GYMNOSPERM FOSSIL WOODS FROM EASTERN KACHCHH, WESTERN INDIA Journal of the Palaeontological Society of India Volume 61(1), June 30, 2016: 111-122 111 ISSN 0522-9630 GYMNOSPERM FOSSIL WOODS FROM GANGTA BET, EASTERN KACHCHH, WESTERN INDIA JYOTSANA RAI1, MAHESH PRASAD1, NEERU PRAKASH1, ABHA SINGH1, SURABHI GARG1, MRIDUL GUPTA2 and D. K. PANDEY3* 1 BIRBAL SAHNI INSTITUTE OF PALAEOBOATNY, 53-UNIVERSITY ROAD, LUCKNOW 2 3 GEOLOGICAL SURVEY OF INDIA, NORTHERN REGION, LUCKNOW DEPARTMENT OF GEOLOGY, UNIVERSITY OF RAJASTHAN, JAIPUR E-MAIL: dhirendrap@hotmail.com *CORRESPONDING AUTHOR ABSTRACT Two gymnospermous fossil woods Araucarioxylon wagadensis n. sp. and Podocarpoxylon gangtaensis n. sp. have been described for the irst time from the younger part of the Gadhada formation exposed around the core of the central dome of the Gangta Bet. The ammonites recorded from the Gangta Bet by earlier workers suggest that these fossil woods come from Callovian sediments forming the basal part of the succession. These fossil woods are characterized by the presence of early and late secondary wood with small resin canals, tracheidal cells, aurocaroid or podocarpoid pits in cross ield area. Dendrological data indicate that the climate was characterized by cycles of tropical wet and dry savanna climate. Keywords: Fossil woods, Araucarioxylon, Podocarpoxylon, Gangta Bet, Gadhada formation, Eastern Kachchh INTRODUCTION MATERIAL AND METHOD The Jurassic rocks of the Kachchh Basin are globally known for their rich macro fauna (Fig. 1). The old fourfold classiication of Jurassic rocks of the Kachchh Basin proposed by Waagen (1875) has been replaced by a different lithostratigraphic classiication (Biswas 1980, Fürsich et al., 2001, 2013). Biswas (1980), in fact, distinguished three lithologic provinces in the Kachchh Basin, viz. Kachchh Mainland, Pachchham "Island" and Eastern Kachchh (Wagad, Khadir and Bela "islands" and Chorar Hill). He called all individual units the uplifts in salt marsh. The stratigraphy of the Eastern Kachchh represents a shallow marginal marine facies, whereas the rocks of the Kachchh Mainland represent comparatively deeper facies. Within the Eastern Kachchh older rocks are exposed in Khadir and Bela "islands" and Chorar Hill, whereas younger rocks are exposed in Wagad region. Lithostratigraphically, six formations have been recognized in the Eastern Kachchh (Table 1). Barring Patcham Formation, all other formations dominantly consist of siliciclatic sediments. Wagad is the largest uplift in Eastern Kachchh (Fig. 1). Gangta Bet (N23º46’ to N23º 43’ and E70º30’ to 70º33’), an islet, is situated very near to the Wagad Uplift, on its northwestern side and connected by about a 4 km motorable road in salt marsh (Figs. 1 & 3). Gangta Bet represents a highly denuded domal structure of ca. 5 km in diameter surrounded by the Great Rann of Kachchh. Lithostratigraphically, the rocks of Gangta Bet represent the Gangta Member of the Gadhada formation (Table 1). On the basis of ammonites, Callovian to Late Oxfordian age has been assigned to the rocks exposed in Gangta Bet (Patel et al., 2012, Pandey et al., 2013). Recently, two fossil woods belonging to the families Araucariaceae and Podocarpaceae have been recorded from the Callovian sediments forming the basal part of the succession exposed in the central part of the dome. The present paper deals with the description of these two wood fossils. Dark brown coloured and anatomically well preserved two pieces of petriied woods, measuring 6.0 x 4.0 cm and 8.0 x 5.0 cm in size, were collected from the Callovian part of Gadhada formation exposed at the base of central dome, southwest of Ravechi Mata Temple, Gangta Bet (Fig. 2). In order to prepare thin sections (transverse, radial and tangential), the specimens were cut and polished using carborundum powder. Slides were prepared for xylotomical studies. These slides were examined under high magniication using microscope after smearing the surface with glycerine under transmitted light. Identiication of the fossil wood taxa was done using key characters, such as presence or absence of resin canals, crossield pitting, height of rays, distinct or indistinct or absence of growth rings, the