Home / Introductions to both Fossil and Recent Plant Taxa / Filicales

P.-c. An et al. (2022): New material of marattialean fern (Danaeopsis fecunda) from the Late Triassic in China with considerations on the tempo-spatial distribution pattern of Danaeopsis. Abstract, Geobios.

! Nan Crystal Arens, C. Strömberg and A. Thompson, Department of Integrative Biology, and Paleobotany Section, Museum of Paleontology (UCMP), University of California at Berkeley: Virtual Paleobotany. The Virtual Paleobotanical Laboratory, a comprehensive treatment of the fossil record of land plants, is divided into 12 chapters, lab I through XII. Each lab has a title page, a page with questions around the group or subject of study, a list of literature and links for further reading and exploration, and a virtual gallery of images from the lab. Go to: Sphenopsids and Ferns.

S.R. Ash (2001): The fossil ferns of Petrified Forest National Park, Arizona, and their paleoclimatological implications. Proceedings of the 6th Fossil Resource Conference.
Provided by the Internet Archive´s Wayback Machine.

! Lorna Ash & Heather Kroening, Department of Biological Sciences, University of Alberta: Instructional Multimedia, Multimedia Topics, Botany. Go to: Equisetum life cycle, Fern Life Cycle. See also here. Online and downloadable flash 4 movies. Excellent!

Centre for Plant Biodiversity Research, Australian National Herbarium, Canberra:
Fern Pages.
Pteridophytes: The Ferns and their Allies.
Websites outdated. Links lead to versions archived by the Internet Archive´s Wayback Machine.

! B. Axsmith et al. (2018): A Triassic Mystery Solved: Fertile Pekinopteris From the Triassic of North Carolina, United States. PDF file, Chapter 10; in: M. Krings, C.J. Harper, N.R. Cuneo and G.W. Rothwell (eds.): Transformative Paleobotany Papers to Commemorate the Life and Legacy of Thomas N. Taylor.
Note fig. 10.1: A suggested reconstruction of Pekinopteris auriculata.

Brian Axsmith (2007): A new species of the fern Cynepteris from the Late Triassic of Arizona: Implications for the early diversification of the Schizaeales. Abstract, Botany & Plant Biology 2007, Botanical Society of America, Chicago.

Brian J. Axsmith et al. (2001): A filmy fern from the Upper Triassic of North Carolina (USA). Open access, American Journal of Botany, 288: 1558-1567.
Note fig. Fig. 21: Suggested reconstructions of Hopetedia praetermissa.

L. Azevedo-Schmidt et al. (2024): Ferns as facilitators of community recovery following biotic upheaval. Open access, BioScience. https://doi.org/10.1093/biosci/biae022.
! Note figure 1: Time-calibrated fern phylogeny [shows additionally major extinction events with and without fern spike].
See also here.
"... The competitive success of ferns has been foundational to hypotheses about terrestrial recolonization following biotic upheaval, from wildfires to the Cretaceous–Paleogene asteroid impact (66 million years ago). Rapid fern recolonization in primary successional environments has been hypothesized to be driven by ferns’ high spore production and wind dispersal
[...] We propose that a competition-based view of ferns is outdated and in need of reexamination ..."

M. Barbacka et al. (2019): Ferns of the Lower Jurassic from the Mecsek Mountains (Hungary): taxonomy and palaeoecology. Free access, PalZ, 93: 151–185. See also here (in PDF), and there.

M. Barbacka et al. (2016): New data about Matonia braunii (Göppert) Harris from the Early Jurassic of Poland and its ecology. In PDF, Geological Quarterly, 60: 857–868. See also here.

! The Museum of Paleontology (UCMP), University of California, Berkeley: Introduction to the Pteridopsida, The Ferns.

A.C. Bippus et al. (2019): Fossil fern rhizomes as a model system for exploring epiphyte community structure across geologic time: evidence from Patagonia. Open access, PeerJ., 7: e8244.
Note figure 2E: Coprolite-filled gallery in osmundaceous leaf base.

C. Blanco-Moreno and Á.D. Buscalioni (2023): Revision of the Barremian fern Coniopteris laciniata from Las Hoyas and El Montsec (Spain): Highlighting its importance in the evolution of vegetation during the Early Cretaceous. Open access, Taxon. Note figure 8: Whole plant schematic reconstruction showing general habit and pinnule morphological diversity.
"... The similarities between these species [Coniopteris laciniata and Sphenopteris wonnacottii], observed in a study of a total of 66 hand specimens from both localities, indicate that they are conspecific ..."

