USA: prehistoric ‘terror birds’ came to North America earlier than thought

Titanis walleriFrom the University of Florida:

A University of Florida-led study has determined that Titanis walleri, a prehistoric 7-foot-tall flightless “terror bird,” arrived in North America from South America long before a land bridge connected the two continents.

UF paleontologist Bruce MacFadden said his team used an established geochemical technique that analyzes rare earth elements in a new application to revise the ages of terror bird fossils in Texas and Florida, the only places in North America where the species has been found.

Rare earth elements are a group of naturally occurring metallic elements that share similar chemical and physical properties.

“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 MacFadden, a curator of vertebrate paleontology at the Florida Museum of Natural History at UF.

“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.”

The study will be published Jan. 23 in the online version of the journal Geology and featured in its February print edition.

The terror bird was carnivorous, weighed about 330 pounds, had powerful feet and a head larger than a man’s.

It is known in the fossil record from a single toe bone in Texas, and in Florida by about 40 bone fragments from different skeletal regions.

MacFadden’s team also analyzed six specimens from the Santa Fe River in north Central Florida.

“We found that the Titanis fossils were 2 million years old and not 10,000 years old as had been suggested,” MacFadden said.

“This also shows the last known occurrence of Titanis in the fossil record and reflects its extinction.”

Diatryma in Germany: here.

7 thoughts on “USA: prehistoric ‘terror birds’ came to North America earlier than thought

  1. Canal fossils give clue to formation of Americas
    July 18, 2008, 9:43 am

    PANAMA CITY (Reuters) – Scientists in Panama have unearthed hundreds of animal fossils dating back 20 million years, which could shed more light on how and when the American continent became connected.

    Geologists from the U.S. Smithsonian Institution, which has a permanent base in Panama, say engineers digging to widen the Panama Canal have uncovered more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles that lived before a land bridge linked North and South America.

    “With these discoveries we will be able to get more information about the process by which the continual land bridge was formed,” Smithsonian geologist Camilo Montes told Reuters.

    Since February, the geologists accompanied engineers on excavations to expand the canal, having been invited by the government to make sure nothing of value was destroyed.

    Scientists believe the South American and Caribbean tectonic plates collided around 15 million years ago, causing volcanic activity that eventually formed a thin strip of land linking the Americas and separating the Pacific and Atlantic oceans.

    The bridge was probably fully formed, in a way that mammals could walk over it, some 3 million years ago.

    By comparing the Panama discoveries to fossil records from each continent, paleontologists hope to determine where individual species came from. Volcanic debris embedded in the same layer of rock as the fossils will help pinpoint the time when the animal was found on either side of the land bridge.

    “We will be able to get a much more precise date for when the continents started to close together,” said Montes.

    The forging of the Americas resulted in a mass migration of animals, while the separation of the two oceans transformed the world’s climate and prompted the development of new species.

    Montes said determining exactly when this closure happened could be key to understanding the link between major changes in ocean currents and our climate, providing some insight into the impact of global warming.

    “The closure could be linked to an ice age which affected North America around the same time, perhaps by altering ocean currents,” Montes said.

    “Some have argued the timing of the ice age is a coincidence. A more accurate timeline for the closure could tell us whether those two things were separate or linked.”

    The excavations are part of an archeological project to explore an area that will soon become part of the $5.25 billion project to expand the overcrowded Panama Canal.

    (Editing by John O’Callaghan)


  2. Pingback: Argentine ‘terror bird’ discoveries | Dear Kitty. Some blog

  3. Pingback: Mammals and extinction of dinosaurs | Dear Kitty. Some blog

  4. Pingback: Extinct terror birds of North America | Dear Kitty. Some blog

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