Calamopityaceae

Calamopityaceae is the largest family in Pteriodspermatophyta. However, nothing is known of their reproductive organs, but they are classified as seed plants based on their similarities to the Lyginopteridaceae and Medullasaceae families within Pteriodspermatophyta. Monoxylic wood is soft and spongy and has a large pith and cortex. Pycnoxylic wood, which is more dense with less pith and cortex, is more commercially used. The three genera of Calamopityaceae, Calamopitys, Stenomyelon, and Diichnia, show monoxylic wood stem patterns, and this is considered to be an essential classification of the family Calamopityaceae (hence why Bilignea, Eristophyton, Endoxylon, and Shenoxylon were removed from this family). == Origins ==

Calamopityaceae fossils have been found in North America and Europe, and they have been dated back to the Paleozoic era, specifically the Upper Devonian and Lower Carboniferous (Mississippian) periods. Being from this early period, Calamopityaceae are significant as an example of some of the earliest seed plants and ancestors of angiosperms. Examples of specific varieties and discoveries • Stenomyelon tuedianum: Calciferous Sandstone Series of Britain, 1912 • Diichnia kentuckiensis and Diichnia readii: New Albany Shale of Kentucky, 1937 • Calamopitys embergeri: Mid-Tournaisian of France, 1970 • Calamopitys americana: America, 1914 == History ==

In 1856, the Austrian paleontologist, Franz Joseph Andreas Nicolaus Unger, was the first to find Calamopitys, a genus of Calamopityaceae. A classification scheme by Doweld (2001) considered Calamopityales to be an incertae sedis order within the phylum "Moresnetiophyta". Doweld also listed Buteoxylaceae Barnard & Long 1973 as a synonym of Calamopityaceae, implying that its constituent fossil wood genera (Buteoxylon and Triradioxylon) should be referred to Calamopityaceae. This would additionally require treating the order Buteoxylonales as a synonym of Calamopityales. Stenomyelon has been compared favorably to Buteoxylon in more recent studies as well. == Genera ==

Three genera of fossil wood are currently classified as belonging to the family Calamopityaceae, and their differences are distinguished by their decreasing primary xylem from Stenomyelon, to Calamopitys, to Diichnia. Additionally, Galtiera, Triichnia, and Bostonia are classified within the family by some authors, and Faironia and Chapelia may also have affinities with the family. Calamopitys Type species - Calamopitys saturnii • Dolichosperma (ovulate organ) • Eurystoma (ovulate organ) • Lyrasperma (ovulate organ) • Kalymma (foliage) • Sphenopteridium (foliage) ==References==