Megaloolithus Dinosaur Nest from the Lameta Formation of Salbardi Area, Districts Amravati, Maharashtra and Betul, Madhya Pradesh

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1 JOURNAL GEOLOGICAL SOCIETY OF INDIA Vol.85, April 2015, pp Megaloolithus Dinosaur Nest from the Lameta Formation of Salbardi Area, Districts Amravati, Maharashtra and Betul, Madhya Pradesh ASHOK K. SRIVASTAVA and RUPESH S. MANKAR P.G. Department of Geology, SGB Amravati University, Amravati ashokamt2000@ hotmail.com Abstract: The present paper contributes the new locality of a nest of sauropod dinosaur from fluvial sediments of the Lameta Formation of Salbardi area. On the basis of shape, size and microstructures of the shell, it is identified as Megaloolithus. The new locality is away from the known nesting sites of dinosaurs already been reported i.e., Nagpur and Jabalpur, therefore bears significance in reconstruction of palaeogeographic boundary of dinosaurs-nesting sites. Keywords: Megaloolithus, Nest and eggs, Salbardi, Sauropod, Lameta. INTRODUCTION In India, the study of dinosaur eggs and nests goes back only three decades ago. The maiden discovery of eggs and nests is from limestone quarry of the Lameta sediments from Baliadeo village, near Balasinor, Kheda district, Gujarat (Mohabey, 1983). However, fragments of eggshells from Bara Simla hill area of Jabalpur were reported earlier (Sahni and Gupta, 1982). After these initial reports, many sites of eggs, nests and eggshells debris were reported from all over India in the time span of about thirty years. The localities are mostly restricted to the Lameta successions exposed at Gujarat, Madhya Pradesh and Maharashtra. Mohabey (1998, 2000) has made an attempt to review the eggs and nests of dinosaurs from the upper Cretaceous Lameta sediments of central and western India to understand their community, structures, nesting habit and extinction. The presently identified locality is a new addition from which solitary nest has been recorded from calcretized sandstone horizon of Lameta succession. An attempt is being made to describe their morphology and classification. Discussions have also been made to interpret the condition of depositional environment in which the eggs were laid. GEOLOGY AND STRATIGRAPHY The Lameta sediments occupy an east-west elongated narrow patch at Salbardi area (lat '15" N: long '00" E), lying at the boundary of districts Amravati, Maharashtra and Betul, Madhya Pradesh (Fig. 1). These sediments along with the Gondwana are exposed as tectonic inliers in regionally exposed Deccan basalt. The Gondwana sediments are mostly represented by arenaceous rocks corelatable with the Jabalpur Formation of early Cretaceous age as evident by pteridophytic and gymnosperm leaf remains (Srivastava et al., 1999, 2007). The Lameta sediments are thinly to thickly bedded units which are mainly represented by arenaceous, argillaceous and calcmarl sediments overlying disconformably on the Gondwana rocks. The basement rock is quartz-feldspathic gneiss of Archaean age which is highly disturbed and frequently intruded by dolerite dykes. The peripheral area is basaltic trap, occurring in the form of minor hillocks of hard, massive to vesicular basalts or weathered in low lying areas. The topmost layer is alluvium or dark coloured soil derived from weathering of the basalt (Table 1). Table 1. Regional stratigraphic set-up of the area Age Stratigraphic units Rock types Quaternary Soil and alluvium Unconformity L. Cretaceous Deccan Trap Grayish black, hard and to Eocene compact, non porphyritic and porphyritic basalts Unconformity L. Cretaceous Lameta Sandstone, claystone, mudstone and limestone Disconformities E. Cretaceous Upper Gondwana Sandstone, siltstone, (Jabalpur Formation) conglomerate, clay and mudstone Unconformity Archaean Quartz-feldspathic gneiss with dolerite intrusions / /$ 1.00 GEOL. SOC. INDIA

458 ASHOK K. SRIVASTAVA AND RUPESH S. MANKAR Fig.1. Location map of Lameta succession exposed in central and western India (left) and geological map of the study area (right).

