A new sigillarian megaspores species Sublagenicula echinata sp. nov., preserved in situ within a volcanic ash bed from the Early Permian (Asselian) Taiyuan Formation, Wuda Coalfield, Inner Mongolia is proposed. The species is distinguished by a circular to subtriangular amb, prominent trilete rays and a pyramidal subgula. The proximal-distal body bears a unique combination of laevigate, granulate, and echinate sculpture, with the echinate processes being mamillate at base and apically constricted. Analysis of the in situ megaspore population reveals a consistent range of intraspecific morphological variation, which is independent of developmental context of spores and found across the strobili. This discovery represents the first and youngest in-situ record of Sublagenicula, confirming its biological link to Sigillaria and significantly expanding the known paleogeographic distribution and diversity of this genus in the Permian of Cathaysia.

Gigantopterids are predominantly distributed in the Permian of the low-latitude Cathaysian and Euramerican floral provinces, with rare survivals into the Early Triassic. They are characterized by megaphyllous leaves with high-order anastomosing venation that have convergent physiognomic resemblance to Cenozoic-Recent angiosperm leaves. However, many questions regarding their systematic affinities, morphology, and paleoecology remain largely unresolved. Here we report an autochthonous to parautochthonous, gigantopterid-dominated assemblage from the Upper Shihhotse Formation (=Shangshihezi Formation) in Luoyang, Henan Province, China. This assemblage belongs to the regional Yuzhou Flora, renowned for exceptional diversity and preservation of the middle and late Cathaysian Flora. New materials are identified as Pinnagigantonoclea guizhouensis (Gu et Zhi) Yang, providing morphological evidence of its creeping habit under tropical, high-precipitation conditions. The paleogeographic distributions of gigantopterids show that they were stenotopic, restricted to tropical coastal and island environments, and that they underwent a gradual expansion from coastal to near-coastal inland areas from the early to late Permian. Diversity of gigantopterids at individual localities, and species and genus numbers decline significantly from the Kungurian to the Wordian, possibly reflecting a middle Permian gap in the fossil record. During the late Permian, a land bridge connecting the Qiangtang and Arabian plates facilitated floral interchange, enabling gigantopterid dispersal from the South China Plate to the Middle East.

A new Kasimovian cordaitalean fossil axis, Shanxioxylon yangquanense sp. nov., is described from the Pennsylvanian Benxi Formation of Yangquan City, Shanxi Province, North China. The axis is composed of the pith, primary xylem, secondary xylem, phloem and cortex. The pith is septate or hollow, heterogeneous, with parenchyma cells and spherical secretory cavities distributed at the periphery. Cauline bundles are endarch. Leaf traces are mesarch, mostly diverging from pith margin as single bundle. Double leaf traces are present occasionally. The secondary xylem is pycnoxylic, featured by dominantly araucarian uniseriate radial tracheid pits and cupressoid cross-field pitting. The fossil axis represents the third and oldest species of Shanxioxylon (Tian et Wang) Wang et al. from the upper Paleozoic of Cathaysia, indicating that this endemic cordaitalean genus had evolved by at least the Kasimovian in North China. Shanxioxylon yangquanense sp. nov. is proposed to have lived as an arborescent form in the clastic wetland of stream riparian zones under a perhumid climate based on its great morphological and anatomical similarities to Agathoxylon leei (Sze) Wang et Wan from the same fossil interval.

