On a routine early morning prayer walk through undeveloped fields near Viridian, Art Sahlstein felt God throw him a bone.
Or, as Sahlstein puts it, “Lots of bones.”
Those bones turned out to be thousands of dinosaur fossils shallowly buried under sediment. The discovery in 2003 would soon change his life and put Arlington on the international map as a one-of-a-kind fossil hub.
To spotlight Arlington’s prehistoric story, the Arlington Historical Society is showcasing fossils from the area at the Historic Fielder House, a house-turned-museum highlighting local history.
The exhibit, “The Seashores of Ancient Arlington: A Rich Fossil Record,” predates the museum’s usual local artifacts by tens of millions of years. It features dinosaur teeth, prehistoric dung and other relics from the Arlington Archosaur Site, which Sahlstein helped establish in the fossil-rich fields neighboring his home.
When Sahlstein discovered the Arlington Archosaur Site, it appeared to be a run-of-the-mill, dried-up, copperhead-filled North Texas hillside. But about 98 million years ago, the site was a swampy river delta filled with mangrove trees and giant crocodiles, scientists believe.
The land that makes up today’s United States was split into two continents. Arlington sat at the southern tip of the Appalachia continent, where a large river gave way to the sea.
Swamps preserve fossils well, giving the area optimal conditions for protecting the prehistoric ecosystem, said Bradley Carter, a diamond seller who frequents Dallas-Fort Worth construction and dig sites for fossils.
The Arlington site is internationally renowned for helping fill a 20-million-year knowledge gap in the late Cretaceous period — the tail-end of the dinosaur age, Carter said. Over 1,200 fossils have come from the site, including a previously unknown species of an amphibious lungfish, now named after Carter, and a large crocodile.
Initially after his discovery, Sahlstein kept the site secret. He and a few others “in the know” — a few locals, including Carter, independently found fossils there a few months after Sahlstein — spent every hour possible digging and collecting new fossils.
Their discoveries kept getting bigger.
Soon the group wanted to have a full-scale excavation. They took their largest finds to local officials and asked for their backing. In 2007, after years of paperwork, the University of Texas at Arlington became officially involved in the project, with graduate student Derek Main leading the fieldwork.
Over the next five years, the community rallied behind the excavation and volunteered to help. More than 4,000 students and locals became part-time paleontologists, Sahlstein said.
“We’d have lawyers, pilots — anyone would show up,” he said. “We’d have someone mention they need help with 501(c)(3)s, then an accountant would pop up and say ‘I’m an expert on 501(c)(3)s.’”
Nancy Bennett, a retired clergywoman, remembered volunteering. She was one of the oldest volunteers at the dig site.
When handling million-year-old fossils, “age doesn’t matter,” Bennett said with a laugh.
Timeline:
2003: Sahlstein finds fossils on an undeveloped Viridian hillside during a morning walk.
2007: Site is officially protected, UT-Arlington leads excavation.
2013: Lead paleontologist Derek Main dies unexpectedly amid conversations to move fossils to the University of Texas at Austin.
2013: Perot Museum takes over project, scaling down excavations.
2020: The COVID-19 pandemic halts official excavations indefinitely.
2024: Arlington Historic Society opens temporary exhibit showcasing fossils from the site.
Following the unexpected death of Main in 2013, shortly after he finished his doctorate, Sahlstein helped the Perot Museum of Nature and Science in Dallas take over. The fossils moved there, and the museum is still the main institute behind the site.
The area isn’t tapped out of discoveries, Sahlstein said, but the large-scale digging operations of Main’s time have petered out. The Perot Museum hasn’t led an official excavation since 2020.
New housing developments now encroach on the borders of the remaining protected sections of the site. When new residents first moved into the neighborhoods, they each got a knock on the door from Sahlstein introducing himself.
“You’ll see me behind your backyards,” he would tell them. “There’s dinos back there.”
Sahlstein, a retired IT administrator, still walks to the Archosaur site most weeks and is its caretaker. He slowly meanders through the dirt, often crawling on his hands and knees and frequently finding new fossils.
“People ask me how often I find new stuff,” Sahlstein said. A beat passed, then he smiled: “Every time I get off the couch.”
In his living room, among various fossils and Jurassic Park memorabilia, a large, framed picture hangs. It depicts the official illustration of a bloody-mouthed crocodile — the species he helped discover a few hundred yards away.
It’s named, aptly, the Scolomastax sahlsteini.
If you go:
What: “The Seashores of Ancient Arlington: A Rich Fossil Record,” fossils, relics and information from the Arlington Archosaur Site
Where: The Historic Fielder House, 1616 W. Abram St., Arlington
When: Open most days through Sept. 29
Price: $5 for ages 12 and older, free for 11 and younger
Drew Shaw is a reporting fellow for the Arlington Report. Contact him at drew.shaw@fortworthreport.org or @shawlings601. At the Arlington Report, news decisions are made independently of our board members and financial supporters. Read more about our editorial independence policy here.
This article first appeared on Arlington Report and is republished here under a Creative Commons license.