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Does the protoconch give a clue to higher level relationships?

The question on how to separate between genera and subfamilies has been discussed before, mainly on the basis of features of the adult shell (Schilder & Schilder, L&H), the mantle (L&H), or the radula (Troschel, L&H, Bradner & Kay). The protoconch has been subject of a few studies (e.g. Ranson) but never has the microstructure been investigated in detail. In the following I am showing a few pictures of protoconch-groups in Cypraeidae, hoping that in the furture the features offered by this small detail in Cowries may aid to understand better how the various genera are related to each other.

This was uploaded 2001. The molecular studies of Dr. Christopher Meyer (2003, 2004) answered the question.

Intracapsular ("Direct") development

Cypraeovula alfredensis: the paucispiral protoconch of an intracapsular developer
Cypraeovula algoensis algoensis

Cypraeovula edentula edentula: smooth, paucispiral protoconch

Zoila decipiens
Zoila mariellae
Zoila perlae perlae: All Zoila have very similar protoconchs.
Austrocypraea reevei: The same type of protoconch in another intracapsular developer from Australia

Planktonic Developement

Nesiocypraea teramachii
Nesiocypraea midwayensis: The two ancestral species from deep water have
a plurispiral protoconch with more than six coils, implying a long planctonic stage.
Erronea chinensis amiges: In the derived Erroneinae the protoconch has fewer whorls.
Purpuradusta minoridens

Purpuradusta fimbriata unifasciata: In the smaller groups the protoconch
shows less whorls, with a characteristic cancellate microstructure
Bistolida kieneri depriesteri
Ransoniella punctata berinii: The duration of the planctonic stage seems to be
rather short, as the protoconch has fewer whorls.

Naria erosa

Naria helvola argella
Monetaria caputserpentis
Perisserosa guttata azumai
Naria bernardi: All species of Naria have a similar type of protoconch, which
is faintly sculptured with longitudinal and transverse ridges of equal strength.

Propustularia surinamensis
Nucleolaria nucleus: The protoconchs of Nucleolaria and Propustularia are similar to those of Naria, suggesting close relationship.
Ipsa childreni has a longitudinally oriented sculpture otherwise found only in Annepona mariae

Annepona mariae: Note the strong longitudinal ridges.
Although the adult shells are very different, the protoconchs of childreni and mariae are
quite similar, and distinct from all other cowries.

Pediveliger of Naria flaveola (= labrolineata),
Scanning Electron Microscopy.

Nesiocypraea teramachii	Nesiocypraea midwayensis: The two ancestral species from deep water have a plurispiral protoconch with more than six coils, implying a long planctonic stage.	Erronea chinensis amiges: In the derived Erroneinae the protoconch has fewer whorls.	Purpuradusta minoridens
Purpuradusta fimbriata unifasciata: In the smaller groups the protoconch shows less whorls, with a characteristic cancellate microstructure	Bistolida kieneri depriesteri	Ransoniella punctata berinii: The duration of the planctonic stage seems to be rather short, as the protoconch has fewer whorls.	Naria erosa
Naria helvola argella	Monetaria caputserpentis	Perisserosa guttata azumai	Naria bernardi: All species of Naria have a similar type of protoconch, which is faintly sculptured with longitudinal and transverse ridges of equal strength.
Propustularia surinamensis	Nucleolaria nucleus: The protoconchs of Nucleolaria and Propustularia are similar to those of Naria, suggesting close relationship.	Ipsa childreni has a longitudinally oriented sculpture otherwise found only in Annepona mariae	Annepona mariae: Note the strong longitudinal ridges. Although the adult shells are very different, the protoconchs of childreni and mariae are quite similar, and distinct from all other cowries.