A marattialean fern with organically connected fertile and vegetative parts is described from the early Permian Wuda Tuff Flora in Inner Mongolia, China. The tripinnate fronds have typical pecopterid vegetative pinnules but do not match any known Pecopteris species. The fertile pinnules are distinctly different from the vegetative ones, with an extended margin that forms long lobes, bending abaxially to cover the synangia. Each fertile pinnule bears 7-10 ovate, pedicellate synangia arranged abaxially in a single row to either side of the midvein, with each synangium composed of 3-4 elongate sporangia. The sporangium wall is three-layered, with the outermost layer differentiated into four areas peripherally to provide differing mechanical strengths and facilitate dehiscence. In situ spores are trilete and 39-45 mu m in diameter. These combined characteristics place the studied fern in the Scolecopteris Minor group of the Psaroniaceae family. The new species, Scolecopteris oxydonta sp. nov., exhibits many evolutionarily advanced traits such as modified fertile pinnules, unvascularized pedicels, differentiated sporangium walls, and a specialized opening mechanism. However, S. oxydonta sp. nov. also retains evolutionarily primitive traits including relatively large spores. S. oxydonta sp. nov. represents the fourth Scolecopteris species recognized from the Wuda Tuff Flora, adding to the growing body of evidence on the morphology and diversity of marattialean plants from the Permian of Cathaysia. We also consider preservational differences among the specimens and suggest that the composition and morphology of fertile pinnules produced closed microenvironments during early diagenesis that facilitated localized anatomical preservation.

Stipules are specialized appendages borne at the leaf base with roles as diverse as sheltering of delicate growing tissues from environmental exposure, vegetative propagation and dispersal, and modification into climbing hooks or protective spines. Stipules are widely present in extant vascular plants, but their origins in geological history remain obscure and must have involved convergent evolution more than once, perhaps as early as the late Paleozoic emergence of forested terrestrial ecosystems. Based on extraordinary collections from the early Permian Wuda Tuff Flora, the earliest known stipule structure in the plant kingdom has been identified in marattialean tree ferns Psaroniaceae, the dominant element of Permo-Carboniferous wetland forests. Psaroniaceous stipules are consistent with protection of juvenile fronds and the stem apex as well as retention of a functional role in mature and withered fronds. Furthermore, the continued and perhaps indeterminate growth and the fully laminated stipules invite speculation of a potential role in vegetative propagation following detachment from the parent frond. However, no direct fossil evidence of stipules acting as vegetative propagules is currently available.

A new genus of bisporangiate sigillarian strobili Bisigillariostrobus with the only species Bisigillariostrobus prolificus is proposed. A large number of strobili originates from the Wuda area in Inner Mongolia, China, fossilized during the early Permian period. The specimens are preserved in volcanic tuff, allowing for the study of both morphology and anatomy. The strobili are pedunculate, cylindrical with helically arranged sporophylls. The megasporophylls are on the basal part and microsporophylls on the apical part with each retaining single adaxial sporangium. The sporophylls have a long pedicel and lateral alations, and abaxial heel on the transitional part and a long distal lamina. In situ megaspores are of the Sublagenicula nuda type and microspores are assigned to the dispersed miospore species Crassispora kosankei. Some ontogenetic stages of strobili and megaspores are described. Sublagenicula and Crassispora-producing sigillarians are given and compared with the current species.

Ancient forests preserved in growth position by rapid sedimentological burial (T-0 assemblages) constitute exceptionally valuable fossil repositories, especially those covered by fine-grained volcanic ash (tuff) that may preserve plant morphology and anatomy in high-fidelity. This study documents the frond morphology and anatomy of a new species, Polymorphopteris mei sp. nov. from the Wuda Tuff Flora, an in situ fossil forest Lagerst & auml;tte of early Permian age from Inner Mongolia, China preserved by volcanic ash. The frond of P. mei is tripinnate, composed of three types of penultimate pinnae and three types of ultimate pinnae. Anatomical features of the frond and penultimate rachises correspond to the stewartiopterid-type leaf trace configuration characteristic of the Marattiales fern evolutionary stem-group family Psaroniaceae. Pyrite-infilled pore-like structures within the rachises are identified as possible evidence of post-mortem fungal action. This study enhances our understanding of the morphology, anatomy, systematic affinity and taphonomy of P. mei and its ecological context in the early Permian peat-forming communities of Cathaysia.

