When did big, toothy lizards become so dino-mite?

As I was standing at the MAC, watching Sue’s skull being bolted to her giant-size frame, I pondered the question: Why are humans so dinosaur-crazy?

This question is particularly apt right now, because we are entering Spokane’s dino-summer. Sue happens to be a full-size cast skeleton of a Tyrannosaurus rex and the star of an exhibit now open at the MAC (Northwest Museum of Arts and Culture) through Sept. 2. In a few months, about 15 life-size robotic dinosaurs will roam the Spokane Arena in the “Walking With Dinosaurs” show.

The city will be crawling with giant, scary lizards, and I am not referring to political conventioneers.

Yet again I ask: Why dinosaurs? Why not some other large, dumb, extinct species?

“ “Coming soon to the Spokane Arena: ‘Dancin’ With the Dodos!’ “

“ “The new audio-animatronic spectacular, ‘Chillin’ With the Giant Sloth!’ “

“ “Live and in person: The Eagles Reunion Tour!” (Oops, wrong kind of fossil).

No, nothing else can compete with dinosaurs in the human imagination. And maybe, just maybe, they lurk somewhere deeper than the imagination.

Maybe they lurk in the (cue the ominous cello music) dark recesses of our primitive human subconscious.

I believe our primitive brain stem is wired to recognize that big, toothy lizards are extremely important personages. A giant, meat-eating lizard is more important than a giant sloth for the very good reason that big, toothy lizards once LIKED TO EAT US.

By us, I don’t mean humans. I do not subscribe to the Flintstones version of pre-history. I subscribe more to the Carl Sagan version of human evolution. As he once wrote in a book called “The Dragons of Eden,” our first little DNA ancestors, the original ratlike or shrewlike mammals, grew up in a world absolutely jammed with enormous, hissing, extremely scary dinosaurs. It was enough to give any small mammal nightmares.

Put yourself into the mind of this tiny mouselike critter:

Tiny mouse thing: Oh, for crying out loud. Here comes another one. Words cannot express how much I hate these big, stupid lizards.

Dinosaur: (Hisses. Chomps teeth)

Tiny mouse thing: It’s getting closer. It’s a good thing I’m up in this tree. He’ll never see me here.

Dinosaur: (Sees mouse thing. Hisses)

Tiny mouse thing: Oh boy. Here it comes. It’s a good thing I have a proportionately much larger brain because … Oww! … (dimly, from the vicinity dinosaur’s stomach) … because someday, my kind will be standing in museums, wondering where their kind went.

So even though you and I no longer are small, shrewlike creatures beset by giant, toothy reptiles, we still retain some of that wiring in the most primitive parts of our brain. That’s why our ancient myths are so full of tales of dragons, which are, after all, just dinosaurs with superpowers.

It might also explain why, when I was walking last year near Hangman Creek, I suddenly jumped about 10 feet backward. It happened so fast, I was unaware of any conscious reason for doing so.

I remember hearing a hiss, and my primitive instinct took over and hurled me backward. It turned out to be a bull snake, coiled by the trail, looking and sounding evil.

A bull snake is not evil at all, of course. It is harmless, but to my subconscious it seemed sinister, because snakes and serpents have always had an outsized place in our nightmares. Many, many people report nightmares about snakes.

So maybe our strange fear of serpents and our strange fascination with dinosaurs comes from the same bundle of vestigial nerve fibers in the old brain stem.

This may explain why an 8-year-old just stood there staring, in open-jawed fascination, at Sue’s skeleton the other day. It touched something ancient and extremely powerful.

And may I speak for my own subconscious when I say: Thank goodness Sue no longer roams the earth. I wasn’t even particularly crazy about stumbling across that bull snake.