C. Blanco-Moreno et al. (2022): Quantitative plant taphonomy: the cosmopolitan Mesozoic fern Weichselia reticulata as a case study. Open access, Palaeontology, 65.
Note figure 7: Taphonomic model proposed for Weichselia reticulata.
"... In the case of the specimens of Weichselia reticulata included in this work, charred remains are the most frequent preservation type ..."

C. Blanco-Moreno (2021): Preparation protocols for SEM visualization of charred fossil plants: the case of Weichselia reticulata pinnule anatomy. In PDF, Spanish Journal of Palaeontology, 36.
See also here.

C. Blanco-Moreno et al. (2020): New insights into the affinities, autoecology, and habit of the Mesozoic fern Weichselia reticulata based on the revision of stems from Bernissart (Mons Basin, Belgium). In PDF, 7: 1351-1372.
See also here.
Note figure 1: Representation of all the reconstructions of Weichselia reticulata to date.

C. Blanco-Moreno et al. (2019): A novel approach for the metric analysis of fern fronds: Growth and architecture of the Mesozoic fern Weichselia reticulata in the light of modern ferns. Open access, PLoS one, 14: e0219192. https://doi.org/10.1371/journal.pone.0219192.

J. Bodnar et al. (2018): Middle Triassic dipterid ferns from west-central Argentina and their relationship to palaeoclimatic changes. In PDF, Acta Palaeontologica Polonica, 63: 397–416.

! B. Bomfleur et al. (2017): The fossil Osmundales (Royal Ferns)—a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes Open access, PeerJ, DOI 10.7717/peerj.3433.

B. Bomfleur et al. (2015): Osmunda pulchella sp. nov. from the Jurassic of Sweden - reconciling molecular and fossil evidence in the phylogeny of modern royal ferns (Osmundaceae). Free access, BMC Evolutionary Biology, 15.

B. Bomfleur et al. (2014): Fossilized Nuclei and Chromosomes Reveal 180 Million Years of Genomic Stasis in Royal Ferns. In PDF, Science, 343. See also here.

! C. Kevin Boyce 2005): Patterns of segregation and convergence in the evolution of fern and seed plant leaf morphologies. PDF file, Paleobiology, 31: 117-140.

C.K. Boyce, (2001): PATTERNS OF MORPHOLOGICAL EVOLUTION IN THE LEAVES OF FERNS AND SEED PLANTS. Abstract, GSA Annual Meeting, November 5-8, 2001.
Snapshot provided by the Internet Archive´s Wayback Machine.

The British Pteridiological Society.
The Objects of the Society are to promote all aspects of pteridology by encouraging the appreciation, conservation, cultivation and scientific study of ferns, horsetails, clubmosses and quillworts through publications, meetings, the provision of grants and other appropriate means. Go to: An Introduction to Ferns.
Snapshot taken by the Internet Archive´s Wayback Machine. This introduction (to ferns and other pteridophytes) is based on a chapter from the book "A World of Ferns", by Josephine M. Camus, A. Clive Jermy & Barry A. Thomas, Natural History Museum Publications, London.

F.M. Cardillo & T.S. Samuels, Department of Biology, Manhattan College and the College of Mt. St. Vincent: WHITTAKER FIVE KINGDOM SYSTEM (1978) Plant Classification, KINGDOM IV - Plantae, Division Pterophyta, Order Filicales.
Snapshots taken by the Internet Archive´s Wayback Machine.

Sean Carrington, Department of Biological" Chemical Sciences, University of the West Indies (UWI), Barbados:
Ferns.
Still available via Internet Archive Wayback Machine.

! T.Y.S. Choo and I.H. Escapa (2018): Assessing the evolutionary history of the fern family Dipteridaceae (Gleicheniales) by incorporating both extant and extinct members in a combined phylogenetic study. Abstract, American Journal of Botany 105: 1–14. See also here (in PDF).

! T.Y.S. Choo et al. (2016): Monotypic colonies of Clathropteris meniscioides (Dipteridaceae) from the Early Jurassic of central Patagonia, Argentina: implications for taxonomy and palaeoecology. In PDF, Palaeontographica, B, 294: 85-109.
See also here.
Note text-figure 3: Artist reconstruction of a Clathropteris meniscioides colony.

! M.J.M. Christenhusz et al. (2011): A linear sequence of extant families and genera of lycophytes and ferns. PDF file, Phytotaxa, 19: 7-54.

