Carnivorous ‘terror bird’ stalked America before isthmus formation
7-foot-tall flightless bird preceded Panamanian land bridge
mongabay.com
January 23, 2007
A prehistoric 7-foot-tall flightless “terror bird,” arrived in North America from South America well before the formation of the Panamanian land bridge according to a study led by University of Florida (UF) researchers. The results will be published January 23 in the online version of the journal Geology.
“It was previously thought that Titanis immigrated to Texas across the Panamanian land bridge that formed about 3 million years ago connecting North and South America,” said UF paleontologist Bruce MacFadden. “But the rare earth element analysis of a fossil Titanis bone from Texas determines its age to be 5 million years old. This shows that the bird arrived 2 million years before the land bridge formed, probably across islands that formed what today is the Isthmus of Panama.”
“We used rare earth elements because they’re highly specific to certain time periods and different groundwater conditions,” MacFadden said. “This is the first time that the uptake of rare earth elements during the early stage of fossilization has been used to determine the age of fossils in North America.”
The terror bird, bones of which have been found in Texas and Florida, was carnivorous and weighed about 330 pounds.
This article is based on a news release from the University of Florida.
