fossils

Titanoboa: The World’s Largest Snake

| ChrisHardmanWriter

IMAGINE A SNAKE so wide it would barely fit through a doorway and so tall it would reach an adult’s waistline. That is how researchers describe the 2,500 pound, 45-foot long Titanoboa cerrejonensis—the biggest snake the world has ever known—who ruled the tropics 65 million years ago. “This was the largest predator on the planet for at least 10 or 20 million years,” says Jonathan Bloch Associate Curator of Vertebrate Paleontology at the University of Florida’s Museum of Natural History. The massive anaconda-like snake lived 6 million years after the dinosaurs went extinct.

During a series of excavations at the Cerrejón coal mine in northern Colombia, an international team of scientists—led by Jonathan Bloch and Smithsonian Tropical Research Institute Staff Scientist Carlos Jaramillo—collected the remains of Titanoboa along with fossils of the giant-sized relatives of modern-day crocodiles and side-necked turtles. According to Bloch, these excavations have yielded the first fossil vertebrates ever found in tropical South America from the Paleocene Epoch 65 to 55 million years ago. “Now we have a window into the time just after the dinosaurs went extinct and can actually see what the animals replacing them were like,” he explains.

Cerrejón, the world’s largest open-pit coalmine, provides an unprecedented opportunity for paleontological research. “The tropics are a horrible place to find fossils because they are completely overgrown,” Bloch explains. To collect fossils, researchers need dry areas with exposed rock—requirements nearly impossible to satisfy in a region covered by dense jungles. Scientists are especially interested in obtaining information about the first 10 million years following the demise of the dinosaurs. “In the tropics we know nothing about that 10 million years,” says Bloch. The opening in the jungle created by the coal mine has created a window into that time period and the creatures that lived then.

Bloch suggests that Titanoboa was similar to modern day green anacondas, giant-sized boas that live in the swamps and rivers of the Amazon and Orionoco basins in South America. At 30 feet and 550 pounds, the green anaconda is the largest species of snake alive today. Without venom, these snakes incapacitate their prey by squeezing them to death and then swallowing them hole. Their strength and size enables them to take down formidable prey including wild pigs, capybara and jaguars. Researchers speculate that Titanoboa sustained a similar diet and may have fed on the giant turtles and crocodiles whose skeletons were also found in Cerrejón.

Titanoboa’s size gives clues to what the climate was like millions of years ago. “We’re looking at a land of giants here where it was much wetter and much warmer than today,” Bloch says. Because snakes and other cold-blooded animals rely on ambient temperature for their growth and survival, warmer temperatures result in larger snakes. A sampling of modern-day snakes shows that the largest snakes live in the warmest equatorial regions of the world. Based on the snake’s size Bloch and his team calculated that the mean annual temperature to support a snake that large would have to be about 91 degrees Fahrenheit—about 10 degrees warmer than today’s average temperature.

For Bloch and other researchers, Titanoboa and its giant companions provide a glimpse into a time period that has puzzled the scientific world. They can begin to answer questions about what happened in the tropics once the dinosaurs went extinct and what predators took their place. “We’re seeing the very beginning of the modern Amazonian rainforest that diversified and evolved into an incredible hot spot of bio diversity once the dinos went extinct.” Bloch says. “We’re seeing things we have never seen before.”

Published in Americas magazine by Chris Hardman

 

March of the Desert Penguins

| ChrisHardmanWriter

THE LIFE OF THE arctic penguin has been well represented in films and documentaries in recent years as 4-foot tall emperor penguins have marched across our movie screens. Now new research shows that the ancestors of these modern-day giants, were larger, sturdier and lived in the deserts of Peru during one of the warmest periods on Earth—some 36 to 42 million years ago. A team of scientists from the U.S., Peru, and Argentina has found two new species of penguins that are challenging accepted theories of penguin evolution and migration.

Peruvian paleontologist Mario Urbina-Schmitt of the Museo de Historia Natural de San Marcos in Lima, who has logged more than 20 years of fieldwork in Peru, helped to locate the fossils. Unexplored areas can lead to exciting discoveries like the new species of giant penguin named Icadyptes salasi, the third largest penguin known to science. With a beak that measures more than two times the length of its skull, Icadyptes had the longest beak of any penguin in the world. A true giant, this magnificent bird stood about 5 feet tall, was sturdy in constitution and waddled about the deserts of Peru about 36 million years ago. The researchers also found a second, much older fossil from a 42-million-year-old deposit. The earlier penguin, Perudyptes devriesi, was three feet tall, which is comparable in size to today’s second largest living penguin, the King Penguin.

Excavations in Peru also produced the first complete sample of a giant penguin skull. “We really only had ideas about what the skulls of these animals looked like,” says North Carolina State University Assistant Professor Julia Clarke, one of the lead scientists who analyzed the remains. “[The skull] is quite different from any living penguin,” she explains. With an actual skull to examine, scientists can more accurately determine what some of the earliest penguins looked like. Although both of the new species had longer and more pointed beaks than today’s birds, the giant penguin had a super-sized beak that is longer than any beak found in any living or extinct penguin. The super-sized beak had a sharp, spear-like point at the end that scientists suggest was used as a weapon to catch fish. To support this massive beak, the penguin’s neck was thick and muscular.

The age of these new fossils pushes back the date of penguin migration from southern latitudes to low latitudes millions of years earlier than previous data had indicated.  Scientists have long believed that penguins migrated to northern South America during a cold era, between four and eight million years ago, but these new fossils hail from a warm period more than 30 million years earlier. Penguin researchers were quite surprised to find penguins living in the tropics during a time period when the earth was even warmer than it is today. “We tend to think of penguins as being cold-adapted species, even the small penguins in equatorial regions today,” says Clarke, “but the new fossils date back to one of the warmest periods in the last 65 million years of Earth’s history. The evidence indicates that penguins reached low latitude regions more than 30 million years prior to our previous estimates.”

Clarke warns that although penguins might have started out living in warm climates, today’s penguins are cold adapted and sensitive to climate change. “These Peruvian species are early branches off the penguin family tree, that are comparatively distant cousins of living penguins,” she explains. “The data from these new fossil species cannot be used to argue that warming wouldn’t negatively impact living penguins.”

Published in Americas magazine by Chris Hardman