The lrgest specimen discovered so far is the one that is 30 centimeters long and has a girth of 25.5 centimeters. (See photograph — left to right: chicken egg, ostrich egg, dinosaur egg). The egg is big enough to hold 3.3 liters of water. It was laid by a 12 meters long dinosaur Sauropod which lived about 80 million years ago.
What were said to be the first dinosaur eggs were found by the well-known geologist Jean-Jacques Pouech in Southern France in 1860, followed by another discovery five years later in the same country.
Note: The photograph of a dinosaur egg provided above is only for the comparison purpose and not the actual one talked about.
Dinosaur egg (Wikipedia)
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