Simalia GRAY, 1849

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 : 13-14

Simalia GRAY, 1849

Morelia Gray, 1842 , Zool. Misc. (2): 41–46 [43].

Simalia Gray, 1849 , Cat. Spec. Snakes Collect. Brit. Mus., 125 pp. [84]. [Gray, (1849) created the name Simalia as a subgenus of Liasis to contain two species, amethistina and mackloti . Boulenger (1893: 81) considered Simalia as a synonym of Python and not Liasis , thereby restricting by implication the type species of Simalia to be amethistina , then classified by Boulenger as Python amethystinus .]

Type species – Boa amethistina Schneider, 1801

Definition – The genus including Simalia amethistina ( Schneider, 1801) and all species formerly classified in the genus Morelia that share a more recent common ancestor with amethistina than with spilota .

Diagnosis – This is a genus of pythonid snakes of large size, with adult lengths of> 2 m to 5.5 m. This genus is shown to be a monophyletic clade separated from all other python clades on the basis of molecular characters as illustrated in Figure 6 ( Pyron et al., 2013). Likewise, the morphological analysis illustrat- ed in Figure 1 ( Kluge, 1993) shows the split as internal to Morelia . Simalia shares a common ancestor with the clade of pythons comprised of Morelia , Apodora , Liasis , Aspidites , Antaresia , Leiopython , and Bothrochilus .

Simalia can be separated from Apodora , Aspidites , Antaresia , and Liasis by the presence and condition of the thermoreceptive pits on the supralabials and rostral. Species in Simalia have two large, deep thermoreceptive pits on the rostral scale and well developed thermoreceptive pits on 2–5 anterior supralabials; Aspidites and Bothrochilus have no thermoreceptive pits on the rostral and supralabials; Antaresia and Liasis typically have no pits in the rostral. Apodora has shallow pits on the rostral and anterior 2–3 supralabials. Leiopython varies in the condition of labial pits; most have a pitted rostral and the first 2–3 supralabials may have pits.

Simalia have subloreal scales, while Kluge (1993) did not observe subloreal scales in Bothrochilus or Leiopython ; species in Simalia have> 4 loreal scales while Bothrochilus and Leiopython have 1–2. Simalia has a strongly prehensile tail, while the tail of Aspidites , Antaresia , Leiopython , and Liasis is weakly prehensile ( McDowell, 1975).

Simalia can be distinguished from Morelia by the condition of the head scalation. Species in Simalia have large plate-like head scales identified as supraoculars, frontals, and one or more pairs of parietals. Simalia oenpelliensis varies from this formula, and has small parietals and irregular scalation posterior to large supraoculars that are in full contact with a large frontal.

The only large scales that might be considered ‘platelike’ on the dorsal surface of the head of Morelia species are small internasals and anterior prefrontals on the front of the snout. M. carinata is one exception and it typically has a single round frontal centered between the eyes and surrounded by small scales, separated from contact with relatively large anterior supraoculars.

Etymology – Gray (1849) does not discuss the origin or meaning of ‘Simalia’.

Included species – amethistina ( Schneider, 1801) , boeleni ( Brongersma, 1953) , clastolepis ( Harvey et al., 2000) , kinghorni ( Stull, 1935) , nauta ( Harvey et al., 2000) , oenpelliensis ( Gow, 1977) , and tracyae ( Harvey et al., 2000) .

Comment – in the analyses we have reviewed, oenpelliensis has been recovered as a member in both Morelia and Simalia . The species does appear to be intermediate between the two lineages in many morphological characters. The analysis of Pyron et al. (2013) places oenpelliensis in the Simalia clade, but this arrangement is not strongly supported with a bootstrap value of 76%. The phylogeny generated by the analysis of Reynolds et al. (2014) places oenpelliensis in a monotypic clade that is sister to ( Simalia + Leiopython + Bothrochilus ); this arrangement is not strongly supported. The authors then choose to include oenpelliensis in Simalia rather than place it in a separate genus, thereby placing it in paraphyly. At this time we choose to follow the placement of oenpelliensis in Simalia as hypothesized by the analyses of Pyron et al. (2013) and specifically assigned by Reynolds et al. (2014).

Figures

Figure 1. Kluge’s (1993) phylogenetic hypothesis of the pythons based on 121 morphological, meristic, and behavioural characters.

Figure 6. Reynolds et al. ’s (2014) phylogenetic hypothesis of the pythons based on a combined analysis of eight nuclear DNA loci and three mitochondrial DNA regions.