Alamosaurus was as big as Texas
Paleontologists would love for you to remember the Alamosaurus — just for not being named after the Alamo. “Sorry, not that Alamo,” said Ron Tykoski, director of paleontology at the Perot Museum of Nature and Science in Dallas.
“Yeah, it’s one of the misconceptions we get quite a bit,” said Thomas Adams, curator of paleontology at the Witte Museum in San Antonio. “In fact, when we were doing the label copy for the dinosaur gallery, I specifically put on there it was not named for the Alamo itself.”
Alas, there’s nothing puro San Antonio about this prehistoric wonder. No Alamosaurus remains have ever been found at the historic battle site or anywhere else in the Alamo City. The long-necked sauropod likely never even poked its head into what’s now Bexar County, back when it roamed the North American southwest 66 million years ago. Sauropods were very large herbivores with a long necks, small heads and massive limbs.
Still, the aptly classified titanosaur continues to make its presence felt in Texas.
The Perot Museum is home to the world’s only rendition of a complete Alamosaurus skeleton, an 85-foot model that towers over visitors with a bony smile some 25 feet above the ground.
Meanwhile at the Witte, two adults and one juvenile Alamosaurus tower over a Tyrannosaurus rex on a large mural, while a 10 ½-foot replica of an Alamosaurus leg dwarfs visitors.
Here are some fun facts about the Alamosaurus that are really worth remembering.
Named after a rock formation, not the Cradle of Texas Liberty. The Alamosaurus (Alamosaurus sanjuanensis) gets its name from the Ojo Alamo trading post and sandstone formation in New Mexico, where geologist John B. Reeside Jr. found the first bones in 1921. Paleontologist Charles Gilmore named the bones Alamosaurus in 1922.
The Alamosaurus was a titanosaur sauropod, one of the largest creatures to ever walk the Earth, or at least North America from around Utah to northern Mexico. This was during the late Cretaceous period, roughly 66 million to 69 million years ago.
One of the biggest ones was found in Texas. In 1997, then-university of Texas at Dallas paleontology student Dana Biasatti stumbled upon the preserved neck vertebrae of an Alamosaurus at Big Bend, with each neck bone measuring around 2 feet long and 3 feet tall and wide. The bones were later encased in plaster to protect them, then airlifted by helicopter since some pieces weighed more than half a ton.
According to the Perot Museum, where the bones are now displayed, the Big Bend Alamosaurus fossils represent the biggest dinosaurs discovered in Texas. Based on those remains, the Big Bend Alamosaurus appears to have measured 85 feet long.
Tykoski noted the Perot Museum skeleton model based on those neck bones is so big, museum architects had to bump up the ceiling an extra 10 feet to fit it.
The average Alamosaurus was still a giant. The typical Alamosaurus likely measured around 70 feet long, with its
neck about a third the length of its entire body. It’s believed to have weighed around 50 tons, with a torso Tykoski described as being about as wide as a car is long. To carry all that tonnage, the dinosaur walked on all fours with thick, muscular legs.
“These guys are the offensive linemen of the dinosaur world,” Tykoski said. “These guys are huge.”
But its face remains a mystery. Save for a few small teeth, no Alamosaurus skull material has been found. However, it’s believed the dinosaur had a small head like most sauropods.
An herbivore with an iron stomach. The Alamosaurus may have been a dinosaur that just ate plants, but like many birds, it likely also swallowed rocks to help help mash the plants it ate.
Alamosaurus also had plenty to eat. Adams noted the environment of southwestern North America at the time of the Alamosaurus would have been lush with trees more than 100 feet high, perfect for the long-necked dinosaur.
“It was putting on hundreds, if not thousands, of pounds a day,” Adams said. “These are animals that are likely eating constantly.”
It rubbed elbows with the largest-known flying animal.
For a dinosaur so large, Alamosaurus had plenty of big company. Adams noted it likely shared its environment with the high-flying Texas pterosaur Quetzalcoatlus, considered the largest flying creature ever to exist. Fossils of both behemoths have been found in the Southwest.
They started out so small. The Alamosaurus hatched from an egg the size of a soccer ball, Adams said, reaching its adult size in 20 to 30 years. While no accurate lifespans are known for Alamosaurus, Adams believes they likely lived at least 50 years.
It probably had its own fiery last stand. Perhaps the Alamosaurus does have one thing in common with the historic mission after all. Just as the Battle of the Alamo ended in a blaze of glory, so, too, did the reign of the Alamosaurus.
“One of the last dinosaurs in Texas that probably saw the asteroid impact was Alamosaurus,” Adams said.