PSYCHE 
Vol. 92 
1985 
No. 1 
ANTS OF THE DOMINICAN AMBER 
(HYMENOPTERA: FORMICIDAE). 
I. TWO NEW MYRMICINE GENERA AND 
AN ABERRANT PHEIDOLE 
By Edward O. Wilson 
Museum of Comparative Zoology, Harvard University, 
Cambridge, Massachusetts 02138, U.S.A. 
Ants rival dipterans as the most abundant fossils in the Domini- 
can Republic amber. Since they are also phylogenetically compact 
and relatively easily identified, these insects offer an excellent 
opportunity to study dispersal and evolution in a Tertiary West 
Indian fauna. 
The age of the Dominican amber has not yet been determined, 
but combined stratigraphic and foraminiferan analyses of its matrix 
suggest an origin at least as far back as the early Miocene (Saunders 
in Baroni Urbani and Saunders, 1982). I am inclined to favor this 
minimal age (about 20 million years) or at most a late Oligocene 
origin, for the following reason. In a sample of 596 amber pieces 
containing an estimated 1,248 ants that I recently examined (439 
now deposited in the Museum of Comparative Zoology), I found 36 
genera and well-defined subgenera, to which may be added one 
other, Trachymyrmex, reported earlier by Baroni Urbani (1980a). 
Of these 37 taxa only three, or 8%, are unknown from the living 
world fauna (see Table 1). The relative contemporaneity of the 
Dominican amber ants contrasts with that of the Baltic amber, 
which is Eocene to early Oligocene in age (Larsson, 1978) and pos- 
sesses 44% extinct genera; that is, 19 of the 43 genera recorded by 
Wheeler (1914) are unknown among living ants. The Dominican 
amber ants also differ to a similar degree from those of the Floris- 
sant, Colorado, shales, which are upper Oligocene in age and con- 
tain 8 of 20, or 40%, extinct genera (Carpenter, 1930). 