This river-cut section is constituted together by arenaceous, argillaceous and calcareous sediments (Fig. 2).

2 458 ASHOK K. SRIVASTAVA AND RUPESH S. MANKAR Fig.1. Location map of Lameta succession exposed in central and western India (left) and geological map of the study area (right). A good section of Lameta sediments attaining a height of about 35m is exposed at the bank of Maru river. This river-cut section is constituted together by arenaceous, argillaceous and calcareous sediments (Fig. 2). The arenaceous unit is dark brown and medium green, hard and compact, medium to fine grained sandstones with ferruginous and calcareous cementing materials. The beds ranging in thickness from 2-3m are interbedded with 1-2m thick, dark reddish brown and greenish brown clay horizons. This entire unit constitutes 9m column in the lower part of the succession. Overlying 18m succession consists of calcrete, clay and sandstone horizons. Calcretes are recorded at two stratigraphic levels, of which, the lower overlains greenish sandstone and is light gray in colour having abundant vertical to inclined, cylindrical root calcrete. It is overlain sharply by light green calcareous sandstone. The overlying 3m succession is again light brown calcrete but nodular in nature having clasts of greenish sandstone, nodular limestone and basalt. It overlies 7m thick column of greenish gray and dark reddish brown clays with interbeddings of 60-90cm thick green sandstone beds. The upper 5m horizon is represented by light bluish gray, medium to coarse grained sandstone with ferruginous nodules, of which, the top one meter egg-bearing lithounit is calcretized. Chertification of this entire arenaceous lithounit is very distinct in the form of lenses, discrete pockets and irregular veins. The rest of the column, constituting upper 8m is dominantly calcareous in nature represented by nodular limestone, chertified limestone and intraformational brecciated limestone. Nodular limestone is ca one-meter thick, bluish gray, hard and compact rock which overlies 3m chertified limestone showing intense silicification. Intraformational brecciated limestone is the topmost unit which is represented by reddish brown, micritic limestone having clasts of nodular limestone and chertified limestone. EGGSHELLS SYSTEMATIC Oofamily MEGALOOLITHIDAE Zhao, 1979 Oogenus MEGALOOLITHUS Vianey-Liaud et al., 1994 Diagnosis: Dinosauroid-spherulithic basic type; tubospherulithic morphotype; tubocanaliculate pore system; Fig.2. Litholog of the Lameta succession exposed at the study area; arrow denotes the egg bearing horizon.

Megaloolithus DINOSAUR NEST FROM THE LAMETA FORMATION OF SALBARDI AREA, MAHARASHTRA 459 Fig.3. Microphotograph showing calcretized sandstone having subangular to subrounded grains of quartz.

having eggshell thickness of 1.5-3.0mm. Material: Incomplete eggs and fragments (Field specimen preserved in the rock; thin sections (SDE 1-4) and chips of egg shell (SDE-5)).

5km on pedestal track to Ghorpend village, precisely, at the spot having GPS coordinates of lat. 21 0 25 827' N: long.78 0 00 320' E which falls in Betul district, Madhya Pradesh.

