Geo.Cro.2-3-61-KB.pdf 341 � Patrick Génot1, Jean-Paul Saint-Martin2 and Ioan I. Bucur3 AB STRA CT Three fragments of reproductive caps have been discovered in the Sarmatian limestones of Tinnye (Hungary). They are assigned to the genus Acetabularia (Polyphysaceae, formerly Acetabulariaceae). Two of these fragments are quite well preserved with nine rays each. One specimen bears distinct spines at the outer ends of long rays, whereas an- other one has short rays with rounded outer ends and, possibly, a partially preserved corona. The third fragment is characterized by very elongated rays containing numerous gametangia. Keywor ds: calcareous algae, Dasycladales, Polyphysaceae, Acetabularia, Sarmatian, Hungary 1 Laboratoire de Planétologie et Géodynamique, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes cédex, France; (patrick.genot@univ-nantes.fr) 2 Département Histoire de la Terre, Muséum National d’Histoire Naturelle, UMR 5143, 8 rue Buffon, 75005 Paris, France; (jpsmart@mnhn.fr) 3 Department of Geology, Babes-Bolyai University, str. M. Kogalniceanu, 1, 3400 Cluj-Napoca, Romania; (ibucur@bioge.ubbcluj.ro) Polyphysaceae fertile caps in Hungarian Sarmatian sediments Geologia Croatica 61/2–3 341–344 7 Figs. Zagreb 2008 Geologia CroaticaGeologia Croatica � 1. INTRODUCTION The Polyphysaceae (Dasycladales) studied in this paper were discovered in the Upper Sarmatian Tinnye Formation, defi ned at Tinnye, a village located in the Zsámbék Basin, about 30 km west of Budapest (Fig. 1). Specimens have been found in limestones with oolitic grapestones, microbial features encrus- tations and crustose foraminifera, within oolitic sandstones series (Fig. 2). Due to rarity of these fossils, their occurrence merits description and illustration. There is a pattern of large oolitic and bioclastic shoals in the Zsámbék Basin, on top of which bio-constructed facies and encrustations developed. Calcareous algae are associated with bivalves (Obsoleti- forma, Paphia, Tapes), gastropods (Granulolabium, Pirenella, Clithon), foraminifera (Elphidium, miliolids, nubecularids) and serpulids. The facies indicates a shallow water environ- ment but the discussion is open with regard to salinity (HARZ- HAUSER & PILLER, 2004). Isotopic analysis undertaken on molluscs shells seems to reveal brackish infl uences, or even fresh water ones (Moissette, pers. comm., 2008). 2. PALAEONTOLOGICAL DESCRIPTION Specimens from Tynnie consist of three fragments of fertile caps lying on a limestone surface. Two of them are quite well preserved with nine cap rays fi rmly held together by strong calcifi cation. Specimen 1 (Fig. 3) Nine cap rays can be observed on this specimen. The entire cap of the living alga was probably composed of 14 rays. The most remarkable feature of this species is the distinct spines at the outer ends of the rays. The gametangia are not visible. Diameter of the cap: 4.45 mm. Length of the rays: 1.75–2 mm (approximate data because of the poor preservation of the cap central zone). Maximum width of the rays: 0.75–0.90 mm. Specimen 2 (Fig.4) The fragment of this small cap is composed of nine rays. The estimated initial number of rays is 14 or 15. Cap rays are short. Their outer ends seem more or less rounded but it is not pos- Geologia Croatica Geologia Croatica 61/2–3 342 sible to confi rm this because of the poor preservation of the peripheral outline of the cap. For the same reason, it is diffi - cult to know if the circular swelling, located at the proximal ends of the rays, in the central area of the cap, is a partially preserved corona. Longitudinal sections of three rays show 5 to 8 hemispherical cavities corresponding to the location of the gametangia. There are only 2 to 3 laterally juxtaposed ga- me tangia in the widest part of the ray. The estimated number of gametangia inside each fertile organ is 8 to10 (but may be 16–20 if gametangia were arranged in 2 superimposed planes, that are diffi cult to determine on the specimen). Diameter of the cap: 2.8 mm. Length of the rays: 1.07–1.14 mm. Maximum width of the rays: 0.51–0.56 mm. Diameter of the central zone: 0.6 mm. Diameter of gametangia: 0.16–0.18 mm. Specimen 3 (Fig.5) The third specimen is composed