Cretaceous Research 150 (2023) 105575 Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes Upper Barremianlower Aptian charophyte biostratigraphy from Arrifes section (Algarve Basin, Southern Portugal): correlation with dinoflagellate cyst biostratigraphy rez-Cano a, b, c, d, *, He Jordi Pe lder J.R. Pereira e, f, Marcia Mendes g, Ze lia Pereira g, e, h f Pedro Miguel Callapez , Paulo Fernandes a  de Paleontologia Miquel Crusafont, Universitat Auto Institut Catala noma de Barcelona, ICTA-ICP Building, c/de les Columnes s/n, Campus de la UAB, Cerdanyola del Vall es, Catalonia E-08193, Spain b Departament de Dina mica de la Terra i de l’Ocea , Facultat de Ci encies de la Terra, Universitat de Barcelona-UB, Barcelona, Catalonia 08028, Spain c Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona, Spain d Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ci encies de la Terra, Universitat de Barcelona-UB, Barcelona, Catalonia 08028, Spain e Centre for Earth and Space Research of the University of Coimbra (CITEUC), Faculty of Sciences and Technology, Earth Sciences Department, University of Coimbra e Po lo II, Rua Sílvio Lima, Coimbra 3030e790, Portugal f CIMA, Centre of Marine and Environmental Research\\ARNET e Infrastructure Network in Aquatic Research, University of Algarve, Campus de Gambelas, Faro 8000-139, Portugal g LNEG, National Laboratory of Energy and Geology, Rua da Amieira, S. Mamede de Infesta 4465-965, Portugal h Grupo de Investigacio n PaleoIberica, Departamento de Geología y Geografía, Universidad de Alcala , Alcala  de Henares 28871, Spain a r t i c l e i n f o a b s t r a c t Article history: The Arrifes section (Algarve Basin, Southern Portugal) has been studied from the viewpoint of char- Received 14 February 2023 ophyte biostratigraphy. The previous sedimentological studies in this section showed that it is built of the Received in revised form interbedding of continental and marine facies that contain both marine and continental palynomorphs 18 April 2023 (pollen, spores, and dinoflagellates), providing an excellent sedimentary context to perform direct cor- Accepted in revised form 5 May 2023 relations between marine and continental domains. In the present work, the identified charophyte Available online 18 May 2023 biozones have been correlated with dinoflagellate biozones previously recognized in the Arrifes section, being the first time that these two biochronologies can be directly correlated. From the charophyte Keywords: Charophyta biostratigraphy viewpoint, two assemblages are distinguished. The older one is found between 65 and Iberia 135 m of the stratigraphic section, and it is composed of the species Echinochara lazarii, Atopochara Cretaceous trivolvis var. triquetra, A. trivolvis var. trivolvis, Clavator grovesii var. jiuquanensis, Clavator harrisii var. Clavatoraceae harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis. This assemblage belongs to the upper Barremian Continental-marine biochronology elower Aptian Clavator grovesii var. jiuquanensis Eurasian biozone and also to the Ascidiella cruciata- Palynology Pseudoglobator paucibracteatus European biozone and it is described in beds with the dinoflagellate cyst Subtilisphaera scabrata (lower to lowermost upper Barremian) and Odontochitina operculata (from upper Barremian upwards). The younger charophyte assemblage is found between 135 and 155 m of the stratigraphic section, and it is composed of the species A. trivolvis var. trivolvis, Clavator grovesii var. corrugatus, Clavator harrisii var. harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis. This assemblage belongs to Clavator grovesii var. corrugatus biozone, previously assigned to upper Aptian (Clavator grovesii var. lusitanicus biozone). However, in the Arrifes section, this assemblage is found in beds assigned to the dinoflagellate cyst Odontochitina operculata (from upper Barremianelower Aptian). The direct correlation of the base of the C. grovesii var. corrugatus biozone with the dinoflagellate cyst O. operculata, indicates that the base of the Clavator grovesii var. corrugatus biozone is in the upper lower Aptian, which is slightly older than was previously suggested, and it is extended until the middle Albian. © 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). * Corresponding author. Institut Catal  noma de Barcelona, ICTA-ICP Building, c/de les Columnes s/n, Campus de la UAB, a de Paleontologia Miquel Crusafont, Universitat Auto s E-08193, Catalonia, Spain. Cerdanyola del Valle rez-Cano). E-mail addresses: jordi.perez@icp.cat, jordi_perez-cano@ub.edu (J. Pe https://doi.org/10.1016/j.cretres.2023.105575 0195-6671/© 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 1. Introduction improves the application, accuracy, and utility of extant upper BarremianeAptian charophyte biozones. Charophyte fructifications (utricles) of the Clavatoraceae family are one of the main fossil groups used for the biostratigraphic 2. Geological setting characterization of Lower Cretaceous continental record (e.g., Grambast, 1974; Rey and Ramalho, 1974; Martín-Closas, 1989; The Algarve Basin is located in southernmost Portugal (Fig. 1A), Musacchio, 1989, 2000; Schudack, 1993; Trabelsi et al., 2016; and its sedimentary infilling is composed of rocks that range from Sanjuan et al., 2021). In the last decades, detailed biozonations have the Upper Triassic to the recent (Manuppella et al., 1988; Fernandes been proposed, especially in European and Chinese basins (e.g., et al., 2013; Terrinha et al., 2013). The first sedimentary cycle is of Wang and Lu, 1982; Riveline et al., 1996; Mojon, 1996, 2002; the Late Triassiceearliest Jurassic age corresponding to the initial Martín-Closas et al., 2009; Pe rez-Cano et al., 2022a). However, few continental rifting phase of Pangaea breakup in the Iberian range data can allow a precise correlation of the charophyte biozonations and formation of the Central Atlantic. The latter comprises a suc- with the coeval standard marine biozonations, as only in some cession of continental red beds, followed by evaporites, and is cases both domains are correlated. Continental-marine correlations capped by volcano-sedimentary deposits related to the Central can be performed in three different manners. 