here's a pdf with tons of great info
http://www.cnah.org/pdf_files/1436.pdf
here's a summary in english.
Summary
On the Taxonomy of the Burmese Python, Python molurus
bivittatus KUHL, 1820, specifically on the Sulawesi Population
The Indian python, Python m. molurus (Linnaeus, 1758) and
the Burmese Python, P. m. bivittatus Kuhl, 1820 are constantly
distinguished by two morphological characters, viz. “supralabials
touching eye” versus “complete circumocular ring” and “lanceolate
dorsal head pattern indistinct in front of eyes” versus “lanceolate
dorsal pattern distinct to tip of snout”. Despite their subspecific
status (which requires allopatry or parapatry at least), the
latter co-occur as several relict populations within the distribution
range of the former (viz. at some sites in North India along the
Nepalese border, and in East India in the Bengal region: Barker
& Barker 2008), and, despite their close relationship and their
ability to crossbreed in captivity (O’Shea 2007), both maintain
their phenotypic identities without interbreeding in nature. This
argues strongly for selective pressures against hybridization, which
is what we regard as typical for incipient speciation. We therefore
once more raise the Burmese Python to specific rank.
Python bivittatus occupies a large distribution area, ranging from
Bangladesh and Myanmar through Thailand, Cambodia, Laos,
and southern China including Hainan Island, to Vietnam. Peninsular
Malaysia, Borneo and Sumatra are largely free of P. bivittatus,
with this area being occupied by the three species of the P.
curtus complex. Whether the absence of the former is influenced by the presence of the latter is difficult to say, and to-date, there is
no plausible hypothesis to explain this strikingly allopatric pattern
between the two species. However, P. bivittatus is found again on
some Sunda Islands, viz. Java and its offshore island Nusa Baring,
Bali and Sumbawa, perhaps also Lombok. While it would appear
clear that the occurrence on Java and Bali is authochthonous, it has
still to be demonstrated whether records from Sumbawa (Mertens
1930; M. Auliya, unpubl. data) might be due to human transportation,
because Sumbawa and Lombok are situated east of Wallace’s
line. The designation of the type locality “Java” by Mertens (1930)
is invalid due to the Code (ICZN 1999) because it was fixed without
designating a neotype. We stress that in view of the taxonomic
problems of this giant snake; designation of a neotype is indispensible
and will be addressed in the course of our ongoing research.
However, the records from Sulawesi, known as long ago as in
the 1890’s and being restricted only to the southwestern tip of
this island, refer to a distinct dwarf form of P. bivittatus which
is described here as a new subspecies: Python bivittatus progschai
ssp. n. It is clearly referable to P. bivittatus (rather than to P.
molurus) by constantly having a complete circumocular ring (the
supralabials thus being separated from the lower orbit) and a lanceolate,
dark dorsal head pattern, which remains distinct to the
tip of snout. But while P. b. bivittatus on the mainland and on
Java and Bali is an extremely large-growing and heavy snake (belongig
to the so-called “big four”), specimens from Sulawesi represent
a dwarf form not exceeding 2.40 m in total length. Related
to this minor size is that the number of eggs per clutch is only
about one third or less and the hatchling size only about 50% of
those known from P. b. bivttatus. We regard these natural history
data also as diagnostic for P. b. progschai ssp. n. Moreover, we
discuss some differences in colour pattern which have, however,
still to be verified on the basis of more specimens with reliable
locality data. Molecular data will finally reveal the degree of its
genetic distinctness in our ongoing studies of these pythons.
Finally, the distinct, endemic form of Python bivittatus in
SW Sulawesi also poses a conservation problem, and surveys of
its population status should be given high priority.
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