How did Nessie survived when the dinosaurs came to extinction?

The Loch Ness Monster or "Nessie" is a cryptid from Scottish folklore that is said to inhabit Loch Ness in the Scottish Highlands. Dinosaurs became extinct around 65 million years ago, while Loch Ness was formed approximately 10,000 years ago, long after the extinction of dinosaurs.

Thus, there is no possibility of Nessie having survived the extinction event that wiped out the dinosaurs.