transition from early to late wood and presence of tracheids. SYSTEMATIC DESCRIPTION Class Pinopsida Burnett 1835 Order Pinales Gorozhankin 1904 Family Araucariaceae Henkel & Hochstetter, 1865 Genus Araucarioxylon Kräusel, 1870 Araucarioxylon wagadensis n. sp. (Pl. I, igs. 1-7) Material: One small piece of petriied wood specimen measuring 6.0 x 4.0 cm and 8.0 x 5.0 cm, basal sediments (Callovian) of Gadadha formation, Gangta Bet, Kachchh Basin. The specimen is dark brown in colour and bears good preservation of anatomical characters. BSIP Museum No. 40567 (Holotype), Description: Growth ring indistinct, almost homogeneous, no proper distinction between early and late wood zone (Pl. I, igs. 1-2). Wood tracheids squarish to polygonal, transverse 112 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY Table 1: Lithostratigraphic framework of the Jurassic rocks of Kachchh (modiied after Fürsich et al., 2013). ExPLANATION OF PLATE I Anatomical structures of Araucarioxylon wagadensis n. sp.; 1-2, Transverse section (TS); 3-6, Transverse longitudinal section (TLS); 7, Radial longitudinal section (RLS); BSIP wood slide nos. 40567 I-VI. Journal of the Palaeontological Society of India GYMNOSPERM FOSSIL WOODS Volume 61 (1), June 30, 2016 FROM EASTERN KACHCHH, WESTERN INDIA 113 Plate I RAI, PRASAD, PRAKASH, SINGH, GARG, GUPTA AND PANDEY 114 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY Fig. 1. Geological map of Kachchh. dimension (t. d.) 17-40 µm, radial dimension (r. d.) 20-70 µm, wall thickness 10-15 µm, 160-200 tracheids per square mm, some tracheids illed with resinous material (Pl. I, igs. 1-2). Radial pits uni-biseriate, bordered, circular to oval in outline with usually elliptic aperture, 10-16 µm in diameter (Pl. I, ig. 6). Cross ield pits 2-5, small in size, 6-8 µm in diameter, circular to elliptical in outline, usually contiguous alternate to opposite with circular to elliptic aperture (Pl. I, ig. 7). Hexagonal or araucaroid thickening occurs on tangential wall of the tracheids. Parenchyma rarely seen, scattered among the tracheids, cells are small with usually truncate to tailed ends. Xylem rays mostly uniseriate, 2-26 cells or 60-410 µm in height and about 30 µm wide (Pl. I, igs. 3-4), rays 15-20 per square mm in cross section (Pl. I, ig. 1), oval to elongated in outline, homogenous, some cells are illed with dark content. Resin canals present, small in size. At places equivalent to tracheidial cells (Pl. I; igs. 1-2). Speciic Diagnosis: Growth rings indistinct, tracheids square to polygonal, transverse dimension (t.d.) 17-40 µm, radial dimension (r. d.) 20-70 µm, sometimes illed with dark content, radial pits uni- biseriate, bordered, circular to elliptic usually contiguous alternate to opposite; xylem rays mostly uniseriate, 2-26 cell or 60-410 µm in height, oval to elongated, more than 3 times in length than in width, cells are also illed with dark content. Parenchyma rare, scattered with truncate to tailed end. Resin canal present small, sometimes as small as tracheidial cell. Holotype: BSIP Museum No. 40567 Locality: Gangta Bet, eastern Kachchh, Gujarat, India Horizon & Age: Gadhada formation, Callovian Derivation of name: Speciic epithet is based after Wagad Uplift. ExPLANATION OF PLATE II Anatomical structures of Podocarpoxylon gangtaensis n. sp.; 1, Transverse section (TS); 3-4, Transverse-longitudinal section (TLS); 5-6, Radial longitudinal section (RLS); BSIP wood slide nos. 40569 I-VII. Journal of the Palaeontological Society of India GYMNOSPERM FOSSIL WOODS Volume 61 (1), June 30, 2016 FROM EASTERN KACHCHH, WESTERN INDIA 115 Plate II RAI, PRASAD, PRAKASH, SINGH, GARG, GUPTA AND PANDEY 116 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY Fig. 2. Geological map of Gangta Bet. indicating fossil locality. Identiication and comparison: Coniferous fossil woods are mainly described under the families Araucariaceae and Podocarpaceae (Bose and Maheshwari, 1974). The anatomical characters such as indistinct growth rings, almost uniform tracheids, exclusively uniseriate xylem rays, presence of small resinous cells and araucaroid bordered pits collectively suggests its afinities with the modern woods of the genus Araucaria Juss, family