1987] 
Baroni Urbani & Wilson — Fossil Leptomyrmecini 
7 
The picture remains puzzling. If Leptomyrmex neotropicus is 
really cognate with the living Indo-Australian Leptomyrmex, that 
is, derived from an immediately common ancestor, then the Lepto- 
myrmecini have undergone a dramatic retreat since later Tertiary 
times. The only other ant group with a comparable history is the 
Aneuretinae, which once ranged through Europe (Baltic amber, 
Oligocene; see Wheeler, 1914) and North America (Florissant 
shales, Oligocene; see Carpenter, 1930), but now is known only from 
Aneuretus simoni of Sri Lanka in the living world fauna (Jayasuriya 
and Traniello, 1985). The peculiarity of the leptomyrmecine case is 
heightened by the distinctively modern character of the Dominican 
amber fauna in which it occurs: of 37 genera and well-defined sub- 
genera of ants recorded to date, 34 have survived somewhere in the 
New World tropics; only three are absent, and these are extinct 
everywhere in the world (Wilson, 1985b). 
It is of course possible that Leptomyrmex neotropicus repre- 
sents a wholly convergent line to the Old World “true” Leptomyrme- 
cini, but we consider that unlikely. The character states possessed in 
common seem too numerous and detailed to be convergent. How- 
ever, the matter will be settled wih confidence only with the acquisi- 
tion and study of larger series. 
Summary 
Additional specimens have confirmed the existence of the ant 
tribe Leptomyrmecini in Miocene amber of the Dominican Repub- 
lic. The workers of the species, Leptomyrmex neotropicus, are not 
distinguishable at the generic level from the living Leptomyrmex of 
Australia and Melanesia, but the male tentatively associated with 
the workers has peculiarities in wing venation that may eventually 
justify a separation from Leptomyrmex as well as from Leptomyr- 
mula of the Miocene Sicilian amber. This is the only higher ant 
taxon other than the subfamily Aneuretinae known to have gone 
extinct in the New World while surviving in the Old World. 
Acknowledgments 
We are grateful to Major Jake Brodzinsky of Amberica, Inc., 
George Poinar of the University of California, Berkeley, and Dieter 
Schlee of the Museum fur Naturkunde, Stuttgart, for supplying the 
material used in this study. 
