Digging up the past
Ghost Ranch sites shed new light on old remains
September 19, 2011
It is often said that the more we know, the more we know we don’t know. That phrase couldn’t be truer in one particular corner of the Presbyterian world, where new knowledge is being dug up — literally — on a regular basis.
Ghost Ranch, one of three national Presbyterian conference centers, is known by many for its stunning vistas and remarkable high desert landscapes made famous by Georgia O’Keefe. But it also attracts some of the nation’s finest paleontologists who are there not to study the living, but the dead.
“The very first vertebrate fossils were collected nearby Ghost Ranch back in the 1870s,” said Alex Downs, the ranch’s curator of paleontology.
Not long after, in 1881, a few pieces of what later became known as Coelophysis (SEE-Low-FY-sis) were found and named. But it wasn’t until 1947, back when Ghost Ranch was a dude ranch, that the bigger discovery began with the unearthing of a virtual graveyard of fossils in what is now referred to as the Coelophysis quarry.
A fairly small, carnivorous biped, Coelophysis is significant in the world of paleontology due to its standing as one of the earliest known dinosaurs that lived during the late Triassic period.
“They were thick in there, little dinosaurs, and they are literally on top of each other so if you tried to cut one out you would run into the others,” Downs said.
Because of this, excavation has been slow, with long delays caused by the need to excavate giant blocks of rock weighing from two to ten tons apiece.
Some sixty years after that initial discovery, Sterling Nesbitt, a graduate student at Columbia University, was working on one of the blocks of rock collected in the 1940s.
“What he found was a new animal that looks like a dinosaur, but it is related to the crocodile, called Effigia okeeffeae,” said Downs, noting the name is in honor of Georgia O’Keefe, whose ashes are scattered at Ghost Ranch.
During that same timeframe, a group of hikers were being lead by a retired forest naturalist named John Hayden. They happened to be hiking on ranch land because the forest service land was closed due to drought. Hayden and his companions unexpectedly came upon a new fossil site, which has since been named the Hayden quarry in his honor.
“Dinosaurs are very unusual in this type of site because, being land animals, they typically would die in the woods, not in the mud,” said Downs.
But in 2004, Ghost Ranch discovered a partial skeleton of a dinosaur that clearly was not the previously known Coelophysis.
“I showed it to Sterling Nesbitt at a paleontology meeting and asked if he could check out the site,” said Downs, adding that he cautioned Nesbitt that it was a lucky find and not likely to be repeated. “In 2005 they went to the site and found dinosaur remains within a half hour.
“At first they started finding some bones that looked kind of dinosaur-like, but they turned out to be bones from the first dinosaur precursors recognized from North America — both had been collected before but hadn’t been recognized because the pieces were so fragmentary,” Downs said.
“In 2007 we named one of the dinosaur precursors Dromomeron,” he said. “That was the first dinosaur precursor from North America.”
The original dinosaur discovered at the Hayden Quarry in 2004 was named Tawa in 2009. Tawa replaces Coelophysis as the older North American dinosaur known from a complete skeleton.
“This new site, the Hayden Quarry, is extremely diverse with over 25 different kinds of land animals,” said Downs.
The site is believed to be approximately 212 million years old.
But perhaps the most interesting discovery that has come from the Hayden Quarry is the light it sheds on the wider understanding of dinosaurs in the Triassic Age.
“One of the strange things about the fauna in the Triassic is that we have only little meat-eating and no big meat-eating or plant-eating dinosaurs. If you reconstruct how the continents were, it should have been easy for them to go many places in the world easily,” Downs said.
But the Hayden Quarry has yielded three species of small predatory dinosaurs, each of whose closest relative is found in Europe, South America or southern Africa.
“What we’ve learned is that we don’t have one species of little dinosaur who came to North America and then evolved, but instead we’ve got three distinct ones. Apparently these animals were freely crossing during the Triassic,” said Downs.
The lack of larger meat-eaters or plant-eaters appears to be due to the climate.
“The places where you find them were drier conditions,” said Downs.
Though there have been other fossil discoveries at Ghost Ranch — an armored aquatic reptile, the Vancleavea, is one of the more recent finds — it is the ‘d-word’ that gets all the attention.
“If it’s not a dinosaur, for the most part, nobody seems to care,” said Downs, who is at work re-doing the exhibits at Ghost Ranch’s Ruth Hall Museum of Paleontology.
Included in the exhibit will be a charcoal drawing of a Tawa, made with actual fossilized bits of burnt wood found in the quarry along with the fossils themselves.
“I assume that this is the first time something like this has been done — the piece is literally drawn with charcoal from the forest that the animal once lived in,” Downs said.
For the budding amateur paleontologist, Downs will be leading his yearly ‘dig’ at the Hayden Quarry the first week of October and still has a few spots left.
Erin Dunigan is a freelance writer, photographer, and pastor who lives in a small coastal community in Baja California, Mexico when she is not following her wanderlust out into the world.