BackgroundStipules are specialized appendages borne at the base of a leaf petiole and may perform a variety of functions including sheltering delicate growing tissues from environmental exposure, facilitating vegetative propagation and dispersal, and providing climbing hooks or protective spines. While stipules are widespread in extant angiosperms and a few fern groups, their origins in geological history remain poorly understood. This study critically reconsiders the absence of stipules in the ancestry of Marattiales.ResultsBased on extraordinary collections from the early Permian Wuda Tuff Flora, we report, for the first time, aphlebia fossils organically attached to psaroniaceous petioles. The psaroniaceous aphlebiae are homologous to marattiaceous stipules, as evidenced by numerous shared characteristics. Functionally, psaroniaceous stipules appear to shelter juvenile fronds and the stem apex, with a continued role in mature fronds. Furthermore, their continued and potentially indeterminate growth, along with their fully laminated structure, suggests a possible role in vegetative propagation after detachment from the parent frond. However, no direct fossil evidence of stipules acting as vegetative propagules is currently available.ConclusionsOur discovery provides unprecedented view of stipules in psaroniaceous tree ferns. The discovery of psaroniaceous stipules is significant, as it represents the earliest known stipule in the plant kingdom and underscores their multifunctional roles in plant development.

The early Permian zygopterid fern Nemejcopteris haiwangii was originally reconstructed as a ground-cover plant with a rhizomatous stem and erect phyllophores bearing primary pinnae aligned perpendicularly to the plane of the frond. While previous studies have described prickle structures in N. haiwangii that could have facilitated climbing, direct evidence for this behavior has been lacking in the palaeontological record. In this study, we present several well-preserved fossils showing clear interactions between the fronds of N. haiwangii and the trunks of Psaronius, providing solid evidence of its climbing behavior on Psaronius tree hosts. The prickle structures on the axes of N. haiwangii suggest a hook-climbing strategy, but the small size and low flexibility of these structures imply a relatively weak climbing ability, likely insufficient for reaching the forest canopy. Given the palaeoenvironmental and palaeoecological contexts, we propose that the shift from a ground-cover to a climbing growth form in N. haiwangii was an adaptive response to periodic submergence in peat-accumulating environments, rather than a strategy for accessing sunlight in a closed-canopy forest.

Premise of research. Reconstructed whole plants provide high-quality information on extinct plant species comparable to the morphological and anatomical information available from living plants but are rarely recognized from the fossil record. On the basis of fossils preserved under a blanket of ash in the earliest Permian-aged Wuda Tuff Flora, Inner Mongolia, China, we reconstruct a new whole-plant species of marattialean tree fern. Methodology. The reconstruction is based on anatomical and morphological information, including an almost entire fossil tree. Pivotal results. Scolecopteris libera is reconstructed as an arborescent tree with an apical crown of fronds above a zone of leaf scars from shed fronds. This species has stems of the Psaronius type, rachises of the stewartiopterid type, leaf scars of the Caulopteris type, small aphlebiae, vegetative leaves of the Pecopteris type, and fertile foliage of the Scolecopteris type bearing Cyclogranisporites microspores. Conclusions. Scolecopteris libera represents the most completely reconstructed in situ preserved Paleozoic marattialean fern and is the first marattialean plant reconstructed from the Wuda Tuff Flora and the Permian Cathaysian floras. Combined with geological information, our reconstruction allows us to interpret the S. libera plant as a middle-story tree fern growing in a peat-forming forest that developed on a low-lying delta plain under a humid, tropical climate, therefore occupying the niche and habitat preferred by the majority of extant marattialean tree ferns. Among late Paleozoic Marattiales, species of the family Psaroniaceae are distinguished by features of their fertile organs that evolved faster than their more evolutionary conservative vegetative organs, including stems, rachises, and leaves.

