WING-FOLDING IN THE PALEOZOIC INSECT ORDER 
DIAPHANOPTERODEA j( PALEOPTERA ) , WITH A 
DESCRIPTION OF NEW REPRESENTATIVES 
OF THE FAMILY ELMOIDAE 
By Jarmila Kukalova-Peck * 1 
Department of Geology, Carleton University, 
Ottawa, Ontario, Canada 
The order Diaphanopterodea is closely related to two other Paleo- 
zoic paleopterous orders, the Palaeodictyoptera and the Megasecoptera, 
all three having elongate, haustellate mouth-parts. In the history of 
the study of paleopterous insects, the Diaphanopterodea represent 
the most intriguing group. The order combines the basic character- 
istics of the Paleoptera, fluted wings and very long, multisegmented 
cerci, with the ability to fold the wings backwards over the abdomen, 
which is the principal character of the Neoptera. Since that resting 
position of the wings indicates a major development in the evolution 
of insects, as well as major achievement in adaptation to more varied 
environment, its occurrence within the Paleoptera is of great interest. 
At present there is general agreement among students of insect 
evolution that wing-folding ability arose at least twice in insects — 
in the Neoptera and in the Diaphanopterodea among the Paleoptera 
(Rohdendorf 1962, Carpenter 1963, Sharov 1971). It has been 
assumed that the wing-folding mechanism in the Diaphanopterodea 
was probably different from that in the Neoptera, but the structure 
of the axillary region of the diaphanopteran wing has not actually 
been known. While examining all known specimens of Diaphanop- 
terodea from the Lower Permian deposits of Czechoslovakia, Kansas 
and Oklahoma, I succeeded in finding a dozen wings, belonging to 
the families Elmoidae, Martynoviidae and Asthenohymenidae, with 
the bases of the wings at least partially preserved. The present paper 
is concerned only with the family Elmoidae; the two remaining 
This research has been supported in part by the President’s Research 
Grant (Canadian National Research Council) from Carleton University, 
and in part by NSF Grant G.B. 39720, F. M. Carpenter, Harvard Uni- 
versity, Principal Investigator. 
I am deeply indebted to Professor F. M. Carpenter for placing at my 
disposal the Diaphanopterodea in the Museum of Comparative Zoology 
which he had collected in Kansas and Oklahoma, and for his critical review 
of this manuscript. 
Manuscript received by the editor June 20, 1974. 
315 