3 Megaloolithus DINOSAUR NEST FROM THE LAMETA FORMATION OF SALBARDI AREA, MAHARASHTRA 459 Fig.3. Microphotograph showing calcretized sandstone having subangular to subrounded grains of quartz. compactituberculate ornamentation. Spherical to subspherical eggs ranging from 120 to 200mm having eggshell thickness of mm. Material: Incomplete eggs and fragments (Field specimen preserved in the rock; thin sections (SDE 1-4) and chips of egg shell (SDE-5)). Locality and Horizons: Lameta Formation of Salbardi area, districts Amravati, Maharashtra and Betul, Madhya Pradesh. Nesting site lies towards north of Salbardi village at a distance of about 1.5km on pedestal track to Ghorpend village, precisely, at the spot having GPS coordinates of lat ' N: long ' E which falls in Betul district, Madhya Pradesh. The eggs are well preserved in one-meter thick, grayish yellow, medium to coarse grained calcretized sandstone. Petrographically, the rock contains sub-angular to sub-rounded, medium to coarse grains of quartz. The entire rock shows calcification in which the carbonate is non-ferroan micritie (Fig. 3). Occurrence: A clutch of incomplete eggs comprises of one eggshell almost completely in circular outline, two broken nearly half circular and one small fragment exhibiting irregular pattern of egg nest (Fig. 4a,b). Diagnosis: Megaloolithus with spherical eggs; diameter mm; shell thickness 2 to 2.3mm; shell units are slenderical, H/W ratio = 4. Description: Upper surface of the calcretized sandstone bed showing preservations of four spherical eggs of almost same diameter i.e., mm, of which, one shows complete circular outline, whereas, the other three are incomplete (Fig. 4a,b). The shell thickness ranges between 2 to 2.3mm having H/W ratio of 4. The outer surface of the eggs reveal compactituberculate ornamentation represented by densely packed nodes of sub-circular and circular shape (Fig. 5a,b). The shell units are discrete, short and slender with acute dome-shaped tops which are mostly straight but occasionally curved (Fig. 6a,b). It is growing from single mammillae (spherolith), however, extra growth centers and chaotically grown, short shell units are also noticed which indicate the abnormality in the process of formation of eggs. The growth lines are distinct and arch in shape throughout the entire shell unit, however, at a few places, they may be fused on the upper part showing contour pattern. The pore canals are distinct, narrow, short and irregular showing tubocanaliculate pattern (Fig. 7). Comparison: Mohabey (1998, 2000) made a detailed comparative study of shape, size, ornamentation, shell thickness, height and width (H/W) ratio and pore system of the dinosaur s eggs in India and established eight oospecies of Megaloolithidae oofamily. Accordingly, the presently reported eggs are identified to be the member of Megaloolithus oogenus. Further subdivision of the same into oospecies is difficult due to the deviations of its certain characteristic properties from those of the eight oospecies proposed by Mohabey (1998, 2000). It has been noted that Fig.4. (a) Photograph showing the upper surface of bed having preservation of the eggs; (b) reconstruction of the nest pattern; dotted line shows the predicted extension.

460 ASHOK K. SRIVASTAVA AND RUPESH S. MANKAR Fig.5.

(a) Slender, elongated shell units having arch shape growth lines; (b) line diagram showing shape and pattern of shell units.

dhoridungriensis (spherical; 140-180 mm; compactituber; tubocanaliculate) and M. balasinorensis (spherical; 140-180 mm; compactituber; tubocanaliculate).

4 460 ASHOK K. SRIVASTAVA AND RUPESH S. MANKAR Fig.5. (a) Close-up of eggshell surface in the field showing compactiturculate pattern; (b) enlargement of the same showing subcircular to circular nodes. Fig.6. (a) Slender, elongated shell units having arch shape growth lines; (b) line diagram showing shape and pattern of shell units. the shape, size, ornamentation and pore system of the present eggs are comparable with M. rahiolienesis (spherical; mm; compactituber; tubocanaliculate); M. dhoridungriensis (spherical; mm; compactituber; tubocanaliculate) and M. balasinorensis (spherical; mm; compactituber; tubocanaliculate). Similarly, the spherolith thickness is comparable with M. khempuensis ( mm) and M. dhoridungriensis ( mm) whereas, height and width ratio matches with M. rahioliensis (4). The microscopic characteristics of shell unit i.e., extragrowth centers and the chaotically grown giant and dwarf shell units are similar to the M. megadermus, however, differs largely in other diagnostic characteristics i.e., spheroidal shape, mm spherolith thickness and

Megaloolithus DINOSAUR NEST FROM THE LAMETA FORMATION OF SALBARDI AREA, MAHARASHTRA 461 Fig.7. Photograph showing a slender shell unit (SU) having arch shape growth lines and distinct pore canal (PU).