1) Direct correlations Atlantic Magmatic Province (Verati et al., 2007; Vilas-Boas et al., are established when continental and marine fossils are found 2022). The following sedimentary cycle consists of Sinemurian to interbedded or together in the same stratigraphic section or the Tithonian shelf carbonates deposited during the passive margin same bed. 2) Indirect correlations are made after performing a phase (Rocha, 1976; Manuppella et al., 1987; Marques and Rocha, lithostratigraphic equivalence between/among different sections, 1988a, 1988b; Azere ^do et al., 2003; Dommergues et al., 2011; describing charophytes and marine organisms, respectively. 3) The Borges et al., 2011, 2012). Changes in the thickness and facies of the compilation correlation is the most common type of marine- carbonate sequences, together with regional unconformities and continental correlation, and it is carried out on a regional scale, hiatuses, are attributed either to carbonate allocyclic processes, using regional geological data, such as sequence stratigraphy or the global sea level variations or regional tectonic events (Manuppella, age of the marine units that overlay and underlay the non-marine 1988; Terrinha et al., 2013; Ramos et al., 2016). ones. The correlation between charophyte biozones with their The Lower Cretaceous sedimentary interval (Berriasian to Cen- coeval standard marine biozones for the Lower Cretaceous Series omanian) is also included in the passive margin succession. How- was first summarized by Riveline et al. (1996). In recent years, the ever, it differs from the Jurassic sequences due to its mixed correlation has been improved for the Barremianelower Aptian carbonate and siliciclastic composition (Rey, 2006, 2009). Berria- timespan by establishing direct correlations (e.g., Martín-Closas sian marls and dolomites are found at the base of the Lower et al., 2009) or using chemostratigraphic methods, such as Sr- Cretaceous sedimentary interval, and it is upwards followed by isotope stratigraphy (Pe rez-Cano et al., 2022a). Valanginian to Barremian marls, dolomites, sandstones, and mud- The present work is focused on the upper BarremianeAptian stones deposited in nearshore and continental settings. The Aptian charophyte biostratigraphy. According to the extant charophyte to lower Albian sedimentary sequences comprise, at the base, biozonation, three biozones are described for this stratigraphic variegated mudstones and carbonates of nearshore to lagoonal interval. The Ascidiella cruciata-Pseudoglobator paucibracteatus Eu- settings, followed by transgressive marl and limestone cycles. Up- ropean biozone and the Clavator grovesii var. jiuquanensis Eurasian per Albian to Cenomanian strata are only known in the eastern biozone are almost equivalent and their ages are upper lower Algarve Basin, where they are represented by shallow water car- Barremianelower Aptian and upper Barremianelower Aptian, bonate platform limestones interbedded with marls and dolomites. respectively (Pe rez-Cano et al., 2022a). The Clavator grovesii var. The age determinations of the Lower Cretaceous strata were mostly corrugatus biozone overlies the previous biozones, and its age is based on foraminifera biostratigraphy (Rey and Ramalho, 1974; considered as late Aptian e middle Albian (Riveline et al., 1996; Ramalho and Rey, 1981; Rey, 1983, 1986, 2006; Correia, 1989, 2009) Perez-Cano et al., 2022a). However, the boundary between both and palynology (Berthou, 1983; Berthou and Leerevel, 1990; biozones is usually difficult to describe and correlate with the Hochuli et al., 2006; Heimhofer, 2007; Mendes et al., 2023). marine domain due to the recorded marine transgression between In the region of Albufeira (Fig.1B), the Lower Cretaceous carbonates the late Barremianelower Aptian in the Tethyan Realm. This that comprise the Arrifes section can be observed on the subvertical transgression reached its peak point in the early Aptian (e.g., and vertical strata outcropping on the coastal cliffs (Fig. 1C). These Hardenbol et al., 1998; Wissler et al., 2003; Pictet et al., 2015; Bover- strata were deformed due to the tectonic inversion of the Algarve Arnal et al., 2016), restricting the deposition of continental facies to Basin, which caused the compression and the uplift of the nearby few basins, where both biozones can be found without sedimentary Albufeira diapir (Terrinha, 1998; Terrinha et al., 2013; Ramos et al., discontinuities (e.g., Trabelsi et al., 2016). The main goal of this 2016). The present work follows the most recent sedimentological work is to improve the correlation and the equivalence between and age determination, based on dinoflagellates, of the Arrifes section integrated continental and marine biozonations in the upper carried out by Mendes et al. (2023). The section probably correlates BarremianeAptian time interval. The charophyte assemblages from with the Salema, Barranc~ ao and Burgau Formations (Fig.1E). However, the Arrifes section (Algarve, Southern Portugal) have been studied there is a lateral change between the western part of the Algarve Basin to achieve this objective. This section is composed of the inter- and the Central part, challenging a clear attribution of the succession bedding of shallow marine to transitional continental marls, lime- in the Arrifes section to particular lithostratigraphic units. stones, and minor sandstones and conglomerates, which yield a significant diversity of terrestrial and marine palynomorphs, 3. Materials and methods including spores, pollen grains, and dinoflagellate cysts, the latter already used as biostratigraphic markers (Mendes et al., 2023) The Arrifes section is located on the coastal cliffs at the western providing a unique context to establish direct correlations between part of Albufeira; base: 37 040 43.1200 N, 8 160 11.10 W; top: terrestrial and marine domains. The present work proposes a direct 37 040 35.3300 N, 8 160 35.5400 W (Fig. 1B-C). The section is 194 m- correlation between the charophyte biozones described in the thick, and it is mainly composed of marls, limestones, and marly study of charophyte assemblages with the dinoflagellate biozones limestones. Sandstones and conglomerates are locally found previously identified by Mendes et al. (2023). This correlation (Figs. 1C, D and 2). For the present work, between 1 and 3 kg of 2 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Fig. 1. A) Location and geologic map of the Algarve Basin (modified from Oliveira et al., 1992; Manuppella, 1992; Ramos et al., 2016). The squared area corresponds to the zone represented in Fig. 1C. B) Simplified map of the Albufeira region, showing the location of the Arrifes section (modified from Rocha et al., 1989). C) Outcrop of the Arrifes section. D) Detail of the Arrifes section. E) Lithostratigraphy of the Algarve Basin (adapted from Rey, 2006, Terrinha et al., 2013; Mendes et al., 2023) and the stratigraphic interval assigned to the Arrifes section in this study. The assignment of the lithostratigraphic units from the Arrifes section is tentative. 