Araucariaceae. Critical study of available modern woods, viz. Araucaria araucana Koch; A. angustifolia Kuntze; A. cunninghamii Ait; A. hunsteinii Schum and A. klinkii Lauterbach suggests undifferentiated early and late woods. The tracheids vary in shape and size. Araucaria araucana Koch and A. klinkii Lauterbach possess squarish to polygonal tracheidial cells and uniseriate, 3-20 cells high xylem rays similar to present fossil wood. The remaining other species can be differentiated easily in having absence of resinous cells with smaller xylem rays. About eight fossil woods indicating anatomical details are described under the name genus Araucarioxylon Kräusel from various sedimentary basins of India (Table 2). The analysis of anatomical characters of the known fossil species as well as the fossil wood described here suggests that the present fossil wood is distinct from all the known species. It differs mainly in displaying the presence of medium sized uniseriate xylem rays and resinous cells as small as trachidial cells of the wood. In view of these characteristic features, present fossil wood is described under a new speciic name Araucarioxylon wagadensis. Family Podocarpaceae, Endlicher 1847 Genus Podocarpoxylon Gothan, 1905 Podocarpoxylon gangtaensis n. sp. (Pl. II, igs. 1-6) Material: The species is based on one piece of petriied wood measuring 8 cm x 6 cm and 7 cm x 5 cm. It is light brown in colour and possesses well preserved anatomical structures. Description: Growth rings distinct (Pl. II, ig. 1). Tracheids of early wood zone quite wide, occupying greater zone than late wood, tracheids, 60-85 cells wide, cell comparatively thick, oval GYMNOSPERM FOSSIL WOODS FROM EASTERN KACHCHH, WESTERN INDIA 117 Fig. 3. Lithocolumn of the succession exposed on the southern slope of the central dome, Gangta Bet (modiied after Pandey et al. 2013). Note the photograph showing panoramic view of south dipping beds on the central dome, Gangta Bet, with indicating fossil locality. 118 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY Table 2: Comparision of Indian records of fossil woods of Araucarioxylon Kräusel. Sr. No. 1. Name of taxa 2. Present microA. santalense scopically (Sah & Jain, distinct 1964) Bose & Maheshwari, 1974 3. A. rajmahalensis (Sahni, 1931) Bose & Maheshwari, 1974 4. Araucarioxylon sp. A Rajanikanth & Sukh-Dev, 1989 5. Present A. agathioides (Krausal and Jain, more or less indistinct 1964) Bose & Maheshwari, 1974 6. A. amraparense (Sah and Jain, 1964) Bose & Maheshwari, 1974 Distinct Oval in shape, 28 gradual X 44 µm to 8-16 transition µm in size from early to late wood, 40 tracheids wide 7. A. mandroense (Sah and Jain, 1964) Bose & Maheshwari, 1974 Distinct with gradual transition Araucarioxylon pranhitaensis Rajanikanth & Sukh-Dev, 1989 Growth Rings Present microscopically distinct Tracheids Parenchyma Absent Rays Resin canal Tracheids pit Uniseriate or rarely partially biseriate, 1-10 cells (average 4-5), cells slightly higher than broad Resin tracheids present at places Trachids angular thick walled , rounded to oval 20-40 µm in diameter Absent Resinous cells scattered Very distinct, broad tracheids thick walled Early wood tracheids zone wide, tracheid 56 µm, late wood tracheid zone narrow 14 µm in diameter Absent Present Early wood zone Absent 24-42 cells, late wood zone narrow, 3-5 cells wide early wood tracheid squarish to polygonal, 3258 X 56-78 µm in size, wall thick, 16-24 µm late wood tracheid, almost squarish 14-30 X 16-40 µm Broad, 31-48 µm Absent Mostly uniseriate sometimes bi or tri seriate, 1-52 cells in height, cells are longer than width, thin walled Uniseriate distantly placed about 3-15 rows of ttracheid, 1-12 cells high. Sometimes 20 cell high, cells oblong or oval (11 X 1 µm) Mostly uniseriate partly biseriate, 1-18 cells or 18430 µm in height, cells longer than broad thin walled Tracheids agular, thick walled, rounded to oval, 20-40 µm in diameter Absent Angular with Absent rounded to oblong lumen, 20-50 µm in diameter Cross ield pits Only radial pits mostly uniseriate and sometime biseriate contiguous, 8 X 12 to 8-25 µm in size, circular 4-6 µm biseriate pits, hexagonal alternate, contiguous Radial wall pits 1-3 seriate