of fi ve very partially preserv- ed cap rays. It looks different from the previous one: rays are elongated and contain numerous rounded gametangia, prob- ably more than 40 in each organ. There are 4 to 5 laterally jux- taposed gametangia in the widest part of the ray. Approximative length of the rays: at least 2.6 mm. Maximum width of the rays: at least 1.1 mm (only 2 rays can be measured). Diameter of gametangia: 0.20–0.23 mm. 3. GENERIC ATTRIBUTION We adopt here the generic concepts recently defi ned by BERG- ER et al. (2003), after a detailed study of the phylogeny and evolution of cap development in living Polyphysaceae (for- merly Acetabulariaceae). Using a combination of morpholog- ical, developmental and molecular characteristics, the authors consider Acicularia as “…completely identical in its morphol- ogy with Acetabularia” and show that earlier stages of cap development are very similar in both genera. The only differ- ence concerns the calcifi cation: gametangia are embedded into a lime matrix in Acicularia, whereas gametangia are uncalci- fi ed and free in Acetabularia, but the authors demonstrate that lime-embedding of gametangia is in fact, a late developmen- tal event of maturing caps. Therefore, they assign the living Acicularia species (A. schenckii) to the genus Acetabularia. They also propose two subgenera within Acetabularia: Acicu- laria, containing all species of Acetabularia, except A. aceta bul- um, with the following defi nition: “unfused cap primordia”, and Fi gu re 2: Oolitic sandstones series of Tinnye. Fi gu re 3: Specimen 1 – external view of a partially preserved cap. Fi gu re 1: Location of the Zsámbék Basin. Geologia CroaticaPatrick Génot et al.: Polyphysaceae fertile caps in Hungarian Sarmatian sediments 343 Acetabularia, containing A. acetabulum, characte rized by “con- genitally fused cap primordia”. There is no mention of the cal- cifi cation in these defi nitions. So, Acetabularia is now the only genus of the Recent Poly- phy saceae (formerly Acetabulariaceae) including species bear- ing fertile caps with gametangia embedded into a lime matrix (Fig. 6). If palaeontologists adopt these new generic concepts, it would be coherent to assign all fossil species of Acicularia to the genus Acetabularia. This is why the three fertile caps studied in this paper are considered as Acetabularia. Associated rays forming caps are also known in the fol- lowing genera: – Orioporella MORELLET & MORELLET, character- ized by its hollow caps with perforated walls and par- tially calcifi ed gametangia; – Chalmasia SOLMS-LAUBACH, with strongly calci- fi ed gametangia but which are free inside the rays; – Parvocaulis BERGER et al., with uncalcifi ed ga me- tangia. Another feature may be observed in these genera (Fig. 6): the presence of lower and upper coronae in Acetabularia, a corona only on the upper side of the cap in Parvocaulis and Chalmasia. But this morphological characteristic is al- most never observed on fossils, even when the specimens Fi gu re 4: Specimen 2 – external and internal views of a partially preserved cap. Fi gu re 5: Specimen 3 – location of gametangia inside two cap rays. Fi gu re 6: Some features of caps in present-day Polyphysaceae (data from VALET, 1969; BERGER & KAEVER, 1992; BERGER et al., 2003; BERGER, 2006). Geologia Croatica Geologia Croatica 61/2–3 344 may be entirely isolated from the sediment (GENOT, 1987). The corona zone is often badly preserved and when the spec- imens are lying on a limestone surface, only one side of the cap can be studied (MORELLET, 1939). This is the case for specimen 2. 