A Tale of Two Eras

A casual discovery leads to a new story about New Mexico’s past

by

Joseph Karnes spends about six hours every weekend running through what he calls New Mexico’s “nowhere lands.” After he moved to Santa Fe to semi-retire in 2006 with a 20-year legal career behind him, the former Olympic Marathon Trials runner burned through all the trails in the area. He next turned his attention to places where few people travel, parking his truck at public access gates and taking off on foot with a GPS and a spirit of adventure.

As he ran on a mesa above the Pecos River near Villanueva on June 6, 2020, Karnes kicked an orange and red sandstone cylinder poking up from an old roadbed. He spotted another one nearby and, finding them curious, stuck both foot-long objects in his backpack. A few weeks later, he emailed photos of the rocks to a handful of paleontologists and paleobotanists who had posted their contact information on the internet.

One of them replied within an hour.

In his role as curator of paleontology for the state Museum of Natural History and Science, Spencer Lucas hears from the general public regularly.

“Every day, really,” he tells SFR in an interview from the lab across the street from the museum. “I got an email a little while ago. It ranges from people who say, ‘Oh, I found a dinosaur,’ ‘I found a dinosaur egg’…to people who come to the museum. Some of them just show up with something, others will email me or one of the other curators and make an appointment.”

Most of the time, curators know what they’re looking at right away. Not so for Karnes’ discovery.

“Say I heard from 1,000 people in the last five years,” Lucas says. “Maybe only five of those people found something new or interesting. So, that’s why what Joseph found is unique…It’s rare for someone to find something that’s really worth studying.”

Lucas, along with William DiMichele, curator in the Department of Paleontology of the Smithsonian Institution National Museum of Natural History in Washington, DC, determined the cylinders were fossil casts of plants from 250 million years ago in a region where scientists previously didn’t know they grew.

What Karnes stumbled over amazed him and shifted how he sees his place in the landscape. It also reinforced an established component of the science of paleontology: ordinary people making extraordinary finds. Because the discovery revolved around plant life, however, and not headline-grabbing, action-packed dinosaurs, it received little fanfare.

Working from home during the pandemic restrictions, Lucas and Karnes exchanged messages about the fossils for months, meeting once that winter in an Albuquerque parking lot so Lucas could get a look at the stone cylinders. Only after lockdowns lifted could they take a field trip together to the Sacastosa Mesa in the summer of 2021.

On the next trip, Lucas invited DiMichele and the trio observed hundreds of the cylinders in two areas. While typically such a visit would yield a fairly quick conclusion for known fossils, the cylinders required more analysis.

“We weren’t sure,” Lucas says. “I’ve been a professional paleontologist for 40 years. And Bill is older than me, he’s been one for almost 50. So we have a lot of experience looking at fossils in the field and in the museums. And for Joseph to find something that we were not sure about, that’s a big deal. That was very intriguing to us.”

Together, the scientists determined the cylinders are most likely sedimentary casts of a type of plant called a woody calamitalean, similar to today’s horsetail fern but mega-sized—with stems ranging up to more than a foot in diameter. The plants grew in an interdunal area on the edge of a lake about 270 million years ago during the Permian Era, a time when desert extended from today’s Grand Canyon across northern Arizona and down into central New Mexico and when dinosaurs were still 100 million years in the future. Those conditions—dry rocky formations—make the plant fossils and casts like the cylinders rare in this region.

The scientific paper, which Karnes co-authored, published in the Fall 2023 issue of New Mexico Geology, and named the specimens “a new, unique fossil assemblage from the New Mexico Permian.”

Karnes, who has returned to the site two dozen times or more, says he found deep meaning in witnessing the scientific process.

“This prehistoric forest connects to a time that was unimaginably long ago but also has happened to produce our fossil fuels,” he says, noting he enjoyed the feeling of “being able to put yourself in a different time in the same place.”

At the same time Lucas spoke to SFR about the cylinders, however, he had just received word another paper had passed its peer review and would soon become public—this one taking a second look at a fossil that had been in the museum collections for 30 years.

That discovery, unlike Karnes’ fossils, became national news. Debra Garcia y Greigo, the state Department of Cultural Affairs secretary, described the paper as “groundbreaking research.” Scientific Reports issued embargoed copies of the Jan. 11 publication to outlets including The New York Times, which ran a story with the headline “New Origin Story for Tyrannosaurus Rex Suggested by Fossil” just minutes after the state’s news conference began. National media including CNN and NPR and The Independent in the UK published stories, too.

Montana State University doctoral candidate Sebastian Dalman returned to a fossilized jaw bone first described in a 1986 paper and made new conclusions with Lucas, who had been one of Dalman’s advisors in undergraduate school, and others. “We’re looking at it through new eyes,” Lucas said at the event. “We know a lot more now than we knew in the ‘80s.”

The fossil landed at the Museum of Natural History and Science in Albuquerque after Donald Stanton and Joe LaPoint, both of Las Cruces, took an outing to Elephant Butte Lake with their sailing club in April 1983. They spotted the jaw bone on the lake’s eastern shore among the purple and maroon shale of the McRae Formation at a time when lake levels ranged somewhat higher than they are today.

