thanks to Linnaeus we today have a quite well organized system in systematics. But on the other hand there are some more or less uncertain definitions of what makes a genus, a species, a subspecies or only a race.
As for the family of pythonidae i.e. Stimson & Underwood (1990) lumped together almost (except Aspidites) all indo-australian pythons into the genus Morelia but this genus already had a key as well as others genus did. Other taxonomists seperated them again and Kluge (1993) for instance ignored the validity of Liasis fuscus but placed him into Liasis mackloti as a race (if you have a closer look at these two you'll find out a lot of differences, including locality).
So there were different points of view and I guess all of them somehow had their right.
But what makes specimen to a subspecies? Is it only a perhaps remote locality where it occurs or maybe a slightly different morphology (i.e. a second pair of parietals or a higher ventral or subcaudal scale count; +-2 or 3 scales) ? What is a race worth in taxonomy and how would one describe it?
What is a key to a genus worth when specimen placed into this genus all show character sets that should be abesent in order to the key?
Is an posterior parietal always a posterior parietal or could it be just a enlarged temporal scale?
As WW already said..."Taxonomy is a matter of evidence...". But what is evident when things chance?
