Palynology ISSN: 0191-6122 (Print) 1558-9188 (Online) Journal homepage: https://www.tandfonline.com/loi/tpal20 Influence of palaeoenvironmental factors on the encystment of Cretaceous dinoflagellate cysts (Ceratiaceae): a study from Godavari Graben, Southern India Edwige Masure, Neerja Jha, Sarah Gonçalves Duarte, Neha Aggarwal, Mitsuru Arai & Harinam Joshi To cite this article: Edwige Masure, Neerja Jha, Sarah Gonçalves Duarte, Neha Aggarwal, Mitsuru Arai & Harinam Joshi (2017) Influence of palaeoenvironmental factors on the encystment of Cretaceous dinoflagellate cysts (Ceratiaceae): a study from Godavari Graben, Southern India, Palynology, 41:4, 472-483, DOI: 10.1080/01916122.2016.1262922 To link to this article: https://doi.org/10.1080/01916122.2016.1262922 View supplementary material Accepted author version posted online: 29 Nov 2016. Published online: 10 Apr 2017. Submit your article to this journal Article views: 156 View Crossmark data Citing articles: 1 View citing articles Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tpal20 PALYNOLOGY, 2017 VOL. 41, NO. 4, 472–483 https://doi.org/10.1080/01916122.2016.1262922 Influence of palaeoenvironmental factors on the encystment of Cretaceous dinoflagellate cysts (Ceratiaceae): a study from Godavari Graben, Southern India Edwige Masurea, Neerja Jhab, Sarah Goncalves¸ Duartec, Neha Aggarwalb, Mitsuru Araid and Harinam Joshib aCentre de Recherche sur la Paleobiodiversite et les Paleoenvironnements, CR2P, UMR 7207, MNHN, UPMC, CNRS, Universite Pierre et Marie Curie, 4 place Jussieu, 75005 Paris, France; bBirbal Sahni Institute of Palaeosciences, 53 University Road, Lucknow, India; cUFRJ, 274 Av. Athos da Silveira Ramos, Maths and Natural Science Center, Department of Geology, University City, Rio de Janeiro, Ilha do Fund~ao, 21949-916, Brazil; dUNESP (S~ao Paulo State University), IGCE/UNESPetro. 13501-070 Rio Claro-SP, Brazil ABSTRACT KEYWORDS Muderongia staurota forms with long appendages at the distal end of the apical, lateral and antapical Dinoflagellate cysts; horns have been recovered from the Lower Cretaceous Gangapur Formation of Upper Gondwana Ceratiaceae; Muderongia; sequence from the Chintalapudi Sub-Basin (India). The number of distal appendages reflects the number India; Cretaceous of plates forming the horns. We include these forms in the new species Muderongia gangapurensis sp. nov. The dinoflagellate cysts recovered suggest a late Berriasian to Valanginian for the lower part and a Hauterivian/Barremian age for the upper part of the studied interval of MJR-11 borehole. Unusual Muderongia and Odontochitina cysts bearing similar long appendages have only occasionally been described or illustrated in the literature from sediments rich in continental organic matter. We suggest that Cretaceous Ceratiaceae bearing such appendages are cysts of thecae that encysted in particular environments, where light, salinity, temperature and chemistry of water masses might have been key to their development. Our conclusion is supported by the high morphological variability of horns in modern Ceratiaceae, which reflects environmental factors. We discuss the plasticity of horns in the fossil record and note that such plasticity is recurring in Ceratiaceae, at least in the Early Cretaceous (145 Ma). 1. Introduction Evitt’s(1975) interpretation – i.e Ceratium with one antapical (1'''') and one posterior intercalary plate (1p) instead of two The Ceratiaceae encompass a group of extant dinoflagellates antapical plates (1'''', 2'''') – was not accepted by some further having three or more prominent horns and inhabiting both authors (Sournia 1986; Balech 1988; Steidinger & Tangen 1997; freshwater and marine environments, as well as marine repre- Temponeras et al. 2000). sentatives from the latest Jurassic to the latest Cretaceous. Liv- Based on small subunit ribosomal RNA genes (SSU rDNA) and ing and fossil Ceratiaceae are the only Gonyaulacales family to the number of cingular plates, Gomez et al. (2010)proposeda develop lateral horns. Although occurring worldwide, extant new genus name, Neoceratium, for all marine species currently Ceratiaceae are most common in temperate areas. They are assigned to Ceratium and designated Neoceratium furca as the harmless, non-toxic organisms, but can produce red tides, if type species. The freshwater species, including Ceratium hirundi- conditions allow for excessive blooming, causing a strain on the nella (taxonomic junior synonym of the type species), form a sub- ecosystem (eutrophication). Ceratium tetraceros Schrank 1793 is clade distinct from the marine cluster. Freshwater Ceratium the type species of the genus Ceratium described by Cleve species possess six cingular plates, while marine Neoceratium (1900). Ceratium hirundinella is a taxonomic junior synonym of species possess five; according to Gomez et al. (2010), the num- C. tetraceros (Muller€ 1786). Based on the shape of the cell body ber of cingular plates is the most robust morphological character and the horns, Vanhoffen€ (1896) proposed to include some spe- for separating the two genera. Previously, Sournia (1984)had cies of Ceratium in three new genera: Amphiceratium, Biceratium suggested that the marine species of Ceratium could be included or Proceratium. However, Kofoid (1907) retained all the species in a new genus. The genus Neoceratium is a potential indicator of in Ceratium, since the four genera have the same tabulation. ocean warming (Tunin-Ley & Lemee 2013). Subsequent authors treated Vanhoffen€ ’s genera as subgenera For many years, resting cysts of Ceratium were known only in (Gran 1902; Ostenfeld 1903; Paulsen 1908; Sournia 1967). Wall & freshwater species (Entz 1925; Wall & Evitt 1975; Sournia 1986). Evitt (1975) proposed the following tabulation: 4', 0a, 6'', 5-6c, However, Gomez et al. (2010) observed resting cysts of the 6''', 1p, 1'''', plus two or more sulcal platelets, suggesting a marine species Neoceratium furca and Neoceratium candela- gonyaulacoid affinity. According to these authors, the right lat- brum (fig. 6 in Gomez et al. 2010) in some samples. Thus, spe- eral horn, the larger, is formed by postcingular plates 4’’’ dor- cies of freshwater Ceratium and marine Neoceratium can sally and 5’’’ ventrally. The left lateral accessory horn is formed develop cellulosic resting cysts. Wall & Evitt (1975, p. 25) noted by postcingular plates 1’’’ ventrally and 2’’’ dorsally. Wall & CONTACT Edwige Masure [email protected] Supplemental data for this article can be accessed at https://doi.org/10.1080/01916122.2016.1262922. © 2017 AASP – The Palynological Society Published online 10 Apr 2017 PALYNOLOGY 473 that freshwater Ceratium cysts would not be preserved below a The Gc-Cysts include six genera: Endoceratium, Muderongia, depth of 1 or 2 cm in lake and also presumably marine, sedi- Odontochitina, Phoberocysta, Pseudoceratium and Xenascus. Pseu- ments. Such cysts could have evolved in latest Cretaceous doceratium is acavate, whereas the other genera are cavate with marine ceratiaceans, thus explaining why ceratiacean cysts a subspherical central body (Evitt 1985). Bint (1986)notedthat have not been recovered from Cenozoic sediments. the tabulation of ceratioid cysts is characterized by having pla- Evitt (1985, p. 210–212) included fossil ceratiacean cysts (Gc- nate 1’’ and camerate 2’’ anteriorly, whereas gonyaulacoid cysts Cysts) in his gonyaulacoid configuration. The Gc-Cysts are dis- have camerate 1’’ and planate 2’’ anteriorly. Bint (1986) accepted tinguished by having mainly three or four horns: one apical and Evitt’s list in the Ceratiaceae and included four other genera; two or three hypocystal horns, one from the 1p/1'''' suture and these were: ?Australisphaera, Balmula, Nyktericysta and Vesperop- the other from the sutures of the left and right sides between sis. In these four genera the endophragm and periphragm are the two postcingulars 1’’’ and 2’’’ and 4''' and 5''', just like the adpressed and a subspherical central body is absent. Fensome antapical and lateral horns of Ceratium. On the ventral surface et al. (1993) placed the family Ceratiaceae in the Gonyaulacales in Gc-Cysts, there are two precingular plates on the right and and added to Bint’s list by also including Ceratium, Aptea and one plate on the left of the sulcal notch. The tabulation of Creta- Odontochitinopsis.AcentralbodyisabsentinAptea but present ceous ceratioids has been described from Muderongia sp. cf. M. in Odontochitinopsis. Mao Shaozhi et al. (1999)describedthe mcwhaei cysts (Wall & Evitt 1975), Endoceratium dettmannae, genus Quantouendinium and demonstrated its ceratioid-style Muderongia sp., Pseudoceratium sp. (Harding & Hughes 1990) tabulation. Quantouendinium and Nyktericysta are two-layered and Odontochitina tabulata (El-Mehdawi 1998). In Muderongia, cysts without a subspherical central body. The endophragm is lateral horns have a broad-based proximal part in line with the closely adpressed to the periphragm; the endophragm extends cingulum, with or without a thin distal part extending in the into the horns but not the tips of the horns in Nyktericysta or the posterior direction. Plates involved in formation of the proximal tip of the apical horn in Quantouendinium. part of the left lateral horn are the precingulars 1” and 2”, one The periphragm and autophragm of species of these 13 gen- or two cingular(s) and the postcingulars 1”’ and 2”’. The proxi- era bear different ornamentation that can be processes,