“LaPoint, a biologist, astutely deduced that they had a jaw of a Tyrannosaurus, the large predatory dinosaur of the Late Cretacious,” reads the paper, concluding that the specimen, which included several teeth and roots, was from a T.rex.

The 3-foot-long jaw has been on display at the museum since 2002 and photographed for various publications, including its The Age of Dinosaurs in New Mexico book. But in 2013, Dalman noticed differences between the fossil and other tyrannosaur specimens. Eleven years later, the paper with him as a lead author relied on the work of eight co-authors, as well as geology faculty and students at New Mexico State University.

Together, they made the case for the new species dubbed T.mcraeensis (named after the rock formation) as a direct ancestor of T.rex. While T.rex lived approximately 66 to 68 million years ago, the jaw bone and other parts of skull found near Truth or Consequences indicates T. mcraeensis dates to 72 to 73 million years ago, the paper concludes. The finding also provided what scientists call a “competing hypothesis” for the origin point of Tyrannosaurus. Previous theories pegged the evolution taking off in modern-day Canada and Montana, but it names the American Southwest as its older location.

T.rex seems to make headlines no matter what people say about it. A story about whether T.rex had lips made the rounds early in 2023, and just before the T.macraeenisis paper, scientists postulated fossils long thought to be juvenile T.rexes come from the species Nanotyrannus lancensis. Just after New Mexico’s T.mac news, dino fans and researchers moved on to discussion of how T.rex likely suffered from arthritis, according to a paper from Mattia Baiano at Argentinia’s National University of Rio Negro.

Like most tyrannosaur news, the New Mexico hypothesis also raised questions. Scientific American reported several paleontologists “aren’t convinced these distinctions are substantive enough to merit declaring the specimen a new species.”

Paleontologist, author and fossil journalist Riley Black, who has published 11 books as well as articles for Smithsonian Magazine, Scientific American and WIRED, along with working as an advisor on Jurassic World, says that’s been a common thread in her early conversations about the T.macraeenisis.

“The researchers I talked to feel Tyrannosaurus macraeensis is just T.rex. It doesn’t seem different enough,” she says, though she also holds out the possibility that “T.macraeensis is something else and we just need more bones to tell because it’s very partial, our understanding of it so far.”

The flashy presentation and the drastic difference in media attention for the calamitalean fossils doesn’t surprise Black. Tyrannosaurs come with infamy; fossilized plants, which are harder to come by in general than animals, don’t have nearly their celebrity status.

“A cult of personality happens around tyrannosaurs in particular. Everybody wants to make their mark. Everybody wants to have a controversial opinion,” she tells SFR in a video chat from Salt Lake City. “The way that people talk about it, and argue about it is so disproportionate where it’s like they identify with this powerful predator to the point that they kind of end up fighting like tyrannosaurs about it…I think it’s something that’s fed into this mystique of the knowledgeable scientist, Indiana Jones-type character, [whose] sense of authority and their sense of who they are and prestige comes from their control of the natural world. That, ‘We are finding and naming things that are big and powerful.’”

The glut of tyrannosaur conversations is partly why her next book will focus on prehistoric plants, she says, “I feel like paleobotanists are underappreciated in their field; because all these big dinosaurs, they got big eating something. So all these food webs and interactions go back to plants.”

DiMichele says there used to be a lot more researchers specializing in the plants of the Permian Era like those that made the casts Karnes found on the mesa. Those specimens are from what’s commonly known as the “coal age,” and in wetter climates in the US and Europe, the Industrial Revolution’s coal mining led to a broad understanding of those plants—largely because deep mines revealed fossils. In 2005, for example, the Peabody Coal Co. allowed access to an Illinois mine when it dug into a fossilized forest of lycopod trees from the same era.

But most of the prehistoric plant research these days focuses on flowering plants that arrived 60 to 80 million years ago, he says. Research about dinosaurs from that time continues to captivate the world.

“I think it’s always been there. I mean, my first interest in paleontology was dinosaurs. Everybody had a set of rubber dinosaurs,” DiMichele tells SFR in a telephone interview from Washington, DC. “We were 8 years old and we pretended we were different kinds of dinosaurs and chased each other around. If you’re a little kid, you know the idea of climbing a lycopod tree doesn’t appeal as much as duking it out with a tyrannosaurus. We’re just at a loss.”

He’s never held a news conference about the dozens of plant research papers in which he’s had a part, for example, but he knows his work matters.

“You’re surrounded by plants everywhere you look,” he says. “That’s the world you see and they set the stage. They are the framework in which all the other things are taking place. And so it takes kind of a leap of imagination to work with the plants.”

Based on the two most recent New Mexico discoveries, the next big piece of ancient animal or vegetable knowledge could come from another ordinary person taking a single step among 35 million acres of public lands. The state has been making investments to get even more people to participate in the growing outdoor recreation industry enjoyed by tourists and locals alike.

Black says the sense of possibility remains something everyone can share.

“When you see a professional paleontologist, on television or highlighted in an article talking about a fossil, they’re kind of the mouthpiece for all this other work that went on to even find those fossils in the first place,” she says. “And I think that’s one of the wonderful things about paleontology is you don’t need a Super Collider to do it. You don’t need a lab bench of all kinds of reagents and enzymes. To do this, you can just be out for a walk and make a contribution to our understanding of the past.”