An Upper Cretaceous Dinoflagellate Assemblage from Vriddhachalam Area, Cauvery Basin, South India

AN UPPER CRETACEOUS DINOFLAGELLATE ASSEMBLAGE FROM VRIDDHACHALAM AREA, CAUVERY BASIN, SOUTH INDIA

1(. P. JAIN Birbal Sahni Institute of Palaeobotany, Lucknow-226007, India

ABSTRACT

Present article reports a dinoflagellate assemblage from Vriddhachalam area, Cau very basin, South India. It includes 13 gcnera with 14 recognizable species and a single acritarch genus Pterospermopsis. The dominant constituents of the as• semblage are: Cordosphaeridiwn, Cyetonephelittm, A reoligera, 5piniferites and DinogymniwYlt with less common occurrence of Apteodinitt1n, LanternosphaeridittYn, Diphyes and Cera• tiopsis. The age of the assemblage has been concluded to be uppermost Maestrichtian, may be representing Maestrichtian-Danian transition.

INTRODUCTION its stratigraphy and palaeontology by Blan• ford (1865); Banerji (1965, 1967, 1968, 1968a, 1969, 1973); Banerji and Mohan UPPERPondicherryCretaceousand palynologyVriddhachalamfrom (1970); Rasheed and Govindan (1963, 1966, areas has been recently worked out 1968), Govindan (1969) and Sastry et at. by Venkatachala and Sharma (1974a, (1972). 1974b). They considered miospores alone The stratigraphic sequence of Vriddha• to correlate the various bore-holes drilled chalam area has recently been published in these areas. The study of dinoflagel• by Banerji (1973). The Upper Cretaceous lates from Vriddhachalam Upper Creta• rock stratigraphic units proposed by ceous is attempted here for the first time, Banerji (1973, Table 4) are reproduced as though much has been contributed towards follows:

GEOLOGICAL AGE ROCK STRATIGRAPHIC UNlTS 0 - •... •...c: ~~.bS •..•::l.-0 ...,'" 0 '"(.)cd•...'" c:cd Upp.ChokanadapuramKallan-Cullmoadtion LowSandstone. kurchiLimcstone.,;~PallakollaiMemberParur MemberMember Pondicherry Formation rJl P< rn0::l SantonianPatti CampanianForma-Member ------::> c: ---- Chendamangalam Member chtian .;:: PalaeoceneMid. •... MemberConiacian

Maestri-

146 JAIN - UPPER CRETACEOUS DINOFLAGELLATE ASSEMBLAGE 147

The two members of Kallankurchi 7f"2/' Formation of Banerji (1973), viz., younger Cullmoad Sandstone and the older Choka• nadapuram Limestone, occur both in Vriddhachalam and Ariyalur areas but are missing on surface in Pondicherry area. The Limestone Member is richly fossili• ferous where as the Cullmoad Sandstone Member is more or less unfossiliferous. Banerji (1973, p. 27) dated the unfossili• ferous member as Middle to Upper Maestri• chtian. Sastry et al. (1972, p. 6) places un fossiliferous poorly sorted sands, sand• stones and clays with dinosaurian bone remains in Ariyalur area at the top of the Maestrichtian under Kallamedu Formation. The purpose of the present article is to demonstrate the occurrence of plank• tonic marine phytoplankton, which are useful indicators of environment and markers for age interpretation, from the palaeontologically unfossiliferous horizon as discussed above. Location G Nature of Samples - The Cretaceous rocks in this area lie within the coordinates 11°31' N: 79°15' E and 11°46'

N: 79°25' E. ~r.,S,q"~LELOCALITY The samples were collected from well cutting sections situated due south of Mattur Village in Vriddhachalam area (Map 1). The section (MT-IIj1) includes medium to coarse grained sandstone at the top, underlying which are the sandy 1.••! - 71 21' I N clays, the lowermost exposed bed of 1 m 30' 7"20' thickness consists of calcareous sand• 0 ,,' stone with no apparent fossils but car• bonaceous streaks. The calcareous sand• stone is greyish-white in colour similar i to Cullmoad Sandstone Member (Banerji, 1973, p. 27). The author is thankful to Map 1. - Geographic set up of Vriddhachalam Dr Surendra Kumar of Geology Depart• area showing the location of samples. ment, Lucknow University for doing the petrology of the samples. The calcareous sandstone lithology alone has been proved to be productive, containing pollen, spores SYSTEMATIC PALYNOLOGY and dinoflagellates. Out of these, only the dinoflagellates and acritarchs have been considered here, the other palynofossils will DINOFLAGELLATES AND ACRITARCHS be published elsewhere. The dinoflagellate cysts and acritarchs Class - Dinophyceae Pascher have been classified according to the systems Subclass - Diniferophycidae Bergh proposed by Sarjeant and Downie (1974) Order - Gymnodiniales Schutt & and Downie et al. (1963) respectively. The Family - Dinogymniaceae Sarjeant type slides are housed at the Museum, Downie Birbal Sahni Institute of Palaeobotany, Genus - Dinogymnium Evitt et al. Ll.lcknow, India. D. acuminatum Evitt et at. 148 THE PALAEOBOTANIST

