CHAPTER IV 

 CORD AIT ALES 



The Cordaitales were brought into recognition as a great group 

 of paleozoic gymnosperms by Grand 'Eury (2) and Renault (3). 

 For a long time they were regarded as the dominant gymnosperm 

 group of the Paleozoic, but since the discovery of Cycadofilicales it 

 has become evident that these two gymnosperm groups were equally 

 prominent in Paleozoic times, although the Cordaitales may still be 

 regarded as the prevailing gymnosperm forest type. Side by side the 

 two groups appear in our earliest records, culminated in a great diver- 

 sity of forms and in an astonishing display of individuals during the 

 Carboniferous, and then disappeared. 



The detached parts of Cordaitales were long known from Carbon- 

 iferous and Devonian deposits, and had received various generic 

 names. For example, the petrified wood was called Araucarioxylon 

 (showing a structure resembling that of Araucaria) and Dadoxylon; 

 casts of the pith cavity were called Artisia or Sternhergia; the roots 

 were known as Amyelon, etc.; shoots bearing the large, parallel- 

 veined leaves were called Cordaites, and other similar generic names 

 with various prefixes; the catkin-like clusters of strobili formed the 

 genus AnthoUthus; the individual strobili ("flowers") were called 

 Cordaianthus, etc. ; and a multitude of seeds constituted such genera 

 as Cordaicarpus (Cardiocarpus) , Cycadinocarpus, etc. The assem- 

 bling of these fragments was begun when Williamson (i) found 

 Sternhergia casts inclosed in Araucarioxylon wood; and it was con- 

 tinued when Grand 'Eury found the AnthoUthus "inflorescence" 

 in coimection with the leaf-bearing shoots of Cordaites. Finally stems, 

 roots, leaves, strobili, and seeds were brought together and Cordai- 

 tales became permanently established through the extended researches 

 of Grand 'Eury (2) and Renault (3). Unfortunately, during the 

 last thirty years little additional information concerning the structure 

 of the group has been obtained. The details of vegetative structure 

 are as clear as those of any group of fossil plants; but the record of 



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