mostly (1-2), alternate sometimes subopposite hexagonal bordered contiguous Radial pits only uniseriate occasionally biseriate and triseriate contiguous or separate circular alternate hexagonal. Bar of sanio absent Crossield pits 2-6 usually 4 bordered, circular separate, 6 µm Resin cells scattered Radial wall pits mostly uniseriate contiguous, 13-16 µm in size Crossield pits 2-5 bordered in groups, 4-5µm in size, oval to circular hexagonal Uniseriate occasionally partly biseriate, 2-20 cell high (average 8 cells) Resinous tracheids abundant as biconcave plate Radial pits 1-2 seriate forming short rows or group 13 X 10-23 X 13 µm in size, biseriate pits are hexagonal and irregularly arranged Uniseriate, 1-15 cells high, average 6 cell, 8x12µm in size Resinous tracheids abundant near medullary rays Uniseriate distantly placed, 1-15 cells high (3-4) higher than broad Absent Radial pits single, 1-3 seriate, oval or circular contiguous or seprate, aperture oval, 4-6 µm in size, bi and triseriate pits usually contiguous, alternate, hexagonal with oblique pore Radial pits in early wood 1-3 seriate, oval, 4-8 µm, alternate, contiguous, hexagonal, some times in groups. In late wood pits are uni to partially biseriate circular, 12-16 µm aperture, circular 4 µm in diameter Crossield pits 2-8 sometimes in group of 5-6, circular to angular, separate or contiguous 10 µm bordered with elliptic aperture Crossield pits Not very well preserved, 2-4 bordered, circular, contiguous 8µm in diameter with elliptic pore 4 X 6 µm in size. Resin canal absent Crossield pits 3-6 in group, circular or elliptical, 6-8 µm in diameter Pitting not preserved Crossield pits In early wood 4-12 circular contiguous 12µm in diameter, in late wood usually 3 or 4, circular, 8 µm in diameter, pit pore 4 X 6 µm in size elliptical GYMNOSPERM FOSSIL WOODS FROM EASTERN KACHCHH, WESTERN INDIA 8. A. bindrabunense Indistinct (Sah and Jain, 1964) Bose & Maheshwari, 1974 9. Araucarioxylon wagadensis n. sp. Indistinct Thick walled, triangular to squarish in shape with almost angular to rounded lumen radial diameter 20-60 µm Thick walled squarish to polygonal, t. d. 17-40 µm, r. d. 20-70 µm, 160200 tracheids per sq mm, wall thickness 10-15 µm, sometimes illed with resinous material Absent Uniseriate, very Absent rarely biseriate 1-45 (average 25) cells high, rod like 8 X 12 to 24 X 32µm in size Present, Uniseriate, 2-26 scattered, cells or 60-410 rare µm high oval to elongated, homogenous sometimes cells are illed with dark content Radial pits only, mostly biseriate sometime triseriate very rarly uniseriate, contiguous alternate and hexagonal with circular pits, 6 µm in diameter Present Radial pits unismall in size biseriate, bordered, circular to oval with elliptic aperture, 10-16 µm in diameter 119 Crossield pits 4-12 usually (4 or 6), bordered circular or oval, separate 6-8 µm, with oval aperture Crossield pits 2-5, small size, 6-8 µm in diameter, circular to elliptic contiguous alternate to opposite Table 3: Comparison of Indian records of fossil woods of Podocarpoxylon, Gothan. Sr. Name of taxa No. Growth Rings Tracheids Parenchyma xylem Rays Resin tracheid canal Tracheids pits Cross ield pits Absent Uniseraite 1-5 cell high, side walls coated with resinous substance Resin canal absent resin illed tracheids present Only radial pits, uniseriate, bordered, separate 10-12 µm in diameter with circular pore Cross ield pits solitary, bordered, oval, inclined 1. Not clearly Pdocarpoxylon seen indicum (Bharadwaj, 1953) Maheshwari & Kumaran, 1974 Early wood wide, 3035 tracheids wide, thin walled subroundedsquarish, late wood narrow, 5-6 cells in width, thick walled squarish or elliptical early wood tracheids 20 X 20-24 µm, squarish-pentaangular, thick walled late wood tracheids, 20 X 1215µm, elliptical or rounded 2. Faintly P. schmidianum (Scheiden, 1855) marked M. schmidianum (Sahni, 1931) Bose & Maheshwari, 1974 Thick walled longer than Scanty broad Uniseriate rarely biseriate numerous 2-10, rarely upto 100 (average 36), thick walled, isodiametric or slightly higher than broad Resin canal absent Radial pits circular or rarely elliptical, 20µm, separate, 1-2 seriate, opposite Cross ield pits 1 or 2 large pore, slit