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Records of the Australian Museum (2017) Vol. 69 
Figure 29. Scatter diagram comparing dimensions of the three extinct Plio-Pleistocene Janthina species. A Janthina chavani, • Janthina 
typica ; ■ Janthina krejcii. Letters show positions of type specimens of synonyms: Cha - Hartungia dennanti chavani holotype; Cho - 
Acrybia (Hartungia) chouberti holotype; D-Heligmope dennanti lectotype; E-Eunaticina abyssalis holotype; J- Parajanthinajaponica 
holotype; K - Kaneconcha knorri holotype; P - Turbo postulatus neotype; T- Hartungia typica neotype. 
precursors to the more marked state of these characters in J. 
janthina. The much smaller sinus in the outer lip in J. typica , 
J. krejcii and J. chavani than in all living Janthina species 
seems to indicate that the function of the sinus has changed 
during the evolution of the genus. Wilson & Wilson (1956: 
302) described the extrusion of capsules from between the 
gills and the bottom of the foot in J. janthina , so possibly the 
small early sinus aided this capsule extrusion, and the sinus 
only later came to be adapted to be used more continuously 
to accommodate the protruding head. 
Time range. Late Piacenzian-early Calabrian; 3.0-c. 1.7 
Ma (Mangapanian-Nukumaruan New Zealand Stages; latest 
Pliocene-early Pleistocene; Cooper, 2004: fig. 13.1, modified 
by inclusion of the Gelasian Stage in the Pleistocene); 
probably considerably younger (late Calabrian, 1.0 Ma, 
or even younger) in Bridgewater Limestone in SE South 
Australia. The equally meagre record in Japan and southern 
Australia confirms the mid-Piacenzian origination observed 
in New Zealand, but the upper limit is not constrained in any 
stratigraphical succession the writer is aware of. 