5 Megaloolithus DINOSAUR NEST FROM THE LAMETA FORMATION OF SALBARDI AREA, MAHARASHTRA 461 Fig.7. Photograph showing a slender shell unit (SU) having arch shape growth lines and distinct pore canal (PU) H/W. Limited numbers of eggs and their entire preservation in the bed rock posses certain limitations for the detail study of the present specimen, therefore, the authors propose the identification up to oogenus level only i.e., Megaloolithus. DISCUSSION AND CONCLUSION Various schemes of classification for the Indian dinosaurs eggshells have been proposed which are mainly based on general morphology including shape and size, ratio of height to width and microstructures of the eggshells (Jain and Sahni, 1985; Vianey-Liaud et al., 1987; Bajpai et al., 1993; Khosla and Sahni, 1995; Mohabey, 1998; 2000). Mohabey (1998, 2000) has proposed systematics of Indian Maastrichtian dinosaur s eggs and categorized them in two families viz., Megaloolithidae and Elongatoolithidae; which are further subdivided into various oogenera on the basis of shape and microstructures. Preservational aspects of the present specimen allow to study only the shape, size and shells thickness i.e., spherical in shape having a diameter of mm and 2-2.3mm of shell thickness. The shell unit is elongated showing irregular growth and arch shape growth lines. On the basis of spherical shape, compactituberculate ornamentation, tubospherulitic shell structure and tubocanaliculate porecanals, the present eggs are considered as Megaloolithus of Megaloolithidae oofamily (Vianey-Liaud et al., 1994; Mohabey, 1998, 2000). Further classification up to oospecies level is difficult because of limitations in number of eggs and their morphological investigation in the field due to solitary exposure of a nest having incomplete preservations of egg shells. Till date, the authors have recorded only one nest in the area. However, it bears significance in a way that this new site is geographically much away from the earlier known localities of the Lameta sediments in Nagpur, Maharashtra and Jabalpur, Madhya Pradesh (Jain and Sahni, 1985; Mohabey, 1990, 2000). Fragments of bones viz., ulna has also been reported from the same area (Srivastava and Mankar, 2013a). It necessitates for reconsideration and revision of the existing palaeogeography of dinosaurs nesting sites in India. The Lameta succession exposed in this area including eggs-bearing lithounit has been studied in detail for its lithofacies architecture, depositional environment and petrological details including diagenetic history (Srivastava and Mankar, 2010; 2012; 2013b). On the basis of lithological architecture, the succession is interpreted to be a product of point bar, channel and flood plain environments of semiarid fluvial setting. The egg-bearing horizon is calcretized sandstone which was deposited probably at the over bank which was also subjected to pedogenic activity during the later phase. Acknowledgement: Authors are thankful to UGC, New Delhi for providing financial support in the form of a Major Research Project (F. 40/295/2011 (SR)) awarded to one of the author (AKS) and also to CSIR, New Delhi as SRF (F- 09/855 (0003)/2012) to second author (RSM). References BAJPAI, S., SAHNI, A. and SRINIVASAN, S. (1993) Ornithoid eggshells from Deccan Intertrappean beds near Anjar (Kachchh), Western India. Curr. Sci., v.64(1), pp JAIN, S.L. and SAHNI, A. (1985) Dinosaurian egg shell fragments from the Lameta formation at Pisdura, Chandrapur district, Maharashtra. Geosci. Jour. (India), v. 6, no. 2, pp KHOSLA, A. and SAHNI, A. (1995) Parataxonomic classification of Late Cretaceous dinosaur eggshells from India. Jour. Pal. Soc.

