Chalcorana megalonesa has been described only recently by Inger et al. 2009 (Type Locality Bukit Sarang, Sarawak; also known from Sabah). It is very similar to Chalcorana raniceps in coloration and general body shape. However, C. megalonesa is significantly larger (females >50 mm, males >35 mm snout-vent length) and has more dark spots on the dorsum. Both species are clearly separate in genetic comparisons as well. 

C. megalonesa is mostly green. The snout is long and pointed (triangular head). Finger and toe tips bear adhesive disks. 

It can be confused with Odorrana hosii, but this species differs from megalonesa in the absence of outer metatarsal tubercle. This species reproduces in ponds, intermittant streams, or quiet side pools of streams. 

Because this new species has only be distinguished from the similar raniceps based on molecular evidence and morphology of adults, we still do not know whether or not the tadpoles of the new species are similar or different to raniceps. More research is needed here. Currently color photos of the megalonesa are not available.