by David Braun
“It is an amazing achievement to have recovered this fossil from an eroding cliff over such a long period of time and without losing any important pieces,” Richard Edmonds, earth science manager for the Jurassic Coast Team, said in a statement. The team is a group of county officials who work to preserve the heritage area.
Arctic Sea Monster
Found in Norway in 2008, one fossilized skull belonged to a 50-foot-long pliosaur that was longer than a humpback whale and had teeth the size of cucumbers.
The Dorset County Council’s museums service purchased the fossil, and later research by University of Southampton scientists suggests that it’s the largest complete pliosaur skull ever found.
Yet Hans-Dieter Sues, a paleontologist at the National Museum of Natural History in Washington, D.C., cautioned in an email that it’s too early to say if the skull is indeed the largest. “Some pliosaurs are gigantic animals, and there is an unfortunate tendency to brand every new find as the largest,” said Sues. “However, no evidence is ever presented to support these claims, which make for good media coverage but are scientifically unwarranted.”
A Different Species?
Pliosaurs were successful predators and evolved features to aid in capturing prey. Some pliosaur species developed supersize eyes, fearsome teeth, or extremely long necks. As for the Dorset specimen, further research—including CT scans—may show whether the 52-foot-long (16-meter-long) beast is a new species. Yet Sues noted that “the classification of late Jurassic pliosaurs is still a mess, and, in absence of a reliable, published, modern review of all European specimens, it is hard to sustain any claim of a new species.”
SUPER-SIZE SNAKE
Biggest Snake Discovered
Was Longer Than a Bus
Steamy year-round temperatures may have created the perfect environment for the world’s biggest snakes. Could climate change bring their kind back?
The world’s biggest snake was a massive anaconda-like beast that slithered through steamy tropical rain forests about 60 million years ago, says a new study that describes the ancient giant.
TRUTH:
THE TITANOBOA CERREJONENSIS WAS LONGER THAN A CITY BUS AND HEAVIER THAN A CAR.
How Big Was He?
Fossils found in northeastern Colombia’s Cerrejon coal mine indicate the reptile, dubbed Titanoboa cerrejonesis, was at least 42 feet (13 meters) long and weighed 2,500 pounds (1,135 kilograms).
“That’s longer than a city bus and … heavier than a car,” said lead study author Jason Head, a fossil-snake expert at the University of Toronto, Mississauga in Canada and a research associate with the Smithsonian Institution. Previously the biggest snake known was Gigantophis garstini, which was 36 to 38 feet (11 to 11.6 meters) long. That snake lived in North Africa about 40 million years ago.
The world’s biggest snake lounges in the tropics in this illustration. (Photo Credit 10.3)
Hans-Dieter Sues, associate director for research and collections at the Smithsonian’s National Museum of Natural History, was not involved with the study but has seen the snake fossils. Sues noted that humans would stand no chance against one of these giants, which killed their prey by slow suffocation.
“Given the sheer size—the sheer cross-section of that snake—it would be probably like one of those devices they use to crush old cars in a junkyard,” Sues said.
Biggest Snake Needed the Heat
In addition, the snake’s heft indicates that it lived when the tropics were much warmer than they are today, a find that holds potential implications for theories of once and future climate change.
Scientists know there’s a link between a snake’s body size, how fast it uses and produces energy, and climate. “We were able to use the snake, if you will, as a giant fossil thermometer,” study author Head said.
His team found that, for Titanoboa to reach its epic proportions, it would mean year-round temperatures would have been about 90 degrees Fahrenheit (32 degrees Celsius)—significantly hotter than today’s tropics.
This supports the idea that tropical temperatures spike as the rest of the world heats up due to global warming, the study authors say. The competing theory is that, during bouts of warming, the tropics stay about the same average temperature as they are today while areas north and south of the Equator heat up.
James Zachos, an expert on ancient climates at the University of California, Santa Cruz, who was not involved in the study, agreed. As the biggest known snake, Titanoboa supports the idea of “much hotter tropics during extreme greenhouse periods,” Zachos said.
The Return of the Giant Snakes?
Study co-author Jonathan Bloch is a vertebrate paleontologist at the University of Florida’s Museum of Natural History in Gainesville. The same Colombian coal mine that contained the biggest snake also yielded massive turtles and crocodiles, he said.
“You can think about it as an ecosystem dominated by giants, I think, and these are probably giants that got large because of the warmer mean annual temperature,” he said.
The findings paint a picture of what the future might hold if supercharged global warming takes place. According to some models, global temperatures could approach the same levels that gave rise to the biggest snake by the end of this century.
Opposite End of the Spectrum
The world’s smallest snake, the Leptotyphlops carlae, is less than four inches long and was discovered in 2008 on the Caribbean island of Barbados. Due to its tiny size, it can easily be mistaken for an earthworm. L. carlae is a new species of snake that belongs to a group called thread snakes, and it may be on the verge of extinction.
If current greenhouse gas emissions continue apace, there’s a chance snakes the size of Titanoboa could return, Bloch said. “Or maybe snakes would go extinct in the tropics,” he said. “In other words, the warming could happen so rapidly that they wouldn’t have time to adapt.”
