Acta Palaeobotanica 57(2): 135–151, 2017 DOI: 10.1515/acpa-2017-0013 Revision of Fedekurtzia (pteridosperm) and allied fronds from the Carboniferous of Gondwana ELIANA P. COTUREL1 and SILVIA N. CÉSARI 2* 1 División Paleobotánica, Museo de La Plata. Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Pasaje Teruggi s/no, Paseo del Bosque, B1900FWA, La Plata, Argentina; e-mail: ecoturel@fcnym.unlp.edu.ar 2 Museo Argentino de Ciencias Naturales B. Rivadavia, CONICET, Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina; e-mail: scesari@macn.gov.ar Received 8 July 2017; accepted for publication 8 November 2017 ABSTRACT. Carboniferous foliage of Fedekurtzia argentina (Kurtz) Archangelsky from Gondwana is systemati- cally described and revised. The frond is reconstructed based on specimens of the late Serpukhovian–Bashkirian Nothorhacopteris/Botrychiopsis/Ginkgophyllum flora of western Argentina, especially from the Jejenes, Tupe and Volcán formations. The whole-frond reconstruction emphasizes the variation in pinnule shape throughout the basal, medial and distal sections of the frond. The basalmost rachis possesses cyclopteroid pinnules grading to pinnae with obovate to wedge-shaped pinnules at the medial section of the frond. Distal pinnae are shorter, bearing imbricate and more dissected pinnules. Specimens from the same type locality from which F. argentina comes, previously assigned to Triphyllopteris cuyana Leguizamón & Vega, are reassigned to F. argentina, as well as ovuliferous and microsporangiate structures in organic connection. Two decades ago a revision of the German Triphyllopteris genus rejected T. cuyana as representative of the taxon, and the Argentinian specimens remained as indeterminate “triphyllopteroid” fronds. The ovulate organ Polycalyx Vega & Archangelsky is con- sidered to be in organic connection with vegetative fragments of F. argentina, and its cupulate character is dis- cussed. Pollen organs represented by multi-forked axes bearing fusiform sporangia of Rinconadia Vega are also in organic attachment and included in the Fedekurtzia argentina reconstruction. The pollen or prepollen grains are trilete and with granulate sculpture. The paper presents a comparison with Botrychiopsis weissiana Kurtz emend. Archangelsky & Arrondo, which differs in its rounded and entire-margin pinnules. Similar specimens from Australia formerly described as Rhacopteris, Sphenopteridium and Archaeopteris and currently included in Fedekurtzia intermedia Rigby share morphological characters with the Argentinian species. A revision of the Australian material is necessary to confirm synonymy. Fedekurtzia belongs to the pteridosperms based on the reproductive organs and is here assigned to Austrocalyxaceae. Its reconstruction now constitutes one of the most complete seed-ferns known from the Carboniferous of Gondwana. KEYWORDS: Fedekurtzia, pteridosperms, taxonomy, Carboniferous, Gondwana INTRODUCTION * corresponding author e-ISSN 2082-0259 ISSN 0001-6594 The earliest findings of Carboniferous fronds in Gondwana come from its two most distant areas: Australia and Argentina. In Australia, McCoy (1847), Etheridge (1888) and Feist- mantel (1878) described the first frond frag- ments, referring them to different northern genera such as Rhacopteris, Sphenopteridium and Archaeopteris, for which they defined new species. Later, White (1965), Rigby (1969, 1973) and Morris (1975) revised the Austral- ian palaeofloras, proposing new combinations and species. In westernmost Gondwana, Sza- jnocha (1891) and Kurtz (1894) reported the first records of upper Palaeozoic plants from Argentina. Kurtz (1894) studied a collection made by Brackebusch in San Juan Province and defined a new genus, Botrychiopsis, which later was considered a key species of the Penn- sylvanian flora of western Argentina (Arch- angelsky & Azcuy 1985). These first studies Unauthenticated Download Date | 1/31/18 5:31 PM 136 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 of Carboniferous floras from Argentina were continued by Frenguelli (1941, 1944, 1946), Archangelsky & Arrondo (1971), Archangel- sky (1981, 1983) and Césari (1986), among others. Other typical fronds from Argentina were referred to Fedekurtzia, defined by Arch- angelsky (1981) based on specimens formerly described as Archaeopteris argentina by Kurtz (1921). During recent decades, important advances in knowledge of the botanical affin- ity of some fronds were made by Vega and Archangelsky (2001), who defined the pteri- dosperm family Austrocalyxaceae. Fronds in organic connection with the fertile organs were referred by these authors to Triphyllopteris Schimper or “triphyllopteroid” fronds. The foliage of these upper Palaeozoic plants shows wide morphological variability, which hinders taxonomic delimitation when small fragments are studied. The aim of this contri- bution is to present an update of the following taxa described for the Gondwanan Carbonifer- ous flora: Fedekurtzia Archangelsky, Triphyl­ lopteris Schimper and Botrychiopsis Kurtz emend. Archangelsky & Arrondo. STRATIGRAPHIC SETTING The Pennsylvanian flora from Argentina is usually assigned to the Nothorhacopteris argen­ tina–Botrychiopsis weissiana–Ginkgophyllum diazii (NBG) Biozone. The NBG Biozone was proposed by Arch- angelsky and Azcuy (1985); today it displays a widespread distribution in central-western Argentina (Césari et al. 2007). The main com- ponents of this flora are lycophytes, cordaitales and pteridosperms. Its age is constrained by several U/Pb datings (Césari et al. 2011) to the late Serpukhovian–Bashkirian. An “Inter- val” flora was suggested by Archangelsky and Cúneo (1991) to include those latest Carbonif- erous assemblages where the first occurrences of conifer and fern remains are identified. This flora is now assigned to the Krauselcladus– Asterotheca Biozone (Carrizo & Azcuy 2015). Correlative Pennsylvanian stratigraphic units of central-western Argentina have been given different names in different regions of the country. Among these units is the Tupe Formation, in which many occurrences of the NBG flora have been reported, and which is the namesake of the “Tupense”, a regional stage (Archangelsky 1971). However, recent findings extend the stratigraphic range of the NBG flora to the underlying Guandacol Formation. Both units comprise glacial and postglacial deposits which characterize the Lower and Middle Penn- sylvanian in westernmost Gondwana (Limarino et al. 2006, 2014). Some coeval stratigraphic units in the Paganzo, Calingasta–Uspallata and San Rafael basins bearing plant remains are the Jejenes, Volcán, Tupe (San Juan Province), El Imperial, Santa Máxima, Tramojo (Mendoza Province) Tupe and Lagares (La Rioja Province) formations. The area between Rinconada and La Carpintería or Retamito (San Juan Prov- ince), where the Jejenes Formation crops out, comprises important fossiliferous sites (e.g. Cladera et al. 2000, Vázquez et al. 2016). Type specimens of two key taxa of the NBG flora, Botrychiopsis and Fedekurtzia, come from these latter localities. HISTORICAL AND NOMENCLATURAL BACKGROUND Rigby (1973) described fronds from the Car- boniferous of Australia, which he referred to ?Sphenopteridium intermedium (Feistmantel) Rigby. This species included Australian speci- mens originally described by Feistmantel (1878, 1879, 1890) as Rhacopteris intermedia, R. sep­ tentrionalis, Archaeopteris wilkinsoni and by Walkom (1934) as ?Sphenopteridium cuneatum. Rigby (1973) included also specimens described by Read (1938) as Rhacopteris sp. cf. R. cune­ ata from the Peruvian Paracas flora. Later, Rigby (1985) defined Fedekurtzia intermedia (Feistmantel) Rigby, combining the specimens described by Feistmantel (1878, 1879) as Rha­ copteris intermedia, R. septentrionalis (fi gured by Rigby 1973, pl. 3, fig. 10), and Archaeo­ pteris wilkinsoni (figured by Rigby 1973, pl. 3, fig. 11a), and selected as lectotype the specimen illustrated by Rigby (1973) in plate 3, figure 12A, from Paterson, New South Wales. In another contribution to the knowledge of the Australian Carboniferous flora, Morris (1975) considered the variable morphology of pinnae remains found in the same locality (the Paterson area) reviewed by Rigby (1973). She highlighted, for the first time, the presence of a complex of intergrading forms which can be related to several well-defined fossil genera such as Triphyllopteris or Sphenopteridium. Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 137 According to Morris (1975), the most common species was named Rhacopteris digitata by Etheridge (1888) together with variable aphle- bia of Rhacophyllum diversiforme Etheridge. She also proposed an intergradation between fronds of Aneimites austrina Etheridge and Dactylophyllum digitatum (Etheridge ) Morris. When Archangelsky (1981) combined the species Archaeopteris argentina, formerly described by Kurtz (1921), as the new genus Fedekurtzia, he included in the diagnosis specimens originally referred to Spheno pteris, Eremopteris, Archaeopteris, Rhacopteris, Sphe­ nopteridium, Adiantites, or Triphyllopteris from Argentina, Peru, and Australia. Accord- ing to the original illustrations (Fig. 1), Kurtz (1921) observed variation in the morphol- ogy of the pinnules and pinnae throughout the frond. This heteromorphism was corrobo- rated by Césari (1986), adding more complete specimens from the Tupe Formation in La Rioja Province, showing significant variation in the morpho logy of the pinnae and pinnules of this species. Archangelsky (1981) regarded the specimens illustrated by Morris (1975) under the name Triphyllopteris austrina as possibly conspecific with Fedekurtzia argen­ tina, but later Archangelsky (1983) proposed that they represent a Botrychiopsis frond, as suggested by Retallack (1980); its incomplete preservation hampered close comparison with any species. After that, Rigby (1985) considered that Aneimites austrina Etheridge and Triphyl­ lopteris austrina (Etheridge) Morris should be included together with Otopteris ovata M’Coy in Botrychiopsis ovata (M’Coy) Rigby. Archangelsky (1981) also described the presence of spike-like male fructifications, which were interpreted to be in organic con- nection to a specimen of Fedekurtzia argentina collected by Frenguelli in Mendoza Province. Leguizamón and Vega (1991) reported, for the first time, the presence of Triphyllopteris Schimper in Argentina and described a new species, T. cuyana, which was considered to be different from Fedekurtzia; this distinction is relevant because the specimens were found in the same stratigraphic unit and fossiliferous area (Cladera et al. 2000) from which comes the lectotype of Fedekurtzia argentina Archan- gelsky. Later, Vega and Archangelsky (1997) described fertile structures in organic connec- tion with these fronds. Gutiérrez (1994) also described fertile structures associated with fragments of pin- nae referred to Fedkurtzia argentina. One of them comes from the same stratigraphic lev- els where Césari (1986) illustrated nearly com- plete fragments of fronds of that species for the first time. The ovuliferous organ is very similar Fig. 1. A – Reproduction of figs. 2, 3 (plate XXIX) from Kurtz (1921), originally assigned to Archaeopteris argentina. B – Repro- duction of fig. 9 (plate XVIII) from Kurtz (1921) originally assigned to A. argentina. Scale bar: 1 cm Unauthenticated Download Date | 1/31/18 5:31 PM 138 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 to those described as Polycalyx by Vega and Archangelsky (2001), associated with triphyl- lopteroid foliage. The latter authors did not compare these specimens. Vega (1995a) defined the microsporangiate species Rinconadia archangelsky based on fer- tile frond specimens bearing lobed pinnules and pinnae identical with Triphyllopteris cuyana Leguizamón & Vega. However, Vega (1995a) remarked upon the uncertain generic assign- ment of the Argentinian species, following Knaus’s (1994) revision of the northern repre- sentatives of this genus. The same criterion was followed by Vega and Archangelsky (2001) when they referred to those fronds as “triphyllopter- oid” type without precise generic endorsement. When Knaus (1994) assigned a neotype for Triphyllopteris collombiana Schimper (type species of the genus), she rejected the species T. cuyana Leguizamón & Vega and T. peru­ viana Jongmans from the genus. Moreover, she noted the need for revision of the original Feistmantel specimens described by Etheridge (1894) and Morris (1975) as T. austrina and moved to Botrychiopsis by Retallack (1980) or Fedekurtzia argentina by Archangelsky (1981). Knaus (1994) constrained the distribution of Triphyllopteris to the European region, and the similar genus Genselia to North America. Knaus’s reconstruction of the Triphyllo­ pteris frond defines a rhombic bipinnate frond with the longer pinnae at the base, which bear 3- or 5-lobed pinnules. The distance between pinnae decreases toward the apex and the pinna arrangement is subopposite. The basal pinnules are rhombic and usually trilobed, the distal pinnules are entire or in some cases slightly lobed, and the apical pinnules are unlobed and ovate to lanceolate. MATERIAL AND METHODS This revision is based on specimens collected in the Jejenes and Volcán formations (San Juan Prov- ince) and Tupe Formation (La Rioja Province); we also compared additional material from coeval units. These well-preserved imprints of foliage allowed reconstruc- tion of the frond architecture and a comparison with isolated or incomplete specimens described under dif- ferent species from other stratigraphic units. The holotype of Fedekurtzia argentina deposited in the Palaeontological Collection of Córdoba University (CORD PB) was re-examined, as well as many speci- mens from the Palaeobotanical Collection of La Plata Museum (LPPB), the Palaeobotanical Collection of the Museum of Natural Sciences of San Juan (PBSJ), the Palaeobotanical Collection of the Museo Argentino de Ciencias Naturales (BA Pb) and the Palaeontological Collection of Buenos Aires University (BAFC PB). Descriptions follow the terms used to describe mul- tipinnate frond architecture in upper Palaeozoic seed ferns (e.g., rachis, pinna, pinnule). The reconstruction of the frond follows the criteria used by Knaus (1994, 1995) with similar Carboniferous material. The speci- mens were selected mainly if at least two pinnae as well as their most apical pinnulae were attached to a rachis. To represent the available evidence, linear tracings over photographs were made and then placed in the reconstruction according to the measured parameters. SYSTEMATICS Family Austrocalyxaceae Vega & Archangelsky 2001 Fossil genus Fedekurtzia (Archangelsky) emend. O r i g i n a l d i a g n o s i s. Frond with a main axis bearing pinnate segments, helicoidally inserted and bilaterally disposed at acute angles. Mature pinnae oval elongate, close to superposed, with pinnules of two types: a) separated at the base, entire, subcircular to oval or wedge-shaped and b) distal or apical, confluent, decurrent, wedge- shaped, narrow, having 2 or 3, rarely more lobes. Venation uniform, dichotomous and fan- shaped. Spike-like fructifications disposed on the same rachides with pinnae, consisting of an axis with compactly arranged free oval to fusi- form bodies (sporangia?), distally rounded and perpendicularly placed on the axis; no visible dehiscence markings. E m e n d e d d i a g n o s i s. Frond heteromor- phic, bipinnate, elliptic in outline and slightly asymmetrical; longest pinnae occurring in mid- dle section. Pinna arrangement subopposite to alternate, and angles of attachment becoming progressively more acute apically. Basalmost rachis with cyclopteroid pinnules and hetero- morphic pinnules in pinnae of medial section of frond; distal pinnae reduced in length, with densely spaced pinnules. Pinnules of medial and distal portions of frond obovate to wedge- shaped, decurrent, and having deep or incipient lobation. Venation uniform, dichotomous and fan-shaped. Apical microsporangiate organ con- sisting of multiforked axis with free sporangia arranged at tips. Ovuliferous organs apically attached to a pinnate rachis, comprising leaf- like receptacles with ovules inserted on one side. Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 139 Type species: Fedekurtzia argentina (Kurtz) Archangelsky 1981 Fedekurtzia argentina (Kurtz) Archangelsky emend. Pl. 1–3 1991 Triphyllopteris cuyana Leguizamón & Vega: 306, pl. 1, figs 1 and 2. 1995b Triphyllopteris cuyana Leguizamón & Vega; Vega, pl. I, fig. 2, pl. II, fig. 6. Additional synonymy in Archangelsky 1981: 1133. L e c t o t y p e. Specimen CORD Pb 402 (Pl. 2, fig. 3) and counterpart CORD Pb 400 (designed by Archangelsky 1981). E m e n d e d d i a g n o s i s. Rachis straight at base, somewhat flexuous at middle part of frond, tapering apically. Attachment of pinnae to rachis at 75° to 40° in middle to distal sec- tions of frond; pinnae arrangement subopposite to alternate, with spacing regular in basal and mid-sections and overlapping of pinnules on api- cal sector. Basalmost rachis with broad, cyclop- teroid, rounded, decurrent pinnules passing upward to pinnules with undulate margins and narrower bases, followed by trilobed pinnules. Number of pinnules and degree of segmenta- tion per pinna increasing distally along frond. Venation uniform, dichotomous and fan-shaped. First pinnae of mid-section five-lobed, lobes decurrent, obovate to wedge- shaped; distal lobe elongate, slightly bilobed. Longest pinnae bear- ing alternate to subopposite pinnules attached by a narrow base and slightly bi- or trilobed; basal anadromous pinnules obovate, larger than the catadromic. Pinnules wedge-shaped towards apex of pinna, and apical pinnule unequally emarginate. In distal section of frond pinnae are shorter, bearing imbricate pinnules, with basal pinnules three to four-lobed and apical elongate pinnules, bilobed at apex. Ovulate structures borne apically on pinnate fronds of diverse grades of development. Main rachis forking twice, each branch supporting a relatively large receptacle consisting of two orbicular laminae with distal margin laciniate into narrow and acute lobes. Oval, elongate ovules, with terminal long and narrow lobes, inserted on adaxial and proximal surface of each lamina. Sporangial masses emerge from terminal multi-forked apex of pinnate rachis. Fusiform sporangia with finely and helically striated surface, containing trilete spores. R e m a r k s. The original diagnosis of the spe- cies was emended and expanded; the first was presented by Césari (1986), mentioning the wide variation in the morphology of the pin- nules along the frond. Gutiérrez (1994) added the character of the venation in the basal part of the frond and the association with multiovu- late cupules. The present emended diagnosis is based on revision of the holotypes of Fedekurt­ zia argentina and Triphyllopteris cuyana, an analysis of many specimens, which allowed recon- struction of the frond (taking into account the available evidence on complete and incomplete fragments), and revision of the fertile material. It should be noted that the almost com- plete specimen illustrated by Leguizamón and Vega (1991, pl. 1) probably represents an early ontogenetic stage in which the morphology of the pinnules changes rapidly from one sector of the fragment to another, but replicating the leaf forms described below for each section of an adult frond. According to the scale in plate 1 of Leguizamón and Vega (1991), the specimen is ca 300 mm in length, not 520 mm as was men- tioned in the text, and thus there is no basis to support the suggestion that the fragment is a third-order pinna in a very large frond. D e s c r i p t i o n. The measurements of the main specimens analysed are detailed in Table 1 and 2. They represent fragments of different plants and probably of different sizes. B a s a l s e c t i o n o f f r o n d. This section includes the most basal simple pinnules identi- fied, attached to the main rachis up to the first pinna with two pairs of pinnules (arrow in Pl. 1, fig. 3). The basal fragments of the fronds bear opposite to subopposite, rounded to obcordate and lobed pinnules, with venation dichotomous and fan-shaped (Pl. 1, figs 7, 8). The bases of the lowermost pinnules are decurrent, forming a narrow wing along the rachis. Upwards in the frond the incipiently lobed pinnules pass to Table 1. Measurements of the basal section in the main specimens analysed Basal section Rachis Pinnule Specimen Width (mm) Distance (mm) Length (mm) Width (mm) PBSJ 1021 PBSJ 1015 BAFCPB 12858 BAPB 5330 BAFCPB 12838 BAPB 12232 4 2.5 6 6 5 4 15 9–12 22.5 20 20 18 13 16–17 19–32 31 20–25 23 14 14 24–25 22.5 22.5–25 16 Unauthenticated Download Date | 1/31/18 5:31 PM 140 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 distinctly lobed pinnules of a narrow base (Pl. 1, fig. 9). Trilobed basal pinnules are also identi- fied in the specimen described by Vega (1995b) as Triphyllopteris cuyana (arrow in Pl. 1, fig. 4). The first foliar laminae can be compared with heteromorphic basal elements of fern- like fronds from the Carboniferous of Europe. Cyclopteroid leaves have rounded laminae Plate 1. Fedekurtzia argentina. 1. Detail of distal pinnae in specimen illustrated in Plate 2, fig. 5. Scale bar: 1 cm; 2. Distal pinnae with apparent torsion in their insertion (arrows), bearing incised pinnules with their apices artificially truncated by preservational factors, Volcán Formation, PBSJ 1018. Scale bar: 1 cm; 3. Trilobed basal pinnules grading to pinna with two pairs of lateral pinnules (arrow), Tupe Formation, BAFCPb 12858. Scale bar: 1 cm; 4. Detail of basal pinnules of the speci- men figured in Plate 2, fig. 2. Scale bar: 1 cm; 5. Medial pinnae, Volcán Formation, PBSJ 1013. Scale bar: 1 cm; 6. Detail of venation, Volcán Formation, PBSJ 1016. Scale bar: 1 cm; 7. Basalmost pinnules, Volcán Formation, BAPb 12232. Scale bar: 1 cm; 8. Basal pinnules, Tupe Formation, BAFCPb 12838. Scale bar: 1 cm; 9. Trilobed basal pinnules, Volcán Formation, PBSJ 1015. Scale bar: 1 cm Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 141 with entire margins or dissected to irregularly lobed leaflets. Bomfleur et al. (2012) mentioned the possibility that the basal outgrowths in the Triassic fronds of Dicroidium are an atavistic expression of the ancestral pinnules of late Paleozoic seed-fern taxa such as Nothorhaco­ pteris and Botrychiopsis. According to Bom- fleur et al. (2012), aphlebia and/or cyclopter- oid pinnules in the basal part of a Dicroidium frond are early leaf-ontogenetic architectural units, which are ephemeral and may be shed during ensuing leaf maturation. However, iso- lated aphlebia-like pinnules are rare in the assemblages from the Argentinian NBG flora. M i d d l e s e c t i o n o f f r o n d. The holotype of Fedekurtzia argentina (Pl. 2, fig. 3), the speci- men illustrated in Plate 2, fig. 1, and the frag- ment of a frond formerly described as Triphyl­ lopteris cuyana (Pl. 2, fig. 2) represent middle sections of fronds. Both specimens possess slight asymmetry due to the development of shorter pinnae on one side of the axis, although the three shorter pinnae on the left side of the specimen in Plate 