So we scraped and scooped and scraped some more until we found more bones. And what incredible bones they were. There were both big and small bones, the smallest of them—Kentucky Fried Chicken size—were exhumed and folded inside paper towels and tissue paper and then wrapped in aluminum foil. The larger bones, the tibias, femurs, pelvises, and caudal (tail) vertebrae of two adult Tyrannosaurs were exposed. Then we slowly followed a trail of dorsal vertebrae of one of the adults. These bones were big as coffee cans and Laura was excited to find them articulated, meaning they were lying there in the same order they had been in life. We also found ribs. Our digging revealed that the other T. rex disappeared beneath the one we were working on. Laura called them the superior and inferior T. The one on top was superior.
“Why is one lying on top of the other?” I asked Laura but it was Tanya who answered.
“We don’t know, Mike. Maybe their skulls will tell us why they are in these positions.”
“I heard Pick say skulls were often washed away,” I recalled. “Something about the neck attachment.”
“That’s true,” Laura replied. “For most dinosaurs, we have hundreds of specimens but just a very few skulls.”
“I think we’re going to find these skulls,” Tanya said, then revealed a surprise. She held up what looked like a brown tusk, then handed the thing to me. It had to weigh a couple of pounds. “What is it?” I asked, somewhat in awe.
“It’s a T. rex tooth. I’ve found six so far,” she said, patting a cloth bag on her hip.
Laura said “Tanya is very good at finding teeth,” then went on to tell us a few things about the T. rex dental plan. “Their teeth were serrated with razor-sharp edges,” she said, “and were biggest in the middle of the maxillae and dentaries. The teeth in the premaxillae—that’s the front teeth, Mike—were smaller, probably for scraping bones.” Most likely, she said, the T’s ate meat by the chunk, swallowing it whole like sharks and lions. The teeth in the upper jaw were also especially sharp and pointed, in effect a combination of butcher knives and daggers. Laura said, “Tyrannosaurs also had an endless supply of teeth. When one was lost, another grew back in the socket. We think they changed out all their teeth at least once a year.”
All this, I thought, was pretty cool. “Did they eat anything besides meat?” I asked. Me being a vegetarian and all, of course I’d wonder about that.
“We don’t think so,” Laura answered. “They were what we call hypercarnivores, on an exclusive meat diet. Oh, another thing about their teeth. They were more conical than most theropods like the raptors or even Giganotosaurus. Since conical teeth are best for crushing bone rather than ripping flesh, that’s one of the reasons Jack Horner hypothesized that T. rex was mostly a scavenger. Nobody knows if that’s so but it’s interesting, nonetheless. We love to argue about things like that at SVP conferences.”
Pick called down from his perch. He had taken to sitting over us on a slab of sandstone like some potentate overlooking his kingdom. “They were both predator and scavenger,” he said, then disappeared back into deep time or wherever he went when he was watching us work. Laura chuckled.
Tanya took the tooth back from me and put it in her hip bag. “Are these teeth from the top T or the bottom T?” I asked.
“Probably the superior T,” Laura answered. Then glanced up at Pick. “Pick will figure it out. He sees everything we do. He will make sense of it.”
After another day of work in the heat, which climbed into the low one hundreds, most of us came down the hill, our bones creaking, our muscles feeling like they’d been torn into little, bloody shreds, our eyes filled with grit, and our fingernails torn and raw. Pick stayed up there, studying the day’s results. Laura and Tanya took turns carrying him food and water. Even after dark, he was there, studying with a flashlight what we’d revealed. I wondered if he was telling himself a story made up from the bones.
The next day, we reached the neck vertebrae and cervical ribs of the superior T. We also found the same bones of the bottom T mixed in which made for a confusing jumble. Pick called a halt to our digging and said we’d best jacket the bones we’d exposed and move them down the hill. This took another week of backbreaking work. Then Montana, after so many hot but otherwise calm days, decided to be Montana, just as I kept fearing she might.
Our beloved state first revealed her plan with a clap of thunder. I was in my tent, having just gone there after dinner and our usual nightcaps. Everyone else, except Pick who was at the dig, were bedded down, too. I waited for more rumbling skyward but that was it. I took that as very strange, then heard the pok of a raindrop on my tent. Then, another pok and another and another. The drops of rain increased until there was a steady staccato of them. I relaxed. This was not going to be a big storm, just a nice little rain. Maybe, I hoped, it would cool things down. I slid off into dreamland, waking a couple of hours later. The staccato of rain was still there, neither increasing or decreasing. That was when I knew we were in trouble.