ANCIENT SPONGE
Oldest Animal Discovered
Aquatic African Ancestor
Mirror, mirror on the wall. Who is the earliest ancestor of us all? The answer might surprise you.
Microscopic, spongelike African fossils could be the earliest known animals—and possibly our earliest evolutionary ancestors, scientists say. The creature, Otavia antiqua, was found in 760-million-year-old rock in Namibia and was as tiny as it may be important.
TRUTH:
THERE ARE 9,000 SPECIES OF SPONGES, AND THEY OCCUPY VIRTUALLY EVERY AQUATIC HABITAT ON EARTH.
Starting Small
“The fossils are small, about the size of a grain of sand, and we have found many hundreds of them,” said study leader Anthony Prave, a geologist at the University of St. Andrews in the United Kingdom. “In fact, when we look at thin sections of the rocks, certain samples would likely yield thousands of specimens. Thus, it is possible that the organisms were very abundant.”
From these tiny “sponges” sprang very big things, the authors suggest. As possibly the first multicellular animals, Otavia could well be the forerunner of dinosaurs, humans—basically everything we think of as “animal.”
A modern-day stove-pipe sponge (Photo Credit 10.4)
Built to Last
Prior to the new discovery, the previous earliest known “metazoan”—animals with cells differentiated into tissues and organs—was another primitive sponge, dated to about 650 million years ago.
Based on where the new fossils were found, Prave and his colleagues think Otavia lived in calm waters, including lagoons and other shallow environments. The team thinks Otavia fed on algae and bacteria, which the animal drew through pores on its tubelike body into a central space. There the food was digested and absorbed directly into Otavia’s cells. The simple setup seems to have worked.
The fossil record indicates Otavia survived at least two long-term, severe cold snaps known as “snowball Earth” events, when the planet was almost completely covered in ice. Despite such wild environmental swings, “the oldest and youngest Otavia fossils al
l have the same quasi-ovid form, with large openings leading from the exterior,” Prave said in an email.
In short, the animals didn’t evolve much, he said—suggesting that, at least for its roughly 200 million years of existence, Otavia was built to last.
SAVAGE SQUIRREL
Ancient “Saber-Toothed Squirrel” Found
Fossils of ancient mammals are very rare—mostly because of their small size. But this latest find, a squirrel with very sharp teeth, gives paleontologists new insight into an ancient world.
The fossilized skull and teeth of a fanged, shrewlike mammal have been found in Argentina, a new study says. The new species—dubbed Cronopio dentiacutus for its narrow snout and long fangs—was about 8 to 9 inches (20 to 23 centimeters) long and likely used its pointy teeth to hunt and eat insects.
The Little Guys
C. dentiacutus was very small, like most mammals at the time. “These were the tiny little guys that would squirrel in between the toes of the dinosaurs trying not to get stepped on,” says Guillermo Rougier, a paleobiologist who specializes in these animals. Mammals didn’t grow to be the size of cats and dogs until after the larger dinosaurs became extinct.
Big Teeth
The second oldest mammal skull ever recovered from South America, C. dentiacutus existed when dinosaurs still roamed Earth. Paleontologists found the mostly complete skull in 2002 outside a rural village in northern Argentina. At the time, however, the skull was mostly hidden in rock, and its identity remained a mystery.
This is an artist’s rendition of what the saber-toothed squirrel might have looked like. (Photo Credit 10.5)
So in 2005 the scientists sent the skull to a technician, who spent three years removing the rock from around the fossil—finally revealing a saber-toothed, squirrel-like creature.
“When [the movie] Ice Age came out, we thought the squirrel character in it looked ridiculous, but then we found something like it,” said study leader Guillermo Rougier, a paleontologist at the University of Louisville in Kentucky. “This animal looks very peculiar, with long snout and canines, and it highlights that we know so little. Surprises like this are bound to happen.”
Rare Remains
Both mammals and dinosaurs appeared near the end of the Triassic period, some 220 million years ago. When dinosaurs disappeared about 65 million years ago, mammals thrived. But ancient-mammal fossils are still exceedingly rare, mostly because of their small sizes.
“Getting on your hands and knees … is how you find small-mammal fossils,” Rougier said. “It is not very glamorous. You basically roll in the dirt all day.” As a result, paleontologists know of roughly one genus of mammal for every million years between 65 million and 220 million years ago—making for a woefully incomplete record. “Imagine trying to reconstruct the history of life with that information,” Rougier said. “We’re certain there were hundreds of [genuses], but for now it’s like trying to reconstruct the brilliance of James Joyce with just ten of his words.”
ARMED AND DANGEROUS
Prehistoric Bird Had Wings Like Nunchucks
Don’t make these ancient flightless birds angry. You wouldn’t like them when they’re angry.
A flightless bird with wings like martial arts weapons once thrashed its foes on what’s now Jamaica, a new study says.