Order - Peridiniales Schutt A. senonensis Lejeune-Carpentier Family - Spiniferitaceae Sarjeant emend. A. volata Drugg Sarjeant & Downie Genus - Spiniferites Mantell emend. Family - Exochosphaeridiaceae Sarjeant Sarjeant & Downie S. cingulatus (Wetzel) Sarjeant Genus - Lanfernosphaeridium Morgen- S. ramosus subsp. spinosus novo roth Jain L. axialis (Eisenack) Morgen• S. ram osus subsp. ramosus roth (Ehrenberg) Lentin & Williams Genus Family - Systematophol'aceae Sarjeant - Achomosphaera Evitt & Downie Achomosphaera sp. d. A. Genus ramulifera (Deflandre) Davey - Diphyes Cookson emend. Davey & Williams & Williams D. colligerum (Deflandre & Family - Apteodiniaceae Eisenack emend. Cookson) Cookson Sarjeant & Downie Family - Uncertain Genus - Apteodinium Eisenack Genus A. maculatum Eisen ack & - Silicisphaera Davey & Verdier Cookson Silicisphaera sp. A Silicisphaera sp. B ?Apteodinium sp. Genus - Cyclopsiella Drugg & Loeblich C. sp. A Family - Deflandreaceae Eisenack emend. Sarjeant & Downie Group - Acritarcha Evitt Genus - Ceratiopsis Vozzhennikova Subgroup - Pteromorphitae Downie et al. C. diebelii (Alberti) V ozzhen• Gen us - Pterospermopsis Wetzel nikova Pt. sp. d. heliantoides De Coninck Family - Hystrichosphaeridiaceae Evitt emend. Sar:jeant & Downie Genus - Hystrichosphaeridium Deflandre DESCRIPTION emend. Davey & Williams Genus - Dinogymnium Evitt, Clarke & H. tubiferunt subsp. brevispi• Verdier, 1967 num (Davey & Williams) Lentin & Williams Dinogymnium acuminatmn Evitt et al., 1967 Family - Cordosphaeridiaceae Sarjeant PI. 1, fig. 9 & Downie Genus - Cordosphaeridium Eisenack Geologic 0- Geographic Distribution - Maes• emend. Davey trichtian, California (Evitt et al., 1967); C. exilimurum Davey & Williams Maestrichtian, Senegal Basin, W. Africa C. fibrospinosum Davey & (Jain & Millepied, 1975); Maestrichtian, Williams J adukata & Mahadek formations, Assam, C. inodes gracilis (Eisenack) India (Jain et al., 1975); for global distri• Gocht bution see Jain (1977). C. sp. A Genus - Spinijerites Mentall emend. Sarjeant Family - Areoligeraceae Evitt emend. 1970 Sarjeant & Downie Genus - Cyclonephelium Deflandre & Spiniferites cingulafus (Wetzel) Sarjeant, Cookson emend. Cookson & 1970 Eisenack PI. 1, fig. 10 C. ordinatum Williams & Downie C. lemniscatum Stanley Geologic 0- Geographic Distribution• Genus - Areoligera Lejeune-Carpentier Cenomanian to Pleistocene (see Davey & emend. Williams & DQwnie Williams, 1966 in Davey et al., 1966). JAIN - UPPER CRETACEOUS DINOFLAGELLATE ASSEMBLAGE 149

Spiniferites ramosus subsp. spinosus novo kata Formation, Assam, India (Jain et al., PI. 1, fig. 3 1975).

Description - Cyst ovoidal, 46 X 36 [J.m in size. Periphragm ornamented with short ?Apteodinium sp. processes, tabulation that of genus. PI. 3, fig. 23 Comparison - S. ramosus subsp. spinosus novo differs from rest of the subspecies Description - Cyst ovoidal, double of S. ramosus in having distinct ornamen• layered, outer surface rugulate, apical tation of short processes on the periphragm. projection very small, cingulum distinct, HolotYPf-Pl. 1, fig. 3; Slide no. 5511-8. tabulation 4', 6", 6c, 6"', 1p, 1"". Archaeo• Type Locality - Mattur, Vriddhachalam pyle precingular, operculum present. area, South India.

Genus - Ceratiopsis Vozzhennikova, 1963 Spimferites ramosus subsp. ramos1ls (Ehren• berg) Lentin & Williams, 1973 Ceratiopsis diebelii (Alberti) Vozzhennikova, PI. 3, fig. 33 1967 Pl. 2, fig. 21; PI. 3, fig. 34 Geologic 0- Geographic Distribution-Middle Barremian to Ypresian (Davey & Williams, Geologic 0- Geographic Distribution • 1966). Senonian, Germany (Alberti, 1959); Maes• trichtian, Poland, (Gorka, 1963); Maestri• chtian-Danian, California (Drugg, 1967) ; Genus - Achornosphaera Evitt, 1963 Palaeocene-Eocene, U.S.S.R. (Vozzhen• nikova, 1967). Achomosphaera sp. cf. A. ramultfera (Deflandre) Davey & Williams, 1966 PI. 1, fig. 4 Genus - Hystrichosphaeridiurn Deflandre emend. Davey & Williams, 1966 Description - Cyst sphelical, surface smooth to faintly granulate, lines marking Hystrichosphaeridium tubiferum (Ehrenberg) the plate boundaries seen; process distri• subsp. brevispinum (Davey & Williams) bution that of genus, hollow, when bifurcate Lentin & Williams divide near base having proximal fenestrate PI. 2, fig. 14 wall, each stem further trifurcates with bifid tips. Some processes (?cingular) show Geologic 0- Geographic Distribution • distal connection between bifid tips. Early Eocene, London Clay (Davey & Archaeopyle large, pentagon aI, precingular. Williams, 1966 in Davey et al., 1966). Remarks - In most of the general features the present specimen resembles A. ramulifera (Deflandre) Davey & Williams Genus - Cordosphaeridiurn Eisenack emend. but differs in having a few larger processes Davey, 1969 with fenestrate proximal wall and varied nature of bifurcation. Cordosphaeridi1.tm exilimllr1t11l Davey & Williams, 1966 PI. 1, fig. 1 Genus - Apteodiniurn Eisenack, 1958 Geologic 0- Geographic Distribution • Apteod1'nium 111ac1l1atu1nEisenack & Early Eocene, Whitecliff Bay, Isle of Wight, Cookson, 1960 London Clay (Davey & Williams, 1966 Pl. 2. figs. 17-18 in Davey et al., 1966). Remarks - C. exilimurum Davey & Geologic 0- Geographic Distribution • Williams (1966) is quite common in the Albian. South Australia (Cookson & present material. Present specimens show Eisenack, 1960), Upper Cretaceous, Jadu- marked resemblance with the forms des- 150 THE P ALAEOBOT ANIST cribed by Stanley (1965, p. 25, figs. 1-6) 1966 in Davey et al., 1966); Lower Eocene, as H. inodes from Fort Union Formation Germany (Gocht, 1969). (Palaeocene). Cyclonephelium lcmniscatum Stanley, Cordosphaeridiw/t fibrospinosum Davey 1965 & Williams, 1966 Pl. 3, fig. 24 PI. 2, fig. 15

