Florida ‘muck’ a factor in Daytona mastodon’s preservation
DAYTONA BEACH, Fla. (AP) – Workers recently stumbled upon remains of an Ice Age mastodon on a construction site, experts say Florida has a unique collection of natural conditions that make it one of the best places in the nation to find preserved fossils.
The dark black muck that surrounded the mastodon bones is nothing visually appealing, but it’s one of the key pieces of scientific magic that helped preserve the fossilized remains found in a half-built retention pond near the intersection of Mason Avenue and Nova Road.
The muck chokes off any oxygen that would cause decay and entombs whatever is in it, paleontology experts say.
The protective muck, mineral-filled natural springs with constant temperatures, low-lying swampy areas, abundant limestone and naturally occurring phosphate in Florida soils have all preserved pieces of history that would have otherwise vanished tens of thousands of years ago, those experts say.
The many layers of soils, steady warm air temperatures and low-lying coastal areas, where deceased animals can be covered up quickly, also help.
“We’ve probably all walked over fossils and skeletons and never known it,” said James “Zach” Zacharias, an education and history curator at the Museum of Arts & Sciences in Daytona Beach. “This whole area up and down Nova Road must have been teeming with Ice Age mammals.”
Some have dubbed parts of Central Florida “Bone Valley” because of the fossils found here.
“In Florida we have a rich fossil layer that runs through the state,” said Russell Brown, president of the Orlando-based Florida Fossil Hunters group and an amateur paleontologist.
One of the only reasons animal bones and teeth thousands of years old aren’t found more often is because there’s usually no good reason to dig 10 to 15 feet down. But when workers creating South Daytona’s Reed Canal Park in 1975 started peeling away the layers of earth, they found the full skeleton of a giant ground sloth in muck there.
When workers building the city government retention pond near Mason and Nova were hitting that 10-foot level about a week ago, they stumbled on the mastodon’s jaw along with some other bone fragments.
Amateur paleontologists and volunteers from the Museum of Arts & Sciences were allowed to look around the 4-acre retention pond, and they started finding things most every day last week. They’ve unearthed most of the two tusks, parts of the skull, ribs, vertebrae, teeth, a partial leg bone, a joint of some sort and various bone pieces they haven’t identified yet.
The remains have been there for at least 13,000 years, when that type of mastodon went extinct, but the animal could have died as long as 130,000 years ago.
The paleontologists and museum officials say they think they’ve got an adult male mastodon — 100,000 years old by their best guess for now — but they aren’t confident they’re going to find its full skeleton. They’re afraid the retention pond workers might have unwittingly sent some mastodon remains through a rock crusher, not realizing what was in their piles of dirt.
The paleontologists and museum officials have had their kids helping sift through debris piles at the site, but Zacharias said most of those kids have been on sites before and they’d know enough to distinguish between remains and rocks.
They also say it’s possible the full skeleton wasn’t preserved there. Maybe other animals, ancient rivers or ocean tides carried off pieces.
They plan to make today their last day to search unless construction workers on the site stumble on more remains. At the city’s request, a St. Augustine archaeologist is tentatively scheduled to be on site Monday to look for Native American remains and artifacts.
Even if nothing else is found, the paleontologists will still count it as an incredible find.
“It’s pretty rare to find the full skeleton,” Zacharias said.
There are only about 12 known full mastodon skeletons that have been found in Florida, said Richard Hulbert, vertebrate paleontology collections manager at the Florida Museum of Natural History in Gainesville.
“Mostly we find pieces of mastodons and mammoths in rivers,” said Valerie First, a historian for the group Florida Fossil Hunters.
First said she also knows of small mastodon tusks found near New Smyrna Beach about 10 years ago when a road was being built.
Zacharias said the mastodon remains found in Daytona Beach have been put in locked storage at the museum. The next step will be cleaning them, examining them and seeing if some of the fragments fit together.
First cautioned the bones will need to be dried out gradually, or else they could “disintegrate into powder.”
Eventually the museum would like to display them, possibly near the sloth.
When the sloth and mastodon were wandering Volusia County, the terrain was pretty different, various experts said. That would have been during the Ice Age, when sea level could have been about 300 feet lower, Florida would have been about three times as wide and Daytona Beach would have been nowhere near the coast, Hulbert said.
Glaciers would have expanded down to the Midwest, Florida’s temperatures would have been cooler and there could have been moderate amounts of snow in the winter.
Daytona Beach also would have been on higher ground relative to the ocean, and the plant life would have been a little different, experts say. There would have been savanna-like areas where animals could have grazed, they say.
The mastodons would have preferred to be near water, and would have been along rivers and the ocean.
The spot where the Daytona mastodon was found “was probably a drainage area like the St. Johns River, or a coastal lowland area,” Zacharias said. “It was very mucky.”
That muck was an ideal spot for preservation, as is water that also prevents the decaying effects of oxygen.
“There’s a good chance here for animals to land in rivers, springs, lagoons and muck,” Brown said. “Anything to keep out air.”
Over many thousands of years, layer after layer built up over the ancient animal remains, he said.
The muck surrounding the Daytona mastodon preserved much of the original bone material, Zacharias said.
“The bone still looks and feels like original bone,” he said. “There’s not much mineralization.”
Sandy marine layers with shells don’t do much for preservation, he said.
“You get more mineralization in the marine layer, and it would be really hard like rock,” he said. “Minerals will fill the cellular spaces and crystallize.”
The abundant phosphate found in Florida’s soil can strengthen bone, which helps preserve it, said Jimmy Waldron, a former president of Florida Fossil Hunters who’s still active with the group.
A few specimens of a more ancient type of mastodon than the one found in Daytona Beach have been found in the phosphate mines of Polk County in the middle of Florida, Hulbert said.
Those who examine the Daytona mastodon’s teeth will be able to determine its age and health, Brown said. Carbon-dating of bone samples is also planned.
Brown said “it’s an opportunity of a lifetime.”
“We may learn something about this one animal that changes what we know about this area,” he said.
Zacharias agrees, saying he’s excited to show off parts of an animal that haven’t been seen in 100,000 years.
“I’m very thankful it didn’t go to the rock crusher,” he said. “It’ll be an excellent educational tool.”
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Online: Daytona Beach News-Journal
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