like, poorly preserved 3. Absent P. godaverianum (Sahni, 1931) Bose & Maheshwari, 1974 Tracheid cells 20-30 µm Resin diameter, full of resin, parynchythick walled ma abundant, scattered Uniseriate 2-15 cells high, average 5 cells often containing resin Resin canal absent Radial pits only, 1-2 seriate, rounded, contiguous, subopposite or even alternate, rims of sanio not seen Cross ield pits 2-6 bordered, circular, 7 µm, sometimes in two rows with several pits 4. P. parthasarathyi Faintly marked (Sahni, 1931) Bose & Maheshwari, 1974 Large, thin walled, isodiametric, not distinction in early and late wood Uniseriate, 1-18 Resin canal cells, average 8, absent high, higher than broad Radial pits uniseriate, circular, separate or contiguous, 9-12 µm Cross ield pits 2-5 or 6 rounded, bordered, pore narrow, Stone cells scattered Not seen 120 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY 5. P. bansaense (Prakash & Rajanikant, 2004 Distinct Early wood wide, 8-22 transition cells, late wood 4-7 cells between wide early and late wood is gradual Scattered present with resinous material Mostly uniseriate Resin rarely biseriate, parenchyma short, 2-14 cells cells high, cell oval 15-40 µm 1-2 seriate, bordered, circular, opposite, 6-11 µm, tangential pits absent Cross ield pits 2-3 podocarpoid, 3-7 µm 6. P. sarmai Varma, 1954 Scarcely visible, pith present, 1 mm in diameter Late wood, 1-6 µm thick, 3-16 X 16-26 µm size, early wood tracheids, 16-32 cells, rounded to elliptical Parenchyma rarely seen, cells oblong or rectangular, 9-16 µm wide Uniseriate, Absent 3-8 cells high, maximum height 18 cells Present only on radial wall, uniseriate, circular, separate, rarely contiguous, 13-16 µm in diameter, simple, oval to oblong, 8-6 µm, bar of sanio not observed Cross ield pits 2-4 (4) small oval to oblong and simple, in or two rows, 8 X 16 µm only 7. P. rajmahalense (Jain, 1965) Bose & Maheshwari, 1974 Growth rings distinct, gradual transitio-n from early to late wood Absent Early wood 10-40 cell wide, late wood 2-3 tracheids wide, broad 12-20 µm in size, thick walled, angular to rounded with oval lumen Uniseriate, 1-10 cell high (average 4) distantly placed resin plugs seen near the rays Resin canal absent resinous tracheids sporadic Only radial pits bordered, uniseriate, sometimes biseriate, uniseriate pits circular or oval, 12 µm in diameter, mostly separate, biseriate pits, separat, alternate to opposite, pit pore rounded or oval, 4-6 µm Cross ield pits Large, 1-2, pinoid type, oval to oblong or rounded, simple 8. Distinctly P. malerianum (Merembrioxylon visible maleranum Sahni, 1931) Bose & Maheshwari, 1974 Not distinct between early and late wood, often contain resin Absent Uniseriate, Resin canal average height 3 absent cells, contiguous but circular sometimes separate 13-14 µm Radial pits uniseriate circular, contiguous, sometime separate, 13-14 µm, pore elliptic oblique, Rim of sanio not seen 3-10, usually 4-6, bordered oval or circular, pore narrow obliquely vertical 9. P. Krauselii Rajanikanth & Sukh-Dev, 1989 Distinct, transition from early to late wood abrupt Early wood tracheids polygonal, 20-38 X 25-55 µm, late wood tracheids round or polygonal, 16-25 X 2532 µm Parenchyma cells scattered Mostly Not uniseriate, 2-28 reported cells in height, oval or bead like wall smooth, thin Radial wall pits uniseriate, circular, bordered, contiguous or separate, aperture oval to round Cross ield pits 4-5 elliptical in groups, bordered 10. Podocarpoxylon gangtaensis n. sp. Distinct Early wood 60-85 cells, thick, t. d. 15-24 µm, r. d. 18-40 µm, oval to circular, sometimes with dark content, late wood zone narrow, 2-5 µm thick, t. d. 6-18 µm, r. d. 16-22 µm, oval to squarish and polygonal also Parenchyma cells scattered, small with transvers-e to tailed end Mostly uniseriate very rarely partially biseriate, oval shaped homocellular, 3-18 cells (average 3-8 cells) or 30-250 µm in height Absent, resinous tracheids present Radial pits usually one or rarely two sereiate, alternate to opposite, circular to elliptic with elliptic aperture, 7-10 µm in diameter Cross ield pits 2-5 small to large, oval to circular, bordered, 6-9 µm in diameter 11. P. chandrapurensis Distinct, transition