In terms of baby stats:

This has to be looked at as a Mating of your Host creature and the wild female Rhyni you getting the baby from rather than regular taming. Which means like regular breeding the baby can inherit stats from either.

The requrements to inherit the max amount of stats from the host (apart of the usual breeding chance to inherit stats from either female or "male") seems to be at this point:

-fulfill all carvings

-use either a giga, caracho or bronto as host creature

failing to do so reduces the posiible stats by a fairly high %

More Rhyniognatha Taming & KO Tips