2, fig. 2, could be attached to an axis not visible underlying the one bearing long pinnae. The holotype of T. cuyana (Legui- zamón & Vega 1991, pl. I) and the specimen figured in Plate 2, figs 1, 2, are the larger speci- mens collected, reaching up to 30 cm in length. The longest pinnae have at least five pin- nules to each side of the secondary rachis. Basal anadromous pinnules may be shallowly lobed and slightly larger than the equivalent catadromous ones. The pinnules range from rounded, with margin slightly bi- or trilobed at the base of the pinna, to distally narrow, wedge-shaped, slightly bilobed pinnules. The apical pinnule is long and sub-bilobed, with the catadromous lobe smaller. The venation is dichotomous and fan-shaped (Pl. 1, fig. 6). The holotype of F. argentina is a fragment of a frond not very well preserved, with the pin- nules superimposed and their apical margins incomplete (Pl. 2, fig. 3), so Kurtz’s illustration of the proximal pinnules is not accurate (Fig. 1). It must be noted that the differences be- tween F. argentina and Triphyllopteris cu yana suggested by Vega (1995b) consist in the heli- cal insertion of the pinnae and the shape of the proximal pinnules in the first species. However, the helical insertion of the pinnae was only illustrated by Archangelsky (1981, figs 3, 4) in one small specimen. Slight torsion of the pinnae can be observed in both species as shown in Plate 1, fig. 2 and Plate 2, fig. 5, even though preservation can mask that true phyllotaxis. The proximal pinnules of the mid- section of the frond are similar in both forms; the similarity can be obscured by the insertion and preservation, which can produce superpo- sition and damage of their apices. D i s t a l s e c t i o n o f f r o n d. The specimens illustrated in Plate 1 (figs 1, 2) and Plate 2 (figs 4, 5) represent the distal section of the frond, where the pinnae decrease in length and their pinnules increase their dissection, looking like a very packed zone with super- position of pinnules. The angle of insertion of the pinnae is more acute in this section than in the mid-section. The proximal pinnules Table 2. Measurements of the medial and distal sections in the main specimens analysed Middle section Main Rachis Pinna Basal pinnule Apical pinnule Specimen Width (mm) Distance (mm) Length (mm) Width (mm) Rachis (mm) Length (mm) Width (mm) Length (mm) Width (mm) PBSJ 1013 PBSJ 1017 PBSJ 1014 BAFCPB 12821 CORD-PB 402 LP Pb 10543 1.4 4.1 2.5 5 3 2 17.1 26 16 25 30 10 48–54 59.5 44 45–90 70 28 26 24 15 3–3.4 30 14 0.85 1 2 1.5–2 1.5 1.5 14–17 14 10 25 22 11 10 13 9 13 15 0.75 13 17 10 25 15 11 7–10 7–10 5 5 7 6 Distal section Main rachis Pinna Basal pinnule Apical pinnule Specimen Width (mm) Distance (mm) Length (mm) Width (mm) Rachis (mm) Length (mm) Width (mm) Length (mm) Width (mm) PBSJ 1018 PBSJ 1019 BAFCPB 12837 BAPB 5331 4 2 3 1–2 24 10 22 14–20 62 40–20 40 87 26 7–13 20 25–30 2 1 1.2 1.5–2 15 12 20 17.5 14 7 8 10 14 13 17 13 4–5 4–2 2.5–3 2.5 Unauthenticated Download Date | 1/31/18 5:31 PM 142 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 are trilobed, with the central lobe commonly slightly dissected and the lateral lobes some- times also slightly dissected. The distal pin- nules are sub-bilobed and resolve at the apex with a long, wedge-shaped apical pinnule of the bilobed margin. These examples are simi- lar to the specimen illustrated by Césari (1986, pl. 2, fig. 3) from the Tupe Formation. Plate 2. Fedekurtzia argentina. 1. Specimen representing medial sector of frond, Tupe Formation, BAFCPb 12821. Scale bar: 1 cm; 2. Medial frond fragment, originally described as Triphyllopteris cuyana by Vega (1995b), Jejenes Formation, BAPb 5330b. Scale bar: 1 cm; 3. Lectotype, Jejenes Formation, CORD Pb 402. Scale bar: 1 cm; 4. Distal portion of frond, Volcán Formation, PBSJ 1019. Scale bar: 1 cm; 5. Distal sector of frond, described as Triphyllopteris cuyana by Vega (1995b), Jejenes Formation, BAPb 5331, white arrow indicates proximal pinnule; black arrows indicate small torsion in insertion of pinnae. Scale bar: 1 cm; 6. Lectotype. Detail of distal pinnules, Jejenes Formation, CORD Pb 402. Scale bar: 1 cm; 7. Lectotype. Detail of slightly bilobed pinnule, Jejenes Formation, CORD Pb 402. Scale bar: 1 cm; 8. Incised pinnules, Volcán Formation, PBSJ 1017. Scale bar: 1 cm Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 143 The specimens illustrated in Plate 1 (figs 1, 2, 5) show how differences in preservation change the shape of the pinnules: although the outline of the pinnules is rounded in Plate 1, fig. 1, the pinnule margin is slightly covered or broken, making it appear to be straight and rough-looking in Plate 1, fig. 2. The fragment originally identified by Kurtz (1921) as Sphe­ nopteris fonsecae Kurtz looks similar to pin- nules of Fedekurtzia argentina when poorly preserved. M i c r o s p o r a n g i a t e s p e c i m e n s. A revi- sion of specimen LPPB 10519 (Pl. 3, fig. 5), from Mendoza Province described by Archan- gelsky (1981) as a fertile fragment of a frond allowed us to make a new interpretation of these plant remains. There are three incom- plete pinnae aligned so that they seem to emerge from a rachis (Pl. 3, fig. 5), which is not preserved and should be located to the bottom of the figure. The fusiform sporangia are preserved close to a robust rachis (arrow in Pl. 3, fig. 8) disconnected from the pinnae; they are closely grouped and aligned at the apex of a short bifurcate axis, numbering at least fifteen. Other masses of sporangia appear isolated on the matrix; the sporangia are fusi- form, 3.2–2 mm long and 0.6–0.8 mm wide, and finely striated helically (Pl. 3, fig. 10). This new analysis of the specimen questions the sugges- tion that the fertile structures arise laterally from the same main rachis bearing pinnae, as has been proposed (Archangelsky 1981, Car- rizo & Archangelsky 2013). However, the spo- rangia and arrangement are similar to those described by Vega (1995a) and Vega & Archan- gelsky (2001) as Rinconadia archangelskyi in association with Triphyllopteris fronds. We consider the specimens of Rinconadia archangelskyi illustrated by Vega (1995a) and Vega and Archangelsky (2001) to be fertile specimens of Fedekurtzia argentina, owing to the similarity of the foliar region and the frequent occurrence of such fertile structures associated with frond fragments (Césari et al. 2001, Coturel & Gutiérrez 2005). The vegeta- tive part of the holotype of Rinconadia archan­ gelskyi (Pl. 3, fig. 1) is bipinnate, with two subopposite basal pinnae or pinnules. One of them preserves two anadromic pinnules and a narrow apical pinnule with the apex slightly bilobed. On the other side of the rachis is a rounded pinnule slightly lobed into at least four lobes. The upper pair of pinnae bears three pinnules on each side of the secondary rachis, and an elongate apical pinnule. The pinnules are wedge-shaped and the first basal catadro- mic pinnule is apically bilobed. Apically, the main axis bifurcates twice, bearing at the apex sporangial masses with fusiform sporangia 1–1.7 mm long and 0.3–0.8 mm wide. The veg- etative sector of the holotype conforms to the reconstruction proposed here for F. argentina. Archangelsky and Archangelsky (1987) also illustrated groups of sporangia associated with specimens of Fedekurtzia argentina from the Tramojo Formation (Mendoza Province). Césari et al. (2001) described a specimen of Rinconadia in close association with F. argen­ tina from the Trapiche Formation, which has excellent preservation allowing recognition of four successive dichotomies in each lateral branch, and recovery of spores from the spo- rangia (Pl. 3, fig. 2). The trilete spores sculp- tured by small grana (Pl. 3, fig. 9) are simi- lar to those obtained from many lyginopterid seed ferns (see Orlova et al. 2009, Serbet et al. 2016) and considered to be prepollen by Stew- art and Rothwell (1983). These spores, when dispersed, have been assigned to Cyclogra­ nisporites rinconadensis Césari & Limarino, Fig. 2. Reconstruction of Fedekurtzia argentina (Kurtz) Arch- angelsky emend. Scale bar: 1 cm. Sporangia out of scale Unauthenticated Download Date | 1/31/18 5:31 PM 144 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 Plate 3. 