6 462 ASHOK K. SRIVASTAVA AND RUPESH S. MANKAR India, v., 40, pp MOHABEY, D.M. (1983) Note on occurrence of dinosaurian fossil eggs from infratrappean limestone in Kheda district, Gujarat. Curr. Sci., v. 52, no. 24, pp MOHABEY, D.M. (1990) Dinosaur eggs from Lameta Formation of Western and Central India: their occurrence and nesting behavior. In: A. Sahni and A. Jolly (Eds.), Cretaceous Event Stratigraphy and Correlation of the Indian Non-marine Strata, Panjab University, Chandigarh, pp MOHABEY, D.M. (1998) Systematics of Indian Upper Cretaceous dinosaur and chelonian eggshells. Jour. Vert. Pal., v. 18, no. 2, pp MOHABEY, D.M. (2000) Understanding community structure, nesting and extinction of Upper Cretaceous (Maastrichtian) Indian dinosaurs: evidences from eggs and nests. Gond. Geol. Mag., v. 15(2), pp SAHNI, A. and GUPTA, V.J. (1982) Cretaceous egg shell fragments from the Lameta formation, Jabalpur, India. Bull. I. G. A., v. 15, no.1, pp SRIVASTAVA, A.K. and MANKAR, R.S. (2010) Sedimentological studies and trace fossils of the Lameta successions of Bairam, Belkher and Salbardi area, district Amravati, Maharashtra and Betul, Madhya Pradesh. Gond. Geol. Mag., Spec. Vol., 12, pp SRIVASTAVA, A.K. and MANKAR, R.S. (2012) Field characteristics, petrography and diagenesis of Lameta sediments exposed at northern boundary of district Amravati, Maharashtra. Gondwana Geol. Mag., v. 27, no. 1, pp SRIVASTAVA, A.K. and MANKAR, R.S. (2013a) A dinosaurian ulna from a new locality of Lameta Succession, Salbardi Area, districts Amravati, Maharashtra and Betul, Madhya Pradesh. Curr. Sci. v. 105, no. 7, pp SRIVASTAVA, A.K. and MANKAR, R.S. (2013b) Lithofacies architecture and depositional environment of Late Cretaceous Lameta Sediments, Central India. Arab. Jour. Geosci. DOI /s y. SRIVASTAVA, A.K., BANUBAKODE, P.D., KALE, V.M., PATIL, G.V. and MANIK, S.R. (1999) Lower Cretaceous plant fossils from Bairam-Belkher area, district Amravati, Maharashtra and district Betul, Madhya Pradesh and their significance in stratigraphy. Palaeobotanist, v. 48, pp SRIVASTAVA, A.K., MANIK, S.R. and GAWANDE, R.R. (2007) Diversity of gymnospermous plant remains from Upper Gondwana (Early Cretaceous) succession of Bairam-Belkher area, district Amravati, Maharashtra and Betul, Madhya Pradesh. Phytomorphology, v. 57, no. 3 & 4, pp VIANEY-LIAUD, M., JAIN, S.K. and SAHNI, A. (1987) Dinosaur egg shells (Saurischia) from the Late Cretaceous Inter-trappean and Lameta Formations (Deccan India). Jour. Vert. Pal., v. 7, pp VIANEY-LIAUD, M., MALLAN, P., BUSCAIL, O. AND MONTGELARD. C., (1994) Review of French dinosaur eggshells: morphology, structure, mineral, and organic composition. In: K. Carpenter, K. F. Hirsch, and J. R. Horner (eds.), Dinosaur Eggs and Babies, Cambridge University Press, Cambridge, pp ZHAO, Z., (1979) Discovery of the dinosaurian eggs and footprints from Neixiang county, Hehan Province. Vert. Pal. Asiat., v. 17, no.4, pp (Received: 29 July 2013; Revised form accepted: 23 January 2014)

Vol.72, August 2008, pp

190 ASHOK JOURNAL K. SRIVASTAVA GEOLOGICAL AND SOCIETY RUPESH OF S. INDIA MANKAR Vol.72, August 2008, pp.190-198 Lithofacies, Depositional Environment and Age of the Upper Gondwana Succession of Salbardi