Dinosaur Eggs

University of Bristol

Sauropod nests

Sauropods produced several kinds of nests. The first is a circular pattern, where 6-8 eggs are found, and the nest is conical in cross-section. These nests are noted from the Tremp Basin, Spain, Balasinor (Rahioli Village, Gujarat) and Bara Simla (Jabalpur) in India. The Indian nests consist of rounded shallow pits with 3-6 eggs distributed randomnly (Mohabey 1984).

These clutches show relatively less complex arrangements than in the theropods, but the close proximity of some of the eggs has suggested to some workers a colonial nesting ground (Jain, 1989).

More randomly-shaped sauropod nests are known from Argentina (Powell, 1985). These contain up to 12 eggs. Nests found recently in Patagonia, identify the egg-layers as titanosaurs, based on embryos with teeth and skin textures. The eggs were laid in clusters, in 1.5 m long groupings, resting on gently sloping floodplains. The rivers must have burst their banks and the embryos were drowned and buried.

Other egg-laying strategies have also been observed in Rennes-le-Chateau, France (Breton, 1986). The eggs are arranged in arc structures, which if connected would form circles of 15-20 eggs. The circles were of a radius of about 1.5 m and have been suggested to correspond to the animal turning while it was laying the eggs. Variation in the size of these circles could be due to different sizes of egg-laying females.

Arcuate egg-laying in titanosaurs.

(modified from Cousin 1994)

Linear patterns have also been observed in titanosaurs (Dughi & Sirugue 1966), that is with eggs alligned in rows. These rows have been described from Romania (Transylvania) in which 15 cm diameter eggs were arranged in four linear rows each containing 2-4 eggs.

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