! Michael Clayton, Department of Botany, University of Wisconsin, Madison: Instructional Technology (BotIT). Some image collections. Excellent! Go to:
Ferns.

! M.E. Collinson (2002): The ecology of Cainozoic ferns. In PDF, Review of Palaeobotany and Palynology, 119: 51-68.
See also here.
! Note table 1: Summary of key conclusions concerning the ecology of Cenozoic ferns.

E.P. Coturel et al. (2018): New species of osmundaceous fertile leaves from the upper Triassic of Argentina. In PDF, Acta Palaeobotanica, 58: 107–119. See also here.

Jim Croft, The Australian National Herbarium: A classification of the ferns and their allies - a work in progress. This classification of the genera of ferns and their allies is a loose, perhaps tenuous, concensus of a number of published systems, some of which are available on the web. It tries to reflect contemporary views on phylogenetic relationships and as such will change from time to time.
The link is to a version archived by the Internet Archive´s Wayback Machine.

S.H. Deng and P. Shang (2000): A Brief Review of the Mesozoic Filicopsida in China. PDF file.

D. Dietrich et al. (2000): Analytical X-Ray Microscopy on Psaronius sp.: A Contribution to Permineralization Process Studies. In PDF, Mikrochim. Acta, 133: 279-283.
See also here.

! W.A. DiMichele and T.L. Phillips (2002): The ecology of Paleozoic ferns. In PDF, Review of Palaeobotany and Palynology, 119: 143-159.
See also here.

! dmoz, the Open Directory Project:
Science: Biology: Flora and Fauna: Plantae:
Polypodiophyta. See also:
Earth Sciences: Paleontology: Paleobotany: Taxa.

X.Y. Du et al. (2021): Simultaneous diversification of Polypodiales and angiosperms in the Mesozoic. In PDF, Cladistics, 37.
See also here.
Note fig. 2: Summary chronograms of Polypodiales.
Fig. 5. Comparison of lineage through time plots for Polypodiales and angiosperms.
"... The estimated divergence patterns of Polypodiales and angiosperms converge to a scenario in which their main lineages were established simultaneously shortly before the onset of the Cretaceous Terrestrial Revolution ..."

J.Y. Dubuisson et al. (2009): Epiphytism in ferns: diversity and history. In PDF, Comptes rendus biologies. See also here (abstract).

Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, UK: Research activities,
Fern palaeobiology.
Now recovered from the Internet Archive´s Wayback Machine.

! Encyclopedia of Earth (supported by the Environmental Information Coalition and the National Council for Science and the Environment). Expert-reviewed information about the Earth. For everyone, please take notice. Provided by the Internet Archive´s Wayback Machine. The scope of the Encyclopedia of Earth is the environment of the Earth broadly defined, with particular emphasis on the interaction between society and the natural spheres of the Earth. Excellent! Go to:
! Fern.

H.J. Falcon-Lang (2005): Adpressed tree-fern trunks from the Early Pennsylvanian Joggins Formation of Nova Scotia. In PDF, Atlantic Geology, 41: 169–172.

M. Farahimanesh et al. (2014): The fern Stauropteris oldhamia Binney: New data on branch development and adaptive significance of the hypodermal aerenchyma. In PDF, C. R. Palevol., 13: 473–481.

T. Fujiwara et al. (2023): Evolution of genome space occupation in ferns: linking genome diversity and species richness. Open access, Annals of Botany, 131: 59–70.

Anthony G. Futcher, Columbia Union College, Maryland: Plant Diversity. A lot of facts about plant groups, fungi, plant-like protists, and monerans, including taxonomy, life cycles, general structure, and representative genera. Go to:
DIVISION FILICOPHYTA (=PTEROPSIDA).
Still available through the Internet Archive´s Wayback Machine.

J.C. Ghildiyal (ed.; 2019):
Pteridology, Gymnosperms and Palaeobotany. Lecture notes, in PDF, Uttarakhand Open University, India.
With many black and white illustrations.
Palaeobotany part starts on PDF page 254.

S.C. Gnaedinger and A.M. Zavattieri (2021): A new Late Triassic dipteridacean fern from the Paso Flores Formation, Neuquén Basin, Argentina. In PDF, Acta Palaeontol. Pol., 66.

G. Grimm et al. (2015): Using more than the oldest fossils: Dating Osmundaceae with three Bayesian clock approaches. Open access, Systematic Biology, 64: 396-405. See also here (in PDF).

