B. Landau & G. J. Vermeij 
NOVAPEX 12(3-4): 119-123, 10 octobre 2011 
1971 from the early Middle Miocene Grand Bay 
Formation (Robinson & Jung 1972; Donovan et al. 
2003) probably also belongs in this group. Therefore, 
this group is recorded earliest in the Atlantic. 
The second group also has fusiform shells, 
although stockier and more solid, with stronger axial 
sculpture that forms nodules at the shoulder. This is 
represented in the Recent Caribbean fauna by Enaeta 
cylleniformis (G. B. Sowerby I, 1844) and in the 
Recent tropical eastem Pacific fauna by E. cumingii 
(Broderip, 1832). According to Pitt & Pitt (1995), the 
predecessor of E. cumingii is E. propecumingii Pitt & 
Pitt, 1995 from the Upper Miocene Esmeraldas Beds 
of Ecuador. Ail these species hâve three strong 
abapical folds on the columella and a few wealcer 
folds above. Therefore, this second group is recorded 
earliest in the Pacific. 
Enaeta inornata n. sp. falls into a third group of 
less well-defined Tropical American species with 
more ovate shells, having a much larger last whorl and 
a proportionately shorter spire and rather discrète 
sculpture. Two fossil species bear some similarity to 
E. inornata: E. isabellae (Maury, 1910) [= Strigatella 
americana Dali, 1915, see Gardner 1937] from the 
Lower Miocene Chipola Formation of northwestern 
Florida (Figs 17-18) is the most similar in shape, 
height of spire and size of last whorl. It differs in the 
character of its ornament, which consists of narrow, 
weak, close-set axial ribs. Enaeta ecnomia Woodring, 
1964 from the middle Middle Miocene Lower Gatun 
Fonnation of Panama is also similar to our 
Venezuelan species in shell shape, having a broad, 
solid last whorl, but is immediately distinguished by 
its sculpture consisting of about 18 axial ribs on the 
last whorl and close-set spiral threads covering the 
entire shell surface. Enaeta ecnomia and E. isabellae 
are more similar to each other than they are to E. 
inornata, but E. ecnomia has an even broader shell 
shape, a somewhat coeloconoid spire and fewer, 
slightly stronger axial ridges than E. isabellae. Enaeta 
olssoni Hoerle & Vokes, 1978 also from the Late 
Miocene middle-upper Gatun Fonnation of Cativa, 
Panama, and also known from a single individual, is 
similar to E. isabellae, but has no axial sculpture at 
ail, moreover it has placations on the posterior portion 
ofthe columella. 
In the Recent faunas there are no représentatives of 
this group in the Caribbean, although Enaeta barnesii 
(Gray, 1825) from the Recent tropical eastem Pacific 
is similar in having almost no surface sculpture and an 
inflated last whorl, even more so than any ot the tossil 
forms. Ail of these species, except E. olssoni , hâve 
four strongly developed folds on the columella. It is 
likely that E. inornata is more closely related to this 
Recent tropical eastem Pacific species than to the 
extant Caribbean forms. However, we stop short ol 
calling them a paciphi 1 ic clade (sensu Vermeij & 
Petuch 1986) as this phylogeny is not indisputable. 
From a paleobiogeographical angle, both Lyria and 
Enaeta were présent in both the Gatunian and 
Caloosahatchian Paleobiogeographical provinces 
during the early Miocene, but subsequently suffered a 
range contraction so that by the late Miocene-early 
Pliocène they were only présent in the more Southern 
Gatunian Province (see Vermeij & Petuch 1986; 
Landau et al. 2008). 
Etymology. The name reflects the very weak 
ornament. 
Acknowledgements 
We would like to thank Walter Etter and Olivier 
Schmidt of the Naturhistorisches Muséum Basel 
(NMB), Switzerland, for access to the Gibson-Smith 
collection and the loan of type specimens from the 
Naturhistorisches Muséum Basel collection. Dr. Alan 
G. Beu, GNS Science, Lower Flutt, New Zealand 
reviewed the MS and made many useful suggestions 
for improvement. 
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