A massive creature tromped its way across an expansive limestone marsh. Horseshoe crabs scurried in its wake, and a reptile similar to a crocodile crossed its path. Weighing between 600 and 800 kilograms (1,760 pounds), the creature left impressive footprints in the limestone deposit. Shifting sand then covered the tracks. The creature's rear foot measured a large 35 centimeters (14 inches).
All this happened around 243 million years ago -- and it took until now for the fossilized tracks of this massive reptile to come to light again. The find was made in a quarry near Bernburg, a small city in the eastern German state of Saxony-Anhalt, and the first details were revealed last week. If the discoverer, paleontologist Cajus Diedrich, is to be believed, these limestone impressions will make for a research coup of global dimensions.
Diedrich believes he's found the world's oldest dinosaur, the ancestor of T. rex, Brontosaurus, Triceratops and all the others. The German weekly newsmagazine Stern obligingly reported the paleontological discovery was a "sensation," but a number of experts in the field believe Diedrich's theory is fundamentally wrong and an all-out scientific brawl is brewing within the profession.
Here are the facts: Diedrich first came across the site in late 2007. In June 2008, together with specialists from Saxony-Anhalt's state Office for Monument Protection and Archeology in the nearby city of Halle, he retrieved material from the limestone quarry near Bernburg from an area about half the size of a soccer field. There they found fossilized tracks from many kinds of reptiles and crabs, as well as skeletal impressions of marine reptiles.
But the set of tracks that Diedrich describes as "spectacular" is the same one making waves among paleontologists now. Covering almost 50 meters (164 feet), it includes 34 individual impressions, each showing five toes. According to Diedrich, the anatomy of the footprints leaves no doubt: "There were relatively large dinosaurs far earlier than previously assumed."
Diedrich speaks of the Prosauropods, dinosaur ancestors of the long-necked giants who later grazed the plains of the Jurassic period. He sees his find as the evolutionary "missing link" between the slow reptiles of the Paleozoic era and the later, lithe dinosaurs.
But the freelance paleontologist has attracted criticism with his theory. It's "ridiculous," declares Hartmut Haubold, a paleontologist from Halle. "It's as if someone found a 10-million-year-old stone and claimed it was a hand axe made by humans." Dinosaurs didn't come into existance until a good 15 million years later than Diedrich claims," he says.
Haubold believes the tracks in question, were most likely left by a Chirotherium, an ancestral reptile long known to scientists and possibly related to the dinosaurs' predecessors. Martin Sander, a paleontologist at Germany's Bonn University, is also skeptical. "The first dinosaurs were smaller creatures," he explains, "about as big as monitor lizards." That a much larger dinosaur would have lived so much earlier, says Sander, is "extremely improbable."
More than anything, though, it's the secretiveness surrounding the allegedly sensational discovery that is causing the most agitation. "In Internet forums on the topic, moderators have had to warn people to temper their word choices," says Michael Schudack, a paleontologist at Berlin's Free University. For weeks Harald Meller, head of the Office for Monument Protection, released very little information about the find -- ostensibly to keep hobby paleontologists away. Now, however, the accusation has been leveled that Meller, as an archeologist, is treading here on ground outside his field of expertise.
"We were only responsible for securing the tracks," Meller says, defending his role. But Haubold suspects there may be another motive: "Mr. Meller wants another Nebra sky disk."
Haubold is referring to a Bronze Age disk that brought Meller's office fame in 1999. Also discovered in Saxony-Anhalt, the disk is known as the oldest depiction of the heavens worldwide. Haubold accuses the agency of looking to create a similar sensation with the fossilized tracks in Bernburg: "That's not science, that's just hype."
Is it charlatanism on the one side, or injured vanity on the other? Diedrich claims his critics are just upset that they didn't get their hands on the discovery first, and he feels he's been attacked unfairly. "I don't turn to colleagues for advice anymore," he says, "because many of them don't follow the scientific code of honor."
Ultimately, that could help the researcher, whom even Haubold admits deserves "a lot of credit." The appraisal of the Bernburg find is so controversial partly because -- so far at least -- no independent dinosaur tracks specialist has examined it.
In the meantime, Diedrich has submitted his data "to an international scientific journal" for review, but that step appears to be insufficient for quieting his critics.
"With only tracks to go on, it's very difficult to draw conclusions about a new dinosaur," says Bonn University's Sander. "There would have to be a skeleton."
Perhaps Diedrich senses that, too. He's already planning for his next coup. He wants to begin the search for evidence that supports his theory in Bernburg soon.
"The tracks continue further into the rock," says Diedrich. "My hope is that the dinosaur who made it is at the end of the tracks." But how probable is it that the creature would have done him the favor of dying right there?