Rajanikanth & from early Sukh-Dev, 1989 to late wood abrupt Early wood tracheids 6-54 cells wide, cells squarish, 18-32 X 1930 µm Resinous parenchyma scattered Mostly uniseriate, simple, 1-18 cell high, cells longer than broad Resinous parenchyma cells scattered Radial wall pits mostly uniseriate, rarely biseriate, contiguous or separate, simple, bordered, circular, 10-12 µm in diameter, aperture oval Cross ield pits 1-2 bordered, round 6-7 µm, aperture round GYMNOSPERM FOSSIL WOODS FROM EASTERN KACHCHH, WESTERN INDIA 12. P. trichinopoliense Present on weathered (M. surface orichinopoliense Varma, 1954) Bose & Maheshwari, 1974 13. P. haburensis Guleria & Shukla, 2008 14. P. kutchensis Lakhanpal, Guleria & Awasthi, 1975 Early wood tracheids rounded or elliptical, 10-45 µm (16-32), in late wood rectangular to elliptical, 3-9 X 19-26 µm, narrow zone than early wood Early wood tracheid pits uniseriate, circular, bordered, separate usually, 13-20 µm and pore 3 µm, bar of sanio absent Cross ield pits 1-2 fusiform obliquely placed pits, 9-13 X 3 µm Fine, uniseriate, Resin canal homocellular, absent 3-10 celled or 34-157 / 180 µm in height Obietineam on radial wall, mostly in one row rarely in two, opposite or subopposite, oval, circular, simple and bordered, 7-35 µm in radial diameter and 6-3 µm in t. d. Cross ield pits not seen due to poor preservation Mostly uniseriate Resinous rarely biseriate, parenchyma homocellular, cells present 1-41 cells or 45-1350 µm in height, usual height 5-18 cells Pitting on both radial and transitional wall, radial pit in one row rarely in two rows, opposite to subopposite, ovalcircular, bordered, 12-20 µm in diameter, aperture 4-8 µm, tangential pits unisetriate, solitary, 8-16 µm in diameter, aperture 4-6 µm Cross ield pits 1-2 small, circular, oval, simple as well as bordered podocarpoid to taxadioid, 8-12 µm, aperture 4 µm, Crystals rarely present in tracheids Parenchyma rarely seen Uniseriate, 1-10 (2-6) cell high, rounded to oblong Tracheid of early wood Present but not zone is quite wide, conspicuous occupy greater portion, 50-60 tracheid cells, thin walled polygonal, t. d. 19-34 µm, r. d. 18-34 µm, late wood 2-4 cells thick, thickwalled, t. d. 6-11 µm, r. d. 3.5-11 µm, lattened or elliptic illed with dark content, 400-550 tracheids/cm2 Present, rarely seen with transvers-e end walls in tangentia-l section Present Tracheids of early wood but not zone occupy greater conspicuous portion, 31-62 cells, thin walled, polygonal, r. d. 37-67 µm, t. d. 2245 µm, late wood with narrow zone, 2-4 cells thick walled, r. d. 3060 µm, t. d. 22-45 µm, lattened to elliptical, 360-500/mm2 Small celled illed with dark content, thin walled, smooth end walls to squarish, transverse diameter (t. d.) 15-24 µm, radial diameter (r. d.) 18-40 µm, sometimes cells contain dark content. Late wood tracheids forming narrow zone, 2-5 cells thick, t. d. 6-18 µm, r. d. 16-22 µm, oval to squarish and sometimes pentagonal, resinous material present, 300-350 cells per square mm (Pl. II, ig. 1). Resin canals absent. Parenchayma present (Pl. II, igs. 1-2), scattered cells small with transverse to tailed end. Xylem rays ine, mostly uniseriate, very rarely partly biseriate, homocellular, composed of upright type of cells (Pl. II, igs. 2-3), 9-12 xylem rays per mm in cross section, 3-18 cells (average 5-8 cells ) and 30-250 µm in height, cells elongated. Tracheidial pits preserved on radial walls, mostly in one row rarely in two, alternate to opposite, usually separate, almost circular to elliptic, 7-10 µm in diameter with elliptic aperture, bordered (Pl. II, ig. 6). Cross ield pits badly preserved, 2-5 small to large, oval to circular, bordered, 6-9 µm in diameter (Pl. II, ig. 5). Speciic diagnosis: Growth ring distinct with gradual transition of early and late wood. Early wood 60-85 cells thick, cells thick walled, transverse diameter (t. d.) 15-20 µm, radial diameter (r. d.) 18-40 µm, oval to circular, late wood narrow, 2-5 cells in thickness, transverse diameter (t. d.) 6-18 µm, radial diameter (r. d.) 16-22 µm, oval to polygonal. Radial pits usually uniseriate, rarely biseriate, 7-10 µm in diameter, alternate to opposite, circular to elliptic, with usually elliptic aperture, cross ield pits 2-5, small to large, oval or circular, bordered, 6-9 µm in diameter. Xylem rays mostly uniseriate, rarely partially biseriate, oval shaped homogeneous, 3-8 cells or 30-250 µm in height. Parenchyma sparse. Resin canal absent. 