Geologic & Geographic Distrib1ttion • Geologic & GeograpMc Distribution • Maestrichtian, Southern Sweden (Kjellstrom, Palaeocene, Cannon Ball Member, Ford 1973); Early Eocene, London Clay (Davey Union Formation, U.S.A. (Stanley, 1965). & Williams, 1966 in Davey et al., 1966); Maestrichtian, Texas (Zaitzeff & Cross, Genus - Areoligera Lejeune-Carpentier, 1939 1970). Areoligera senonensis Lejeune-Carpentier, Cordosphaeridi1l1n inodes gracil£s (Eisenack) 1939 Gocht, 1969 PI. 2, fig. 16 PI. 2, figs. 19-20

Geologic & Geographic D1'striblltion • Geologic & Geographic Distribution • Eocene, Germ:my (see Gocht, 1969; pp. Senonian, Belgium (Lejeune-Carpentier, 41-42). 1939); Maestrichtian, Denmark (Wilson, 1971); Maestrichtian, U.S.A. (Zaitzeff & Cordosphaeridi·um sp. A Cross, 1970); Eocene, London (Williams & PI. 2, fig. 13 Davey, 1966 in Davey et al., 1966).

Description - Cyst body ovoidal, endo• Areoligera volata Drugg, 1967 phragm smooth, periphragm pitted, giving rise to tubiform, hollow processes. Pro• PI. 1, figs. 6-7; PI. 3, figs. 27-28 cesses variable in width, generally un• Remarks - Vriddhachalam specimens have branched, fibrous, stem striate, distally been described as A. volata in view of two open, secate, tips bifid, in some terminal low antapical lobes and microreticulate tubules present. Archaeopyle haplotabular, surface ornamentation. The process com• tabulation that of genus plexes ar.e variable and resemble to A. Measure17lents coronata (Wetzel) Lejeune-Carpentier (1938). The specimen photographed by Zaitzeff and Cross (1973, pI. 4, fig. 33) and desig• Body size - 44 X 34 fLm nated to A. senonensis shows close re• Process length - upto 26 f1

Genus - Diphyes Cookson emend. Davey & Silicisphaera sp. 13 Williams, 1966 PI. 3, figs. 29-30

Description - Cyst spherical, body 40 [Lm Diphyes colligerum (Deflandre & Cookson) Cookson, 1965 in diameter, periphragm thin, microgranu• late, gives rise to 10-20 [Lmhigh processes PI. 1, fig. 2 having narrow proximal and broader distal ends, striated, distally truncate to slightly Remarks - The present specimen pos• recurved; archaeopyle indistinct, ? precin• sesses numerous processes with closed distal gular. ends and a broad distally closed antapical Remarks - Only a single specimen has process. The archaeopyle is apical. These been found. It shows comparison with features suggest their closest affinity with Silicisphaera ? torulosa Davey & Verdier D. colligerum and Lingulasphaera spinula (1976) but differs in having distally broader Drugg (1970). But Lingulasphaera spimtla and proximally narrower processes. differs in possessing proximally closed pro• cesses and five sided apical archaeopyle Genus - Cyclopsiella Dru~~ & Loeblich, 1970 with 4 apical plates. The main characteristic features described for Lingulasphaera are similar to Diphyes. Cyclopsiella sp. A They are more or less overlapping genera. PI. 1, fig. 12; PI. 3, fig. 32 The holotype of Diphyes needs further study to confirm the separate generic status Description - Cyst oblong, 70-84 X 54-60 of Lingulasphaera. [Lm in size, double layered, outer thin, Geologic & Geographic Distribution • smooth, extending beyond body margin; Eocene, Australia (Deflandre & Cookson, inner one micropunctate; ornamentation 1955); Palaeocene, Fort Union Formation, denser around circular opening (14 [Lmin U.S.A. (Stanley, 1965); Lower Tertiary diameter) having no distinct rim. U.S.A. (Drugg, 1967); Eocene, Southern Remarks - No specific comparison has England (Eaton, 1976); Cretaceous-Tertiary been attempted due to lack of specimens. (Williams & Lentin, 1975).

