Phylogénie générale des Calliptéridiacées (Pteridospermopsida)

The systematic and palaeoecological value of foliage anatomy in Late Palaeozoic medullosalean seed-plants

“…The pinnules showed both lateral and apical meristematic growth resulting in pinnules expanding length-wise and width-wise (Zodrow & Cleal 1998). Laveine et al (1977) regarded Palaeoweichselia as most closely related to Callipteridium (Cyclopteridaceae), but in our view the lack of cyclopterids, the tendency to develop anastomosed veining and the anatomical data summarized here (notably the abundant epidermal hairs and the apparent lack of a Hamer & Rothwell (1988) correlated the anatomically preserved fragments of fronds borne on Late Pennsylvanian Medullosa endocentrica Baxter, 1949 stems with the adpression genus Eusphenopteris Gothan ex SimsonScharold. This is most unlikely as there is ample evidence that Eusphenopteris fronds were borne by lyginopteridalean plants ( van Amerom 1975;Shadle & Stidd 1975).…”

“…The morphology and architecture of these leaves have been extensively studied and forms an important (but not the only) character used in medullosalean supraspecific taxonomy (e.g. Gothan 1941;Laveine et al 1977Laveine et al , 1998Cleal & Shute 1991a;Cleal et al 1996Cleal et al , 1998Laveine 1996;Laveine & Belhis 2007). There have also been many monographic studies on the species taxonomy of these fossils (summarized by Cleal 2008) and they have been extensively used in biostratigraphy and palaeobiogeography (e.g.…”

Douropteris alvareziigen. nov., sp. nov., a new medullosalean pteridosperm from the Late Pennsylvanian of Portugal

“…However, overall, the closest comparison seems to be with the Cyclopteridaceae, especially with Margaritopteris . Margaritopteris is regarded as a typically Westphalian group of fronds with small pinnules, from which Callipteridium fronds were derived during very late Westphalian times through a process of growth retardation (Laveine et al, ). Douropteris gen. nov. evidently occurs in much younger macrofloras than Margaritopteris (e.g., Cleal, ; Germer & Engel, ; Josten & van Amerom, , ).…”

“…Margaritopteris (Laveine, Coquel, & Loboziak, 1977). Among comparable species of Callipteridium, Callipteridium costei ( The pinnules are also not closely spaced and marginally decurrent as seen in Callipteridium but are rather spaced and slightly retracted at basis; the midvein is also much broader, and the lateral veins are very irregular and stronger.…”

“…The Douro fossils also have similar shaped pinnules with dense veining and pinnule margins to Callipteridium (Weiss) Zeiller, emend. Wagner, , which is regarded as closely related to Margaritopteris (Laveine, Coquel, & Loboziak, ). Among comparable species of Callipteridium , Callipteridium costei (Zeiller) Wagner, from the upper Stephanian of Blanzy in the Massif Central (south‐central France) and Callipteridium virginianum (Fontaine & White) Wagner & Álvarez‐Vázquez, from the lower Dunkard of West Virginia (USA) have proximal pinnules (from lower parts of ultimate pinnae) with slightly undulate (or poorly lobed) and asymmetrical margins (Wagner & Álvarez‐Vázquez, , pl.…”