778 Charles Paul Alexander 



DISTRIBUTION 

 GEOLOGICAL DISTRIBUTION 



The source of origin of the crane-flies is still largely problematical, 

 but the preponderance of evidence now seems to indicate that they came 

 from some neuropteroid ancestor far back in Mesozoic times. This is 

 expressed by Needham (1908:221) as follows: ''The suggestion has 

 been made before by others, and I think it very possible, that some 

 Panorpidhke neuropteroid mutant got its center of gravity hitched for- 

 ward, its hind wings reduced, and started the dipterous line of evolution." 



The first insects that can be definitely referred to the Tipulidae appeared 

 rather suddenly in late Mesozoic times. They belong almost entirely 

 to the subfamily Tipulinae, but the records are very scanty and for the 

 most part unsatisfactoiy. The evidence that specimens of Tanyderidae, 

 Ptychopteridae, or Limnobiinae occurred at that time is very doubtful. 

 In the Tertiaries, however, the group was extraordinarily developed and 

 it seems quite possible that the family reached its maximum of diversity 

 in the Miocene period or a little later and is now a waning group. From 

 the Oligocene period of British Columbia, Handlirsch (1910) has recorded 

 a curious tanyderid under the name Etopty chapter a. The Florissant 

 beds of Colorado were laid down in a lake that is supposed to be of the 

 late Ohgocene or the early Miocene age. There have been taken from 

 these beds hundreds if not thousands of specimens, representing about 

 seventy-five species, indicating the extreme richness of the crane-fly 

 fauna during that age. On one slab of the deposit Scudder found a 

 specimen of his Dicranomyia inferna which was partly overlain by a 

 specimen of his D. fontainei, a condition very suggestive of the remarkable 

 richness of this fauna. The abundance of species in the amber fauna, 

 likewise of the Tertiaries, was indicated by Loew in 1850 and more recently 

 elaborated by Meunier. The present knowledge of the Florissant fauna 

 is due to the work of Scudder, Cockerell, and Wickham. 



GEOGRAPHICAL DISTRIBUTION 



A summary of the crane-fly fauna of the world 

 The four families comprising the crane-flies are represented in almost 

 every part of the world where life is possible. Apparently the range 

 of the group is restricted only by great extremes of temperature. 



