When humans first came to the island of Madagascar around 600 AD, it was home to the largest birds that ever lived, the giant, flightless elephant birds (Aepyornis maximus). The last one probably died about 800 years ago.
Like their living cousins the ostriches, elephant birds were running birds with thick, muscular legs and vestigial wings.
The liquid capacity of one elephant bird egg was about two gallons (7.5 liters), 180 times that of a chicken egg, possibly making it the largest single cell ever. An adult bird probably weighed about one thousand pounds (450 kilograms).
The elephant birds were among many species of large animals that disappeared from Madagascar after humans arrived. Today, the island’s animal life is much reduced. Destruction of habitat has eliminated many species, and many more are threatened.
The embryology of trilobites is unknown, but after hatching and development of a hard exoskeleton (which presumably occurred soon after hatching) they molted their exoskeletons as they grew, as all arthropods today, leaving a record of their developmental stages.