G. Guignard et al. (2009): A dipteridaceous fern with in situ spores from the Lower Jurassic in Hubei, China. In PDF, Review of Palaeobotany and Palynology, 156: 104–115.

! C.H. Haufler (2014): Ever since Klekowski: Testing a set of radical hypotheses revives the genetics of ferns and lycophytes. Free access, American Journal of Botany, 101: 2036-2042.

Xiaoyuan He et al. (2010): Anatomically Preserved Marattialean Plants from the Upper Permian of Southwestern China: The Trunk of Psaronius laowujiensis sp. nov. PDF file, Int. J. Plant Sci 171: 662-678.

F. Herrera et al. (2017): An exquisitely preserved filmy fern (Hymenophyllaceae) from the Early Cretaceous of Mongolia. Free access, American Journal of Botany, 104: 1370-1381. See also here (in PDF).

Monte Hieb and Harrison Hieb, Plant Fossils of West Virginia: Ferns and Seed Ferns. Fossil Plants of the Middle Pennsylvanian Period. Go to: How to tell Neuropteris from Pecopteris or Alethopteris?
Snapshots taken by the Internet Archive´s Wayback Machine.

Josef Hlasek: Photo Gallery wildlife pictures, Plants. Go to: Plants - Pteridophyta.

G. Holzhüter et al. (2003): Structure of silica in Equisetum arvense. In PDF, Anal. Bioanal. Chem., 376: 512-517.
Snapshot taken by the Internet Archive´s Wayback Machine.

A. Jarzynka (2016): Fossil flora of Middle Jurassic Grojec clays (southern Poland). Raciborski's original material reinvestigated and supplemented. II. Pteridophyta. Osmundales. In PDF, Acta Palaeobotanica, 56: 183–221. See also here.

SHARON D. KLAVINS et al.: MATONIACEOUS FERNS (GLEICHENIALES) FROM THE MIDDLE TRIASSIC OF ANTARCTICA. Abstract, Journal of Paleontology, 2004; v. 78; no. 1; p. 211-217.

John A. Knouse, Athens, Ohio: Ferns and Fern Allies. See also: Fern Book Bibliography. Periodicals and books dedicated to pteridology.

E. Kustatscher et al. (2012): Danaeopsis Heer ex Schimper 1869 and its European Triassic species. Abstract, Review of Palaeobotany and Palynology, 183: 32-49.

E. Kustatscher & J.H.A. van Konijnenburg-van Cittert (2011): The ferns of the Middle Triassic flora from Thale (Germany). Abstract, Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 261: 209-248.

A. Lakehal et al. (2023): Specification and evolution of lateral roots. In PDF, Current Biology.
See also here.
"... we point out that positional control of lateral root stem cell specification has not been the prevailing mechanism among all plants and discuss the process in ferns ..."
Note figure 1: Evolution of root branching in land plants.

B.B. Lamont et al. (2022): Gondwanan origin of the Dipterocarpaceae-Cistaceae-Bixaceae is supported by fossils, areocladograms, ecomorphological traits and tectonic-plate dynamics. Free access, Frontiers of Biogeography, 14.

S. Lehtonen et al. (2020): Exploring the phylogeny of the marattialean ferns. Open access, Cladistics.
Note fig. 4: Parsimony-dated phylogeny and Bayesian historical biogeography of the marattialean ferns.
"... We resolved the fossil genera Marattiopsis, Danaeopsis and Qasimia as members of the monophyletic family Marattiaceae, and the Carboniferous genera Sydneia and Radstockia as the monophyletic sister of all other marattialean ferns. ..."

S. Lehtonen (2011): Towards Resolving the Complete Fern Tree of Life. In PDF.

D. Li et al. (2022): Leaf scar and petiole anatomy reveal Pecopteris lativenosa Halle is a marattialean fern. In PDF, Geobios, 72–73: 37-53.
See also here.
"... reveal that Pecopteris lativenosa possesses Caulopteris-type stem, stewartiopterid petioles and rachises, and belongs to the Paleozoic Marattiales family Psaroniaceae. ..."

! F.-W. Li et al. (2018): Fern genomes elucidate land plant evolution and cyanobacterial symbioses. Open access, Nature Plants, 4: 460–472.

Y.-F. Li et al. (2024): New material of Coniopteris simplex from the Middle Jurassic of the Ordos Basin, Inner Mongolia, China and implications on its spatio-temporal distribution and paleogeography. Free access, Journal of Palaeogeography.