121 Absent Holotype: BSIP Museum No. 40569 Locality: Gangta Bet, eastern Kachchh, Gujarat, India Horizon and Age: Gadhada formation, Callovian Derivation of name: Speciic epithet is based after Gangta Bet locality from where the fossil wood is collected. Identiication and comparison: The characteristic features of the present fossil wood undoubtedly suggest its afinity with the modern woods of the family Podocarpaceae. Further, the presence of xylem parenchyma and the smaller xylem rays (upto 18 cells in height) shows afinity with the genus Podocarpus (L'Hérit) (also Presl of the family Podocarpaceae. Critical study of the slides of the modern woods of different species of the genus Podocarpus viz. P. amara Blune; P. falcatu R. Br. Et Mirb.; P. imbricatus Blune; P. henpepelii Stapf.; P. latifolius R. Br.; P. eumphii Blune; P. wallichianus Presl and Podocarpus sp. has been carried out in order to identify upto speciic level. Among all the modern species P. wallichianus and P. imbricatus show resemblance with the fossil wood in having marked growth rings differentiating in early and late wood as well as with same length of xylem rays which are sometimes paired. However, in other species the rays are exclusively uniseriate and sometimes with upto 50 cells in height. Fossil woods showing resemblance with the genus Podocarpus (L'Hérit) Presl have been incorporated under the form genus Podocarpoxylon Gothan. So far, 13 fossil woods (Table 3) have been described from various sedimentary basins of India. The comparative study suggests that the Podocarpoxylon gangtaensis is quite different from the earlier known fossil 122 J. RAI, M. PRASAD, N. PRAKASH, A. SINGH, S. GARG1, M. GUPTA AND D.K. PANDEY woods in the nature of early and late wood tracheids, xylem rays and biseriate nature of xylem rays. Thus, the wood described here is different from all the known species (Table 3) of Podocarpoxylon, so a new speciic name Podocarpoxylon gangtaensis is assigned to it. REFERENCES Quarterlary Journal of Geological, Mining and Metallurgical Society of India, 49: 1-62. Biswas, S. K. 1993. Geology of Kutch volume I, p. 1-415. K. D. Malaviya Institute of Petroleum Exploration, Dehradun. Biswas, S. K. and Deshpande, S. V. 1968. The basement of the Mesozoic sediments of Kutch, Western India. Bulletin Geological, Mining and Metallurgical Society of India, 40: 7. Bharadwaj, D. C. 1953. Jurassic woods from the Rajmahal Hills, Bihar. Palaeobotanist, 2: 59-69. Bose, M. N. and Banerji, J. 1984. The fossil loras of Kachchh. I – Mesozoic megafossils. Palaeobotanist, 33: 1-189. Bose, M. N. and Maheshwari, H. K. 1974. Mesozoic conifers, p. 212-233. In: Aspects and appraisal of Indian palaeobotany (Eds. Surange, K.R. et al.), Birbal Sahni Institute of Palaeobotany, Lucknow. Fürsich, F. T., Alberti, M. and Pandey D. K. 2013. Stratigraphy and palaeoenvironments of the Jurassic rocks of Kachchh-Field Guide. Beringeria, special issue 7: 1-174. Gothan, W. 1905. Zur Anatomie lebender und fossiler Gymnospermen Hölzer. Preussische Geologische Landesanstalt und Bergakademie, 44: 1-105. Guleria, J.S. and Shukla, A. 2008. Occurrence of a conifer wood in the desert of Rajasthan and its climatic signiicance. Geopytology 37(1): 1-5. Jain, K. P. 1965. A new species of Mesembrioxylon, M. rajmahalense, from the Rajmahal Hills, Bihar. Palaeobotanist, 13(2): 153-154. Kräusel, G. 1870. Bois Fossiles de Coniferes, p. 363-385. In: Traité de Paléontologie Végetale, Strasbourg (Ed. Schimper, W. P.), J B Baillière et ils 2, Paris. Kräusel, R. and Jain, K. P. 1964. New fossil coniferous woods from the Rajmahal Hills, Bihar, India. Palaeobotanist, 12(1): 59-67. Kreshaw, P. 2001. The history, palaeoclimatic signiicance and present day status of the southern conifer families Araucariaceae and Podocarpaceae. Geociências, VI(6): 5-21. Lakhanpal, R. N., Guleria, J. S. and Awasthi, N. 1975. A podocarpaceous wood from the Pliocene of Kutch. Geophytology, 5(2): 