Gen. indet. Genus - Silicisphaera Davey & Verdier, 1976 PI. 3, figs. 25 -26

Silicisphaera sp. A Description - Cyst spherical, two layeT'ed, endophragm smooth, periphragm gives rise PI. 3, fig. 31 to tubular, hollow processes, distally ex• panded, sometimes bifurcate, recurved, Description - Cyst subspherical, 58 [Lm having 4-5 points. Stem appears to be in diameter; surface microgranulate, wall four sided, striated, four apical and six bearing simple and complex inflated precingular processes distally and proxi• processes. Antapical process large, longer mally free. Polygonal plates along cingulaI' than broad, faintly striated, distally trun• area do not develop complete cingulaI' cated. Postcingular and precingular pro• zone. Cingular processes indeterminable, cesses thin, complex, distally pfovided with postcingular 6 in number. Antapical plate tubules but no spines, tubules terminal possesses one bifurcated large process. or arise at any place on stem length. Base CingulaI', postcingular and ant apical pro• of each process covers most of each plate cesses distally united by trabeculae. Trabe• area. Archaeopyle precingular (3"). culae solid, forming slight net work. Remarks - Present form compares best Archaeopyle ?precingular. with Silicisphaera tenera Davey & Verdier Remarks - Deflandre and Cookson (1955, (1976) in having numerous narrow terminal p. 269) described Hystrichokibotium trabe• tubules, but differs in having ornamented culiferum from Middle Miocene of Victoria. wall. It is characterized by having polygonal 152 THE PALAEOBOTANIST fields which do not appear to form a quite conspicuous, representing about 20-25% distinct equatorial girdle. The processes of the total counts. The specific diversi• are both free or connected distally to one fication is distinct but individual specimen another by filiform or ribbon-like trabe• are few. The significant dinoflagellate culae. These features are similar to the species reGognized in the flora are, viz., present form. The archaeopyle in this Dinogymnium acuminatum, Cordosphae• specimen, though doubtful, appears to be ridium jibrospinosum, C. exilimurum, C. precingular. It differs from 5pinijerites inodes gracilis, Apteoclinium maculatum, pseuclojurcata (Klumpp) Sarjeant (in Gocht, Ceratiopsis cliebelii, Diphyes colligerum, 1969, p. 32, pI. 4, figs. 12-13) in having Cycionepheliurn ordinatum, C. lemniscatum, distally united cingular, postcingular and Areoligera senonensi::;,A. volata and Lanter• antapical processes through solid trabe• nosphaeridium axialis. culae. Verdier (in Deflandre et al., 1970, Comparison with I nclian Dinoflagellate p. 41) assigned H. trabeculijerum Deflandre Assemblages - The records of fossil dinofla• & Cookson (1955) to Nematosphaeropsis gellates from Indian Mesozoic and Cenozoic sp. indet. But the characteFistic feature sediments are mostly found as casual of free apical and precingulaF processes mentions alon?,"with rich spore-pollen des• with distally united other processes pose criptions (Jain, 1974). Detailed dinofla• doubt to place it under Nematosphaeropsis. gellate floras have only been recorded Deflandre and Cookson (1955, p. 269) con• by Sah et al. (1970); Banerjee and Misra sidered that there was a tendency to (1972); Jain and Taugourdeau-Lantz (1973), develop connected processes in H. trabe• Jain (1977a) and Jain et al. (1975). culijerum. The dinoflagellate assemblage described by Sah et al. (1970) from the Langpar For• mation of Therriaghat, South Shillong Genus - Pterospermopsis Wetzel, 1952 Plateau, Assam is dominated by the presence of 5pinijerites-Achomosphaera ele• Pterospermopsis sp. cf. Pt. heliantoicles De ments. It has been dated Upper Cretaceous Coninck, 1968 in age, but none of the constituents PI. 2, fig. 22 supports the age determination, and also does not compare with the present as• Description - Body spherical, 68 [Lmin semblage. This Theniaghat assemblage is diameter, thick-walled (4-5 [Lm) scabrate, pliobably younger than Cretaceous (Per• flange well-developed around central body, sonal communication by Dr R. Y. Singh). 30 [Lmin width; flange possesses numerous The Maestrichtian-Danian dinoflagellate equidistant folds. flora described from Jadukata (Gumaghat), Remarks - In most of the morphological Mahadek and Langpar formations in Assam features the present specimen resembles (Jain et al., 1975; Sah & Singh, 1977, Pt. heliantoiclesDe Coninck (1968) described 1977a & MS.) compares best with the from Ypresian of Belgium but differs mainly present Vriddhachalam dinoflagellate assem• in having numerous folds and scabrate blage in having common elements of both central body. Only a single specimen has Mahadek and Langpar, viz., Dinogym• been recovered. nium, Cycionephelium, Apteodinium, Cordo• sphasridium, Ceratiopsis and Lanternosphae• ridium. The Mahadek Formation is of DISCUSSION Maestrichtian age and consists of the following major dinoflagellate taxa, viz., The palynological assemblage recovered Dinogymnium, Oclontiochitina, Apteoclinium from calcareous sandstone sample of Vrid• and Gonyaulacysta. Out of these, Dinogym• dhachalam area is a mixture of dispersed nium and Apteoclinium are common to pteridophytic spores, angiospermic pollen, present flora. Cycionephelium, Areoligera, algal cysts (dinoflagellates & acritarchs), Cordosphaeridium and Ceratiopsis are absent. recycled Palaeozoic gymnospermous pollen The latter four genera are conspicuous grains and detritus of larger plants. elements of the Vriddhachalam assemblage The dinoflagellate and acritarch cons• and in Assam appear only in the Langpar tituents in the composite assemblage are sediments. JAIN - UPPER CRETACEOUS DINOFLAGELLATE ASSEMBLAGE 153

