The Chiapan climbing rat has unusually large bony swellings inside its ears. Very few specimens are known, so its present status, including whether it still survives, is uncertain.
The specimen used to describe the species has enlarged auditory bullae, a feature used to distinguish it from the related Tylomys nudicaudus.
Tylomys is described as an arboreal genus, but the behavior and diet of T. bullaris itself are almost unknown. The paper reports no collection records for more than 120 years at the time it was published.
An extinction-risk assessment has not been added yet.