This story is 73 million years in the making.
Now the life of the Ziapelta sanjuanensis will be told, thanks to Robert M. Sullivan and his team.
The five-member team was searching the Bisti/De-na-zin Wilderness of northwestern New Mexico in 2011. The team was working on a Bureau of Land Management-funded survey of the area when it came upon a preserved skull.
The skull, which was slightly smashed due to rock weight around it, was unveiled at the New Mexico Museum of Natural History and Science on Wednesday. It will be on display at the museum for visitors to view.
Sullivan, who has more than three decades of experience, describes the skull as a “great find” because it was not only well-preserved but it was that of a new species.
“It’s a rare thing to actually find a new species,” he says. “When we found the skull, we were impressed with how well it was preserved.”
The Ziapelta would be about 15 to 20 feet long, depending on if it were an adult, Sullivan says.
It is a new kind of armored dinosaur – or ankylosaur – which is distinguished by unique features of the armor plates on the skull and the uniquely shaped horns that adorn the posterior edges of the skull. It also would have had a hammer-like tail.
Its closest relatives are Late Cretaceous ankylosaurs found north of New Mexico, particularly in Alberta, Canada.
Sullivan says the name of the dinosaur is for the Zia sun symbol, Latin pelta (small shield) and San Juan County.
Sullivan has found other fossils before but after this skull was discovered, he wanted to find more.
“It was tough because you begin to wonder why is the head alone,” he says. “(There are) scenarios like the dinosaur dying in the river bed and the body deteriorating only leaving the skull. Or because this dinosaur was a herbivore, it was killed by a bigger dinosaur and just the head was left. But we can’t tell all of these stories because there were no other fossils found. It remains a mystery.”
Sullivan has been digging in the San Juan Basin area for more than three decades and now resides in New Mexico.
Spencer G. Lucas, curator of paleontology and geology at the museum, says it’s once a decade that a new dinosaur species is found.
“What’s amazing is that this species is named after New Mexico,” he says. “It’s been about three years for us to actually to get the public to see it.”
The fossil is approximately 73 million years old, so it dates it to the late Cretaceous period.
An article describing Ziapelta will be published in the journal PLOS ONE next week, which also will give more insight to the origin of the dinosaur.