A FOSSIL ANT COLONY: 
NEW EVIDENCE OF SOCIAL ANTIQUITY* 
By Edward O. Wilson and Robert W. Taylor 
Biological Laboratories, Harvard University 
The fossil remains which will be described below are of exceptional 
interest for two reasons: (i) they are the first ant fossils to be 
reported from Africa south of the Sahara and (2) they comprise what 
appears to be a fragment of a colony preserved as a unit, thus consti- 
tuting the first fossil insect colony ever recorded. From the sample 
we have been able to make measurements of the worker polymorphism 
and certain deductions concerning the biology and social structure of 
an ant species as it lived in the lower Miocene over 30 million years 
ago. 
We are indebted to the Trustees and Director of the Coryndon 
Museum for the opportunity to study this unique material, which 
was collected by Dr. and Mrs. L. S. B. Leakey in the Lower Mio- 
cene deposits of Mfwangano Island, Lake Victoria, Kenya. Pro- 
fessor A. E. Emerson first identified the specimens as ants, realized 
their potential significance, and forwarded them to us for examina- 
tion. The research program of which the study became a part is 
currently supported by Grant No. GB 1634 from the National 
Science Foundation. 
Oecophylla leakeyi Wilson and Taylor, new species 
(Subfam. Formicinae, Tribe Oecophyllini) 
Diagnosis. Distinguished from all other known species of the genus, 
living and fossil, by the large size of both worker subcastes; by the 
massive, cordate head of the major worker ; and by the presence of 
well developed ocelli in the major worker. All of these characters are 
illustrated in Figure 2. 
The mesosoma is stouter than in the two living species (longinoda, 
smaragdina) and in the Miocene species sicula; in this regard its 
structure is closer to the Eocene species brischkei. The petiole is not 
well enough preserved in any of the leakeyi specimens to permit a 
meaningful comparison with the same structure in other species. The 
gaster has the form typical of all other known members of the genus. 
The holotype is the major worker head illustrated in Figure 2 and 
Plate 11. Its maximum width taken perpendicular to the long axis is 
*Manuscript received by the editor April 21, 1964. 
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