The description of this species by paleobotanists Kathleen Pigg, Steven Manchester, and Wesley Wehr was based on the study of thirty-four compression fossil specimens found at the Republic Flora.
22.
"Hsua robusta " is very well preserved in cherts and as compression fossils in the Xujiachong Formation, Yunnan, China . " Hsua deflexa " comes from the same formation, which is Early Devonian ( ~ Pragian to Emsian, around ).
23.
"Pertica quadrifaria " ( the type species of the genus ) was described in 1972 from compression fossils found in the Trout Valley Formation of northern Maine, USA . It was an upright plant which grew to perhaps as much as a metre ( 3 ft ) in height.
24.
The long specimen is a nearly complete compression fossil missing only a small section near the tip of the wing due to a break in the matrix, and having well preserved dark and light coloration . " Dinopanorpa " possesses an " R 1 " vein which almost reaches the apex of the wing and turns down towards the wing tip near its termination.
25.
As of 2015, six species of " Proceratium " had been described from fossils . " P . petrosum ", the first species to be described from a compression fossil, is from diatomite deposits of the Bol shaya Svetlovodnaya site on the Pacific coast of Russia . " P . eocenicum " is of similar age to " P . petrosum ", the only other species with a described fossil male.
26.
Description of the new genus was based on the study of over 20 compression fossil specimens from five fossil producing locations in the highlands . " Dinokanaga " and " Dinopanorpa ", currently the only known genera in the family Dinopanorpidae, are distinguished by a number of wing vein characters including lack of fine reticulated crossveins in " Dinopanorpa ", and the " Rs " vein branched 3-5 times in " Dinokanaga ".
27.
Description of the new species by Dr . Kathleen B . Pigg, Wes Wehr, and Stefanie Ickert-Bond was based on the study of 11 complete and 55 partial compression fossil specimens with the holotype specimen, number " SR 98-02-01 ", being housed in the type description of the species in the " International Journal of Plant Sciences " volume number 162 . and named the species " nastae " in honor of Charlotte G . Nast for her work on extinct and living members of the Trochodendrales.
