The most complete dinosaur fossil ever discovered in Mississippi, called “incredibly unusual” by state officials, still remains 85 percent buried since its discovery in 2007.
Paleontologists confirmed that this specimen was a once-living hadrosaur: a family of duck-billed vegetarian dinosaurs that existed more than 82 million years ago.
But the hadrosaur is a large family of herbivorous giants – experts say it includes at least 61 identified individual species and possibly hundreds of unique species that once roamed the Earth.
Researchers secured parts of the specimen’s spinal vertebrae, parts of its forearms, feet and pelvic bones, but the rest proved difficult to unearth from its location outside Booneville in the northeastern part of the state.
“This thing sat for a while because we didn’t have anybody working on it,” admitted one state Geological Survey official, James Starnes.
Hadrosaurs are a large family of giant plant-eating dinosaurs – including at least 61 identified individual species and possibly hundreds of unique species that once roamed the Earth, according to experts. The hadrosaurs above are an artist’s reconstruction of a Russian find
The most complete dinosaur fossil ever discovered in Mississippi is now known to be from the hadrosaur family — but only 15 percent of them have been safely recovered. Researcher Derek Hoffman (above) turns to 3D forensic analysis of bones to determine the exact species of hadrosaur
For nearly two decades, it remained a mystery which of the many hadrosaur species was actually the species unearthed in this Booneville, Mississippi, find.
But scientists are now turning to the 3D method of forensic bone analysis to solve the puzzle before it is fully revealed.
University of Southern Mississippi (USM) geology graduate student Derek Hoffman is now analyzing hadrosaur remains using a method known in many scientific disciplines as “geometric morphometrics.”
“What geometric morphometrics does,” as Hoffman put it simply, “is use a shape analysis approach.”
Key features or “landmarks” are determined for a given bone sample and their respective distances and ratios of these distances are then compared using complex statistical models to confirm differences and similarities to known bones.
The method has also proven itself in anthropology as well as in studies of human evolution, including comparisons of the brain cavities of modern humans and our Neanderthal ancestors.
However, Hoffman’s search for answers about this hadrosaur fossil is hampered by the fact that some pieces of the creature are in the hands of private collectors.
Above, the upper arm of an ancient hadrosaur unearthed in northeastern Mississippi
Hoffman’s work is primarily focused on bones publicly held by the Mississippi Museum of Natural Science.
“We have quite a few vertebrae,” paleontology museum curator George Phillips told the local Clarion Ledger newspaper. “We have one humerus.
“We have one ulna. The ulna is the back of the forearm.’
“We have some leg bones,” Phillips continued. “Then we have the pubis.
The ulna of an adult hadrosaur is roughly two feet long, and its humerus is about a foot and a half long. And only one complete, adult hadrosaur has a total weight greater than 50 pounds.
But the dinosaur skull – the most unique identifier for distinguishing between hadrosaur species – has yet to be found, to researchers’ frustration.
It is well known that different species of hadrosaurs evolved a wide and strange variety of crowns on their duck-billed heads, even from pliable material like a rooster’s red “comb”.
Paleontologists still debate what biological purpose these unusual and sometimes flamboyant features may have served, but their diversity contributed to the recorded diversity of the hadrosaur family.
Hoffman at USM focused on the dinosaur’s pubis, a bone from the front of the pelvis, as the next best bet for identifying the species of this fossil.
While the differences between hadrosaur pubic bones are subtle, often too subtle for the naked eye, their hidden differences can be refined by rigorous mathematical approaches such as geometric morphometrics.
A USM geology graduate student hopes to at least narrow down the number of potential hadrosaur species this Mississippi fossil could be.
Or, “What’s the lowest taxonomic level we can get this hadrosaur to,” as Hoffman put it.
What is now known about this particular hadrosaur is that it probably measured about 25-26 feet in length and was about 16 feet tall when sitting on its hind legs.
Hadrosaurs as a family of species are “undoubtedly the best-represented dinosaurs in the fossil record,” according to Hoffman. Pictured: an artist’s rendering of another duck-billed dinosaur from the group, one from 80 million years ago discovered nearby in Texas
While scientists believe the hadrosaur lineage began in North America, the herbivores eventually migrated around the world, with fossils discovered in Asia, South America, Europe and North Africa.
“They are by far the best-represented dinosaurs in the fossil record,” Hoffman said.
The name hadrosaurs comes from the ancient Greek for “stout lizard,” and the heavy animals actually ranged from about 2.2 to 4.4 US tons (or between 2,000 and 4,000 kilograms).
Many species of hadrosaurs lived between 75 and 65 million years ago during the Late Cretaceous period.
Other examples of dinosaurs from the hadrosaur family include Parasaurolophuswhich had a long, backward-curved crest on its head and appeared in the 2022 film ‘Jurassic World Dominion’ and Edmontosauruswhich had said crest made of soft tissue like a rooster.
State official James Starnes of the Mississippi Department of Environmental Quality’s Bureau of Geology said the 2007 discovery of this hadrosaur near Booneville was just ‘incredibly unusual.’
“We just don’t have a lot of skeletons,” Starnes said. “We have bits and pieces, but not the skeleton.
Despite the nearly two decades it took to unearth just a fraction of this hadrosaur fossil, Starnes hopes the project will one day be completed.
“We keep getting more of this specimen,” Starnes said.