1. Holotype of Rinconadia archangelskyi Vega, Jejenes Formation, BAPb 5348. Scale bar: 1 cm; 2. Detail of Rinconadia archangelskyi Vega, showing group of sporangia, Volcán Formation, BAPb 12235. Scale bar: 5 mm; 3. Detail of fig. 3, show- ing pinna with elongate pinnules. Scale bar: 1 cm; 4. Specimen described by Vega & Archangelsky (2001) as Poycalyx laterale, with trilobed basal pinnules and distal ovulate organs, Jejenes Formation, BAPb 5363. Scale bar: 1 cm; 5. Specimen preserving groups of sporangia (arrow) described by Archangelsky (1981), Santa Máxima Formation, LP Pb 10519. Scale bar: 1 cm; 6. Holo- type of Polycalyx laterale, Jejenes Formation, BAPb 5364. Scale bar: 1 cm; 7. Specimen described by Vega & Archangelsky (2001) as Polycalyx tetramera, Jejenes Formation, BAPb 5362. Scale bar: 1 cm; 8. Detail of 5, showing a short forked axis bearing fusi- form sporangia. Scale bar: 1 cm; 9. Trilete spore recovered from the sporangia illustrated in Fig. 2. Scale bar: 10 µm; 10. Detail of sporangia in Fig. 8. Scale bar: 3 mm; 11. Small ovuliferous organ with distal long and narrow lobes, Jejenes Formation. BAPb 5366. Scale bar: 1 cm; 12. Small ovule with long distal Jejenes Formation, described by Vega (1995b), BAPb 5346. Scale bar: 1 cm Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 145 a component of palynofloras from central-west- ern Argentina (Césari & Limarino 2002). The sporangiate organ of Genselia uberis (Skog & Gensel) Knaus is similar to Rincona­ dia in its apical position and attachment to bifurcated axes. As in Rinconadia specimens, the fertile branch has immature or character- istic pinnules of basal fronds with few lobes per pinna. Diplopteridium teilianum Walton, a mem- ber of the Lyginopteridaceae, bears sporangia at the apex of dichotomously branched axes, resembling the structure of Rinconadia, but the architecture of the bifurcate frond is differ- ent (see Walton 1940). The Rinconadia pollen organs are also similar to some species of Pte­ ruchus Thomas, the most common reproduc- tive structure of Triassic Corystospermales, which have alternately arranged microsporo- phylls attached to an axis and bearing elon- gate pollen sacs with bisaccate pollen grains. Although Rinconadia lacks a distinctive nar- row microsporophyll lamina, the pattern of organization is comparable. Moreover, similar- ities are recognized with the peltasperm organ Antevsia Harris, which includes branched axes that bear groups of elongate pollen sacs at their distal tips. These pollen organs contain monosulcate grains. O v u l a t e s p e c i m e n s. The first female fer- tile organs associated with Fedekurtzia were described by Gutiérrez (1994) from the Agua Colorada and Tupe formations in the Paganzo Basin. One specimen from the same local- ity (La Cortadera creek) where Césari (1986) recovered the complete fronds of F. argentina (Pl. 2, figs 1, 4) preserves an orbicular lami- nar structure with a narrow base and the apex divided into narrow and long lobes. Scars of possible attachment of oval ovules are aligned over the lower part of the lamina. The finding of ovules attached to this type of structure by Vega and Archangelsky (1997) validated the interpretation given by Gutiérrez (1994) as female reproductive organs. Vega and Archangelsky (1997) reported the finding of compound cupulate receptacles in organic connection with a rachis bearing pin- nae with wedge-shaped to obovate pinnules. The rachis forks apically, bearing bivalve cupules (Pl. 3, figs. 4, 6, 7) encircling oblong ovules with long and narrow distal integu- mentary lobes. These authors described the vegetative frond as “triphyllopteroid”, and it is worth noting that the sample comes from the type locality of Fedekurtzia argentina. Later, Vega and Archangelsky (2001) estab- lished the genus Polycalyx to encompass these female structures. Revision of the vegetative pinnae associated with Polycalyx, according to the reconstruction presented here, allows us to assign them to Fedekurtzia argentina. The vegetative parts of Polycalyx show lobate pin- nules similar to those of F. argentina fronds (Pl. 3, figs 3, 4). However, two species of Polycalyx were dis- tinguished by Vega and Archangelsky (2001): P. laterale and P. tetramera, according to the presence of two or four apical multiovu- late organs. In our analysis of fertile speci- mens we identified four laminar structures with a rounded base and deeply laciniate in their distal part. The specimen illustrated as P. laterale in Vega and Archangelsky (2001, pl. 1, fig. 1) has a main rachis which divides at a wide angle into two short axes bearing rounded, deeply laciniate, laminar receptacles. The right secondary axis (Pl. 3, fig. 6) seems to divide once more, and each division bears a laminar structure according to the orienta- tion of the long lobes. On the counterpart of this specimen can be seen the ovules and their points of insertion arranged in the same con- centric pattern observed by Gutiérrez (1994) in specimens from the Tupe Formation. Vega and Archangelsky (2001, pl. 2, fig. 3) illustrated another specimen showing only two ovulate structures but the other two may be buried in the matrix. The platyspermic ovules described by Vega and Archangelsky (2001) in the ovulate struc- ture have long apical lobes as well as dispersed ovules associated (Pl. 3, fig. 12) that resemble Jejenia alata Vega and Archangelsky, which preserves some internal structural informa- tion (Vega & Archangelsky 2000). Vega and Archangelsky (2001) interpreted the drooping multiovulate organs as rigid and globose cupules, but these leaf-like reproduc- tive receptacles are usually preserved split into flat valves (Pl. 3, fig. 11). We find it difficult to suppose that the small pinnae would support large, heavy, fleshy structures. Moreover, the flattened and leaf-like features of Polycalyx, its unusually large size and the ovules embed- ded on one side (apparently the adaxial sur- face) suggest that it should be interpreted as Unauthenticated Download Date | 1/31/18 5:31 PM 146 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 a megasporophyll rather than a cupule, which implies a set of structures surrounding one or more ovules or seeds (Taylor et al. 2009). As well as in Rinconadia, the pinnules attached to the main axis of Polycalyx repre- sent the basal to mid-sections of Fedekurtzia’s frond, suggesting that reproductive structures could be developed on young plants. The speci- mens illustrated in Plate 3 resemble the archi- tecture of the extant fern Botrychium boreale Milde, which was also compared by Kurtz (1894) with Botrychiopsis, a closely related Gondwanan frond. A s s o c i a t e d s t e m s. Anatomically pre- served stems have been described from the same deposits from which the holotype of Fedekurtzia argentina and fertile specimens were recovered. Césari et al. (2005) described Amosioxylon australis, a single stem 6 cm in diameter with several vascular segments sur- rounded by secondary xylem. The primary xylem is two- or three-ribbed and the rays are heterocellular, with tracheids having reticu- late or spiral thickenings. The tissue between the vascular strands shows reticulate thicken- ings. The pycnoxylic wood is characterized by triseriate-bordered