.~ tL .....• _0 •....•n•....••....• .. -- ;p-•....• ;p- LallternosphaeridiumCordosphaeridiumCyclonephelium- :::d...,+'"dZn::r:tIj:::dUl;p-;J>;p-;J>:::d...,H•....•..., ;p-volata Apteodillium ..., ..., tr1 H :s.:C+:::d;p-ZO;J>0;p-ntr1graciliscolligerum0tIj"sellollellsisdiebeliimaculatumAreoligeraCRETACEOUSCordosphaeridiumZCeratiopsis 0 . Z :s.:;J> n;p-H z~Z0 Areoligera UPPER 0n;p-H Z 0r'tIjZ fibrospillosumlemilliscattlm z Eo Eo ;p-;p-0~ - Diphyesaxialis ------I - , exilimurumillodesordillatum Cyclollephelium I - I Dillogymnium acumillatum -+ Eoi-Eo Eo 4- +Cordosphaeridium - •.. - 154 THE PALAEOBOTANISt

Comparison with other Dinoflagellate As• the Albert Canal (Belgium & Holland)' in• semblages - Several Upper Cretaceous cludes Areoligera-Cyclonephelium elements dinoflagellate assemblages are known from with moderate representation of Cordo• various parts of the world reported by sphaeridium and no Odontochitina. This Drugg (1967), Zaitzeff and Cross (1970), floral aspect is also represented in the Malloy (1970), Wilson (1971, 1976), Bride• Vriddhachalam assemblage but having only aux (1971, 1971a), COHadini (1972), Felix a few very thin-walled, large Odontochitina• and Bm:bridge (1973), K jellstrom (1973), like forms. Williams and Brideaux (1975), Evitt (1973), A perusal of the Upper Cretaceous and Jain and Millepied (1973, 1975), Herngreen Palaeocene dinoflagellate literature reveals (1975), Harland (1976), Doerenkamp et al. that Odontochitina and Dinogymnium are (1976) and Koch et al. (1977). Of these, significant stratigraphic markers (Harker & most of the assemblages remain uncompar• Sarjeant, 1975). The upper limit of known able with the present one due to the pre• Odontochitina species is as young as Cam• sence of important genus Deflandrea which panian-Lower Maestrichtian (Harland, 1977; forms the basis of Upper Cretaceous zonation Wilson, 1971; Kjellstrom, 1973 ;Williams in Europe and Canada. & Lentin, 1975) where as Dinogymnium The dinoflagellate assemblage from extends throughout Maestrichtian (Jain, Maestrichtian Marca shale of Upper Moreno 1977). Recently, Schumacker and Chateau• Formation, Escarpado Canyon, California neuf (1976) recorded three species of (Drugg, 1967), compares well with the Dinogymnium and two species of Odonto• present flora in having Dinogymnium, chitina from the marls of Gelinden, Belgium. though different species, the genus does These occurrences appear to be due to not extend into the Danian Lower Dos reworking of Upper Cretaceous forms. Palos shales. Compa.able Ceratiopsis diebelii Chateauneuf in a personal communication occurs in both the shales where as common to author (4th August, 1977) also agrees Areoligera volata appears only in the Dos with this possibility which confirms the Palos shale. Palaeocene dating of Gelinden marls and Zaitzeff and Cross (1970) have listed restricts the Upper Cretaceous extent of 62 taxa from Maestrichtian of Navaro Odontochitina and Dinogymnium. Group, C'lifornia. Of these, Cordosphae• The stratigraphic distribution of Dinofla• ridium jibrospinosum, Diphyes d. colligfffum, gellate species recovered from Mattur, Areoligera senonensis d. Achomosphaera Vriddhachalam area (Table 1) and the ramulijera, Cyclonephelium spp., Cordosphae• above discussions and comparisons clearly ridium inodes and Dinogymnium acumi• indicate that this assemblage represents natum (their Dinogymnium sp. 4, pl. 4, an Uppermost Maestrichtian or transitional fig. 42, resembles to D. acuminatum) are floral aspect of Cretaceous-Tertiary boun• common. These forms characterise the dary. The equivalent of this assemblage Upper Zone Band C of Navaro Group. is missing at Dawki and Cherrapunji in Zone A is older Maestrichtian and is charac• Assam area. However, the possibility of terized by the presence of Odontochitina its occurrence elsewhere in Assam can not striatoperforata. be ruled out at present. In a preliminary report on European Present study significantly suggests that Late Cretaceous dinoflagellate Wilson (1971) the dinoflagellates would be of greater summarized some interesting results. The help in deciphering the precise zonation rich dinoflagellate flora from Upper Maes• and correlation of Cretaceous and Tertiary trichtian of Enci Quarry, Curfs Quarry and sediments in India.

