Scientists discover unusual new species of dinosaur that lived underground

The discovery of the burrowing dinosaur, Fona herzogae, from the middle of theCretaceous period reveals a complex ecosystem with dinosaurs occupying underground niches. This underscores the diversity and ecological adaptability of dinosaurs, expanding our understanding of their roles in ancient environments.

The age of dinosaurs didn’t just take place on land. A newly discovered ancestor of Thescelosaurus reveals that these animals spent part of their time in underground burrows. This new one species adds to our understanding of life during the mid-Cretaceous period, both above and below ground.

the new dinosaur, Phone [/Foat’NAH/] herzogae lived 99 million years ago in what is now Utah. At the time, the area was a large floodplain ecosystem, sandwiched between the shores of a massive inland ocean to the east and active volcanoes and mountains to the west. It was a warm, wet, muddy environment with many rivers running through it.

Paleontologists from North Carolina State University and the North Carolina Museum of Natural Sciences discovered the fossil—and other specimens of the same species—in the Mussentuchit Member of the Cedar Mountain Formation beginning in 2013. The preservation of these fossils, along with several distinctive features, of alerted them to the possibility of excavation.

Physical features and excavation evidence

Phone was a small-bodied, plant-eating dinosaur about the size of a large dog with a simple body plan. It lacks the bells and whistles that characterize its highly decorated relatives such as horned dinosaurs, armored dinosaurs and crested dinosaurs. But that doesn’t mean Phone it was boring.

Phone shares some anatomical features with known burrowing or burrowing animals, such as large biceps muscles, strong muscle attachment points in the hips and legs, fused bones along the pelvis—which may aid in stability while burrowing—and hind limbs that are proportionally larger than the fore limbs. But this is not the only evidence that this animal spent time underground.

“The bias in the fossil record is toward larger animals, largely because in flood environments like the Mussentuchit, small bones at the surface are often dispersed, decayed, or buried before burial and fossilization,” says Haviv Avrahami, a Ph.D. . student at NC State and digital technician for the new Dueling Dinosaurs program at the North Carolina Museum of Natural Science. Avrahami is the first author of the paper describing the work.

“But Phone is often found complete, with many of its bones preserved in its original death pose, chest down with the forelimbs spread out, and in remarkably good condition,” says Avrahami. “If it had been underground in a cave before death, would have made this type of preservation more likely.”

Lindsay Zanno, associate research professor at NC State, head of paleontology at the North Carolina Museum of Natural Sciences and corresponding author of the paper, agrees.

“Phone Skeletons are much more common in this area than we would expect for a small animal with fragile bones,” Zanno says. “The best explanation for why we find so many of them and recover them in small herds of many individuals, is that they lived at least part of the time underground. Basically, Fona did the hard work for us, burying themselves in this whole area.”

Although researchers have not yet identified the underground lairs of Phonethe tunnels and chamber of his nearest relative, Orychtodromeus, have been found in Idaho and Montana. These findings support the idea that Phone also used dens.

The cultural and scientific importance of Fona

Genus name Phone comes from the creation story of the ancestors of the Chamorro people, who are the indigenous populations of Guam and the Mariana Islands of the Pacific. Fo’na and Pontan were brother and sister explorers who discovered the island and became earth and sky. The species name honors Lisa Herzog, manager of paleontology operations at the North Carolina Museum of Natural Sciences, for her invaluable contributions and dedication to the field of paleontology.

“I wanted to honor the indigenous mythology of Guam, where my Chamorro ancestors are from,” says Avrahami. “In the myth, Fo’na became part of the earth when she died and from her body a new life was born, which for me is associated with fossilization, beauty and creation. Phone it was most likely covered with a layer of colorful feathers. The species name is for Lisa Herzog, who has been integral to all this work and discovered one of the most remarkable. Phone specimens of several individuals preserved together in what was likely a burrow.

Phone is also a distant relative of another famous North Carolina fossil: Willo, a Thescelosaurus neglectus specimen currently housed in the museum and is also thought to have adaptations for a semifossorial – or partially subterranean – lifestyle, research published in late 2023 by Zanno and former NC State postdoctoral researcher David Button.

“T. malpractice was at the end of this line – Phone it is its ancestor about 35 million years ago,” says Avrahami.

Researchers believe Phone is key to expanding our understanding of Cretaceous ecosystems.

“Phone it gives us insight into the third dimension that an animal can occupy by moving underground,” says Avrahami. “It adds to the richness of the fossil record and expands the known diversity of small-bodied herbivores, which are poorly understood despite being incredibly integral components of Cretaceous ecosystems.”

“People tend to have a myopic view of dinosaurs that doesn’t keep up with the science,” Zanno says. “We now know that the diversity of dinosaurs ranged from small arboreal crawlers and nocturnal hunters, to sloth-like grazers and yes, even underground denizens.”

Reference: “A new semi-fossorial tecelosaurine dinosaur from the Cenomanian-age Mussentuchit Member of the Cedar Mountain Formation, Utah” by Haviv M. Avrahami, Peter J. Makovicky, Ryan T. Tucker, and Lindsay E. Zanno, 09 July 2024, Anatomical Registration.
DOI: 10.1002/ar.25505