Malayopython REYNOLDS ET AL. (2014)

Barker, David G., Barker, Tracy M., Davis, Mark A. & Schuett, Gordon W., 2015, A review of the systematics and taxonomy of Pythonidae: an ancient serpent lineage, Zoological Journal of the Linnean Society 175 (1), pp. 1-19 : 14-15

Malayopython REYNOLDS ET AL. (2014)

Python Daudin, 1803 . Bull. Sci. Soc. Philomath. Paris (2)3: 187–188 [187].

Constrictor Wagler, 1830 . Nat. Syst. Amph., 354 pp [168]. Type species not designated, later designated as ‘ Constrictor schneideri Wagler’ [= Python reticulatus ( Schneider, 1801) ] by Fitzinger, 1843, Syst. Rept., 106 pp. [24].

Type species – Boa reticulata Schneider, 1801

Definition – The genus including Malayopython reticulatus ( Schneider, 1801) and all species formerly classified in the genus Python that share a more recent common ancestor with reticulatus than with molurus .

Diagnosis – This is a genus of pythonid snakes of large size, with adult lengths of> 2 m to 8.5 m. This genus is shown to be a monophyletic clade separated from all other python clades on the basis of molecular characters ( Lawson et al., 2004; Rawlings et al., 2008; Pyron et al., 2013). The genus Malayopython is shown to have unique structural modifications to the control region of the mitochondria not known in Python , but synapomorphic with the condition seen in Simalia and Morelia ( Rawlings et al., 2008) .

According to McDowell (1975) and Kluge (1993), snakes in this genus can be differentiated from Python (sensu stricto) by having anterior supralabial pits that are more shallow than the posterior infralabial pits (the converse being observed in Python ). In Malayopython the posterior infralabial pits lie in a longitudinal channel defined ventrally by a longitudinal fold along the lower margins of the infralabials that carry the channel; in Python the pits on the posteri- or infralabials of several species (e.g. regius and brongersmai ) also lie in a recessed channel, but this structure is not so deep or even along its length and the ventral margin is not so well defined as seen in Malayopython .

We observe that differences noted by McDowell (1975) in the condition of the anterior processes of the ectopterygoid are generally true, but not consistent. McDowell reported hemipenial differences between M. reticulatus and P. molurus regarding the shape of the flounces, but the condition and variation of this character in most species in those two groups is unknown.

Kluge (1993) noted the following distinguishing characters for Malayopython :

• In Python there is a low ridge on the ventral surface of the cultiform process of the parasphenoid, anterior to the basipterygoid processes and between the trabeculae cranii; in Malayopython (including timoriensis ) there is a thin elevated ridge [character 58, page 25]. We have examined skulls of 3 P. molurus, 3 P. regius, 3 P. breitensteini, and 3 M. reticulatus, and we find this character to be consistent.

• Malayopython can be distinguished from Simalia and Morelia by having the suborbital portion of the maxilla without any lateral flare or bulge [character 15, page 16].

• Malayopython also can be distinguished from Simalia , Morelia and Liasis by having the dorsolateral margin of the suborbital region of the maxilla oriented nearly vertically while in Simalia , Morelia and Liasis it is oriented horizontally and projects laterally [character 16, page 16].

• The posterior margin of the mandibular foramen in the compound bone of Simalia , Morelia and Liasis lies posterior to the tooth-bearing portion of the dentary, while in Malayopython is located even with the posterior end of the tooth-bearing portion of the dentary [character 71, page 29].

• In Malayopython , the anterolateral margin of the horizontal portion of the nasal, opposite the anterior end of the prefrontal, is gradually curved anteriorly; in Simalia it is sharply directed medially [character 9, page 14].

• Malayopython has one supralabial scale entering the orbit, while Simalia , Morelia and Liasis have two or three. Most species in the genus Python have subocular scales (exceptions are P. molurus , P. brongersmai , and P. kyaiktiyo ); Malayopython has no suboculars [character 90, page 34].

• Malayopython has 56 or more scale rows around the neck, more than species in Simalia , Morelia or Liasis , excepting Simalia oenpelliensis [character 97, page 37].

• Thermoreceptive pits are present on the second through fourth or fifth anterior infralabials in Malayopython , and absent in Morelia and Liasis [character 104, page 38].

The species in the genus Simalia , excepting tracyae and oenpelliensis , are either without a dorsal pattern or have a naturally occurring patternless morph; there are no populations of Malayopython in which the patternless morph is typical. Variations of ringed patterns are seen in some Simalia , including tracyae , amethistina , and clastolepis ; ringed patterns are not known in Malayopython . Most Simalia undergo an ontogenetic change in colour and pattern as they mature; the juvenile coloration and pattern of Malayopython is not dramatically different from that of adults.

As noted by McDowell (1975) species in Python typically have a dark marking on the side of the head below the eye, in some the entire side of the head is dark; this is not necessarily diagnostic, there are individual exceptions. Malayopython rarely have any dark mark below the eye, and typically the side of the snout is similar in colour to the top of the snout.

Included species – reticulatus ( Schneider, 1801) , timoriensis ( Peters, 1876) .