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BANER)I, R. K. (1966). The genus Clobolruncana fiandre Addendum-par Verdier, J. Postface-par and biostratigraphy of the Lower Ariyalur Stage Deflandre. Paris 1970. (Upper Cretaceous) of Vridhachalam, South DOERENKAMP, A., JARDINE, S. & MOREAN, 1'. India. j. geol. Soc. India, 7: 51-69. (1976). Cretaceous Tertiary palynomorph BANER)I, R. K. (1967). New species of Upper assemblages from Banks Island and adjacen t Cretaceous foraminifera from the lower Ari• areas (N.W.T.). Bull. Can. Petrol. Geol., 24 yalur stage of Vridhachalam and Pondicherry, (3): 372-417. India. Contr. Cushman Fdn foramin. Res., DOWNIE, c., EVITT, W. R. & SAR)EANT, W. A. S. 18: 158-163. (1963). Dinoflagellates, hystrichospheres, and BANER)l, R. K. (1968). Statistical study of fora• the classification of the Acritarchs. Stanford miniferal fauna from the Lower Ariyalur Stage Univ. Pubis. Geol. Sci., 7 (3): 1-16. (Late Cretaceous) of Vridhachalam area, South DRUGG, W. S. (1967). Palynology of the Upper India. Mem. geol. Soc. India, 2: 50-65. Moreno Formation (Late Cretaceous-Palaeocene) BANER)I, R. K. (1968a). Observations on the Escarpado Canyon, California. Palaeontogra• Upper Cretaceous foraminifera from Vridha• phica, 120B (1-4): 1-71. chalam, South India. j. Palaeont. Soc. India, 13: DRUGG, W. S. (1970). Some new genera, species 1-19. and combinations of phytoplankton from the BANER)I, R. K. (1969). Marine Upper Cretaceous Lower Tertiary of the Gulf Coast, U.S.A. ostracods from the Lower Ariyalur Stage of North Amer. Paleont. Conv., Sept. 1969, Proc. G: Vridhachalam, South India. j. Palaeont. Soc. 809-843. India, 14: 28-46. EATON, G. L. (1976). Dinoflagellate cysts from BANERjI, R. K. (1973). Stratigraphy and micro• the Bracklesham beds (Eocene) of the Isle of palaeontology of the Cauvery Basin. Part 1. Ex• Wight, Southern England. Bull. Br. Mus. posed Area. j. Palaeont. Soc. India, 17: 7-30. Nat. Hist. (Geol.), 26 (6): 230-332. BANER)I, R. K. & MOHAN, R. (1970). Foramini• EVITT, W. R. (1973). Maestrichtian Aquilapolle• feral biostratigraphy of Meso-Cenozoic sequence nites in Texas, Maryland, and New Jersey. of the Cauvery Basin, South India. j. geol. Geosci. Man, 7 (1): 31-38. Soc. India, 11: 348-357. EVITT,W. R., CLARKE, R. F. A. & VERDIER, J. P. BLANFORD.H. F. (1865). On the Cretaceous and (1967). Dinoflagellate studies 111. Dinogym• other rocks of South Arcot and Trichinopoly nium acuminatum n· sp. (Maestrichtian) and districts. Mem. geol. Surv. India, 4 (1): 1-217. other fossils formerly referable to Gymnodinium BRIDEAUX, W. W. (1971). Palynologic evidence Stein. Stan. Univ. Pubis. Geol. Sci., 10 (4): for a very Late Cretaceous age of Little Bear 3-27. and East Fork formations, District of Macken• FELIX, F. J. & BURBRIDGE,p. P. (1973). A Maes• zie. Ceol. Surv. Canada, paper, 71-1B: 86• trichtian age microflora from Arctic Canada. 91- Geosci. Man. 7 (1): 1-30. BRIDEAUX, W. W. (1971a). Palynology of the GOCHT, H. (1969). Formengemeinschaften altter• Lower Colorado Group, Central Alberta, Canada• tiii,ren Microplanktons aus Bohrproben des I. Introductory remarks, Geology, and Micro• erdolfeldes Meckelfeld bei Hamburg. Palae• plankton studies. Pataeontographica, 135 : ontographica, 126B (1-3): 1-100. 53-114. GORKA, H. (1963). Coccolithosphoridcs, Dino• COOKSON, I. C. & ElSENACK, A. (1960). Upper fiagelles, Hystrichosphaerides et micro fossiles Mesozoic microplankton from Australia and incertae sedis du Cretace superieur de Pologne. new Guinea. Palaeontology, 2 (2): 243-261. Acta palaeontol. pol., 8 (1): 1-90. CORRADINI,D. (1971). Preliminary report on the GOVINDAN,A· (1969). A preliminary note on the study of non-calcareous microplankton assem• occurrence of Ostracodes from the Upper Creta• blages from the Upper Cretaceous of the Nor• ceous rocks of Vridhachalam, South India. thern Apennines. Proc. II. Planktonic Con• Bull. geol. Soc. India, 6 (4): 127-129. ference, 1: 321-329. HARKER, S. D. & SAR)EANT, W. A. S. (1975). The CORRADINI,D. (1972). Non-calcareous microplank• stratigraphic distribution of organic-walled dino• ton from the Upper Cretaceous of the Northern flagellate cysts in the Cretaceous and Tertiary. Apennines. Bull. Soc. Paleont. Italiana. 11 (2): Rev. Palaeobot. Palynol., 20: 217-315. 119-127. HARLAND, R. (1977). Dinoflagellate cysts from DAVEY, R. J., DOWNIE, C., SAR)EANT, W. A. S. & the Bearpaw Formation (?Upper Campanian to WILLIAMS, G. L. (1966). Studies on Mesozoic Ma"lstrichtian) of Montana. Palaeontology, 20 and Cainozoic dinoflagellate cysts. Bull. Br. (1): 179-193. Mus. nal. Hist. (Ceol.) Suppl., 3: 1-248. HERNGREEN, G. F. W. (1975). Palynology of DAVEY, R. J. & VERDIER, J. P. (1976). A review Middle and Upper Cretaceous strata in Brazil, of certain non-tabulate Cretaceous Hystrichos• Meded Rijks. geol. Dienst, New Series, 26 (3): pherid dinocysts. Rev. Palaeobot. Palynol., 39-91. 22: 307-335. JAIN, K. P. (1974). Fossil dinoflagellates, Acri• DEFLANDRE, G. & COOKSON,I. C. (1955). Fossil tarchs, tasmanitids and calcareous nannoplank• microplankton from Australian late Mesozoic ton, in: Aspects &- Appraisal of Indian Palaeo• and Tertiary sediments. Aust. j. mar. Freshwat. botany, Birbal Salllli Institute of Palaeobotany, Res., 6 (2): 242-313. Lucknow: 586-602. DEFLANDRE, G., VERDIER, J. & DEFLANDRE, R. JAIN, K. P. (1977). Morphologic reinterpretation (1970). Microplancton fossile de sediments du of some Dinogymnium species with remarks On Mesozoique Superieur et du Tertiarie d'Austra• palaeogeographic and stratigraphic distribution lie. Novelle Edition Avant-Propos-Par G. De- of the genus. Palaeobotanist, 24 (2): 132-139. 156 TilE PALAE0130TANlsf