4. COMPARISONS Polyphysaceae fertile caps have already been discovered in Sarmatian limestones from Hungary, near Ecseg (BODA, 1959). The author assigned to a new species, Acicularia con- ica, different specimens which, in fact, belong to distinct spe- cies (see the discussion in BUCUR et al., 1993). Among these specimens, two of them are reproductive caps lying on a lime- stone surface (ibid., pl. 44, fi g. 1–2). The most complete spec- imen is an entire cap composed of 25 rays. The rays look much more elongated, compared with our specimens 1 and 2. Un- fortunately, the comparison cannot go further because the out- line of the caps is badly preserved and the internal aspect of the rays remains unknown. The presence of spines at the distal ends of the rays, ob- served on specimen 1, is known in present-day species, such as Acetabularia crenulata LAMOUROUX, A. dentata SOL- MS-LAUBACH (Fig. 7a) and A. kilneri AGARDH (Fig. 7b). But this is the only common feature with the Sarmatian caps: the rays are much more elongated in A. crenulata and A. kil- neri (VALET, 1969; BERGER & KAEVER, 1992; BERGER, 2006). Specimen 2 bears, at the centre of the cap, a fragment of a circular swelling which might be a corona. Despite the ex- ceptional occurrence of this feature on fossils, it has already been possible to describe a rather well preserved corona on Sarmatian Acetabulariaceae from Romania (GÉNOT et al., 2002) with the characteristic protuberances (ibid., pl. III, fi g.2) on which branched sterile hairs develop in living representa- tives. These protuberances are unknown on the Hungarian specimen. Concerning the cap rays, only one Romanian spec- imen (ibid., pl.III, fi g.1) has similarities with specimen 2: short rays containing a small number of gametangia. 5. CONCLUSION Hungarian specimens from Tinnye probably belong to Acetab- ularia, because of the strong calcifi cation fi lling the spaces be- tween the gametangia. This type of calcifi cation is unknown inside the fertile caps of the other genera of Poly physaceae. Concerning the specifi c attribution of these three speci- mens, we consider that is not possible, with a so small number of partially preserved fossil caps, to determine if they may be assigned to previously described species or if they correspond to new ones. Thus, more samples would be necessary to pre- cisely establish the morphological features of these species, so as to avoid future confusion in the literature. ACKNOWLEDGEMENT The specimens of Polyphysaceae described here were sampled dur- ing fi eld exploration with P. Moissette, J. J. Cornée (UMR 5125, Lyon University), A. Dulai (Hungarian Natural History Museum, Budapest) and M. Kazmér (Eötvös University, Budapest). We are grateful to A. Barreau and A. Cossard (Nantes University) for their technical assis- tance in the realization of the drawings and the SEM photos. We also thank B. Granier for his review and for improving this paper. REFERENCES BERGER, S., FETTWEISS, U., GLEISSBERG, S., LIDDLE, L., RICH- TER, U., SAWITZKY, H. & ZUCCARELLO, G. (2003): 18S rDNA phylogeny and evolution of cap development in Polyphysaceae (formerly Acetabulariaceae; Dasycladales, Chlorophyta). – Phyco- logia, 42/5, 506–561. BERGER, S. (2006): Photo-Atlas of living Dasycladales. – Carnets de Géologie, 2006/02, 348 p. (http : //paleopolis.rediris.es/cg/CG2006_ BOOK_02/). BODA, J. (1959): Algae. – In: Das Sarmat in Ungarn und seine Inverte- braten-Fauna. Ann. Inst. Geol. Publ. Hung., 47/3, 749–752. BUCUR, I.I., NICORICI, E. & SURARU, N. (1993): Sarmatian calca- reous algae from Rumania. – In : BARATTOLO, F., DE CASTRO, P. & PARENTE M. (ed.): Studies on Fossil Benthic Algae. Boll. Soc. Paleont. Ital., spec. vol. 1, 81–91. GÉNOT, P. (1987): Les Chlorophycées calcaires du Paléogène d’Europe nord-occidentale – Bassin de Paris, Bretagne, Cotentin, Bassin de Mons. – Thesis, Nantes (France), 500 p. GÉNOT, P., IONESI, V. & BUCUR, I. I. (2002): Preliminary results from the study of Acetabulariaceae fertile caps discovered in Sarmatian sediments from Moldavia (Rumania). – In: BUCUR, I.I. & FILI- PESCU, S.(ed): Research advances in calcareous algae and micro- bial carbonates. Cluj University Press, 95–101. HARZHAUSER, M. & PILLER, W. E. (2004): Integrated stratigraphy of the Sarmatian (Upper Middle Miocene) in the western Central Paratethys. – Stratigraphy, 1/1, 1–22. MORELLET, L.& J. (1939) : Sur une nouvelle espèce d’Acicularia du Sarmatien moyen d’Azam, Iran septentrional. – Eclog. Geol. Helv., 32/1, 31–32. VALET, G. (1969): Contribution à l’étude des Dasycladales. – Nova Hedwigia, 17, 551–644. Manuscript received February 27, 2008 Revised manuscript accepted May 19, 2008 Fi gu re 7: Reproductive caps of living Acetabularia dentata (a) and A. kilneri (b) (BERGER & KAEVER, 1992, modifi ed; BERGER, 2006)