3 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Fig. 2. A) Stratigraphic log of Arrifes section with the stratigraphic position of the studied samples, and the charophyte and dinoflagellate cysts biostratigraphy (modified from Mendes et al., 2023). The palynological sample's position and results were provided by Mendes et al. (2023). B) Key to Figure A. 4 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 over the last decades (e.g., Feist and Wang, 1995; reply by Martín- Closas and Schudack, 1997), resulting in the establishment of two different visions, i.e., the phenetic and the cladistic vision. The present study follows the phylogenetic approach developed by Martín-Closas (1989, 1996) and Schudack (1993). Rey and Ramalho (1974) first described Lower Cretaceous char- ophytes in the Algarve Basin, particularly in the BarremianeAptian deposits of the western part of the basin (Burgau and Luz sec- tions). Later, Grambast-Fessard (1980a, 1980b, 1986) described Aptian (and Albian?) charophyte flora also in the western part of the basin (Luz and Zavial sections). These studies enabled the description of Ascidiella reticulata var. irregularis (Grambast-Fessard, 1986) Martín-Closas 1996, which is, until now, only found in the Algarve. Charophyte remains in the Arrifes section were found in seven samples, that were gathered in the middle to upper part of the stratigraphic section (Fig. 2). The charophyte assemblage is composed of 11 taxa, including charophyte fructifications and thalli (Figs. 3 and 4; Appendix 2). Most of the recovered charophyte fructifications show superficial erosion and are sometimes broken suggesting lateral transport. Charophyte thalli are very rare and when occur they are very small portions. These taphonomical features of the fructifications and thalli indicate some degree of biostratinomic selection before deposition (see e.g., Vicente et al., 2016; Perez-Cano et al., 2022b); for that reason, the studied as- semblages are usually considered parautochthonous (locally allochthonous), suggesting a short-term transport towards de inner carbonate platform. The abundance of charophyte fructifications in each sample is found in Appendix 2. 4.1. Charophyte fructifications Division Charophyta Migula, 1897 Class Charophyceae Smith, 1938 Order Charales Lindley, 1836 Family “Porocharaceae” (Grambast, 1962) emend. Schudack, 1993 €dler, 1955) emend. Schudack, 1986 Genus Porochara (Ma Morphogroup Porochara fusca sensu Martín-Closas (1989, 2000) and Schudack (1993) Fig. 2. (continued). Porochara cf. fusca marls were collected from 20 marl beds along the entire section. Fig. 3AeB Samples were prepared in the Palaeontological Laboratory of the €dler p. 19e20, Pl. A, figs. 22e25. 1952 Aclistochara fusca nov. sp. e Ma Departament de Dina mica de la Terra i de l’Ocea , Universitat de 1955 Porochara fusca (Ma €dler 1952) nov. comb. e Ma €dler, p 271. Barcelona. Each sample was put in a solution of water, oxygen peroxide (H2O2; eliminates the organic matter), and sodium car- Description. Five porocharacean gyrogonites have been found in bonate (Na2CO3; deflocculates the clays). After a few days, the sample C127W (Appendix 2). They are small (<500 mm height and samples were sieved using three meshes of 1000, 500, and 200 mm. wide), and ellipsoidal. The base is rounded, and the apex has an Once the samples were dried, the microfossils (including char- apical pore (Fig. 3B). The number of convolutions varies between 8 ophytes fructifications and thalli, ostracods, vertebrate remains, and 10. The inner part is recrystallized, impeding the observation of and other associated microfossils) were hand-picked using small the basal plate, and consequently, these gyrogonites could be also brushes under a binocular microscope AmScope SE305R-PZ-LED attributed to the genus Feistiella Schudack, 1986. Nevertheless, they under the magnifications of 10, 20, 30, and 60. The picked have been assigned to the genus Porochara as no Feistiella species up charophytes and other fossils are temporarily stored at Institut are described in the Barremian nor the Aptian and there are no  de Paleontologia Miquel Crusafont and will be housed in the Catala Festiella species with a width or length <500 mm. The species Geological Museum of Portugal (Lisbon) once their study is assignation remains as ‘coffer to’, as the number of gyrogonites is concluded. Figured specimens have provisional references (Arr-Ch- very low to make a clear morphometric analysis and identification. 1 to Arr-Ch-37) that will have their equivalence once they are Chronostratigraphic distribution. The oldest occurrence of this definitively housed. Appendix 1 shows the equivalence of figured species is in the Bajocian, Middle Jurassic (Tiss et al., 2019) and it is specimens with this provisional reference. extended until the and Berriasian (Martín-Closas, 2000). Its asso- ciation with Clavator grovesii var. jiuquanensis (Fig. 2; Appendix 2) may indicate that this species has a very long timespan. 4. Systematic charophyte palaeobotany Family Clavatoraceae Pia, 1927 The taxonomy and systematic discussion of charophytes are not Subfamily Atopocharoidae (Grambast, 1968) emend. Martín-Closas the focus of this study. This topic has been extensively discussed ex Schudack, 1993 5 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Fig. 3. SEM pictures of charophytes from the Arrifes section: Porochara, Echinochara, and Atopochara. AeB) Porochara cf. fusca (sample C127W; specimen Arr-Ch-1). A) Lateral view. B) Oblique-apical view, showing the apical pore. C) Echinochara lazarii (sample C152; specimen Arr-Ch-2). Wide arrow marks the apical neck of the gyrogonite. Thin arrow marks the basal rounded cell of the trifurcation. DeH) Atopochara trivolvis var. triquetra (sample C127W). DeE) Lateral view (specimens Arr-Ch-3 and Arr-Ch-4); F) Antheridium shield; G) Basal view (specimen Arr-Ch-5); H) Apical view (specimen Arr-Ch-6). IeP) Atopochara trivolvis var. trivolvis. I) Lateral view (sample C127W; specimen Arr-Ch-7). JeP) Atopochara trivolvis var. trivolvis (sample C178). JeL) Bigger specimens. J) Lateral view (specimen Arr-Ch-8); K) Basal view (specimen Arr-Ch-9); L) Apical view (specimen Arr-Ch-10). MeP) Smaller specimens. MeN) Lateral view (specimens Arr-Ch-11 and Arr-Ch-12); O) Basal view (specimen Arr-Ch-13); P) Apical view (specimen Arr-Ch-14). 