calum'sfossils
Renaultia sp.
Age: 343-337Ma
Viséan
Middle Mississippian Epoch
Carboniferous Period - Giant arthropods and amphibians, early reptiles, most plants fern or lycophyte-like, known for tropical forests and seas
Paleozoic Era - pre-Dinosaurs
Location: England
Lancashire
Hurst Green (Stonyhurst)
Dinckley
Dinckley Hall
The brook east of Dinckley Bridge
Rock Type: Bowland Shale Formation mudstone.
Renaultia is an extinct genus of true ferns that lived during the Carboniferous period, particularly in the Late Mississippian to Pennsylvanian epochs (approximately 330 to 300 million years ago). Unlike the superficially similar pteridosperms (seed ferns), Renaultia was a genuine spore-bearing fern and is typically classified within the family Botryopteridaceae, under the order Marattiales—a lineage of eusporangiate ferns that also includes extant genera such as Marattia and Angiopteris (Taylor et al., 2009; Stewart & Rothwell, 1993), though only one extant family from within the order is still extant: the Marattiaceae.
Members of the Botryopteridaceae, including Renaultia, are regarded as early representatives of the eusporangiate fern clade, which sits at the base of the fern evolutionary tree. Unlike the more derived leptosporangiate ferns (which comprise the majority of living fern diversity today), eusporangiate ferns bear thick-walled sporangia that develop from multiple initial cells and are generally larger and more robust in structure. This places Renaultia among the most anatomically primitive of true ferns, although still distinct from more basal vascular plant groups like lycophytes (Stewart & Rothwell, 1993; Hilton & Bateman, 2006).
Renaultia is primarily known from permineralised fossils that preserve its internal structure in remarkable detail. The stems were generally erect or sprawling, often surrounded by a dense mantle of frond bases. Internally, the plant exhibits a solid vascular cylinder, with multiple leaf traces diverging from the stele, consistent with other marattialean ferns (Taylor et al., 2009). The cortex is thick and often contains evidence of aerenchyma, suggesting an adaptation to swampy or waterlogged environments—common for many Carboniferous plants.
The foliage of Renaultia was finely divided, likely compound to multiple levels, and bore eusporangiate synangia on the underside of fertile fronds. These synangia (clusters of fused sporangia) are a defining characteristic of Marattiales and distinguish Renaultia from both seed ferns and leptosporangiate ferns (Galtier, 1981). Like modern ferns, Renaultia reproduced by spores and had an alternation of generations, with a dominant diploid sporophyte and an independent gametophyte stage.
Ecologically, Renaultia is interpreted as part of the understorey or mid-canopy vegetation of Carboniferous swamp forests, coexisting with arborescent lycopsids like Lepidodendron and Sigillaria, horsetails (Calamites), and a variety of seed ferns. Its structure and frond density suggest it may have formed dense thickets in moist, shaded environments. Anatomically preserved specimens are often found in calcareous nodules or ironstone concretions, such as those from the famous fossil sites of North America and Europe.
The genus is named in honour of Bernard Renault (1836–1904), a pioneering French palaeobotanist whose studies of coal ball plants and fossil ferns laid much of the groundwork for Carboniferous palaeobotany (Taylor et al., 2009).
Renaultia sp.
Age: 343-337Ma
Viséan
Middle Mississippian Epoch
Carboniferous Period - Giant arthropods and amphibians, early reptiles, most plants fern or lycophyte-like, known for tropical forests and seas
Paleozoic Era - pre-Dinosaurs
Location: England
Lancashire
Hurst Green (Stonyhurst)
Dinckley
Dinckley Hall
The brook east of Dinckley Bridge
Rock Type: Bowland Shale Formation mudstone.
Renaultia is an extinct genus of true ferns that lived during the Carboniferous period, particularly in the Late Mississippian to Pennsylvanian epochs (approximately 330 to 300 million years ago). Unlike the superficially similar pteridosperms (seed ferns), Renaultia was a genuine spore-bearing fern and is typically classified within the family Botryopteridaceae, under the order Marattiales—a lineage of eusporangiate ferns that also includes extant genera such as Marattia and Angiopteris (Taylor et al., 2009; Stewart & Rothwell, 1993), though only one extant family from within the order is still extant: the Marattiaceae.
Members of the Botryopteridaceae, including Renaultia, are regarded as early representatives of the eusporangiate fern clade, which sits at the base of the fern evolutionary tree. Unlike the more derived leptosporangiate ferns (which comprise the majority of living fern diversity today), eusporangiate ferns bear thick-walled sporangia that develop from multiple initial cells and are generally larger and more robust in structure. This places Renaultia among the most anatomically primitive of true ferns, although still distinct from more basal vascular plant groups like lycophytes (Stewart & Rothwell, 1993; Hilton & Bateman, 2006).
Renaultia is primarily known from permineralised fossils that preserve its internal structure in remarkable detail. The stems were generally erect or sprawling, often surrounded by a dense mantle of frond bases. Internally, the plant exhibits a solid vascular cylinder, with multiple leaf traces diverging from the stele, consistent with other marattialean ferns (Taylor et al., 2009). The cortex is thick and often contains evidence of aerenchyma, suggesting an adaptation to swampy or waterlogged environments—common for many Carboniferous plants.
The foliage of Renaultia was finely divided, likely compound to multiple levels, and bore eusporangiate synangia on the underside of fertile fronds. These synangia (clusters of fused sporangia) are a defining characteristic of Marattiales and distinguish Renaultia from both seed ferns and leptosporangiate ferns (Galtier, 1981). Like modern ferns, Renaultia reproduced by spores and had an alternation of generations, with a dominant diploid sporophyte and an independent gametophyte stage.
Ecologically, Renaultia is interpreted as part of the understorey or mid-canopy vegetation of Carboniferous swamp forests, coexisting with arborescent lycopsids like Lepidodendron and Sigillaria, horsetails (Calamites), and a variety of seed ferns. Its structure and frond density suggest it may have formed dense thickets in moist, shaded environments. Anatomically preserved specimens are often found in calcareous nodules or ironstone concretions, such as those from the famous fossil sites of North America and Europe.
The genus is named in honour of Bernard Renault (1836–1904), a pioneering French palaeobotanist whose studies of coal ball plants and fossil ferns laid much of the groundwork for Carboniferous palaeobotany (Taylor et al., 2009).