Non-pollen palynomorphs notes: 2. Holocene record of Megalohypha aqua - dulces , its relation to the fossil form genus Fusiformisporites and association with lignicolous freshwater fungi Lyudmila Shumilovskikh, Astrid Ferrer, Frank Schlütz To cite this version: Lyudmila Shumilovskikh, Astrid Ferrer, Frank Schlütz. Non-pollen palynomorphs notes: 2. Holocene record of Megalohypha aqua - dulces , its relation to the fossil form genus Fusiformisporites and association with lignicolous freshwater fungi. Review of Palaeobotany and Palynology, Elsevier, 2017, 246, pp.167-176. 10.1016/j.revpalbo.2017.07.002. hal-01790616 HAL Id: hal-01790616 https://hal-amu.archives-ouvertes.fr/hal-01790616 Submitted on 14 May 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Review of Palaeobotany and Palynology 246 (2017) 167–176 Contents lists available at ScienceDirect Review of Palaeobotany and Palynology journal homepage: www.elsevier.com/locate/revpalbo Review papers Non-pollen palynomorphs notes: 2. Holocene record of Megalohypha aqua-dulces, its relation to the fossil form genus Fusiformisporites and association with lignicolous freshwater fungi Lyudmila S. Shumilovskikh a,b,c,⁎,AstridFerrerd, Frank Schlütz e a University of Goettingen, Goettingen, Germany b Tomsk State University, Tomsk, Russia c Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology, Aix-en-Provence, France d University of Illinois, Urbana-Champaign, USA e Lower Saxony Institute for Historical Coastal Research, Wilhelmshaven, Germany article info abstract Article history: The first Holocene record of the freshwater ascomycete Megalohypha aqua-dulces from the sediment core Kongor Received 4 April 2017 (NE Iran) is presented here. Based on the similarity of the spore morphology with the fossil form genus Received in revised form 29 June 2017 Fusiformisporites, we establish a link between extant and fossil taxa. Comparative analysis of morphological char- Accepted 3 July 2017 acteristics of fossil spores of Fusiformisporites indicates that several different fungal groups might be included in Available online 6 July 2017 this form genus. At least five species of Fusiformisporites share similar morphology with spores of Megalohypha aqua-dulces: Fusiformisporites annafrancescae, Fusiformisporites crabbii, Fusiformisporites keralensis, Keywords: Palaeomycology Fusiformisporites paucistriatus, and Fusiformisporites pseudocrabbii. Based on Fusiformisporites, the evolution of Xylomyces Megalohypha aqua-dulces can be traced to the late Cretaceous, corresponding with diversification of the flowering Dictyosporium plants and pointing to a co-evolution of both groups. Megalohypha aqua-dulces has a tropical to subtropical dis- Sporoschisma tribution but also occurs in the semi-arid steppe environments of Kongor together with other freshwater fungal Freshwater fungi genera such as Xylomyces, Dictyosporium,andSporoschisma, which spores we describe here. The ecological re- Lignicolous fungi quirements of Megalohypha indicate that its spores can be used for the palaeoecological sign of dead submerged Fossil fungi wood as well as of tropical to subtropical conditions. © 2017 Elsevier B.V. All rights reserved. Contents 1. Introduction.............................................................. 168 2. Materialandmethods.......................................................... 169 3. Results................................................................ 169 3.1. Spore morphology of Megalohypha aqua-dulces ........................................... 169 3.2. RecordsoffreshwaterfungiinKongor............................................... 169 4. Discussion............................................................... 173 4.1. Taxonomic relationship between Fusiformisporites and Megalohypha aqua-dulces ........................... 173 4.2. Ecologyandpalaeoecology.................................................... 173 4.3. Geologicalevidencefortheevolutionofaquaticascomycetes..................................... 174 5. Conclusions.............................................................. 175 Acknowledgements............................................................. 175 References................................................................. 175 ⁎ Corresponding author at: University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Palynology and Climate Dynamics, Wilhelm-Weber-Str. 2a, 37073 Goettingen, Germany. E-mail address: [email protected] (L.S. Shumilovskikh). http://dx.doi.org/10.1016/j.revpalbo.2017.07.002 0034-6667/© 2017 Elsevier B.V. All rights reserved. 