6 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 rez-Cano, Bover-Arnal et Genus Echinochara (Peck, 1957) emend. Pe (Appendix 2). This variety is distinguished from the previous one by Martín-Closas, 2020 having a more packed structure, more spiralized long cells, and very small to absence of the imprint of the antheridium shields. rez-Cano, Echinochara lazarii (Martín-Closas, 2000) Mojon ex Pe Chronostratigraphic distribution. The older occurrence of this Bover-Arnal et Martín-Closas, 2020 variety is in the upper Barremian, where few utricles of this species Fig. 3C are found in a population dominated by Atopochara trivolvis var. 2000 Echinochara peckii var. lazarii nov. var. e Martín-Closas, p. 70, triquetra (Pe rez-Cano et al., 2020, 2022a). Homogeneous pop- Pl. 6: figs. 1e8, Pl. 7: figs. 1e6. ulations of this variety are found between the lower Aptian and the 2020 Echinochara lazarii (Martín-Closas, 2000) comb. nov. Mojon ex  middle Albian (e.g., Martín-Closas, 2000; Alvarez-Parra et al., 2021). rez-Cano, Bover-Arnal et Martín-Closas e Pe Pe rez-Cano et al. p. Subfamily Clavatoroidae (Grambast, 1969) emend. Martín-Closas ex 6e8, figs. 6e9. Schudack, 1993 Description. A few utricles of this species are only found in Genus Clavator (Reid and Groves, 1916) emend. Martín-Closas ex sample C152 (Appendix 2). This utricle is composed of two super- Schudack, 1993 imposed series of bract-cells that cover the gyrogonite in its abaxial part (see Perez-Cano et al., 2020). However, all the specimens of Clavator grovesii Harris, 1939 this taxon found in the Arrifes section only preserve the inner series Clavator grovesii var. jiuquanensis (Wang, 1965) Grambast, 1970 of the utricle, which is composed of the characteristic fork-like unit emend. Martín-Closas, 1996 formed of three long cells basally attached to a small and rounded Fig. 4AeF cell. Sometimes the cast of the non-calcified gyrogonite is found 1965 Perimneste jiuquanensis sp. nov. e S.Wang, p. 467, Pl. 1. attached. This species is widely distributed in the Western Tethyan 1970 Clypeator jiuquanensis (S. Wang 1965) nov. comb. e Grambast, basins (Perez-Cano et al., 2020 and references therein), but this is p.1965, Fig. D; Pl. 3, figs. 1e5. the first time that it is described in Portugal. 1973 Clypeator europaeus n. sp. e Ma €dler in Neagu and Georgescu- Chronostratigraphic distribution. This species is described be- Donos, p. 178, Pl. I, fig. 7e8; Pl. II, figs. 1e9. tween the lower Barremian and lower Aptian (Martín-Closas, 2009; 1980a Clypeator europaeus Ma €dler e Grambast-Fessard, p. 37e38, rez-Cano et al., 2022a). Pe Fig. 1e2; Pl. 1, figs. 1e9; Pl. 3, fig. 2. Genus Atopochara (Peck, 1938) 1996 Clavator grovesii var. jiuquanensis (Wang, 1965) Grambast, 1970 emend. e Martín-Closas, p. 278, Firsg. 12. Atopochara trivolvis (Peck, 1938) emend. Martín-Closas, 1996 Atopochara trivolvis var. triquetra (Grambast, 1968) Martín- Description. This species is common in the lower part of the Closas, 1996 stratigraphic section, being very abundant in samples C127E and Fig. 3DeH C127W (Appendix 2). It is characterized by having a bilateral symmetry with two lateral and prominent cells-shields in which 1968 Atopochara trivolvis subsp. triquetra subsp. nov. e Grambast, p. the 12 cells have the same length. Some specimens can have 9, Pl. 3, figs. 14AeC. slightly twisted cells in the lateral shields with 13 cells (Fig. 4BeD). 1996 Atopochara trivolvis var. triquetra (Grambast, 1968) Martín- They are considered as intermediated morphologies between Closas nov. comb. e Martín-Closas, p. 272, Firsg. 8. C. grovesii var. jiuquanensis and the C. grovesii var. corrugatus, i.e., Description. Few utricles of this variety only appear in samples C. grovesii var. jiuquanensis advanced or C. grovesii var. corrugatus C32, C127E, and C127W (Appendix 2). In samples C127W and primitive. C127E, this variety is associated with Atopochara trivolvis var. triv- Chronostratigraphic distribution. This variety appears in the olvis, being the latter dominant in the Atopochara trivolvis popula- lower upper Barremian (Pe rez-Cano et al., 2022a) and it is found in tion (Appendix 2). Studied specimens correspond to the advanced the upper Barremian and Aptian in the whole Eurasia (e.g., Martín- morphotype defined by Martín-Closas and Grambast-Fessard Closas, 2015; Li et al., 2020). (1986) and are distinguished by the observation of a very small Clavator grovesii var. corrugatus (Peck, 1941) Martín-Closas, 1996 antheridium shield imprint (Fig. 3F). Fig. 4GeL Chronostratigraphic distribution. This species firstly appears in the Hauterivian, where it is found associated with Atopochara 1941 Perimneste corrugata n. sp. e Peck, p. 295e297, Pl. 42, figs 15e24. trivolvis var. ancora (Grambast, 1967) Martín-Cloas, 1996 (e.g., 1962 Clypeator corrugatus (Peck, 1941) nov. comb. e Grambast, p. Martín-Closas and Salas, 1994). Homogeneous populations are 295. firstly found at the base of the Barremian (Martín-Closas and Salas, 1980a Clypeator lusitanicus n. sp. e Grambast-Fessard, p. 39e41, 1994; Pe rez-Cano et al., 2022a). In the upper Barremianelower Fig. 3; Pl. 1, fig. 10e12; Pl. 2, figs. 1e5; Pl. 3, fig 3e5. Aptian it is found associated with Atopochara trivolvis var. trivolvis 1996 Clavator grovesii var. lusitanicus (Grambast-Fessard, 1980a) Peck, 1938 (see Pe rez-Cano et al., 2020, 2022a). comb. nov. e Martín-Closas, p. 278, fig. 11. 1996 Clavator grovesii var. corrugatus (Peck, 1941) nov. comb. e Atopochara trivolvis var. trivolvis Peck, 1938 Martín-Closas, p. 278, fig. 11. Fig. 4IeP 2000 Clavator grovesii var. corrugatus (Peck, 1941) Martín-Closas, 1938 Atopochara trivolvis n. sp. e Peck, p. 173e176, Fig. 1; Pl. 28, figs. 1996 e p. 142e145, Pl. 14, figs. 10e12. 