! F. Löcse et al. (2021): Paläobotanische Kostbarkeiten aus den Versteinerten Wäldern von Nová Paka (Tschechien) und Chemnitz (Deutschland)&xnbsp;– Originale zu Stenzel (1889, 1906) und Rudolph (1906) in der paläobotanischen Sammlung der Geologischen Bundesanstalt in Wien. PDF file, in German. Jb. Geol. B.-A., 159: 289–313. See also here.
About old findings of Psaronius tree ferns and Medullosa seed ferns: Ankyropteris brongniartii, Asterochlaena laxa, Asterochlaena ramosa.

The Los Angeles International Fern Society: FERN BASICS.

Department of Botany, University of Wisconsin, Madison:
Plant Systematics Collection. This web site provides structured access to a teaching collection of plant images representing over 250 families and 1000 genera of vascular plants. Go to:
Phylum Pterophyta. The Ferns.
Still available via Internet Archive Wayback Machine.

Eugene Marinus, Department of Biodiversity and Conservation Biology, University of the Western Cape: Ferns in the Carboniferous Period (Powerpoint presentatation).
Now recovered from the Internet Archive´s Wayback Machine.

M.R. May et al. (2021): Inferring the Total-Evidence Timescale of Marattialean Fern Evolution in the Face of Model Sensitivity. Free access, Systematic Biology, syab020, https://doi.org/10.1093/sysbio/syab020. See also here.

! Palaeobotanical Research Group, Münster, Westfälische Wilhelms University, Münster, Germany. History of Palaeozoic Forests, FOSSIL FERNS. Link list page with rankings and brief explanations. Images of Psaronius, Psaronius melanedrus, Tietea singularis, Pecopteris, Pecopteris cyathea, Pecopteris oreopteridia, Pecopteris arborescens, P. (Senftenbergia) plumosa, Asterotheca, Scolecopteris, Scolecopteris (P.) mertensiodes, Ptychocarpus (P.) unita, Ptychocarpus (P.) unita, Senftenbergia crenata, Alloiopteris coralloides, Anachoropteris involuta, Ankyropteris, Botryopteris, Etapteris, Oligocarpia gutbieri, Pseudosporochnus, Saccopteris cristata, Stauropteris.
Snapshot taken by the Internet Archive´s Wayback Machine.

! A.G. Murdock (2008): Phylogeny of marattioid ferns (Marattiaceae): inferring a root in the absence of a closely related outgroup. Free access, American Journal of Botany, 95: 626-641.

Dennis C. Murphy, ("Devonian Times", a paleontology web site featuring Red Hill): Who's Who at Red Hill, Gillespiea randolphensis (Early "Fern"), and Rhyacophyton ceratangium (Early "Fern"). See also: More about Ferns.

Nederlandse Varenvereniging (in Dutch):
Varenlinks.

S.V. Naugolnykh (2013): Permian ferns of western Angaraland. In PDF, Paleontological Journal, 47: 1379–1462.
See likewise here.

Karl J. Niklas & Tom Silva, Department of Plant Biology, Cornell University, Ithaca, NY: Introductory Botany. Review Topics, Review of Algae, Bryophytes, Pteridophytes- Common Links Between Each Group of Plants.
These expired links are available through the Internet Archive´s Wayback Machine.

J.H. Nitta et al. (2022): An open and continuously updated fern tree of life. Free access, Front. Plant Sci., 13: 909768. doi: 10.3389/fpls.2022.909768.

! C.N. Page (2002): Ecological strategies in fern evolution: a neopteridological overview. Abstract, Review of palaeobotany and palynology, 119: 1-33. See also here and there (in PDF).

Paläontologische Gesellschaft:
Fossil of the Year 2023.
About Medullosa stellata and fronds of the type Alethopteris schneideri. More information from the website in German.

! C.J. Phipps et al. (1998): Osmunda (Osmundaceae) from the Triassic of Antarctica: an example of evolutionary stasis. Free access, American Journal of Botany, 85: 888-895.

A.R.G. Plackett et al. (2015): Ferns: the missing link in shoot evolution and development. Front. Plant Sci., 6.

! Plantillustrations.org (by Max Antheunisse and Jan Koeman).
Plantillustrations.org is a completely non-commercial website. On top you see 2 search boxes at the right. The white one is for entering scientific names, the grey one for vernacular ones.
You may likewise navigate from:
the List of currently included artists.
Don't miss the useful link list

! PPG I (2016); This project was organized by Eric Schuettpelz: A community-derived classification for extant lycophytes and ferns. Free access, Journal of Systematics and Evolution.