pitting of the tracheids in the tangential and radial walls; the cross-fields show 5–10 simple circular pits. The presence of transverse tracheids was also recognized in Callixylon by Beck (1970), and suggests shared characters with the progymnosperms. However, the presence of more than one vas- cular strand, which is considered a primitive character, also promotes comparisons with early pteridosperms. A s s o c i a t e d p a l y n o l o g i c a l a s s e m b l a - g e s. Gutiérrez and Césari (1987) reported a poorly preserved palynological assemblage from the same levels of the Jejenes Forma- tion bearing original specimens of Fedekurt­ zia argentina in the San Juan Province. Mon- osaccate pollen predominates, represented by Plicatipollenites malabarensis (Potonié & Sah) Foster, Potonieisporites novicus Bharadwaj, Caheniasaccites sp. and Crucisac­ cites sp., together with subordinate spores which include Lundbladispora braziliensis (Pant & Srivastava) Marques-Toigo & Pons. The presence of pollen grains supported the inferred Bashkirian-Moscovian age of the unit. Nearby fossiliferous outcrops of the Jejenes Formation provided palynofloras studied by González Amicón (1973), Gutiérrez and Césari (1987) and Césari and Bercowski (1997), char- acterized also by abundant pollen and more diverse spores. All these palynofloras have been included in the Raistrickia densa/Convo­ lutispora muriornata Biozone (DM) defined by Césari and Gutiérrez (2000). Similarly, specimens of Fedekurtzia argen­ tina from the Tupe Formation are associated with palynological assemblages studied by Césari (1985), which characterize Subzone B of the Raistrickia densa/Convolutispora murior­ nata (DM) Biozone. COMPARISONS Coeval Pennsylvanian floras from Australia are characterized by the so-called enriched Nothorhacopteris flora or Sphenopteridium flora by Morris (1985) or Nothorhacopteris argentinica/Fedekurtzia floras by Rigby (1985). These are characterized by N. argenti­ nica, Fryopsis frondosa (=Cyclopteris sp. sensu Rigby), Botrychiopsis ovata, Dactylophyllum digitatum (=Fedekurtzia intermedia sensu Rigby) and Sphenopteridium sp. The last three species are bipinnate fronds with a leafy foot- stalk, and occur associated with fertile organs described as Dictyothalamus by Morris (1985). Unlike the palaeoenvironmental conditions in Argentina, this Australian flora underlies gla- cial deposits. Among those species, Fedekurtzia interme­ dia (Feistmantel) Rigby is most comparable to F. argentina. The original specimen figured by Feistmantel (1878, pl. 2, fig. 2; 1890, pl. IV, fig. 3), although lost, is similar to the basal section of F. argentina. The neotype selected by Rigby (1973) resembles distal pinnae of F. argentina, even though the pinnules would be slightly buried in the sediment. Rigby (1973) remarked that pinnules are better preserved in the specimen illustrated in his plate 3, fig- ure 11b. Other specimens synonymized with F. intermedia, such as Rhacopteris septentrio­ nalis Feistmantel and Archaeopteris wilkin­ soni Feistmantel, are also closely comparable to mid- and distal sections of F. argentina according to the reconstruction presented here (Fig. 2). New specimens from the Australian flora need to be analysed in order to confirm the relationship between F. intermedia and F. argentina fronds. Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 147 Specimens illustrated by Morris (1975, 1980) as Triphyllopteris austrina have been reassigned to Botrychiopsis by Rigby (1985), Archangelsky (1983) and Iannuzzi and Pfeffer- korn (2002), or with doubts to Fedekurtzia by Archangelsky (1981). Archangelsky (1981) was the first to consider that the original specimen of Aneimites austrina Etheridge (1888) figured by Rigby (1973, pl. 1, fig. 2) corresponds to Botrychiopsis plantiana (Carruthers) Archan- gelsky & Arrondo. Iannuzzi and Labandeira (2008) illustrated frond fragments that con- form in part to Triphyllopteris austrina, from the same locality where Morris (1975, 1980) reported the species, and concluded that they and the holotype of Aneimites austrina Ether- idge should be excluded from B. plantiana and F. argentina. Specimens illustrated by Ian- nuzzi and Labandeira (2008) as T. austrina “minor form” are similar to medial pinnae of F. argentina but the pinnules differ in their entire apical margins apparently being dimin- utively crenulate. Similar foliage from the Peruvian Paracas flora (late Visean to early Serpukhovian in age) was described by Iannuzzi and Pfeffer- korn (2002). In that flora, Sphenopteridium sp. is represented by a bipinnate fragment with a robust axis bearing pinnules irregularly and deeply subdivided into wedge-shaped seg- ments. Although fragmentary, the pinnules resemble distal sections of F. argentina. These authors also described the presence of Triphyl­ lopteris boliviana with small pinnules with many lobes, which are different even from the more laciniate pinnules of the Argentinian species. Botrychiopsis weissiana is another Argen- tinian taxon applied to identify comparable Pennsylvanian fronds, related to cold palaeoen- vironmental conditions (Jasper et al. 2003). Unfortunately, the holotype from the Retamito locality (Jejenes Formation) is a bipinnate fragment with the pinnules partially buried in the sediment, obscuring their complete outline (Archangelsky & Arrondo 1971, pl. 2, fig. 4). This specimen coincides in its dimensions and morphology with a more complete sample from the Tupe Formation at the Mina La Negra locality (Archangelsky & Arrondo 1971, pl. 4), which allows a more precise characteriza- tion of the genus. According to Archangelsky (1981), Fedekurtzia differs from Botrychio­ psis because “Botrychiopsis never have truly bipinnate fronds (at most they are imperfectly bipinnate); pinnules have fused bases, entire margins, and are more rounded.” Despite the abundance of Botrychiopsis weissiana specimens in the Carboniferous of Argentina, the structure of its frond was not reconstructed up to now. Two sectors can be differentiated in Botrychiopsis fronds: the basal, with rounded and entire pinnules fused with the main rachis through a narrow wing; and the mid- and upper sections, with regu- lar, 5-pinnule rounded symmetrical pinnae. There is no development of a distinctive pin- nae rachis along the frond and each pinnule is rounded and broadly inserted, and even though the pinnules tend to be subtriangular they are attached broadly. The apical pinnule is larger, spathulate, and with an entire margin (Fig. 3). The most conspicuous character to differ- entiate Botrychiopsis weissiana from Fede­ kurtzia pinnae is that the first genus shows a broad basal insertion of the pinnae and pinnules, which are rounded with an entire and regular margin, whereas even the most rounded pinnules from Fedekurtzia have at least an incision and/or irregular apical mar- gin. A close relationship between Botrychio psis and Fedekurtzia is suggested by the degree and types of shape differences between these two foliage genera, variation that is compa- rable to that seen among some species of the extant fern genus Botrychium (e.g. Botry­ chium boreale Milde, Botrychium pinnatum St. John). Moreover, fragments of Rinconadia have been described in close association with B. weissiana pinnae (Artabe et al. 1987, Césari & Limarino 1988). Fig. 3. Reconstruction of medial pinnae of Botrychiopsis weis­ siana Kurtz emend. Archangelsky & Arrondo. Scale: 1 cm Unauthenticated Download Date | 1/31/18 5:31 PM 148 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 Fedekurtzia argentina differs from the North American tryphyllopteroid Genselia Knaus in the presence of cyclopteroid basal elements, the regular spacing between pinnae along the rachis, the intra-pinna