5e12. Description. The utricle of this species shows the characteristic 1996 Atopochara trivolvis var. trivolvis e Martín-Closas, p. 113e116, bilateral symmetry, with two lateral bract-cell shields that are Pl. 9, figs. 9e10. characterized by having 14 twisted cells. It first appears in samples Description. These utricles are especially abundant in sample C127E and C127W, where it represents <10% of the total population C178, where it forms homogeneous assemblages with bimodal dis- which is dominated by Clavator grovesii var. jiuquanensis (Appendix tribution (Fig. 3JeL and MeP, respectively), but it is also dominant in 2). C. grovesii var. corrugatus forms homogeneous populations in samples C127E and C127W associated with A. trivolvis var. triquetra sample C178 upwards. 7 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Fig. 4. SEM pictures of charophytes from the Arrifes section: utricles of genus Clavator and thalli portions. AeF) Clavator grovesii var. jiuquanensis. I) Lateral view of the typical morphotype (sample C127W; specimen Arr-Ch-15). BeD) Lateral views of the intermediate morphotype between C. grovesii var. jiuquanensis and C. grovesii var. corrugatus, 8 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 In the Algarve Basin, this species was described as Clypeator reyi and C. harrisii var. zavialensis and they are referred them as lusitanicus by Grambast-Fessard (1980a). Later, Soulie -Ma €rsche Clavator harrisii var. reyi advanced or Clavator harrisii var. zavialensis (1994) compared the type population of Clypeator corrugatus with primitive. Clypeator lusitanicus, and observed that the morphology between Chronostratigraphic distribution. The first occurrences of this both taxa was very similar. Following the strong similarities be- taxon are in the lower Barremian, where it rarely appears asso- tween both taxa, they were synonymized by Martín-Closas (2000). ciated to C. harrisii var. harrisii, which is the dominant variety Chronostratigraphic distribution. This taxon is found between the rez-Cano et al., 2020, 2022a). Clavator harrisii var. reyi is (Pe Aptian and lower-middle Albian in Europe of Western Europe and especially abundant and dominates the Clavator harrisii pop- United States (Martín-Closas, 2000, 2015 and references therein). ulations in the upper Barremianelower Aptian where it forms homogeneous populations (e.g., Martín-Closas, 2000; Pereira and Clavator harrisii (Peck, 1941) emend. Martín-Closas, 1996 Cabral, 2005; Vicente and Martín-Closas, 2013) or can be asso- Clavator harrisii var. harrisii Peck, 1941 ciated to C. harrisii var. harrisii, being C. harrisii var. reyi dominant Fig. 4MeO upon C. harrisii var. harrisii (Pe rez-Cano et al., 2020, 2022a). 1941 Clavator harrisii nov. sp. e Peck, p. 292e294, Pl. 42, figs. 25e37. Clavator harrisii var. zavialensis (Grambast-Fessard, 1980a) 1996 Clavator harrisii var. harrisii Peck e Martín-Closas, p.278e279. Martín-Closas, 1996 Description. Small populations of this species are found in Fig. 4SeT samples C32, C127W, C127E, and C178. The utricles show the 1980 Stenochara zavialensis n. sp. eGrambast-Fessard, p. 44, Pl. 3, characteristic bilateral symmetry with two fans of cells in a lateral figs. 10e13. position. The posterior part shows strong similarities with the 1996 Clavator harrisii var. zavialensis (Grambast Fessard, 1980a) nov. Barremian specimens described in Pe rez-Cano (2021). It is always comb. e Martín-Closas, p. 279. associated with C. harrisii var. reyi and C. harrisii var. zavialensis, being the latter taxa the dominant variety of the C. harrisii pop- Description. Clavator harrisii var. zavialensis represents the last ulations (Appendix 2). variety of the evolutionary lineage of Clavator harrisii (see Martín- Chronostratigraphic distribution. The chronostratigraphic distri- Closas, 1996) and it is characterized by preserving only the gyro- bution of this taxon is lower Valanginianemiddle Albian. In the gonite that has slightly concave spiralled units separated by a lower Valanginian, it appears associated with the older variety, double ridge. The Ringstruktur-calcification pattern, described by Clavator harrisii var. dongjingensis (Hu and Zeng, 1981) Martín- Schudack (1993) for clavatoroid gyrogonites is often visible at the Closas, 2000. Clavator harrisii var. harrisii usually forms homoge- apical tips of the spiral cells. In the Arrifes section, this taxon always neous assemblages in the lower Barremian (Martín-Closas, 2000; appears associated to C. harrisii var. reyi and C. harrisii var. harrisii. Perez-Cano et al., 2020, 2022a) but sometimes also in the Aptian (De Chronostratigraphic distribution. This variety of Clavator harrisii is Sosa Toma  s et al., 2017) and in the lower-middle Albian (Alvarez- found in the upper Aptianelower Albian, when it usually forms Parra et al., 2021). However, in the upper Barremianelower Aptian homogeneous assemblages (see e.g., Martín-Closas, 2000; Trabelsi it is frequently found associated with Clavator harrisii var. reyi (e.g., et al., 2016). Martín-Closas, 2000; Pe rez-Cano et al., 2020, 2022a), while in the upper Aptian to lower-middle Albian it is usually found forming mixed populations with Clavator harrisii var. zavialensis (e.g., Martín- 4.2. Charophyte thalli Closas, 2000; Tibert et al., 2013; De Sosa Tomas et al., 2017). Clavator harrisii var. reyi (Grambast-Fessard, 1980a) Martín- Genus Munieria (Deecke, 1883) emend. Granier in Granier et al., Closas, 1996 2015 Fig. 4PeR Munieria grambastii Bystrický, 1976 1980a Stellatochara reyi n. sp. e Grambast-Fessard, p. 42e44, Pl. 3, Fig. 4U figs. 6e9. 1976 Munieria grambastii n. sp. e Bystrický, p. 48e54, Pl. I, figs. 1996 Clavator harrisii var. reyi (Grambast-Fessard, 1980a) nov. comb. 1e14; Pl. II, figs. 1e16; Pl. IV, fig. 2. e Martín-Closas p. 279. 2020 Munieria grambastii Bystrický 1976 e Pe rez-Cano et al. p. 2005 Luzochara reyi (Grambast-Fessard 1980a) nov. comb. e Pereira 21e22, Firgghgs. 16AeG, Fihug. 