! K.M. Pryer and E. Schuettpelz (2009): Ferns. PDF file, In: S.B. Hedges and S. Kumar (eds.): The Timetree of Life (see here).

! Kathleen M. Pryer, Alan R. Smith and Carl Rothfels (2009): The Tree of Life Web Project, Ferns, Polypodiopsida Cronquist, Takht. & Zimmerm. 1966.

! K.M. Pryer et al. (2004): Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. Open access, American Journal of Botany, 91: 1582-1598.

K.M. Pryer et al. (2001): Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants. Abstract, Nature, 409: 618-622.
! See also here (in PDF).

! Kathleen M. Pryer, Department of Botany, The Field Museum, Chicago, and Alan R. Smith, University Herbarium, University of California, Berkeley (part of Tree of Life, the University of Arizona): Leptosporangiate Ferns. Next to the flowering plants, the leptosporangiate ferns are the most diverse group of living land plants. Recent estimates place their diversity at about 12,000 species in 300 genera.
The link is to a version archived by the Internet Archive´s Wayback Machine.

J. Pšenièka and E.L. Zodrow (2006, starting on PDF page 18 (Sec1:16)): Pennsylvanian fern taxonomy: New approach through the compact model. In PDF, Newsletter on Carboniferous Stratigraphy, 24.

The Pteridophyte Phylogeny Group (PPG), Smithsonian National Museum of Natural History. PPG aims to produce, and continually update, a community-derived classification for lycophytes and ferns - based on the understanding of phylogeny - at the family and genus levels.

H. Qian et al. (2023): Spatial patterns and climatic drivers of phylogenetic structure for ferns along the longest elevational gradient in the world. Open access, Ecography, doi: 10.1111/ecog.06516 2023: e06516.

Y. Qu et al. (2019): Evidence for molecular structural variations in the cytoarchitectures of a Jurassic plant. Free access, Geology, 47: 325–329.

P.M. Rees (1993): Dipterid ferns from the Mesozoic of Antarctica and New Zealand and their stratigraphical significance. In PDF, Palaeontology, 36: 637-656.
! Note text-fig. 2: Schematic diagram explaining frond-, rachis and pinna terminology.

L. Regalado et al. (2017): A fossil species of the enigmatic early polypod fern genus Cystodium (Cystodiaceae) in Cretaceous amber from Myanmar. Scientific Reports, 7.

J.W.F. Reumer et al. (2020): The Rhaetian/Hettangian dipterid fern Clathropteris meniscioides Brongniart found in erratics in the eastern Netherlands and adjacent Germany. In PDF, Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 295: 297–306.

M.A. Romanova et al. (2023): All together now: Cellular and molecular aspects of leaf development in lycophytes, ferns, and seed plants. In PDF, Front. Ecol. Evol., 11: 1097115. doi: 10.3389/fevo.2023.1097115. See also here.
"... To understand leaf origin in sporophytes of land plants, we have combined the available molecular and structural data on development of leaves with different morphologies in different plant lineages ..."
Note figure 10: Phylogenetic tree for land plants and their structural and regulatory innovations.
Figure 11: Hypothesized scenario for the evolutionary emergence of leaves in lycophytes.

! R. Rößler (2000): The late Palaeozoic tree fern Psaronius - an ecosystem unto itself. In PDF, Review of Palaeobotany and Palynology, 108: 55-74.

! C.J. Rothfels et al. (2012): A revised family-level classification for eupolypod II ferns (Polypodiidae: Polypodiales). In PDF, Taxon, 61: 515-533.

G.W. Rothwell et al. (2002): Ashicaulis woolfei n. sp.: additional evidence for the antiquity of osmundaceous ferns from the Triassic of Antarctica. Open access, American Journal of Botany, 89: 352-361.

Scott Russell, Department of Botany and Microbiology, University of Oklahoma, College of Arts and Sciences, Norman: Morphology of Vascular Plants. Lecture notes, chiefly PDF files, including palaeobotany topics.
These expired websites are now available through the Internet Archive´s Wayback Machine.
See also here.

H. Schneider (2019): Celebrating Research Devoted to Seed-Free Land Plants. Free access, Journal of Systematics and Evolution, 57: 303-304. See also here (table of contents, free access).

H. Schneider et al. (2016): Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns. In PDF, Perspectives in Plant Ecology, Evolution and Systematics, 18: 70–78. See also here (abstract).

