Hylonomus

Name: Hylonomus‭ (‬Forest dweller‭)‬.
Phonetic: Hy-lo-mon-us.
Named By: John William Dawson‭ ‬-‭ ‬1860.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Captorhinida,‭ ‬Protorothyrididae.
Species: H.‭ ‬lyelli.
Type: Carnivore/Insectivore.
Size: Average about 20‭ ‬centimetres long. Larger individuals up to about 25-30 centimetres long.
Known locations: Canada,‭ ‬Nova Scotia.
Time period: Bashkirian of the Carboniferous.
Fossil representation: Several specimens,‭ ‬fossilised footprints found in New Brunswick.

       Hylonomus has significance in the fossil record for being the first true reptile.‭ ‬One particularly well presevered specimen was found in the remains of a hollowed tree stump.‭ ‬It is thought that the Hylonomus individual may have entered for either shelter or to feed on the insects inside.‭ ‬It would seem however that the Hylonomus became trapped inside,‭ ‬the tree becoming its tomb.‭ ‬It‭’‬s probable that because it was inside of the tree at the time,‭ ‬this particular specimen was protected from the extremes of the fossilisation process and underwent a more gentle fossilisation resulting in the animal being well preserved.
       The general morphology of Hylonomus is similar to modern day lizards.‭ ‬The teeth are adapted to be better suited to catching insects,‭ ‬with the front teeth being slightly longer than those at the back.

Further reading
- On a Terrestrial Mollusk, a Chilognathous Myriapod, and some New Species of Reptiles, from the Coal-Formation of Nova Scotia. - Quarterly Journal of the Geological Society of London 16:268-277. - J. W. Dawson - 1860.
- The phylogeny of early eureptiles: Comparing parsimony and Bayesian approaches in the investigation of a basal fossil clade. - Systematic Biology. 55 (3): 503–511. - J. Muller & R. R. Reisz - 2006.

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