Are you Ready for The World's Largest Dinosaurs?
By David Boitano
Sauropod. Not a kind of word that usually conjures up visions of dinosaurs.
When the public thinks of prehistoric animals, they are more likely to name Tyrannosaurus, Brontosaurus and Triceratops.
But Sauropods, those plant eating, slow-moving behemoths, were a major species in the Mesozoic era, and worthy of research by generations of paleontologists, like Dr. Scott Sampson.
Sampson is now the executive director of the California Academy of Sciences, but he spent years digging for dinosaur bones around the world and discovering how these ancient animals lived and survived.
He is clearly in his element when talking about sauropods in the academy’s newest exhibit “The World’s Largest Dinosaurs” on display now through January, 2024.
Sauropods such as Mamenchisaurus could grow up to 150 feet in length, and Sampson is dwarfed standing next to a 60-foot model of the beast that dominates the exhibit’s main viewing area.
The room was too small to accommodate an even bigger model of Argentinosaurus so only the head protrudes from a wall containing a drawing of the remaining torso.
Excavating enormous sauropod skeletons is a monumental task, but the extra work did not dim Sampson’s enthusiasm for the monumental creatures.
“These things are absolutely astounding,” he said. “They were the biggest animals.”
“People like to say that the blue whale is the biggest animal that ever lived, but the blue whale lives in water and does not have to support its weight. “These animals were truly the biggest animals to walk on land.”
He added, “This exhibit is great because it celebrates these animals and tries to help us understand how they evolved and could possibly have lived.”
Evolution provided sauropods with the physical attributes needed to maintain their enormous bulk. Their extremely long necks were useful for reaching plants high above the ground and rotating to pluck food in adjoining trees.
Very helpful for an animal that avoided cardio exercise even it was just walking.
“When you weigh close to 100 tons, every step you take is a big deal,” Sampson said. “Moving your neck while standing saves a lot of energy.”
To offset their enormous weight, a sauropod’s neck vertebrae contained air pockets that reduced its neck weight by half and allowed for greater mobility.
A huge hose in the exhibit demonstrates how the animal breathed more than 174 pints of air with each breath, compared with a human who takes in only a single pint.
The sauropod lung system is not unlike that of birds because these giants of the land before time evolved into birds over millions of years.
“Dinosaurs are not extinct. There are a lot more dinosaurs today than there are mammals. We call them birds,” Sampson said.
“All big ones disappeared” he added. “But a hummingbird is a very close relative to a T-Rex.”
The prehistoric world was a far different environment from the Earth we know today. Smaller plant-eating dinosaurs had to constantly be on the lookout for carnivores, including 50-foot crocodiles capable of snatching and drowning even a 30-foot long animal.
It was a hotter environment due to the lack of ice caps at both poles. Dinosaurs eventually adapted to the hotter temperatures, but that cannot happen now because the pace of global warming from fossil fuel pollution exceeds the ability of animals to evolve in time.
A fatal collision with a comet or asteroid spelled the end of the dinosaur era, but their extinction paved the way for the rise of mammals and eventually, humans.
And it left behind plenty of remains for scientists to excavate. In the past two decades, researchers have uncovered more dinosaur species than in all of previous history, Sampson said. He attributes the new discoveries to “‘more people out their looking in more places” for Jurassic skeletons.
The advent of the “Jurassic Park” movie franchise might also be stirring up interest in the prehistoric world. But the filmmaker’s portrayal of velociraptors as full-sized antagonists is wrong. The beasts were much smaller and covered with feathers, according to Sampson
“It’s closer to a screaming chicken,” he said.
And the exhibit is certain to spark the imaginations of adults and children who learn all those multi-syllabic dinosaur names with abandon.
Sampson, who appears as “Doctor Scott” on the PBS children’s series “Dinosaur Train,” has a theory regarding a child’s interest in the dinosaur world.
“Dinosaurs are big, they are bizarre and they’re extinct so they won’t come out from underneath the bed to get you,” he said.
"The World's Largest Dinosaurs" is currently on display at the The California Academy of Sciences, 55 Music Concourse Drive, Golden Gate Park, San Francisco.
Photo by David Boitano