H. Schneider and E. Schuettpelz (2016): Systematics and evolution of lycophytes and ferns: Editorial. Abstract, Journal of Systematics and Evolution, 54: 561–562. See also here (in PDF).

! H. Schneider et al. (2004): Ferns diversified in the shadow of angiosperms. In PDF, Nature, 428: 553–557. See also here (abstract).
! Note figure 1: Phylogenetic chronograms of ferns (a) and angiosperms (b), and proportional lineages-through-time (LTT) plots for angiosperms and polypods (c).
"... we report divergence time estimates for ferns and angiosperms based on molecular data, with constraints from a reassessment of the fossil record. We show that polypod ferns (>80% of living fern species) diversified in the Cretaceous, after angiosperms ..."

H. Schneider et al. (2002): Evolution of vascular plant body plans: a phylogenetic perspective. PDF file, Pp. 330–364, in: Cronk, Q. C. B., Bateman, R. M. & Hawkins, J. A. (eds.), Developmental Genetics and Plant Evolution. Taylor & Francis, London.
See also here.

Harald Schneider, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Georg-August-Universität, Göttingen: Vielfalt der Farne entwickelte sich im "Schatten" der neuen Blütenpflanzen (in German).
Now recovered from the Internet Archive´s Wayback Machine.

! E. Schuettpelz and K.M. Pryer (2008): Fern phylogeny. In PDF.

E. Schuettpelz and K.M. Pryer (2007): Fern phylogeny inferred from 400 leptosporangiate species and three plastid genes. In PDF, Taxon, 56: 1037–1050. See also here (abstract).

! C.S. Shi et al. (2013): Characterization of the stem anatomy of the Eocene fern Dennstaedtiopsis aerenchymata (Dennstaedtiaceae) by use of confocal laser scanning microscopy. Free access, American Journal of Botany, 100: 1626–1640.

J.-P. Shu (2022): Phylogenomic Analysis Reconstructed the Order Matoniales from Paleopolyploidy Veil, Open access, Plants.

J.E. Skog (2001): Biogeography of Mesozoic leptosporangiate ferns related to extant ferns. In PDF, Brittonia, 3: 236-269.

Andrew C. Scott et al. (2009): Scanning Electron Microscopy and Synchrotron Radiation X-Ray Tomographic Microscopy of 330 Million Year Old Charcoalified Seed Fern Fertile Organs. PDF file, Microsc. Microanal., 15: 166-173.
See figure 4, SEM of charcoalified pteridosperm ovule from the mid-Mississippian (Carboniferous). See also here.

M.K.A. Smith et al. (2015): Mesozoic Diversity of Osmundaceae: Osmundacaulis whittlesii sp. nov. in the Early Cretaceous of Western Canada. Abstract, Journal of Plant Sciences, 176: 245-258. See also here (in PDF).

! A.R. Smith et al. (2008): Fern classification. In PDF.

! A.R. Smith et al. (2006). A classification for extant ferns. PDF file, Taxon 55: 705-731.

! K.L. Sporne (1962): The morphology of pteridophytes; the structure of ferns and allied plants (PDF file). See also here.

Hans Steur, Ellecom, The Netherlands: Hans´ Paleobotany Pages. Plant life in the Silurian, Devonian, Carboniferous, Permian and Cretaceous. Go to: The tree fern Psaronius, and The tree fern Tempskya.

Ralph E. Taggart, Department of Botany and Plant Pathology/Department of Geological Sciences at Michigan State University, East Lansing:
BOT335 Lecture Schedule.
Psaronius: a Carboniferous tree-fern;
Snapshots taken by the Internet Archive´s Wayback Machine.

M. Taghi Badihagh and D. Uhl (2019): The first occurrence of Phlebopteris dunkeri and P. woodwardii (Matoniaceae) from the middle Jurassic of Iran, In PDF, # Journal of Palaeogeography. See also here.

! W. Testo and M. Sundue (2016): A 4000-species dataset provides new insight into the evolution of ferns. Abstract, Molecular Phylogenetics and Evolution, 105: 200–211. See also here (in PDF).

Herbarium, Department of Biology, Texas A&M University, College Station: Field Systematic Botany, PTERIDOPHYTES (ferns and allies). An overview and link list.

