One of the most fascinating phenomena in the world is the existence of dinosaurs millions of years ago. I was always intrigued by these mystical creatures as a kid—and I think today’s children are just as awed by the often enormous reptiles who can be predators. It’s the stuff that films are made of—just look at the popularity of Jurassic Park and the Dinosaur animated flick.

Dinosaurs lived in the Mesozoic Era—also called the ‘Age of Reptiles’—and had scaly skin and hatched from eggs. The word 'dinosaur' translates to ‘terrible lizard.’  If you've ever had a pet lizard, you can see the resemblance: it's a dinosaur on a tiny scale. Snakes and turtles, other creepy crawlers, are relatives of dinosaurs.

Scientists have deducted that dinosaurs evolved 247 and 240 million years ago. They lived on Earth for about 175 million years until almost all of them died off about 65.5 million years ago. Researchers cannot say what made them extinct, but the theory is that it could have been a combination of natural events like chemicals from erupting volcanoes, an asteroid hitting earth, or climate change. All that remained were avian dinosaurs that were more closely related to birds.

Now, a new discovery has paleontologists buzzing—it is the unveiling of the world’s largest Tyrannosaurus Rex.

I did some research and learned the Herrerasaurus (try pronouncing that!) is the oldest dinosaur dating back to the Triassic Era. What is unique about this species is that it had a sliding jaw joint, an unusual feature that might have helped it to grip onto prey with its mouth.

OK, that’s the oldest, but how about the biggest?

Well, ‘Scotty' is now officially confirmed as the largest dinosaur that ever lived. This incredible find was originally unearthed in 1991, in Alberta, Canada. However, it took more than ten years for paleontologists to extract the skeleton because it was completely encased in sandstone and another 20 years to clean and assemble the bones. The result is stunning and the recreation produced a much bigger skeleton than scientists could have predicted.

The lead author of the study, Scott Persons, called Scotty (named for a bottle of Scotch!) "the Rex of Rexes."

The gargantuan dinosaur weighed in at a whopping 19,000 pounds-- 9.5 tons-- and measured over 42 feet--3 times the height of your average building. Wow—can you imagine coming face-to-face or more accurately face-to-toe with Scotty (your face looking at Scotty's toe)? It is just incredible to think about an animal that size roaming the earth, but he did and I’ll bet with a savoir faire until he died.

I thought about the connection between dinosaurs' extinction and climate change. Could dinosaurs come back?!? Maybe my thinking's not totally irrational.

A respected Paleontologist Jack Horner, who served as an advisor for Jurassic Park, says capturing and reversing some of the DNA from birds might do just that—probably far off but fascinating to ponder!