172-177. Maheshwari, H. K. and Kumaran, K. P. N. 1974. Some new conifer remains from the Jabalpur Group. Palaeobotanist, 23(1): 30-39. Pandey, D.K., Alberti, M and Fürsich, F.T. 2013. Ammonites from the Oxfordian (Biofurcatus Zone) strata of Gangta Bet, Kachchh, western India. Journal of the Palaeontological Society of India, 58(2): 139-174. Patel, S. J. and Joseph, J. K. 2012. Deepening upward sequence of Callovian-Oxfordian Gangta bet, Wagad, Eastern Kachchh, India, P. 13-18. In: Annual International Conference on Geological and Earth Sciences. Patel, S. J., Joshi, P. N. and Joseph, J. K. 2012. Ammonite zonation of the Jurassic rocks of the Gangta Bet area, Wagad region, Eastern Kachchh, India. Journal of the Palaeontological Society of India, 57(2): 35-39. Peralta-Medina, E. and Falcon-Lang, H. J. 2012. Cretaceous forest composition and productivity inferred from a global fossil wood database. Geology, 40: 219-222. Prakash, N. and Rajanikanth, A. 2004. Podocarpoxylon bansaense n. sp. from the Bansa beds, South Rewa Gondwana Basin. Palaeobotanist, 53(1-3): 177-180. Rajanikanth, A. and Sukh-Dev. 1989. The Kota Formation: Fossil lora and stratigraphy. Geophytology, 19(1): 52-64. Sah, S. C. D. and Jain, K. P. 1964. Some fossil woods from the Jurassic of Rajmahal Hills, Bihar, India. Palaeobotanist, 12(2): 169-180. Sahni, B. 1931. Revisions of Indian fossil plants: part II- Conifers (b. Petriications). Memoir Geological Survey of India. Paleontologica Indica, n. s., 11: 51-124. Schmid, E. E. and Scheiden, M. J. 1855. Ueber die Natur d. Kieselhölzer, 4: 36. Varma, C. P. 1954. On two new species of Mesembrioxylon from the Cretaceous rocks of Trichinopoly District, Madras. Palaeobotanist, 3: 97-102. Biswas, S.K. 1977. Mesozoic Rock stratigraphy of Kutch, Gujarat. Manuscript Accepted December 2015 CONCLUDING REMARKS Only two conifer wood taxa, Araucarioxylon and Podocarpoxylon, have been recorded for the irst time from Gangta Bet. The other Mesozoic loral components have so far not been recorded from here. Although, during JurassicCretaceous periods, conifers, bennettitales, cycadales along with ilicales were the chief components of the palaeo-vegetation as known from Kachchh Mainland (Bose and Banerji, 1984), indicating thereby that Podocarpus and Araucaria might be the main canopy forming trees as they evolved in response to major extinction phase of arid conditions at the end of Permian (Bose and Banerji, 1984). Both the families (Araucariaceae and Podocarpaceae) increased in abundance and diversity during Jurassic-Cretaceous periods and maintained presence in the vegetation of the southern hemisphere landmasses. It was likely that the rising sea levels through the Jurassic resulted in both precipitation and temperature that facilitated the development of forest vegetation (Kreshaw, 2001). The coniferous canopy was almost certainly evergreen as indicated by leaf physiognomy and its comparison with modern podocarps and araucarians as they show major adaptability in light of competition with angiosperms. The environmental conditions are relected in growth rings. The ring width ratio of early – late wood and other anatomical features are directly inluenced by ambient environmental conditions such as sunlight, water and related ecological factors during the growth period resulting in the formation of wider growth rings. The weakly deined growth and interruptions, that cannot be traced, are characteristics of growth under humid tropical climates and consistent with the broad tropical belt that existed in the Jurassic-Cretaceous periods (Peralta-Medina and Falcon, 2012). Dendrological data indicate that the climate was characterized by tropical wet and dry cycles of savanna climate. ACKNOWLEDGEMENTS The authors express their gratitude to Dr. Sunil Bajpai, Director, Birbal Sahni Institute of Palaeobotany, Lucknow for permission (BSIP/RDCC/Publication no. 88/2014-15), work facility and encouragement. JR, DKP and SG acknowledge the inancial support to carry out ield work and lab studies under DST- sponsored Project SR/S4/ES/-521/2010 (G). Drs. Rahul Garg, Vandana Prasad and Biswajeet Thakur of B.S.I.P. are thanked for help and discussion during the preparation of the manuscript.