Age: Westphalian D to Lower Permian

Classification: FILICOPSIDA PICHI-SERMOLLI, MARATTIALES ENGLER & PRANTL.

Data base: In total 1,100 sterile and 500 fertile pecopterids from Sydney Basin, Nova Scotia Canada - Plzeň, Kladno-Rakovnik, Krkonoše Piemont, and Intrasudetic Basins, Czech Republic.

Preservation: Compression/impression, natural maceration, moderate maturation level (vitrinite reflectance Ro% 0.7%, reaching locally 1%). Cuticle is studied for the first time: recovery ratio better than 60%.

Unrevised Canadian pecopterid species:

P. abbreviata P. acadica P. arborescens P. candolleana P. clarkii P. cyathea

P. herdii P. lamuriana P. micromiltonii P. miltonii P. paleacea P. pectinata

P. polymorpha P. robbii P. sterzeliformis P. untia. (P. plumosa,

nonmarattialean).

Unrevised Czech pecopterid species:

Asterotheca alpina Acitheca ambigua Ast. arborescens Ast. aspidioides

Ast. candolleana Ast. cyathea Ast. densifolia Ast. hemitilioides Ast. imbricata

Ast. lepidorhachis Ast. miltonii Ast. nyranensis Ast. permica Ast. potoniei

Aci. polymorpha Ast. raconensis Ast. thuringiaca Ptychocarpus unitus.

We have larger fertile higher-order rachides specimens consisting of at least 2-order pinnae (ultimate and penultimate pinnae). Pinnules up to 10 mm long, 2-3 mm wide, attached to a rachis by entire base, or constricted; margins entire, straight, parallel, or slightly convex; midveins well developed; laterals veins simple or forked, straight or curved; ultimate and higher-order rachides striate, punctate (trichome bases), scaly, or with well-preserved tracheids.

Conclusion: Species are completely separable based on stomatal type, e.g. :
P. arborescens (paracytic), P. aspidioides (cyclocytic), P. polypodioides
(anomocytic). Most common is P. polymorpha (monocyclocytic).

In-situ spore recovery: 70%

Comparison: To known sporae dispersae

Groups: Laevigatosporites-Punctatosporites 11-38 μm
           Punctatosporites-Torispora 28-51 μm
           Punctatisporites 34-76 μm
           Cyclogranisporites 33-110 μm

           Most complete studied group to date: P. polymorpha
           Range: 34(82)116 μm
                Species: Verrucosisporites microtuberosus, Punctatisporites sp.
                            Cyclogranisporites sp.

Conclusion: Most conservative spore is from P. arborescens, most diverse from P. Polymorpha. It is not possible to determine pecopterid species from in situ spores. Distribution of fertile pinnules is similar to living ferns.