The recognition of plant biogeographic ranges over time and migration routes is crucial for understanding ancient global plate tectonic configurations. This paper deals with a new fossil plant from the uppermost part of the Taiyuan Formation (earliest Asselian) in the Wuda Coalfield, Inner Mongolia, China. It has a taeniopterid morphology comprising strap-shaped leaves with a prominent midrib and arching secondary veins, and it exhibits dimorphism between its fertile and vegetative leaves. The fertile leaf has a slightly lobed margin, with each lateral vein terminating in a marginal lobe that bears a synangium. Each synangium consists of primarily two, occasionally three, oval sporangia. Based on these distinctive characteristics it is identified as a new species of Ilfeldia. Previously, Ilfeldia had a highly restricted record in the Upper Pennsylvanian of Portugal and Germany into the lower Permian of Germany. The sedimentary and floral context suggests Ilfeldia was a xerophilous element that underwent long-distance dispersal during the Late Pennsylvanian to earliest Asselian, migrating from Gondwana (Iberia) to Cathaysia (North China) via Euramerica (Eastern Avalonia). The palaeogeographical distribution over time of Ilfeldia supports the continental model of the Wegenerian Pangaea configuration and underscores the continental connection between Euramerica and Cathaysia in the Late Pennsylvanian.

Two partly anatomically preserved axes parallelly situated on a slab collected from an in situ volcanic ash bed called "Bělka" of the Whetstone Horizon, Kladno Formation (Pennsylvanian), Czech Republic, were studied in detail. Anatomically, both axes possess a C-shaped xylem strand with protoxylem tracheids situated on the convex side, demonstrating an inversicatenalean-type anachoropterid affiliation. They are further suggested to belong to one biological species, as they share a number of similar characteristics and common structures. Systematically, one of the two studied axes retains a primitive form of foliar anatomy with the oldest known anachoropterid plant (Anachoropteris sp.) in having two rather short lateral arms compared to the long median region. Although lacking foliage information, both axes likely belong to the rachis part of Discosoropteris zlatkokvacekii Pšenička, Zhou, Boyce, Votočková Frojdová, Bek and Wang, a fern species that was recently established based on the same slab where the two studied axes were preserved. Such a combination may further indicate the presence of a new family in the late Paleozoic anachoropterid plants. In addition, selected anatomically preserved ferns from the Whetstone Horizon were reviewed, which promotes a better understanding of the anatomical variability of fern species.

Interactions between arthropods and plants have been documented extensively in late Paleozoic trees and ground cover plants, but they have rarely been recorded in late Paleozoic climbers. In this study, we present the second example of coprolites preserved within the plant tissue from the early Permian fossil Lagerst & auml;tte Wuda Tuff Flora. The host axis is identified as a phyllophore of the climbing fern Hansopteris uncinatus by the combined evidence of anatomy, morphology, and associated plants. Unlike the first coprolites, which were suggested to be produced by oribatid mites, the culprit of the studied coprolites was likely a myriapod or beetle, indicated by their slightly larger size and the boring behaviour. Furthermore, anomalous parenchymatous cells, sclerenchymatous cells, and metaxylem tracheids have been observed surrounding the tunnel, suggesting responses to traumatic stimulus caused by arthropod damage. This discovery provides an informative example of arthropod herbivory on late Paleozoic climbers and sheds light on how the host plant responded during the early stage of injury.

A botryopterid plant is described based on five anatomically preserved fronds from the early Permian Wuda Tuff Flora. Fronds are tripinnate with oval to triangular pinnules. Fertile pinnae concentrate proximally on the frond, while vegetative pinnae mainly occur distally, but occasionally position proximally as the first ultimate pinna of the penultimate fertile pinnae. Fertile pinnules are strongly involute and enclose the reproductive organs. Fertile organs comprise six to ten sporangia grouped in a sorus with a receptacle. Individual sporangia are stalked and have a proximal horizontal biseriate annulus. In situ spores are trilete, triangular to circular, with baculate sculptures. Anatomically, the foliar trace is rake-like, with up to eight median xylary ridges composed of mixed metaxylem and protoxylem tracheids. The specimens are established as a new species of Botryopteridium Doweld, a substituted name for Botryopteris Renault due to its later homonym with Botryopteris Presl. Botryopteridium sinensis sp. nov. displays a combination of features that were previously known individually from different species within Botryopteridium. Although information on its stem morphology is unknown, the new species is suggested to be a small tree-fern living in the forest understory. Moreover, the new plant shows a strong resemblance to late Paleozoic catenalean ferns including Rastropteris, Skaaripteris, and several basal osmundalean genera, thus providing an evolutionary link between members of the first and second evolutionary radiation of Paleozoic ferns.