heteromorphy, the con- tinuous presence of rough or incised pinnules, and the absence of a distinctive rachis in the pinnae of the basal and medial sections of the frond. The overall tendencies of pinnule inci- sion and the diminishing heteromorphy along the frond are considered enough to maintain the separation between these genera. Thus, the Austrocalyxaceae are now interpreted as pteridosperms, which include monopinnate and heteromorphic bipinnate fronds (Nothorhacopteris, Fedekurtzia and, probably, Botrychiopsis). The fertile fronds have the main rachis, unforked or distally forked, bearing apical reproductive structures. Megasporangiate fronds bear cupule-like lami- nar structures with a rounded base and distally laciniated (Polycalyx, Austrocalyx), with ovules inserted on the adaxial and proximal surface of each lamina. The dispersed ovules have elongate apical integumentary lobes. Micro- sporangiate fronds are composed of multiply dichotomized axes forming clouds of fusiform sporangia (Rinconadia); the recovered prepol- len is trilete with small grana (Cyclogranispo­ rites-type). CONCLUSIONS Our revision of some Argentinian Carbon- iferous fronds and the associated reproduc- tive organs confirms the absence of the genus Tryphyllopteris in southern Gondwana. The palaeogeographic distribution of this type of foliage is represented by Tryphyllopteris in Europe, Genselia in North America, and Fede­ kurtzia on the western and eastern margins of Gondwana. Despite their foliar similitude, their relationship and botanical affinities should be corroborated with the findings and a comparison of their reproductive structures. Although the fronds of Botrychiopsis are certainly different from those of Fedekurtzia, some dispersed pinnae of both genera can be erroneously referred to any one of the gen- era. We conclude in this study that the most conspicuous characters to differentiate these pinnae are both the nature of the margin and the shape of the pinnule, being entire and rounded in Botrychiopsis, whereas a notched margin having at least one incision is seen in the wedge-shaped pinnules of Fedekurtzia. It is likely that Botrychiopsis belongs to Aus- trocalyxaceae, in view of its association with Rinconadia remains and the foliage variation within Fedekurtzia’s fronds. Two taxa, Polycalyx and Rinconadia, are interpreted as fertile organs of Fedekurtzia according to the foliage in organic connec- tion. In the revision of the ovulate organs we addressed the nature of the leaf-like structure containing the ovules, which was originally interpreted as a large and globose, fleshy, cupulate organ, but it is proposed here that the structure could be described as a flattened megasporophyll-like receptacle. The architecture of the different fossil gen- era (Nothorhacopteris, Fedekurtzia, Botry­ chiopsis) associated with the Austrocalyxaceae suggests that they were small bushes with reproductive structures growing in different ontogenetic plant stages. ACKNOWLEGDMENTS Constructive comments and suggestions by William A. DiMichele and an anonymous reviewer are grate- fully acknowledged. Special thanks to Luis Fauqué and Carlos O. Limarino for providing the specimens of the Volcán Formation. Funding for this study was provided by Agencia Nacional de Promoción Científica y Tecnológica (grant no. PICT 584). REFERENCES ARCHANGELSKY S. 1971. Las tafofloras del Sistema Paganzo en la República Argentina. Anais da Acade- mia brasileira de Ciençias, 43 (Suplemento): 67–88. ARCHANGELSKY S. 1981. Fedekurtzia, a new Car- boniferous frond from Gondwanaland and its fruc- tification. Am. J. Bot., 68: 1130–1138. ARCHANGELSKY S. 1983. Nothorhacopteris, a new generic name for some Carboniferous Monopinnate fronds of Gondwanaland (= Rhacopteris ovata auct. and Pseudorhacopteris Rigby 1973). Rev. Palaeo- bot. Palynol., 38: 157–172. ARCHANGELSKY A. & ARCHANGELSKY S. 1987. Tafoflora de la Formación Tramojo, Paleozoico tardío en la región de Uspallata, provincia de Mendoza, República Argentina. Ameghiniana 24: 251–256. ARCHANGELSKY S. & ARRONDO O.G. 1971. Paleo- phytologia Kurtziana III. 2. Estudio sobre el género Botrychiopsis Kurtz (Gondwanidium Gothan) del Carbónico Pérmico Gondwánico. Ameghiniana, 8: 189–227. Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 149 ARCHANGELSKY S. & CÚNEO R. 1991. The Neo- paleozoic floristic succession from Northwestern Argentina. A new perspective. Gondwana Seven, Proceedings, (eds.: H.Ulbrich y A.C. Rocha Cam- pos): 469–481. ARCHANGELSKY S. & AZCUY C.L. 1985. Carboni- ferous palaeobotany and palynology in Argentina. Compte Rendus X International Congress of Car- boniferous Stratigraphy and Geology, 4: 267–280. ARTABE A., ARCHANGELSKY S. & ARRONDO O.G. 1987. Sobre una masculina asociada a frondes de Botrychiopsis del Carbonifero de Ciénaga del Val- lecito, provincia de San Juan, Argentina. Actas VII Simposio Argentino de Paleobotánica y Palinología: 21–24. BECK C.B. 1970. The appearance of gymnospermous structure. Biol. Rev., 45: 379–399. BOMFLEUR B., ESCAPA I.H., TAYLOR E.L. & TAYLOR T.N. 2012. Modified basal elements in Dicroidium fronds (Corystospermales). Rev. Pal- aeobot. Palynol., 170: 15–26. CARRIZO M. A. & ARCHANGELSKY S. 2013. Kladis­ tamuos golondrinensis nov. gen. et comb., a fertile foliage from the mid to late Permian of Patagonia, Argentina. Rev. Palaeobot. Palynol., 196: 1–8. CARRIZO H. & AZCUY C. 2015. Floras neodevónicas- eocarboníferas de Argentina. Opera Lilloana 49, Tucumán, 292 pp. CÉSARI S.N. 1985. Palinología de la Formación Tupe (Paleozoico Superior), sierra de Maz, provincia de La Rioja. Parte II. Ameghiniana, 22: 197–212. CÉSARI S.N. 1986. Megafloras de la Formación Tupe (Carbonífero) en Sierra de Maz y Ciénaga del Vallecito, Cuenca Paganzo, Argentina. Anales de la Academia de Ciencias Exactas, Físicas y Natu- rales, 38: 111–137. CÉSARI S.N. & BERCOWSKI F. 1997. Palinología de la Fm. Jejenes (Carbonífero) en la Quebrada de Las Lajas, Prov. de San Juan, Argentina. Nuevas inferen- cias paleoambientales. Ameghiniana, 34: 497–509. CÉSARI S.N. & GUTIÉRREZ P.R. 2000. Palynostratig- raphy of Upper Paleozoic sequences in central- western Argentina. Palynology, 24: 113–146. CESARI S. & LIMARINO C. 1988. Fructificaciones asociadas a Botrychiopsis en sedimentitas lacus- tres del Carbonífero, provincia de San Juan, Argen- tina. Boletín Asociación Latinoamericana de Paleo- botánica y Palinología, 11: 7–11. CÉSARI S.N. & LIMARINO C.O. 2002. Palynology of glacial sediments from the Guandacol Formation (Middle Carboniferous) in the Cerro Bola area, Paganzo Basin, Argentina. Alcheringa, 26: 159–176. CÉSARI S.N., ARCHANGELSKY S. & VEGA J. 2005. Anatomy of a new probable pteridosperm stem from the Late Carboniferous of Argentina. Revista del Museo Argentino de Ciencias Naturales, nueva serie, 7: 7–15. CÉSARI S.N., LIMARINO C.O. & GULBRANSON E. 2011. An Upper Paleozoic bio–chronostratigraphic scheme for the western margin of Gondwana. Earth–Sci. Rev., 106: 149–160. CÉSARI S., GUTIÉRREZ P., FAUQUÉ L. & LIMA- RINO C. 2001. La secuencia carbonífera de Trapi- che (Precordillera de San Juan, Argentina): ubi- cación estratigráfica y contenido paleoflorístico. Publicación Especial de la Asociación Paleon- tológica Argentina, 8: 19–28. CÉSARI S.N., GUTIÉRREZ P.R., SABATTINI N., ARCHANGELSKY A., AZCUY C.L., et al. 2007. Paleozoico Superior de Argentina un registro fos- ilífero integral en el Gondwana occidental. Pub- licación Especial de la Asociación Paleontológica Argentina, 11: 35–54. CLADERA G., ARCHANGELSKY S. & VEGA J.C. 2000. Geographic, stratigraphic and paleoenvi- ronmental precisions about the horizons bearing pteridospermic cupules in the Jejenes Formation, Carboniferous of San Juan Province, Argentina. Ameghiniana, 37: 213–219. COTUREL