JAIN, K. P. (1977a). Additional dinoflagellates and tion of Therriaghat, South Shillong Plateau, acritarchs from Grey Shale Member of Dalmia• Assam, India. Palaeobotanist, 18 (2): 143• puram Formation, South India. Pataeobota• 150. nist, 24 (3): 170-194. SARJEANT, W. A. S. & DOWNIE, C. (1974). The JAIN, K. P. & MILLEPIED, p. (1973). Cretaceous classification of dinoflagellate cysts above gene• microplankton from senegal Basin, N. W. Africa• ric level; A discussion and revision. Symp. on I. Some new genera, species and combinations Stratigyaphical Palynology, Bi.rbal Sahni Insti• of dinoflagellates. Pataeobotanist, 20 (1): 22-32. tute of Palaeobotany, Lucknow, No.3: 9-32. JAIN, K. p. & MILLEPIED, P. (1975). Cretaceous SASTRY,M. V. A., MAMGAIN,V. D· & RAo, B. R. J. microplankton from Senegal Basin, "V. Africa (1972). Ostracod fauna of the Ariyalur group Pt. II. Systematics and biostratigraphy. Geo• (Upper Cretaceous) Tiruchirrapalli District, Tamil phytology, 5 (2): 71-125. Nadu. Mem. geol. Surv. India Palaeont. Indica, JAIN, K. P., SAH, S. C. D. & SINGH, R. Y. (1975). N.S., 40: 1-48. Fossil dinoflagellates across Maestrichtian• SCHUMACKER-LAMBRY,J. & CHATEAUNEUF, J. J. Danian boundary in Lower Assam. Palaeo• (1976). Dinoflagellates et Acritarhes des Mar• botanist, 22 (1): 1-18. nes Heersiennes De Gelinden (Base du Lande• JAIN, K. P. & TAUGOURDEAu-LANTZ,J. (1973). nien, Paleocene, Belgique). Rev. Palaeobot. Palynology of Dalmiapuram grey shale, Dalmia• Palynol., 21: 267-294. puram Formation, district Tricllinopoly, South STANLEY, E. A. (1965). Upper Cretaceous and India-I. Taxonomy. Geophytology,3 (1): 52-68. Palaeocene plant microfossils and Palaeocene KJELLSTROM,G. (1973). Maestrichtian microplank• dinoflagellates and hystrichosphaerids from north ton from the Hollviken Borehole No.1 in Scan• western South Dakota. Bull. Am. Paleont., 49 ian, Southern Sweden. Sv. geol. under ok. Ser. (222): 179-384. CNR 688, 67NR8: 6-59. VENKATACHALA,B. S. & SHARMA, K. D. (1974a). KOCH, R. C. & OLSSON, R. K. (1977). Dinofla• Palynology of the Cretaceous sediments from gellate and planktonic foraminiferal biostrati• the subsurface of Pondicherry area, Cauvery graphy of the Uppermost C£etaceous of New Basin. New Botanist, 1 (3-4); 170-200. Jersey. j. Palaeont., 51 (3): 480·49I. VENKATACHALA,B. S. & SHARMA,K. D. (1974b). LEJ UNE-CARPENTIER,M. (1939). L'etude micros• Palynology of the Cretaceous sediments from copique des silex (7 ieme Note). Un nouveau the subsurface of Vridhachalam area. Geo• Peridinien Cretacique, Gonyaulax wetzeli. Ann. phytology, 4 (2): 153-183. Soc. Geol. Belg., 62 (10-11): B525-529. VOZZHENNIKOV'A,T. F. (1967). Fossilized Peri• MALLOY,R. E. (1972). An Upper Cretaceous dino• dinid algal in the Jurassic, Cretaceous and flagellate cyst lineage from Gabon, West Africa. Palaeogene deposits of the U.S.S.R. (English Geosci. Man, 4: 57-65. translation, 1971): 1-300. RASHEED, D. A. & GoV'INDAN,A. (1963). Occur• WILLIAMS, G. L. & BRIDEAUX, W. W. (1975). rence of some larger foraminifera in the Creta• Palynologic analysis of Upper Mesozoic and ceous rocks near Vridhachalam, Madras. Curro Cenozoic rocks of the Grand Banks, Atlan tic Sci., 32: 210-211. continental margin. Bllll. geol. Surv. Canada, RASHEED, D. A. & GOV'INDAN,A. (1966). Strati• 236: 1-160. graphy of the Cretaceous rocks of Vridhachalam, WILLIAMS,G. L. & LENTIN, J. K. (1975). Selected South India. Bull. geol. Soc. India, 3 (3): 71-74. Cretaceous dinoflagellates (Late Cretaceous). RASHEED, D. A. & GOV'INDAN,A. (1968). Upper Proc. AmeY. Assoc. Stratigy. Palynol. Contrib., Cretaceous Foraminifera from Vridhachalam, 4: 65. South India. Geol. Soc. India, Mem., 2: 66-84. WILSON, G. J. (1971). Observations on European SAH, S. C. D. & SINGH, R. Y. (1977). Status of late Cretaceous dinoflagellate cysts. Proc. IInd palynology in the Tertiary stratigraphy of Planktonic Conference, 2: 1259-1276. Assam and Gujarat. Proc. 4th Colloq. Ind. Micro• WILSON, G. J. (1976). Late Cretaceous (Senonian) palont., Stratigt'., 134-143. dinoflagellate cysts from the Kahuitara Tuff, SAH, S. C. D. & SINGH, R. Y. (1977a). Mesozoic• Chatham Islands. N. Z. Jour. Geol. Geophys., Cainozoic Boundary in Assam. j. geol. Soc., 19 (1): 127-130. 18 (8); 445-455. ZAITZEFF, J. B. & CROSS,A. T. (1970). The use of SAH, S. C. D. & SINGH, R. Y. (MS). Palynological dinoflagellates and acritarchs for zonation and zonation of the Cretaceous-Tertiary sediments correlation of the Navaroo Group (Maestrich• in Assam Basin. tian) of Texas. Symposium on palynology of the SAH, S. C. D., KAR, R. K. & SINGH, R. Y. (1970). Late Cretaceous and Early Tertiary. Geol. Soc. Fossil microplankton from the Langpar Forma- Amey., Special paper, 127: 341-377.