! B.A. Thomas and C.J. Cleal (2021): Pteridophytes as primary colonisers after catastrophic events through geological time and in recent history. Open access, Palaeobiodiversity and Palaeoenvironments.
"... This paper brings together information on the reasons for pteridophyte success in colonising barren land, and examples taken from both the historic and geological records. ..."

N. Tian et al. (2016): A systematic overview of fossil osmundalean ferns in China: Diversity variation, distribution pattern, and evolutionary implications. Abstract, Palaeoworld, 25: 149–169. See also here (in PDF).

C. Trevisan et al. (2022): Coniopteris antarctica sp. nov. (Pteridophyta) and associated plant assemblage from the Upper Cretaceous of Rip Point, Nelson Island, Antarctica. In PDF, Cretaceous Research, 136.
See also here.

J.H.A. Van Konijnenburg-van Cittert et al. (2020): Ferns and fern allies in the Rhaetian flora of Wüstenwelsberg, Bavaria, Germany. In PDF, Review of Palaeobotany and Palynology 273. See also here.

J.H.A. van Konijnenburg-van Cittert et al. (2018): Phialopteris heterophylla (Sternberg ex Göppert, 1836) comb. nov., A rare schizaeaceous fern from the Early Jurassic of Bavaria. In PDF, Fossil Imprint, 74: 5–64.

! J.H.A. Van Konijnenburg-Van Cittert (2002): Ecology of some Late Triassic to Early Cretaceous ferns in Eurasia. In PDF, Review of Palaeobotany and Palynology, 119: 113-124.

A. Vasco et al. (2016): Challenging the paradigms of leaf evolution: Class III HD-Zips in ferns and lycophytes. In PDF, New Phytologist, 212: 745–758. See also here.

! A. Vasco et al. (2013): The evolution, morphology, and development of fern leaves. In PDF, Frontiers in plant science.
This expired link is now available through the Internet Archive´s Wayback Machine.
See also here (abstract).

M. Vicent et al. (2014): Insight into fern evolution: a mechanistic approach to main concepts and study techniques. In PDF, Botanica Complutensis, 38: 7-24. See also here.

J. Wang et al. (2021): Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation: Open access, Proceedings of the National Academy of Sciences, 118, e2013442118.
Note fig. 2: Reconstruction of the aerial parts of Paratingia wuhaia from the early Permian of China.

D.-M. Wang et al. (2015): Leaf evolution in early-diverging ferns: insights from a new fern-like plant from the Late Devonian of China. Annals of Botany.

Y. Wang et al. (2015): Fertile structures with in situ spores of a dipterid fern from the Triassic in southern China. In PDF, Journal of Plant Research, 128.

Thomas R. Warne and Leslie G. Hickok, Department of Botany, University of Tennessee Knoxville, TN (supported by the National Science Foundation (NSF-DUE): C-Fern. Ceratopteris as a model plant system.

! J. Watson (2010; start on PDF page 72): Pteridophytes in the English Mesozoic. In PDF, Pteridologist.

R. Weber (2008): Phlebopteris (Matoniaceae) en el Triásico y Jurásico de México (PDF file, in Spanish). In R. Weber (ed.): Plantas triásicas y jurásicas de México: Universidad Nacional Autónoma de México, Instituto de Geología, Boletín, 115: 85-115.
Available through the Internet Archive´s Wayback Machine.
See also here.

Biology Department, Western Washington University, Bellingham, Washington:
! Seedless Vascular Plants (Ferns, etc.) Powerpoint presentation. See also here, or there.

Wikipedia, the free encyclopedia: Fern. See also here (in German).
Fern spike.

A. Yañez et al. (2023): Fertile Goeppertella from the Jurassic of Patagonia: mosaic evolution in the Dipteridaceae-Matoniaceae lineage. Open access, AoB Plants, 15: 1–19.
Note figure 3: Hypothetical reconstruction of Goeppertella unicyclica.

! W. Zhou et al. (2022): Diodonopteris virgulata sp. nov., a climbing fern from the early Permian Wuda Tuff Flora and its paleoecology. In PDF, Review of Palaeobotany and Palynology, 304.
See also here.

N. Zhou et al. (2021): Pattern of vegetation turnover during the end-Triassic mass extinction: Trends of fern communities from South China with global context. Free access, Global and Planetary Change, 205.

W.-M. Zhou et al. (2021): An upright psaroniaceous stump and two surrounding pecopteroids from the early Permian Wuda Tuff Flora. In PDF, Palaeoworld, 30: 451-460.
See also here.
Note figure 2: Morphology and measurements of the Psaronius stump.