(3005) Botryopteris Renault in Compt. Rend. Hebd. Séances Acad. Sci. 80: 202. Feb (sero)–Apr (prim.) 1875, nom. cons. prop. Typus: B. forensis Renault. (H) Botryopteris C. Presl, Reliq. Haenk. 1: 76. 12 Jun–30 Nov 1825, nom. rej. prop. Typus: B. mexicana C. Presl. The genus Botryopteris C. Presl (Reliq. Haenk. 1: 76. 1825) was first established for a single extant fern species, B. mexicana C. Presl. Sprengel (Syst. Veg. 4: 23. 1827) transferred B. mexicana to Helminthostachys as H. mexicana (C. Presl) Spreng., considering Botryopteris to be a later heterotypic synonym of Helminthostachys Kaulf. (Enum. Filic.: 28. 1824), ultimately based on Osmunda zeylanica L. (Sp. Pl.: 1063. 1753) (≡ Botrychium zeylanicum (L.) Sw. in J. Bot. (Schrader) 1800(2): 111. 1801) but that Kaulfuss illegitimately named H. dulcis. Based on additional specimens from Ceylon, Hooker (Gen. Fil.: t. 47B. 1840) concluded that B. mexicana C. Presl did not just belong in Helminthostachys but was conspecific with its type (O. zeylanica L.) and combined them as H. zeylanica (L.) Hook. (l.c.). Presl (Suppl. Tent. Pterid.: 60. 1845) initially accepted Hooker's assignment of Botryopteris to Helminthostachys, but renamed B. mexicana as the illegitimate H. crenata because the original specimen of B. mexicana was collected from the Philippines but erroneously labelled as from Mexico. Although Presl (in Abh. Königl. Böhm. Ges. Wiss., ser. 5, 5: 324. 1848) reinstated Botryopteris and replaced H. crenata by B. crenata C. Presl., this opinion was not generally accepted as subsequently discovered specimens from the Philippines were consistently attributed to H. zeylanica (L.) Hook. (Coritico & Amoroso in Nat. Conservation Res. 5: 82. 2000). Consequently, today, Botryopteris is considered a synonym of Helminthostachys and all the aforementioned species names are treated as either homotypic or heterotypic synonyms of H. zeylanica (L.) Hook. (see the POWO, https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:17116690-1). In 1875, seemingly unaware of Botryopteris C. Presl, Renault (in Compt. Rend. Hebd. Séances Acad. Sci. 80: 202. Feb–Apr 1875a) established another genus Botryopteris which is now a widespread and common fossil-genus with over 20 species documented in Carboniferous and Permian-aged strata of both Southern and Northern Hemispheres (see Zhou & al. in Rev. Palaeobot. Palynol. 311(104849). 2023). Botryopteris was first published by Renault in two different but almost contemporaneous publications, that cited above and in Ann. Sci. Nat., Bot., sér. 6, 1: 223. Apr–Mai 1875b. The former (l.c. 1875a) was merely a summarized report of Renault's presentation on “Étude du genre Botryopteris” to the Academy of Sciences at their “Séance du 18 janvier 1875” without any of the illustrations that were included in the full account published later in the Annales des sciences naturelles, but nevertheless included a full diagnosis and so fulfils the requirements of Art. 38.1 of the ICN (Turland & al. in Regnum Veg. 159. 2018) for valid publication of a generic name. The full account of the genus in Renault (l.c. 1875b) has been almost universally accepted as providing the legitimate protologue of Botryopteris Renault (e.g., Renault in Ann. Sci. Nat., Bot., sér. 6, 3: 7. 1876; Darrah in Bot. Mus. Leafl. 7: 162. 1939; Galtier in Bull. Soc. Hist. Nat. Autun 88(4): 18. 1978; Rößler & Galtier in Rev. Palaeobot. Palynol. 127: 105. 2003). The precise dates of the two publications are difficult to establish (see below), but it is clear that the report in the Comptes rendus predates the fuller account in the Annales. Despite its general neglect, the earlier publication must be accepted as there is no provision to conserve a name against itself, i.e., against an earlier isonym (cf. Art. 14 Note 1). [The range of dates of publication of each of the two accounts of Botryopteris Renault has been determined as follows: Each volume of the Comptes rendus hebdomadaires des séances de l'Académie des Sciences (Compt. Rend. Hebd. Séances Acad. Sci.) appeared first in a series of parts (fascicles) published weekly. Volume 