The abundance of specimens made the excavation even more difficult. “You’re playing Mikado with a pile of dinosaur bones,” says NHMLAC paleontologist Alyssa Bell. “They’re all tangled up and wedged together.” In 2014, the team discovered what turned out to be an entire neck, back and pelvis still cemented into stone. “I remember just standing there scratching our heads, trying to figure out how on earth we were going to get all of this apart,” says Bell.
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They then encased the fossils in a thick layer of plaster, which formed a protective shell. Some shells, like this vertebral segment, weighed more than a ton.
Excavation involves digging trenches around the rock blocks containing the fossils and digging beneath them, leaving temporary pedestals for support. To protect the fossils, casings made of burlap and plaster are placed around them. At first, the crew managed to keep the weight of the casings to a size that the workers could lift out by hand. But soon the casings weighed a ton or more, requiring heavy machinery to lift them.
Stephanie Abramowicz, the LA Museum’s scientific illustrator at the excavation, spent days creating a detailed map of the “dinosaur dam” buried at the bottom of a prehistoric river.
Team members Jonatan Kaluza, Pedro Mocho, Alyssa Bell and Domenic D’Amore used concrete saws, geologist’s hammers, chisels and other tools to expose the dinosaur bones, which were still encased in rock or matrix. They then encased the fossils in a thick layer of plaster to form a protective casing.
When it came time to recover a huge basin, “they had ropes on either side and teams of people rocking it back and forth,” says Stephanie Abramowicz, the museum illustrator on the dig. The moment it came loose, there was a crash. “It was very clear that Gnatalie was talking to us, released from the ground, ready to live a new life,” says Abramowicz.
Step 2: Prepare the bones
The next stop for bones From the dig came the museum’s preparation lab in Los Angeles. The fossils were a challenge, says Doug Goodreau, who runs the lab, because the surrounding material was like cement. The preparators used an angle grinder to remove excess rock, sending sparks and stone chips flying, and hammers, chisels and dental instruments for finer work. Another important tool: an eye for the unexpected.
