A tectonic plate laid a clutch of continents. To keep them safe, it made a nest of fluffy cumulus clouds in the sky and put the unhatched continents inside. But while it was absent, another tectonic plate came along and laid a continent of its own among them.
The first tectonic plate soon returned but it didn't realise anything was amiss and it sat on the new addition without suspecting it wasn't a rightful landmass. Time passed. The false continent was the first to hatch and then it instinctively pushed out the others.
“Feed me! Feed me!” it shrieked blindly.
The foster mother was kept busy collecting the trappings of advanced civilisations to satisfy it and “I'm worn out,” it gasped one day. “You are more demanding than I anticipated.”
The cuckoo continent considered this and said:
“Don't worry. It's time for me to leave the nest anyway. Thanks for all the temples, coffee shops and monorails you adorned me with! I think I'll settle down in the Gulf of Mexico.”
“Shame about your brothers and sisters,” said the tectonic plate. “I still find it strange how you accidentally nudged them out of the nest like that. Poor little Atlantis, Lemuria and Mu!”
“Yes, I guess they are lost continents now.”
¶ Don't leave unhatched continents unattended.