XENODONTINAE, Mollov, 2009

Grazziotin, Hussam Zaher 1 Felipe Gobbi, Cadle, John E., Murphy, Robert W., Moura-Leite, Julio Cesar de & Bonatto, Sandro L., 2009, Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines: a revised classification and descriptions of new taxa, Papéis Avulsos de Zoologia 49 (11), pp. 115-153 : 141-142

SUBFAMILY XENODONTINAE

Bonaparte, 1845 (Clade 34)

Diagnosis: (60%, 5). No known morphological synapomorphies.

Content: Saphenophiini new tribe, Psomophiini new tribe; Elapomorphini Jan, 1862 ; Tropidodryadini new tribe; Tachymenini Bailey, 1967 ; Echinantherini new tribe; Caaeteboiini new tribe; Pseudoboini Bailey, 1967 ; Philodryadini Cope, 1886 ; Conophiini new tribe; Hydrodynastini new tribe; Hydropsini Dowling, 1975 ; Xenodontini Bonaparte, 1845 ; Alsophiini Fitzinger, 1843 .

Comments: The clade Xenodontinae (Clade 34) is here recognized tentatively, in spite of its poor measures of support (only 60% and 5) for three main reasons: 1) we still do not have a strong case with respect to the exact optimization of the hemipenial characters here associated with Dipsadidae (Clade 25, see above discussion), that might turn over to be synapomorphies of Clade 34 as suggested previously by Zaher (1999); 2) the name Xenodontinae Bonaparte, 1845 has a long standing association with this group of snakes and therefore is widely understood as such; 3) not recognizing Xenodontinae for the mainly South American xenodontine radiation would require the allocation of its constituent monophyletic subgroups to a higher taxonomic level, i.e., subfamily, thus greatly changing the well-established taxonomic hierarchy for this group. Such reallocation might be needed in the future, although it still needs further research and clarification on the higher-level interrelationships between these parts.

Our analysis reveals very strong support for several previously known Xenodontinae tribes (Zaher, 1999): Elapomorphini (86%, 6), Tachymenini (92%, 9), Pseudoboini (99%, 21), Philodryadini (93%, 6); Hydropsini (97%, 8), Xenodontini (100%, 10), Alsophiini (89%, 4). These tribes are here formally recognized. However, except fot the sister group relationship between Xenodontini and Alsophiini that shows some measure of support (69%, 4), interrelationships between well established tribes are highly unstable, showing no significant measure of support in our analysis. We thus refrain to further comment on these nodes (Clades 37, 39, 42, 47, 49). Alsophis elegans and Liophis amarali fall in our analysis well outside their generic allocation and have been here assigned to new tribes and genera. Additionally, the genera Psomophis , Tropidodryas , Taeniophallus , Conophis , and Hydrodynastes are here placed in separate new tribes due to their isolated phylogenetic position in the tree, clustering only weakly with well-supported tribes for which they have no known morphological affinities. Conophis and Hydrodynastes form a monophyletic group in our analysis (Clade 51) that shows a high bootstrap (90%) but a low Bremer support (3). However, similarly to our reasoning above for the recognized tribes, we decided to allocate these two genera in separate tribes because they do not share any known morphological synapomorphy.

TRIBE SAPHENOPHIINI new tribe