80 was that for the first half of 1875 and would comprise 26 fascicles. The account of Botryopteris on p. 202 is in the third fascicle, the front wrapper of which is retained in the Gallica copy on the web (https://gallica.bnf.fr/ark:/12148/bpt6k3037k/f138.item). This is dated “18 Janvier 1875” but this is the date of the proceedings at the Academy not of publication of the fascicle. According to the editing process described on the following page of the wrapper (https://gallica.bnf.fr/ark:/12148/bpt6k3037k/f139.item) the manuscripts should have been provided by Thursday 21 January, and the printing sometime after, but delays were common. The Société Botanique de France cite Renault's article in the Compte rendus in its “Revue Bibliographique” for April–June 1875 (Bull. Soc. Bot. France 22, Rev. Bibliogr.: 72. 1875, https://www.biodiversitylibrary.org/item/8645#page/393/mode/1up), not in that for January–March. The Revue bibliographique universelle cited this fascicle of the Compte rendus in its March 1875 number (Rev. Bibliogr. Univers., sér. 2, 1: 113. 1875, https://gallica.bnf.fr/ark:/12148/bpt6k4242848/f113.item), but it is lacking from the February issue. From all this we conclude that Botryopteris was first published (in the Compte rendus) between end of February and early April 1875. Volume 1 of Ann. Sci. Nat., Bot., sér. 6 was also the volume for the first half of 1875. Although no copies with the original wrappers have been detected, this journal seems also to have been published in a number of parts. The information on the 16-page signatures of which the volume was composed appears at the foot of the relevant pages (e.g., pages 17, 33, 65, 81, etc.) along with the Cahier (part) to which the signature belonged. From this, there appear to have been six cahiers which might have appeared monthly, and as p. 223 was in cahier 4, this would suggest a late-April publication date. On the other hand the Bibliographie de la France reports a reprint of the memoir (no. 5422) from Annales des sciences naturelles with a publication date of 22 May 1875 (https://gallica.bnf.fr/ark:/12148/bpt6k867407/f628.item). From this, we conclude that the relevant portion of the journal was published in late April or May 1875, clearly after the publication in the Compte rendus.] Two species were originally described within Botryopteris Renault: B. forensis Renault (l.c. 1875a) and B. dubius Renault (l.c. 1875a). Botryopteris dubius Renault was later referred to the fructification fossil-genus Zygopteris Corda (Beitr. Fl. Vorwelt: 81. 1845) by Renault (Étud. Gîtes Minér., Bassin Autun Épinac., Fl. Foss.: 42. 1896), and now has been recombined into Biscalitheca as B. dubius (Renault) Galtier (in Bull. Soc. Hist. Nat. Autun 88(4): 22. 1978). Darrah (l.c.: 157) appears to be the first account to state that Botryopteris forensis Renault was the type of Botryopteris Renault, in accord with Art. 10.2. This is earlier than the selection by Mamay (in Ann. Missouri Bot. Gard. 37: 413. 1950) cited in Index Nominum Genericorum (https://naturalhistory2.si.edu/botany/ing/). The problem of Botryopteris Renault being a later (junior) homonym of Botryopteris C. Presl was mentioned in several publications (e.g., Potonié in Naturwiss. Wochenschr. 15: 313. Jul 1900; Reed in Taxon 4: 107. 1955; Kerp in Taxon 30: 662. 1981). Potonié (l.c. Jul 1900: 314, in Engler & Prantl, Nat. Pflanzenfam. I(4): 479. Aug 1900) suggested to use a prefix “p” for the later homonyms of some late Paleozoic fossil genera (i.e., p-Botryopteris), but even he and Gothan did not use this scheme in their later publications (Potonié, Lehrb. Pfl.-Palaeont., ed. 2: 121. 1921). Pichi-Sermolli (in Webbia 26: 500. 1972) argued that “Botryopteris Renault is a well-known genus and ought to be included in the list of Nomina Generica Conservanda.” In the Nomenclature Committee for Fossil Plants at Leningrad (Stafleu in Taxon 24: 690. 1975), it was recommended to propose the conservation of Botryopteris Renault against Botryopteris C. Presl. Unfortunately, however, no formal proposal has been submitted to the Committee since the Leningrad Congress. Therefore, the decision was “‘no recommendation’ on Botryopteris until and unless a proposal to conserve is presented” (Traverse in Taxon 30: 473. 