17AeK and Cabral, p. 173e178, Pl. 1, figs. 1e6. Description. A few small portions of this thallus (isolated in- Description. This species is found in samples C32, C127E, C127W, ternodes) are found in samples C127E and C127W, C178, and C182. and C178. The specimens are characterized by only the gyrogonite The biological affinity of Munieria has been extensively discussed, with the convex cells separated by slightly undulated structures. In as it has been attributed to charophytes (e.g., Martín-Closas, 2000; samples C127W and C178, there are observed gyrogonites whose rez-Cano et al., 2020) or dasylacladeans (Feist et al., 2003). The Pe cells show different degrees of calcification, showing convex and interdigitation of the cortical cells in the middle part of the inter- concave cells in the same gyrogonite (see Fig. 4R). These gyrogonites node and the inner growth of the internode (Martín-Closas, 2000; are considered as intermediate morphotypes between C. harrisii var. rez-Cano et al., 2020; respectively), demonstrated its pertaining Pe (C. grovesii var. jiuquanensis advanced or C. grovesii var. corrugatus primitive). BeC) (sample C127E; specimens Arr-Ch-16 and Arr-Ch-17); D) sample C127W; specimen Arr-Ch-18) E) Abaxial view (sample C127W; specimen Arr-Ch-19); F) Adaxial view (sample C127W; specimen Arr-Ch-20). GeL) Clavator grovesii var. corrugatus (sample C178). GeI) Lateral view, showing different morphologies of the shield (specimens Arr-Ch-21, Arr-Ch-22, and Arr-Ch-23). JeK) Adaxial view (specimens Arr-Ch-24 and Arr-Ch-25). L) Abaxial view (specimen Arr-Ch-26). MO) Clavator harrisii var. harrisii (sample C127W). MN) Lateral view. Each specimen shows different morphologies of the lateral fan (specimens Arr-Ch-27 and Arr- Ch-28). P) Adaxial view, showing the phylloid imprint and different cells at the top that completely cover the gyrogonite in the adaxial part (specimen Arr-Ch-29). PeQ) Clavator harrisii var. reyi. P) Lateral view (sample C32; specimen Arr-Ch-30); Q) Apical view (sample C178; specimen Arr-Ch-31). R) Lateral view of the morphotype between C. harrisii var. reyi and C. harrisii var. zavialensis (C. harrisii var. reyi advanced or C. harrisii var. zavialensis primitive), (sample C127W; specimen Arr-Ch-32). SeT) Clavator harrisii var. zavialensis. S) Lateral view (sample C178; specimen Arr-Ch-33). T) Apical view (sample C127W; specimen Arr-Ch-34). UeW) Charophyte thalli. UeV) Munieria grambastii (sample C127W, specimens Arr-Ch-35 and Arr-Ch-36, respectively). W) Clavatoraxis sp. (sample C127W, specimen Arr-Ch-37). 9 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 to the Clavatoraceae family. This thallus morphology is associated The correlation between the Clavator grovesii var. jiuquanensis with some species of the genus Clavator except Clavator harrisii. biozone with the dinoflagellate biozones is in agreement with the previous correlation of both biozones with the ammonite bio- guez, 1998 Genus Clavatoraxis Martín-Closas et Die zonation. Thus, the base of C. grovesii var. jiuquanensis biozone was Clavatoraxis sp. correlated with the Toxancyloceras vandenheckii ammonite bio- Fig. 4V zone, based on a direct correlation between both biozones (Martín-Closas et al., 2009) and Sr-isotope stratigraphy (Pe rez- Description. This thallus morphology has been found in samples Cano et al., 2022a). The upper part of the Subtilisphaera scabrata C127W, and C178. It consists of a corticated thallus with the char- biozone was also correlated with the T. vandenheckii ammonite acteristic hemispherical spine-cell rosettes upon the cortical cells. biozone (Leereveld, 1995, 1997). Moreover, charophyte assem- The portions are very short, impeding their identification at the blages that belong to the European Ascidiella cruciata- specific level. This thallus morphology has been associated to the Pseudoglobator paucibracteatus charophyte biozone and the species Atopochara trivolvis (e.g., Martín-Closas, 2000) and Clavator Eurasian Clavator grovesii var. jiuquanensis charophyte biozone harrisii, the latter due to the anatomical connection between both were correlated against the lower Aptian Deshayesites weisii organs (e.g., De Sosa Tom rez-Cano, 2021). as et al., 2017; Pe ammonite biozone (Deshayesites forbesi ammonite biozone ac- cording to Reboulet et al., 2011) in the Subalpine Chains and Jura 5. Charophyte biostratigraphy and correlation with marine Mountains (Martín-Closas et al., 2009; Fig. 5). Furthermore, domain Clavator grovesii var. jiuquanensis is also described in lower Aptian strata that were chemostratigraphically correlated with the ma- The present work follows the charophyte biozonation pro- rine domain in the Chinese basins (Li et al., 2020). Odontochitina posed by Riveline et al. (1996) and later modified by Martín- operculata biozone is also correlated with the lower Aptian Closas et al. (2009) and Pe rez-Cano et al. (2022a). These bio- ammonite biozones (Leereveld, 1995, 1997). zones are partial range biozones, i.e., defined by the FAD of index species (or at the first homogeneous population in the case of the 5.2. Lower Aptian anagenetic lineages), but with the inclusion of several other species that enabled to identify of the biozone in the case that The second assemblage is described from the 135 m until the top the index species is not observed. By the way, these biozones can of the section (Fig. 2) and is characterized by the co-occurrence of be considered equivalent to assemblage biozones or Oppelzones. homogeneous populations of Atopochara trivolvis var. trivolvis, ho- Two clavatoracean assemblages with biostratigraphic interest are mogeneous populations of Clavator grovesii var. corrugatus, Clavator distinguished in the middle to upper part of the studied Arrifes harrisii var. harrisii, Clavator harrisii var. reyi, and Clavator harrisii section and are correlated with the dinoflagellate cyst biozones var. zavialensis. This assemblage corresponds to the typical previously described in the section (Fig. 2). assemblage of the Clavator grovesii var. lusitanicus biozone of Riveline et al. (1996), which was described on the basis of the Tincup Creek biozone of Grambast (1974). The First Occurrence (FO) 5.1. Upper Barremianelower Aptian of C. grovesii var. corrugatus in the Arrifes section is in a sample in which it is associated with C. grovesii var. jiuquanensis (C127W; The lower assemblage is described between 65 m and 135 m Fig. 2). However, in the case of anagenetic lineages the occurrence of the stratigraphic section (Fig. 2), and it is characterized by the of mixed populations with two varieties that also contain speci- association of Echinochara lazarii, mixed populations of Ato- mens that are intermediate morphotypes between two varieties is pochara