EXPLANATION OF PLATES

(All microphotographs magnified 500 X)

PLATE 1 3. Spinifeyites ramosuS subsp. spinosus nov.; Slide no. 5511-8. 1. CoYdosphaeridium exilinmrum Davey & 4. Achomosphaeya sp. d. ramulifeya (Deflandre) Williams, 1966; Slide no. 5508-24. Davey & Williams, 1966; Slide no. 5511-5. 2. Diphyes colligerum (Deflandre & Cookson) 5. Cyclonephelillln ordinatum Williams & Downie, Cookson, 1965; Slide no. 5577-4. 1966; Slide no. 5515-6. JAl J - UPPER CRETACEOUS DiNOFLAGELLATE ASSEMBLAGE 157

6-7. A reoligera volala Drugg, 1967; Slide nos. 19-20. Cordosphaeridium inodes gracilis (Eisenack) 5508-20 & 5517-12. Gocht, 1969; Slide nos. 5515-10 & 5517-17. 8. Cyclonephelium ordinatum Williams & Downie, 21. Ceratiopsis diebelii (Alberti) Vozzh., 1967; 1966; Slide no. 5511-23. Slide no. 5508-18. 9. Dinogymnium acttminatum Evitt et al., 1967; 22. pterospermopsis sp. d. Pt. heliantoides De Slide no. 5505-14. Coninck, 1968; Slide no. 5505-12. 10. Spiniferites cingulatus (Wetzel) Sarjeant, 1970; Slide no. 5511-20. 11. Lanternosphaeridium axialis (Eisenack) Mor• genroth, 1966; Slide no. 5517-13. PLATE 3 12. Cyclopsiella sp. A.; Slide no. 5517-21. 23. ?Apleodinium sp.; Slide no. 5505-20. PLATE 2 24. Cyclonepheli1tm lemniscatum Stanley, 1965; Slide no. 5507-13. 13. Cordosphaeridium sp. A.; Slide no. 5511-4. 25-26. Gen. indet.; Slide nos. 5518-19. 14. Hystrichosphaeridium tubiferum Subsp. brevi• 27-28. Areoligera volala Drugg, 1967; fig. 27 spinum (Davey & Williams) Lentin & Williams, shows the presence of plates; Slide no 5511-20. 1973; Slide no. 5518-15. 29-30. Silicisphaera sp. B; Slide no 5518-16. 15. Cordosphaeridium fibrospinosum Davey & 31. Silicisphaera sp. A.; Slide no. 5517-9. Williams, 1966; Slide no. 5515-14. 32. Cyclopsiella sp. A.; Slide no. 5517-20. 16. Areoligera senonensis Lejeune-Carpentier, 33. Spiniferites ramosus Subsp. ramosus (Ehren• 1939; Slide no. 5511-10. burg) Lentin & Williams, 1973; Slide no. 5508-1. 17-18. Apteodini1tm maculatum Eisenack & Cook• 34. Ceratiopsis diebelii (Alberti) Vozzhennikova, son, 1960; Slide nos. 5508-17 & 5515-23. 1967; Slide no. 5517-26. 158 THE PALAE0:i30T ANtsl'

PLATE ~ JAtN - UPPER CRETACEOUS DINOFLAGEtLA1'E ASSEMBLAGE B<) r--"---- '-,--"- -, ,- I i, I· I I I

I i l_ ~,~

PLATE 2 , . 160 THE PAtAEOBOT A '1ST

\ /

~._~I' . • ~r' -/ 3'

PLATE 3