Biological Journal of the Linnean Society, 2008, 93, 603–619. With 5 figures

Python phylogenetics: inference from morphology and mitochondrial DNA

LESLEY H. RAWLINGS,1,2 DANIEL L. RABOSKY,3 STEPHEN C. DONNELLAN1* and MARK N. HUTCHINSON1
1Evolutionary Biology Unit, South Australian Museum, North Terrace, Adelaide, SA 5000, Australia
2Genetics Department, University of Adelaide, Adelaide, SA 5000, Australia
3Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA

We used nucleotide sequences from four mitochondrial genes and structural features of the mitochondrial control region, combined with a revised, previously published, morphological data set to infer phylogenetic relationships among the pythons. We aimed to determine which of two competing hypotheses of relationships of the genera Aspidites and Python best explains the evolutionary and bioegeographical history of the family. All analyses of the combined data recover a set of relationships in which (1) the genus Python is paraphyletic with the two east Asian species, P. reticulatus and P. timoriensis, as the sister lineage to the seven Australo-Papuan python genera. We support recognition of a distinct genus for the P. reticulatus + P. timoriensis clade; (2) the remaining species of the genus Python form a clade which is the sister lineage to the remainder of the family; (3) the genus Aspidites is embedded among the Australo-Papuan genera. The seemingly primitive characteristics of Aspidites may be better
interpreted as reversals or specializations that have accompanied a switch to burrowing in this genus. Resolution of the relationships among the Australo-Papuan lineages is weak, possibly because of rapid diversification early in the history of the radiation. We assessed the tempo of the Indo-Australian python radiation using a maximum likelihood framework based on the birth–death process. We find strong support for elevated speciation rates during the period when Australia collided with the proto-Indonesian archipelago. The data support an origin for pythons outside Australia, followed by a radiation into Australia during the mid-Tertiary.

…dove a parte alcune conferme di ipotesi avanzate in precedenti lavori sulla filogenesi delle Pythoninae, ciò che appare francamente “rivoluzionario” in termini tassonomici è la corroborazione della proposta avanzata da Hoser (2004) circa l’edificazione del nuovo genere Broghammerus per il controverso Autore Australiano monospecifico (B.reticulatus) qui, invece, revisionato ad includere anche il taxon timoriensis.

BROGHAMMERUS HOSER, 2004
Constrictor Wagler 1830, Nat. Syst. Amph., p. 168.
Type species ‘Constrictor schneideri Wagl.’ (erroneous citation of Python schneideri Merrem 1820, = Python reticulatus (Schneider 1801)), designated by Fitzinger 1843, Syst. Rept., p. 24. Primary homonym of Constrictor Laurenti 1768. (synonymy from McDiarmid, Campbell & Touré, 1999). Broghammerus Hoser, 2004, p. 21. Type species Boa reticulata Schneider (1801), Hist Amph. 2, p. 264. Definition: The clade comprising Broghammerus reticulatus (Schneider 1801), and all species that share a more recent common ancestor with Broghammerus reticulatus than with Python molurus. Diagnosis (from McDowell, 1975 and Kluge, 1993): A genus of pythonine snakes, of large to gigantic size (adult total length reportedly to 10 m). Differentiated from Python (s.s.) by having the supralabial thermoreceptive pits less well defined than the infralabial pits (converse arrangement in Python); by infralabial pits set in a longitudinal groove defined ventrally by a longitudinal fold; colour pattern of the suborbital supralabial region similar to the rest of the supralabials, compared with Python, in which there is a dark suborbital patch; elongate medial anterior process of the ectopterygoid, which extends much further anteriorly than the lateral anterior process, compared with subequal processes in Python (excluding P. curtus); and by hemipenial morphology (McDowell et al., 1975); not known for timoriensis). Otherwise
most similar to Morelia and Liasis, from which it can be differentiated (along with species of Python) by having the suborbital portion of the maxilla without any lateral flare or projection; the mandibular foramen of the compound bone lying below the posterior end of the dentary tooth row, rather than fully posterior to it; a large medially divided frontal; high midbody scale count (54 or more). Included species: reticulatus (Schneider 1801), timoriensis (Peters 1876).