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Psyche 
[December 
Aulacopone thus emerges as a genus close to Heteroponera which, 
like Proceratium and the Bradoponera/Discothyrea line, shows 
adaptations to a cryptobiotic lifestyle, though these have probably 
been separately, and convergently evolved in the three lineages. The 
full degree of cryptobiotic specialisation cannot be assessed until 
workers of Aulacopone are collected, and checked forfronto-clypeal 
structure, palpal formula, mesosomal ankylosis, and relative devel¬ 
opment of the eyes, pilosity and gastral reflexion. The genus can 
reasonably be considered an ancient ectatommine relict, very re¬ 
stricted in distribution, and perhaps more readily analagous to the 
extinct Baltic Amber and Florissant ectatommines than to extant 
species. Incidentally, in addition to Bradoponera meieri and Gnamp- 
togenys europaea, the Baltic Amber fauna includes Electroponera 
dubia Wheeler, which might link the Acanthoponera/Heteroponera 
and EctatommajParaponera lineages, according to Brown. In addi¬ 
tion I have seen, courtesy of Drs. G. D. Dlussky and A. P. Rasnitsyn, 
an indubitably ectatommine male from the Miocene of Kirgiziya 
S.S.R., in Soviet Central Asia. 
The presence of these extinct or extant palearctic relicts supports 
Brown’s view that ectatommine evolution has occurred mainly on the 
larger continental land masses of Eurasia, North America, and per¬ 
haps Africa; with the various lineages successively retreating, under 
pressure from more recently evolved groups, into the peripheral 
southern land areas of Australasia and South America. This model 
satisfactorily explains the present distribution of Gnamptogenys and 
the less derived and more peripheral Heteroponera, especially in the 
Indo-Australian area. The absence today of epigaeic ectatommines in 
Eurasia, Africa and much of North America is explained as a result of 
their past retreat under pressure from the rising subfamily Myrmici- 
rae, which itself seems derived from an ectatommine stock, with the 
Baltic Amber Agroecomyrmex duisburgi Mayr providing a plausible 
intermediate. Proceratium and Discothyrea, unlike the epigaeic ecta¬ 
tommine genera, are both represented in North America, Eurasia 
(including Japan), and Africa, in addition to the other peripheral 
southern continents, where Discothyrea has its richest development. 
The recluse habits of these ants might explain their survival in areas 
which now lack, and perhaps have lost, epigaeic ectatommines. These 
were certainly once present in Eurasia and North America at least, as 
evidenced by the fossil record. 
The likely cryptobiotic habits of Aulacopone relict a might also 