E. & GUTIÉRREZ P. 2005. La megaflora de la Formación Tupe (Carbonífero Superior-Pér- mico Inferior), en la Mina La Delfina, San Juan, Argentina. Revista del Museo Argentino de Cien- cias Naturales nueva serie, 7: 17–29. ETHERIDGE R. 1888. Additions to the fossil flora of eastern Australia. Proc. Linn. Soc. N. S. W., 2: 1300–1309. ETHERIDGE R. 1894. Occasional descriptions of New South Wales fossils, Palaeontologia Novae Cam- briae Meridionales. Records Geological Survey of New South Wales, 4: 32–37. FEISTMANTEL O. 1878. Palaeozoische und meso- zoische Flora des östlichen Australiens. Palaeonto- graphica Suppl., 3: 53–130. FEISTMANTEL O. 1879. Palaeozoische und meso- zoische Flora des Australiens. Palaeontographica Suppl., 3: 133–195. FEISTMANTEL O. 1890. Geological and Palaeon- tological Relations of the Coal and Plant-bearing Beds of Palaeozoic and Mesozoic Age in Eastern Australia and Tasmania. Memoirs Geological Sur- vey New South Wales, Palaeontology, 3: 1–183. FRENGUELLI J. 1941. Sobre una flórula Carbonífera de Agua de los Jejenes, San Juan, conservada en el Museo de La Plata. Notas del Museo de La Plata, 6: 459–478. FRENGUELLI J. 1944. Apuntes acerca del Paleozoico superior del noroeste argentino. Museo Ciencias Naturales de La Plata, Revista n.s. Geol., 2: 213–265. FRENGUELLI J. 1946. El carbonífero argentino según sus floras fósiles. Asociación Geológica Argentina Revista, 1: 107–115. GONZÁLEZ AMICÓN O.R. 1973. Microflora carbónica de la localidad de Retamito, provincia de San Juan. Ameghiniana, 10: 1–35. GUTIÉRREZ P.R. 1994. Fructificaciones asociadas a Fedekurtzia Archangelsky en el Carbonífero de Unauthenticated Download Date | 1/31/18 5:31 PM 150 E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 la prov. de La Rioja, Argentina. Ameghiniana, 31: 239–248. GUTIÉRREZ P.R. & CÉSARI S.N. 1987. Nuevos ele- mentos microfloristicos de la Formación Jejenes (Carbónico), Provincia de San Juan. I Jornadas de Geología de Precordillera, Actas, 1: 168–173. IANNUZZI R. & LABANDEIRA C.C. 2008. The oldest record of external foliage feeding and the expan- sion of insect folivory on land. Ann. Entomol. Soc. Am., 101: 79–94. IANNUZZI R. & PFEFFERKORN H.W. 2002. A pre-gla- cial, warm-temperate floral belt in Gondwana (Late Visean, Early Carboniferous). Palaios, 17: 571–590. JASPER A., GUERRA-SOMMER M., CAZZULO-KLE- PZIG M. & MENEGAT R. 2003. The Botrychio­ psis genus and its biostratigraphic implications in Southern Paraná Basin. Anais da Academia Bra- sileira de Ciências, 75: 513–535. KNAUS M.J. 1994. Triphyllopteris collombiana: A clarification of the generic concept based on rediscovered specimens from Kossberg bei Plauen, Germany, and a reassignment of the North Ameri- can species of Triphyllopteris to Genselia gen. nov. Int. J. Plant Sci., 155: 97–166. KNAUS M.J. 1995. The species of the Early Carbo- niferous fossil plant genus Genselia. Int. J. Plant Sci., 156: 61–92. KURTZ F. 1894. Contribuciones a la Palaeophytología Argentina. 1. Botrychiopsis, un género nuevo de las Cardiopterídeas. Revista del Museo de La Plata, 6: 117–126. KURTZ F. 1921. Atlas de plantas fósiles de la República Argentina. Actas Academia Nacional de Ciencias de Córdoba, 7: 129–153. LEGUIZAMÓN R. & VEGA J.C. 1991. El género Tri­ phyllopteris (morfogénero de frondes) en el Carbo- nífero de la República Argentina. Ameghiniana, 27: 305–309. LIMARINO C.O., TRIPALDI A., MARENSSI S. & FAUQUÉ L. 2006. Tectonic, sea-level, and cli- matic controls on Late Paleozoic sedimentation in the western basins of Argentina. J. S. Am. Earth Sci., 22: 205–226. LIMARINO C.O., CÉSARI S.N., SPALLETTI L.A., TABOADA A.C., ISBELL J.L., GEUNA S. & GUL- BRANSON E.L. 2014. A paleoclimatic review of southern South America during the late Paleozoic: A record from icehouse to extreme greenhouse con- ditions. Gondwana Res., 25: 1396–1421. MCCOY F. 1847. On the fossil botany and zoology of the rocks associated with the coal in Australia. Ann. Magaz. Nat. Hist., 20: 145–157. MORRIS L.N. 1975. The Rhacopteris Flora in New South Wales: 99–108. In: Campbell H.S.W. (ed), Gondwana Geology, Canberra, Australia. MORRIS L.N. 1980. Carboniferous floral succession in eastern Australia: 350–358. In: Herbert C. & Helby, R. (eds), A guide to the Sydney Basin. Bull. Geol. Surv. New South Wales, 26. MORRIS L.N. 1985. The floral succession in eastern Australia: 118–123. In: Roberts J. (ed.) Australia. The Carboniferous of the World II. IGME. ORLOVA O.A., MEYER-MELIKIAN N.R. & ZAVIA- LOVA N.E. 2009. A new microsporangiate organ from the Lower Carboniferous of the Novgorod Region, Russia. Paleontol. J., 43: 1316–1329. READ C.B. 1938. The age of the Carboniferous strata of the Paracas Peninsula, Peru. J. Wash. Acad. Sci., 28: 396–404. RETALLACK G.J. 1980. Late Carboniferous to middle Triassic megafossil floras from the Sydney Basin: 384–430. In: Herbert C. & R. Helby (eds), A Guide to the Sydney Basin. Bull. Geol. Surv. New South Wales, 26. RIGBY J.F. 1969. A revaluation of pre-gondwana car- boniferous flora. Anais da Academia Brasileira de Ciencias, 41: 394–413. RIGBY J.F. 1973. Gondwanidium and other similar Upper Palaeozoic genera, and their stratigraphic significance. Geol. Surv. Queensl., Publ. 350, Pal- aeontological Papers, 24: 1–19. RIGBY J.F. 1985. Aspects of Carboniferous palaeo- botany in eastern Australia. Compte Rendu Dix- ième Congrès International de Stratigraphie et de Géologie du Carbonifère, 4: 307–12. SERBET R., HAGEMAN S., HOFFMAN B.L., TAY- LOR T.N. & TAYLOR E.L. 2016. A new Pennsylva- nian pollen organ from northwestern Missouri with affinities in the Lyginopteridales. Rev. Palaeobot. Palynol., 234: 136–146. STEWART W.N. & ROTHWELL G.W. 1993. Paleobot- any and the evolution of plants. Cambridge Uni- versity Press, 521 pp. SZAJNOCHA L. 1891. Über einige Carbone Pflauzeur- este aus den Argentinische Republik. Sitzungsber. Akad. Wiss. Math. Naturwiss. Kl., 100: 203–213. TAYLOR E.L., TAYLOR T.N. & KRINGS M. 2009. Paleobotany: the biology and evolution of fossil plants. Academic Press, 1–1230. VÁZQUEZ M.S., CORREA G., COLOMBI C., DRO- VANDI J. & CÉSARI S.N. 2016. Revisión de una localidad clásica del carbonífero de Precordillera: Retamino, provincia de San Juan. Acta geológica Lilloana (Supl.), 28: 177–183. VEGA J.C. 1995a. Rinconadia archangelskyi, gen. et sp. nov., a new fertile structure bearing sporangium-like bodies attached to bipnnate fronds from the Jejenes Formation (Carboniferous, San Juan Province, Argentina). Actas 6° Congreso Argentino de Paleon- tología y Bioestratigrafía (Trelew, 1994): 291–299. VEGA J.C. 1995b. La flora fósil de la Formación Jejenes (Carbonífero). Implicancias paleoclimáti- cas y paleobiogeográficas. Ameghiniana, 32: 31–40. VEGA J.C. & ARCHANGELSKY S. 1997. The first Gondwana Carboniferous compound cupules and associated seeds. A preliminary note. Rev. Palaeo- bot. Palynol., 99: 55–59. Unauthenticated Download Date | 1/31/18 5:31 PM E.P. Coturel & S.N. Césari / Acta Palaeobotanica 57(2): 135–151, 2017 151 VEGA J.C. & ARCHANGELSKY S. 2000. Jejenia gen. nov., a new Carboniferous disseminule from San Juan, Argentina. Boletín de la Academia Nacional de Ciencias, 64: 61–69. VEGA J.C. & ARCHANGELSKY S. 2001. Austroca- lyxaceae, a new pteridosperm family from Gond- wana. Palaeontographica, B, 257: 1–16. WALKOM A.B. 1934. Notes on some Carboniferous plants from New South Wales. Proc. Linn. Soc. N. S. W., 59: 430–434. WALTON J. 1940. An introduction to the study of fos- sil plants. Adam and Charles Black, London, 1–188. WHITE M. 1965. Plant fossil collection from the Georgetown/Clarke River Area. Appendix 3, in D.A.White (ed.) The Geology of the Georgetown/ Clarke River Area, Queensland. Bull. Bur. Miner. Res., Geophysics of Australia, 71: 152–165. Unauthenticated Download Date | 1/31/18 5:31 PM