Largest Egg-Laying Animal
When we talk about the largest eggs in the animal kingdom, the undisputed record holder on land is the ostrich (Struthio camelus). This giant bird, native to Africa, lays eggs that can weigh up to 1.5 kilograms and measure around 15 centimeters in length. While these eggs are the biggest among living birds, they are actually small in comparison to the body size of the ostrich, which can stand over 2.5 meters tall. Still, an ostrich egg is so large that one can feed a family for breakfast.
In comparison, other large birds such as emus and rheas also lay big eggs, but they are noticeably smaller than those of the ostrich. An emu egg, for example, weighs around 500–700 grams and is deep green in color, making it quite distinctive.
If we look beyond birds to the ocean, the situation becomes even more fascinating. Among marine animals, the whale shark (Rhincodon typus), the largest fish in the world, produces the biggest known eggs. Although whale sharks are ovoviviparous (meaning the eggs hatch inside the mother’s body before birth), scientists have discovered enormous leathery egg cases measuring up to 30 centimeters long. These eggs remain inside the mother until the baby shark is ready to emerge, which gives the young a greater chance of survival.
Historically, even larger eggs belonged to the elephant bird (Aepyornis), a giant, flightless bird from Madagascar that went extinct about 1,000 years ago. Its eggs could weigh up to 10 kilograms and were nearly 30 centimeters long—about eight times the size of an ostrich egg. Today, fossilized elephant bird eggs are rare collector’s items and can still be found in museums.
In summary, the animal that lays the largest eggs among living species is the ostrich, with whale sharks holding the record in the marine world. In the past, however, the title of the absolute champion went to the extinct elephant bird, whose eggs remain the largest ever known in history.