trivolvis var. triquetra and Atopochara trivolvis var. triv- very common (e.g., Martín-Closas, 1989; Martín-Closas and Salas, olvis, mixed populations of Clavator grovesii var. jiuquanensis and 1994; Pe rez-Cano et al., 2020, 2022a). For this reason, in the pre- Clavator grovesii var. corrugatus (rare) and intermediate mor- sent work, the base of the biozone is pointed at the first homoge- photypes between both taxa, and mixed populations of Clavator neous population of C. grovesii var. corrugatus (Fig. 2), at sample harrisii var. harrisii, Clavator harrisii var. reyi, and Clavator harrisii C178, following the criterion established in Pe rez-Cano et al. var. zavialensis, and intermediate morphotypes between (2022a) for biozones based on anagenetic varieties. C. harrisii var. reyi and C. harrisii var. zavialensis. Based on the Clavator grovesii var. lusitanicus was synonymized to Clavator occurrence of Clavator grovesii var. jiuquanensis, this charophyte grovesii var. corrugatus by Martín-Closas (2000). Following this association has been ascribed to the upper Barremianelower synonymy, the charophyte biozone Clavator grovesii var. lusitanicus Aptian Clavator grovesii var. jiuquanensis Eurasian biozone of Riveline et al. (1996) is here redefined as follows: rez-Cano et al., 2022a). This charophyte assemblage partially (Pe Name: Clavator grovesii var. corrugatus. corresponds to the upper lower Barremianelower Aptian Asci- Definition: Partial range biozone defined between the FAD of diella cruciata-Pseudoglobator paucibracteatus European biozone homogeneous populations of Clavator grovesii var. corrugatus and (see, Perez-Cano et al., 2022a). homogeneous populations of Atopochara trivolvis var. restricta The lowermost part of the upper Barremianelower Aptian (Grambast-Fessard 1980b) Martín-Closas 1996. Clavator grovesii var. jiuquanensis biozone could be correlated with Correlations: In the Arrifes section, the base of Clavator grovesii the occurrence of Subtilisphaera scabrata dinoflagellate cyst biozone var. corrugatus biozone is placed in a marly layer inside an interval (Fig. 2; Mendes et al., 2023). This key dinoflagellate cyst ranges that contains the dinoflagellate key taxa Odontochitina operculata from the FO of the aforementioned species to the FO of Odonto- and attributed to the homonymous biozone (Fig. 2; Mendes et al., chitina operculata (Leereveld, 1995, 1997), being assigned to the 2023). This interval is defined by the occurrence of this taxon, lower Barremianelowermost upper Barremian. The upper part of and ranges from the FO of Odontochitina operculata to the FO of the Clavator grovesii var. jiuquanensis biozone is correlated with the Cribroperidinium tenuiceras, indicating an age no older than the late Odontochitina operculata dinoflagellate cyst biozone (Fig. 2). The Barremian (Costa and Davey, 1992; Leereveld, 1995, 1997). The base Clavator grovesii var. jiuquanensis biozone was tentatively corre- and the top of this dinoflagellate biozone are also well-correlated lated with the key marine dinoflagellate cyst identified by Mendes with the standard ammonite biozonations. Thus, the FO of et al. (2023) for the Arrifes section. O. operculata is correlated with the Toxancyloceras vandenheckii 10 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Fig. 5. Correlation of the upper Barremianelower Aptian charophyte biozones with the dinoflagellates biozones and the standard ammonite biostratigraphy. Ammonite biozonation after the latest proposal of Reboulet et al. (2018). Dinoflagellate biozonation after Leereveld (1995, 1997) and Moullade et al. (1998). Dinoflagellate biozonation includes those biozones identified in the studied section, i.e., Subtilisphaera scabrata and Odontochitina operculata (see Mendes et al., 2023), and follows the biozonation schemes proposed by Leereveld (1995, 1997). Charophyte biozonation partially modifies the proposal of Pe rez-Cano et al. (2022a). Greyish Area corresponds to the range in which the base of C. grovesii var. corrugatus biozone must be placed (see explanation in text). The comparison with other charophyte biozonations can be seen in Appendix 3. ammonite biozone (Leereveld, 1995, 1997), while the FO of Cri- biozone indicates that the base of the Clavator grovesii var. corru- broperidinium teuniceras correlates with the Dufrenoyia furcata gatus biozone must be lower Aptian, below the lowereupper ammonite biozone (Moullade et al., 1998) close to the lowereupper Aptian boundary. Aptian boundary (Masure et al., 1998). The FO of C. teuniceras was Following previous correlations of the Clavator grovesii var. used as a tentative marker for the lowereupper Aptian boundary in jiuquanensis biozone against the standard ammonite biostratig- the Luz section, in the western part of the Algarve Basin (Heimhofer raphy (see chapter 5.1), and the direct correlation of the base et al., 2007). However, this key taxon was not recorded in the Clavator grovesii var. corrugatus biozone with the Odoncthinia Arrifes section (Mendes et al., 2023). operculata dinoflagellate biozone described in this work, the base The base of the Clavator grovesii var. lusitanicus biozone of of the Clavator grovesii var. corrugatus biozone must be upper Riveline et al. (1996) was placed in the lowereupper Aptian lower Aptian, between the top of the Deshayesites forbesi and the boundary. However, only the upper part of this biozone (lower Dufrenoyia furcata ammonite biozones (Fig. 5). The top of this Albian) was previously correlated with the coeval marine biostra- charophyte biozone is in the middle Albian, as charophyte as- tigraphy (Riveline et al., 1996 and references therein). The direct semblages of this biozone are correlated against middle Albian correlation between the FAD of the first homogeneous population ammonite biozones (see Riveline et al., 1996 and references of C. grovesii var. corrugatus, considered the base of the Clavator therein). grovesii var. corrugatus biozone, and the O. operculata dinoflagellate Horizon: upper lower Aptianemiddle Albian. 