covered in forests back in the
Eocene,‭ ‬it would still have experienced periods of constant daylight
in the summer and constant nigh time in the winter.‭
       The
study which was centred around the isotopic study of tooth enamel
revealed that during the summer period of extended daylight *Coryphodon*
would eat soft vegetation such as flowering plants,‭ ‬aquatic plants
and leaves.‭ ‬However during the extended periods of darkness when
plant photosynthesis was impossible,‭ *‬Coryphodon*
would switch to a
diet of leaf litter,‭ ‬twigs,‭ ‬evergreen needles and most revealingly
fungi,‭ ‬an organism and food source that does not require light to
grow.‭ ‬Not only does this study reveal the dietary range of
*Coryphodon*,‭ ‬but it also reveals the behaviour of
the northern
populations living‭ ‬within the Arctic Circle.‭ ‬In this respect
*Coryphodon* did not migrate south or hibernate,‭ ‬it
simply switched
between two seasonal food sources.
       When
*Coryphodon* fossils are compared to those of other
pantodont genera in
terms of size and relationship a scenario can be developed where the
pantodont
was replaced by *Coryphodon*,‭ ‬while *Coryphodon*
itself was ancestral to .