1981). In an attempt to resolve these issues, Doweld (in Bot. Zhurn. 86(12): 73. 2001) proposed replacing Botryopteris Renault, non C. Presl, with a new name Botryopteridium Doweld and, at the same time, proposed to split the genus into three, Primofilix Doweld, Parabotryopteridium Doweld and Botryopteridium Doweld to replace Botryopteris sensu stricto. However, almost all subsequent authors have rejected this reclassification and still use Botryopteris Renault instead of Botryopteridium and include in it Doweld's new proposed generic names (Rößler & Galtier, l.c.; Taylor & al., Paleobotany, ed. 2: 443. 2009; Wang & al. in Cui & Shijun, Foss. Fl. China 1. 2009; Krings & al. in Mycoscience 52: 18. 2011; Barthel in Geol. Saxon. 61(2): 166. 2016; Ma & al. in Rev. Palaeobot. Palynol. 234: 11. 2016, in Palaeoworld 26: 490. 2017; He & al. in Rev. Palaeobot. Palynol. 273(104136): 2. 2020). One of the few exceptions is a publication by Zhou & al. (l.c.), in which Botryopteridium Doweld was simply used as a substitution of Botryopteris Renault (see also Bek & al. in Rev. Palaeobot. Palynol. 316(104932): 3. 2023). Zhou & al. (l.c.) highlighted numerous inaccuracies in Doweld's generic diagnoses and disagreed with his reclassification. The use of Botryopteridium Doweld is considered legitimate. However, this practice may potentially give rise to new nomenclatural disputes in cases where palaeobotanists hold differing opinions regarding the acceptance and scope of the three newly proposed fossil genera (e.g., we may see three different names “Botryopteridium antiqua”, “Promofilix antiqua” and the original “Botryopteris antiqua” in future publications). Doweld's decision to replace Botryopteris Renault with Botryopteridium Doweld essentially resulted in the displacement of a well-established name for purely nomenclatural reasons (Greuter & Nicolson in Taxon 42: 927. 1993). Keeping the nomenclatural stability of Botryopteris Renault is scientifically important in palaeobotanical research because it represents one of the potential ancestors of modern leptosporangiate ferns (He & al., l.c. 2020; Zhou & al., l.c.). For this reason, we propose the conservation of the generic name Botryopteris Renault against Botryopteris C. Presl under Art. 14.1, especially considering the fact that the earlier homonym Botryopteris C. Presl has fallen out of use, having, since 1840, been replaced by the earlier heterotypic synonym Helminthostachys Kaulf. (Hooker, l.c.). Acceptance of this proposal will permit the legitimate precedence of Botryopteris Renault over Botryopteridium Doweld under Art. 11.3, and will allow palaeobotanists to continue using the names of the fossil-genus Botryopteris Renault and its component fossil-species which have been widely and extensively documented, and almost universally accepted for more than 100 years. W-MZ, https://orcid.org/0000-0001-6190-6234 X-YH, https://orcid.org/0009-0000-2563-6222 S-JW, https://orcid.org/0000-0001-9147-6511 JP, https://orcid.org/0000-0001-9240-9206 RR, https://orcid.org/0000-0002-9692-2960 GWR, https://orcid.org/0000-0003-0186-6546 JH, https://orcid.org/0000-0003-0286-8236 JW, https://orcid.org/0000-0002-2193-2195 The authors thank Patrick S. Herendeen (Chicago Botanic Garden) and Christopher J. Cleal (Bristol University) for their valuable discussions on the nomenclatural issues and their help on the format of the text. They also thank Valéry Malécot (Institut de Récherches en Horticulture et Sémences, Angers, France) for his extensive advice on the dates of publication in 1875 of Comptes rendus hebdomadaires des séances de l'Académie des Sciences and Annales des sciences naturelles, Botanique. Financial support was granted by the National Natural Science Foundation of China (42172018, 42230210) and the Youth Innovation Promotion Association of Chinese Academy of Sciences (2022312). This paper is a contribution to the Deep-time Digital Earth (DDE) Big Science Program.

