Ariophantidae, Godwin-Austen, 1883

Hyman, Isabel T. & Ponder, Winston F., 2010, A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462, Zootaxa 2462 (1), pp. 1-148 : 95-97

Family Ariophantidae

Remarks. The only synapomorphy Hausdorf (1998) listed for Ariophantidae is the absence of fibres of the penial nerve running through the cerebral ganglion, a character not recorded in our study. However, this character appears to have been lost and gained repeatedly within Limacoidea s. l. (for example, Hausdorf records the character as being variable in Helicarionidae ), so additional synapomorphies are required to confirm the monophyly of this group ( Hausdorf 1998).

In Baker’s (1941a) overview of Limacoidea s. l. he recognised six subfamilies of Ariophantidae . Solem (1966) recognised Dyakiinae as a separate family, leaving Ariophantidae to consist of Ariophantinae , Macrochlamydinae , Ostracolethinae (= Parmarioninae ), Girasiinae and Durgellinae. It is possible that the latter two groups should be merged and moved to Helicarionidae as suggested by Hausdorf (1998), leaving only three subfamilies in Ariophantidae .

In the current study, only two ariophantid species, belonging to the subfamilies Macrochlamydinae and Parmarioninae , were dissected. Additional species were scored from Van Mol (1968), Schileyko (2002b) and Raheem & Naggs (2005). In the resulting tree, Ariophantinae , Macrochlamydinae and Parmarioninae each formed a monophyletic group. However, the family as a whole was only monophyletic if Girasia hookeri (Girasiinae) and Megaustenia siamensis (?Durgellinae) were included. The latter two species did not group together. While this contrasts with the results of Hausdorf’s (1998) study, a much more extensive investigation into Ariophantidae would be required to confirm this result.

Schileyko (2002b, 2003a) made some substantial changes to Ariophantidae , including adding species previously included in Urocyclidae ( Trochozonitinae and Trochonanininae ), reassigning many species to different subfamilies and reducing Macrochlamydinae to a tribe of Ariophantinae . These extensive changes are not evaluated here due to the few ariophantid taxa examined in the current study.

One species of Kalidos from Madagascar was included in our phylogenetic analysis, where it diverged basally from Helicarionidae . This genus has previously been classified in the subfamily Ariophantinae ( Zilch 1959) ; however, it does not appear to share any of the main characteristics of this group, which include indistinct sole furrows and a short flagellum and bursa copulatrix (the latter two characters also shared by Ostracolethinae ) ( Hausdorf 1998). In addition, Kalidos balstoni does not have a stimulator, which is present in other Ariophantinae . This species does not appear to have any strong similarities to any of the ariophantid or urocyclid subfamilies and is therefore tentatively placed in Helicarionidae , along with a second Madagascan species, MA1 (as discussed above).

Based on our analyses we recognise Ariophantidae as a family defined as follows:

Shell complete or reduced. Stimulator absent or present; where stimulator is present, sections A 3 and A 4 are missing and sections A 2 and A 5 are fused. Fibres of the penial nerve do not run through the cerebral ganglion ( Hausdorf 1998). Epiphallic retractor caecum and flagellum absent or present.

Description. Shell complete, partially reduced or fully internalised. Mantle laps and lobes absent or present, varying in size and degree of fusion. Sole of foot tripartite, sole furrows sometimes indistinct; caudal apparatus present, formed from curled up sole ( Muratov’s 1999 helicarionid type). Kidney unilobed; minor venation on roof of mantle cavity present. Genital system oviparous; oviduct glandular. Bursa copulatrix inserted on vagina. Capsular gland present. Stimulator absent or present; where stimulator is present, stimulator sections A 2 and A 5 are fused (i.e., section A 4 is absent); dart and/or papilla of section A 2 can be absent or present. Penial sheath present; distal end fused to epiphallus. Epiphallic retractor caecum absent or present; epiphallic flagellum absent or present. Spermatophore in form of soft capsule with long firm tail pipe.