168 L.S. Shumilovskikh et al. / Review of Palaeobotany and Palynology 246 (2017) 167–176 1. Introduction the case of Caryospora callicarpa led to the discovery of species thought to be extinct (Hawksworth et al., 2016). Further connections Morphologically distinctive fungal spores present in the geologi- of fossil fungal spores to recent species are required for a deeper un- cal record provide valuable information about a wide variety of envi- derstanding of the history, evolution, ecology and (palaeo)geogra- ronmental conditions, including climate, hydrological conditions, phy of fungal taxa. fire and erosion history, vegetation type, and organismal interactions During palynological investigations of a sediment core from (e.g. Elsik, 1976; Sherwood-Pike, 1988; Pirozynski, 1989; Van Geel Kongor (NE Iran), covering the last 6000 years (Shumilovskikh et and Aptroot, 2006; Taylor et al., 2015). The description of fossil fun- al., 2016), fungal spores of Megalohypha aqua-dulces Ferrer et Shear- gal spores is usually carried out based on fossil material, which rarely er were documented (Plate I)andidentified using mycological liter- provides identification to extant taxa (Elsik, 1976; Jansonius and ature (Ferrer et al., 2007). These spores share similar characteristics Kalgutkar, 2000). Studies on the relationship between extant and to additional fossilised spores fromgeologicalrecords described as fossil taxa however deliver important information for geological Fusiformisporites Rouse, 1962.Continuingourseriesof“non-pollen and mycological research by combining geological records with palynomorphs notes” (Schlütz and Shumilovskikh, 2017), in this known fungal ecology. For example, investigation of the monotypic paper we provide the first Holocene record of the extant species genus Potamomyces indicate that it likely contains several species Megalohypha aqua-dulces and discuss its relation to the fossil form (Schlütz and Shumilovskikh, 2013; Nuñez Otaño et al., 2016), or in genus Fusiformisporites. Plate I. Spores of Megalohypha aqua-dulces (KNG 62) from the sediment core Kongor, NE Iran, showing variation in spore morphology and different preservation grade (1–2: 176 cm core depth, 3: 224 cm, 4: 64 cm, 5–6: 48 cm, 7–8: 96 cm, 9: 72 cm, 10: 80 cm). Photos at 500× magnification with oil immersion. L.S. Shumilovskikh et al. / Review of Palaeobotany and Palynology 246 (2017) 167–176 169 2. Material and methods thickness 1–1.5 μm, up to 3 μmatapices.Theaxisisstraight,2sym- metrical cells are separated by a septum 2–3 μm thick. The sculpture The Kongor core was obtained from the temporary lake Kongor, lo- is longitudinally striate with 5–7 ridges exposed on each flattened cated in the Artemisia-steppe of the eastern Gorgan Plain, NE Iran. Sam- sector. The striate pattern merges to a coarse reticulum at the apices. ples from the core were treated with standard palynological laboratory The morphology corresponds to the original description of spores of procedures and studied for pollen and non-pollen palynomorphs in- the extant fungus Megalohypha aqua-dulces (Ferrer et al., 2007): asco- cluding microscopic plant, animal and fungal remains (details in spores 40–55 × 19–22 μm (mean = 48.3 × 18.8 μm, SD = 2.8 × 0.91 Shumilovskikh et al., 2016). For the purpose of this paper we present μm, n = 30), ellipsoidal, acutely tapered at apices, brown to dark an abbreviated version of the palynological diagram with freshwater brown, 1-septate, septum appearing as a dark band, both cells of equal fungi, arboreal pollen and tree and shrub macroremains (Fig. 1). The de- shape and size, rough walled with longitudinal sulcate striations lacking scription of the Megalohypha aqua-dulces spores (Plate I) and of the appendages or a gelatinous sheath (Plate II). spores of other freshwater fungi (Plate III) from the sediment core In addition, the spores from Kongor resemble spores of the fossil Kongor follows the scheme of Elsik (1983) with an abbreviation KNG form genus Fusiformisporites Rouse, 1962 with holotype (Kongor) for the first described types. Spore measurements were car- Fusiformisporites crabbii Rouse, 1962 (Kalgutkar and Jansonius, 2000): ried out on 1000× magnification. spores are distinctly fusiform in outline. The unit is split into two The samples from Panama were collected from freshwater habitats equal halves by an equatorial wall that appears to be continuous, thus at the Soberania National Park, which support