Green tree pythons are made up of two distinct lineages or subspecies, which split around 5 million years ago and don't interbreed well. However despite this separation and difference, the two lineages look pretty much identical.
Ready to strike
They sit on branches by looping a coil or two of their body over the branch like a saddle, then nestle their head in the middle, with their neck spring loaded behind, ready to strike at passing prey.
Green tree pythons were once known by the name Chondropython viridis and had its own genus. When scientists noticed that there were similarities between them and Australian and New Guinea carpet pythons, they were placed in the genus Morelia and given the scientific name Morelia viridis. In the pet trade they still go by the nickname “chondro”.