Why The Land Drifted Apart

Way out in the middle of the land was a small cottage. The land was rich and food was plentiful. It was perfect. A cemetary out a little ways from the cottage dimmed the mood, but Joshua didn't care. He questioned his mother about several things. He was obviously, a curious boy, possibly too curious.
His mother told him the story of the men who lived on the land before them. A little yonder from the house, was a passage blocked by trees and boulders. His mother recited the rather bleack and saddening story to him before a toasty fire.
" There were about twenty men here before us, 'twas hard times, food was scarce. And ,bein' the fools we are, curiosity got the better of us. The passage way up yonder was open at the time, and was closed for good reason. A young lad much like yourself was searching for deer, when he happened apon a small cave. He dared not go inside, for ominous growls and the occasional yelp made him fear of bears. Then soft pads came towards him,closer,and closer. Fear took over and he fired his bow. A cry came, followed by many different whines,hisses,and growls. Suddenly, fire blew from the mouth of the cave, scorching his hands and face." A saddened look came over her, this only intensified the story, thought Joshua.
"The poor lad didn't make it. Days went bye, each day more and more missing persons came up. The village was in distress. They were sure the young lad had cursed them. Then, there was no one."
"But who buried them mama? If no one was left, how did they get buried?"
"It does us no good asking questions like that! Now off with you! Go play! And don't you go near that cave!"
Young Joshua always knew better than to disrespect his mother, but like in all stories, someone has to come along.
"You're not really gonna listen to that bull are ya'?"
A wee bird came down from the roof.
"I hears that there is treasure in that cave! Enough ta help you and you're mama get outta here! I'll show ya',only of ya' take me with ya'a outta this dump!"
"But mama says it ain't allowed!"
"Feh..mothers are overrated! Come on!"
They slowly snuck away from the small houe, and into the trees. The bird could fly over the boulder, lucky for Joshua, he was small enough to fit into a small crack. Once they got through, right in front was the cave.
"Uhhh..you first." The bird nudged him with his beak.
The trees obscured everywhere around the cave, making an rather creepy feel.
Joshua walked in. He wasn't afraid, he was curious. Then he saw somehing so horrifying that he could scarcely believe it. He screamed and ran for his life, not daring to look back. Through the crack and trees, all the way back to his house.
Running inside he locked the door and hugged his mother.
"I didn't mean it mama! I didn't mean it!" He was in tears.
Then the ground shook. Looking out the window, his mother saw unbelievable things. A dragon stood, right outside fierce and proud. Next to it was a giant with only one eye. Everything she had ever heard about in fairy tales was right outside! Chupacabras,Golems,dragons,giants, everything!
Then the giant became angry and started jumping up and down, up and down until a small crack was formed. The crack grew bigger and bigger, tearing the land. The bird flew through the open window right as water fooded the openings and cracks. Dragons flew to the mountains with the thunderbirds, giants drowned as well as unicorns. Some learned how to swim rather quickly such as the chupacabra and swam after the floating continents,while others were born on water such as water monsters . The cottage floated aimlessly until it hit land.
The mother hugged her boy, and looking at him in the eye, she said,
"Now do you see why you weren't supposed to go to the cave?"

And that is my explaination for why the land broke apart and certain cryptids are seen while others aren't! :P