The Tully Monster, an oddly configured sea creature with teeth at the end of a narrow, trunk-like extension of its head and eyes that perch on either side of a long, rigid bar, has finally been identified.
A Yale-led team of paleontologists has determined that the 300-million-year-old animal—which grew to only a foot long—was a vertebrate, with gills and a stiffened rod (or notochord) that supported its body. It is part of the same lineage as the modern lamprey."I was first intrigued by the mystery of the Tully Monster. With all of the exceptional fossils, we had a very clear picture of what it looked like, but no clear picture of what it was," said Victoria McCoy, lead author of a new study in the journal Nature. McCoy conducted her research as a Yale graduate student and is now at the University of Leicester.
For decades, the Tully Monster has been one of the great fossil enigmas: It was discovered in 1958, first described scientifically in 1966, yet never definitively identified even to the level of phylum (that is, to one of the major groups of animals). Officially known as Tullimonstrum gregarium, it is named after Francis Tully, the amateur fossil hunter who came across it in coal mining pits in northeastern Illinois.
One thousand years ago, on a floodplain of the Mississippi River near modern-day St. Louis, the massive Native American city known today as Cahokia sprang suddenly into existence. Three hundred years later it was virtually deserted.
The reasons for Cahokia's quick emergence and precipitous decline have been among the greatest mysteries in American prehistory, but new research suggests a possible cause of the city's demise: a catastrophic flood.
A team led by Samuel E. Munoz, a doctoral student at the University of Wisconsin, Madison, reported at the 2013 conference of the Geological Society of America that their study of sediment cores from a lake adjacent to the site of Cahokia reveals calamitous flooding of the area around 1200 C.E., just as the city was reaching its apex of population and power.
While analyzing cores from Horseshoe Lake, an oxbow lake that separated from the Mississippi River some 1,700 years ago, Munoz's team discovered a layer of silty clay 19 centimeters (7.5 inches) thick deposited by a massive ancient flood.
It's unlikely that the ancient floodwaters were high enough to inundate the ten-story mound at Cahokia's center, a structure now called Monk's Mound. (See "Cahokia: America's Forgotten City.") But a flood of such magnitude would have devastated croplands and residential areas, and may have made it impossible for a population numbering as many as 15,000 to continue inhabiting the area.
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