A new permineralized gymnospermous fossil stem, Parnaiboxylon wangi sp. nov., is described from the Moscovian Benxi Formation of Yangquan City, Shanxi Province, North China. It is composed of pith, primary and secondary xylems. The pith is solid, heterogeneous, with numerous secretory canals, ducts, and parenchymatous cells at the periphery. The primary xylem is endarch to mesarch. The secondary xylem is pycnoxylic, characterized by the presence of uni- to quariseriate araucarian radial tracheidal pitting, cupressoid to araucarioid cross-field pitting, and axial parenchyma. The fossil stem represents the fourth species of gymnosperms with anatomical features preserved from the Pennsylvanian of the Cathaysia. Anatomical characters, including solenoid pith and growth interruptions, and sedimentological evidence suggest a coastal environment with intermittent droughts or occasional incursions of seawater when the tree was alive. The presence of fungal hyphae, coprolites, and decayed tunnels in the secondary xylem of P. wangi sp. nov. indicate well-developed fungi–plant and animal–plant interactions when the Cathaysian flora at its early evolutionary stage.

The eusporangiate fern order Marattiales are represented in the living flora by the family Marattiaceae but have an extensive fossil record stretching back to the Carboniferous. The family Psaroniaceae included important wetland plants in the Carboniferous and Permian. In this work we present a new member of the Psaroniaceae from the Lloyd Cove Seam of the Brogan's Mine, Sydney Coalfield, Nova Scotia, Canada dated to the Kasimovian Stage (lower Stephanian, Pennsylvanian) of the Carboniferous. The new fern is represented by a small specimen with distinctive fertile pinnules and reproductive organs including large synangia that possess a well-developed synangial sheath with a central parenchymatous filling. Small monolete in situ spores are compared to the dispersed miospore species Punctatosporites pygmaeus. Based on well preserved reproductive organs, we are proposing a new species Diplazites campbellii sp. nov. A new evolutionary model combining species that produced the smallest monolete spores and significant characters of their reproductive organs is suggested. Four following subgroups are suggested: the Unita, Hemitelioides, Multisporangiate and Crenulopteris.