11 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 6. Conclusions Alejandro Gallardo (technician of the Palaeontological Laboratory of the Departament de Dina mica de la Terra i de l’Ocea) is acknowl- The present study shows a marine-continental correlation be- edged for his assistance in preparing the samples studied here. The tween the charophyte biozones and the dinoflagellate key taxa manuscript has been highly improved during the peer-review after previously described in the Arrifes section (Algarve Basin, Portugal) the detailed revisions and suggestions of the editor, Dr. Eduardo in the upper BarremianeAptian record. This is the first time that Koutsoukos, and the reviewers, Dr. Carles Martín-Closas (University these two biochronologies can be directly correlated and it has cnico Nacional, La Paz, of Barcelona), Dr. Alba Vicente (Instituto Polite allowed the improvement of the charophyte biochronology and Mexico), and Dr. Khaled Trabelsi (University of Vienna). Dr. Carles biostratigraphy of the Aptian record. Martín-Closas is also acknowledged for the productive discussions The Clavator grovesii var. jiuquanensis biozone is identified by the in the early stages of this work. occurrence of the index species, Clavator grovesii var. jiuquanensis, and the clavatoracean species associated, including Echinochara lazarii, Atopochara trivolvis var. triquetra and A. trivolvis var. trivolvis, References Clavator harrisii var. harrisii, Clavator harrisii var. reyi, and C. harrisii  Alvarez-Parra, S., Perez-de la Fuente, R., Pen ~ alver, E., Barron, E., Alcala , L., Pe rez- var. zavialensis. The base of this biozone at the Arrifes section is Cano, J., Martín-Closas, C., Trabelsi, K., Mele ndez, N., Lo pez Del Valle, R., directly correlated with the occurrence of the dinoflagellate cyst Lozano, R.P., Peris, D., Rodrigo, A., Sarto i Monteys, V., Bueno-Cebollada, C.A., Subtilisphaera scabrata. This correlation agrees with previous cor- Menor-Salva n, C., Philippe, M., Sa nchez-García, A., Pen ~ a-Kairath, C., Arillo, A., relations with the Toxanclyoceras vandenheckii ammonite biozone Espílez, E., Mampel, L., Delclo s, X., 2021. Dinosaur bonebed amber from an original swamp forest soil. eLife 10, e72477. made for each biozone and reinforces the previous timespan sug- Azere^do, A., Duarte, L., Henriques, M., Manuppella, G., 2003. Da dina ^mica conti- gested for this biozone. nental no Tri asico aos mares do Jur assico Inferior e Me dio. Cadernos de Geo- The C. grovesii var. corrugatus biozone is described after the logia de Portugal. Instituto Geolo gico e Mineiro, Lisboa, 43 pp. Berthou, P.Y., Leereveld, H., 1990. Stratigraphic implications of palynological studies occurrence of the index species, C. grovesii var. corrugatus, that is on Berriasian to Albian deposits from western and southern Portugal. 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Comp- AEI/10.13039/501100011033 and the European Regional Develop- tes rendus de l'Acade mie des Sciences 264, 581e584. ment Fund (ERDF). This study also had the financial support Grambast, L., 1968. Evolution of the utricle in the charophyta genera Perimneste Fundaça~o para a Cie ^ncia e Tecnologia (FCT), under the projects UIDB/ Harris and Atopochara Peck. Journal of the Linnean Society (Botany) 61, 5e11. Grambast, L., 1969. La syme trie de l’utricule chez les Clavatorace es et sa signification 00611/2020 and UIDP/00611/2020 CITEUC and LA/P/0069/2020 netique. Comptes rendus de l'Acade mie des Sciences 269, 878e881. phyloge granted to the Associate Laboratory ARNET and UID/00350/2020 Grambast, L., 1970. Origine et e volution des Clypeator (Charophytes). Comptes CIMA. JP-C Margarita Salas postdoctoral contract and research is rendus de l'Acade mie des Sciences 271, 1964e1967. supported by the Ministerio de Universidades of Spain, “Plan de Grambast, L., 1974. 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Museum Fig. 3 A and B Porochara cf. fusca C127W Arr-Ch-1 C Echinochara lazarii C152 Arr-Ch-2 D Atopochara trivolvis var. triquetra C127W Arr-Ch-3 E and F Atopochara trivolvis var. triquetra C127W Arr-Ch-4 G Atopochara trivolvis var. triquetra C127W Arr-Ch-5 H Atopochara trivolvis var. triquetra C127W Arr-Ch-6 I Atopochara trivolvis var. trivolvis C127W Arr-Ch-7 J Atopochara trivolvis var. trivolvis C178 Arr-Ch-8 K Atopochara trivolvis var. trivolvis C178 Arr-Ch-9 L Atopochara trivolvis var. trivolvis C178 Arr-Ch-10 M Atopochara trivolvis var. trivolvis C178 Arr-Ch-11 N Atopochara trivolvis var. trivolvis C178 Arr-Ch-12 O Atopochara trivolvis var. trivolvis C178 Arr-Ch-13 P Atopochara trivolvis var. trivolvis C178 Arr-Ch-14 Fig. 4 A Clavator grovesii var. jiuquanensis C127W Arr-Ch-15 B Clavator grovesii var. jiuquanensis adv. C127E Arr-Ch-16 C Clavator grovesii var. jiuquanensis adv. C127E Arr-Ch-17 D Clavator grovesii var. jiuquanensis adv. C127W Arr-Ch-18 E Clavator grovesii var. jiuquanensis C127W Arr-Ch-19 F Clavator grovesii var. jiuquanensis C127W Arr-Ch-20 G Clavator grovesii var. corrugatus C178 Arr-Ch-21 H Clavator grovesii var. corrugatus C178 Arr-Ch-22 I Clavator grovesii var. corrugatus C178 Arr-Ch-23 J Clavator grovesii var. corrugatus C178 Arr-Ch-24 K Clavator grovesii var. corrugatus C178 Arr-Ch-25 L Clavator grovesii var. corrugatus C178 Arr-Ch-26 M Clavator harrisii var. harrisii C127 Arr-Ch-27 N Clavator harrisii var. harrisii C127 Arr-Ch-28 O Clavator harrisii var. harrisii C127 Arr-Ch-29 P Clavator harrisii var. reyi C32 Arr-Ch-30 Q Clavator harrisii var. reyi C178 Arr-Ch-31 R Clavator harrisii var. zavialensis primitive C178 Arr-Ch-32 S Clavator harrisii var. zavialensis C178 Arr-Ch-33 T Clavator harrisii var. zavialensis C178 Arr-Ch-34 U Munieria grambastii C127W Arr-Ch-35 V Munieria grambastii C127W Arr-Ch-36 W Clavatoraxis sp. C127W Arr-Ch-37 14 J. Perez-Cano, H.J.R. Pereira, M. Mendes et al. Cretaceous Research 150 (2023) 105575 Appendix 2. Distribution of the charophyte taxa in the studied samples. Supplementary material 1 The number of charophyte fructifications found in each sample of the Arrifes section. Samples C32 C127W C127E C152 C178 C182 C199 Porocharaceae Porochara cf. fusca. 5 Clavatoraceae Atopocharoidae Echinochara lazarii 15 Atopochara trivolvis var. triquetra 2 15 3 1 Atopochara trivolvis var. trivolvis 60 231 9 Clavatoroidae Clavator grovesii var. jiuquanensis 10 27 76 Clavator grovesii var. corrugatus 2 9 327 18 4 Clavator harrisii var. harrisii 1 24 5 3 Clavator harrisii var. reyi 5 20 48 53 1 Clavator harrisii var. zavialensis 124 64 220 7 Appendix 3. Comparison of the described herein upper BarremianeLower Aptian biostratigraphy with Riveline et al. rez-Cano et al. (2022a). (1996), and Pe 15