Dubbed Xenicibis, the prehistoric bird wielded its unusual wings like nunchucks, or nunchakus, swinging its upper arms so that thick, curved hand bones hinged at the wrist would deliver punishing blows. The weaponlike wings are so unique that study co-author Nicholas Longrich of Yale University at first assumed the odd limbs were evidence of a deformity.
“There are a lot of birds that do have weaponry,” Longrich said. “They just don’t have anything like this.”
“No animal has ever evolved anything quite like this. We don’t know of any other species that uses its body like a flail. It’s the most specialized weaponry of any bird I’ve ever seen.”
Nicholas Longrich
research leader, Yale University
Wings That Bear Arms
Xenicibis is an extinct member of the ibis family that grew to be the size of a large chicken. Although the ancient animal had been known for years, new analysis of several recently discovered partial skeletons has only now revealed the odd wing bones.
Wings are among the most powerful parts of birds, and some modern species boast specialized wing weapons. Screamer birds, for instance, use daggerlike spurs to fight for mates, while steamer ducks have wrist knobs that can break bones or even kill other birds. Since Xenicibis was flightless, Longrich and colleagues think the ancient bird evolved to have wings that were even more specialized for combat.
Weapon Wings
Examinations of the skeletons uncovered evidence of past violence—one wing had a fractured hand bone, and another had a centimeter-thick upper-arm bone that had been cleanly snapped in half. The bird’s living ibis relatives are anatomically similar except for the “weapon wings,” so modern ibis behavior may shed light on when and how Xenicibis used its built-in arsenal. Male ibis, for example, regularly battle each other over territories for nesting and feeding.
But Xenicibis may also have needed its powerful wings to fight off other threats. “Most flightless birds, like the dodo, had absolutely no predators around. But Jamaica had many snakes, raptors, and other potential predators,” Longrich said. “So maybe they just needed a bit more defense.”
Boxing Birds
The prehistoric Phorusrhacid, also known as the terror bird, had a hatchet-like skull that was used to kill prey with a succession of punishing blows. The skull was the size of a modern-day horse’s head, and was very strong and rigid when driven straight down into prey. Like the Xenicibis, the terror bird was also flightless, so it most likely evolved to have such a skull in order to survive on land.
Nunchucks for Dinner?
Longrich and colleagues are most curious about the ultimate fate of the prehistoric birds. Fossils indicate Xenicibis lived at least as recently as 12,000 years ago. But the record is too sparse at this point to know exactly when they vanished—or if ancient humans might have been involved.
“Did they disappear long before people arrived in Jamaica [several thousand years ago] or last long enough for people to wipe them out?” Longrich said. “They were a convenient size for a family dinner and couldn’t fly. Humans are pretty handy with clubs also, so it might not have been a very fair fight. But at this point we just don’t know.”
SAUROPOD SELF-DEFENSE
“Thunder Thighs” Dinosaur
Thrashed Predators to Death?
Ill-tempered dinosaur used her massive muscular legs to kick away fearsome raptors, expert says.
A newfound dinosaur species that used its “exceptionally powerful” thighs to kick predators likely had a bad temper to boot, one expert says.
The 46-foot-long (14-meter-long) Brontomerus mcintoshi had an immense blade on its hipbones, where strong muscles would have attached, according to a new study. “These things don’t happen by accident—this is something that’s clearly functional,” said study co-author Mathew Wedel.
Thunder Thighs Attack
The team suspects the dinosaur—a type of sauropod, or plant-eating, four-legged lumberer—used its massive legs to either maneuver over hilly ground or deliver “good, hard” kicks to predators, said Wedel, assistant professor of anatomy at Western University of Health Sciences in Pomona, California.
Brontomerus—“thunder thighs” in Greek—may have even attacked like a modern-day chicken, relentlessly kicking and stomping pursuers to death, he added. “I could only imagine how ill-tempered these sauropods would have been,” Wedel said—as are most birds, dinosaurs’ modern-day descendants.
TRUTH:
THE LARGEST DINOSAURS WERE VEGETARIANS.
A “thunder thighs” dinosaur mother protects her offspring in an artist’s conception. (Photo Credit 10.6)
In both cases, “you’ve got a little
brain, you’re permanently paranoid about all these meat-eaters around, and you’re trying to protect your young.”
Big Leg Muscles
Thunder thighs’ bones were first found in 1994, when scientists rescued two partial skeletons of the then unidentified dinosaur from a fossil quarry that had otherwise been looted in eastern Utah.
When Wedel and colleagues examined the bones in 2007, they realized they’d found a new species—and an “extreme” one at that, Wedel said. For instance, the shapes of the newfound species’ bones showed it had the largest leg muscles of any sauropod yet found.
B. mcintoshi likely needed such extreme defenses to fight off “terrifying” predators such as Deinonychus and Utahraptor, raptors that lived alongside the plant-eater about 110 million years ago in the early Cretaceous period, he said.
Sauropod Safari
The prehistoric animals roamed a landscape that would have resembled Africa’s Serengeti, laced with rivers and mud holes and distinguished by vast, dry upland areas, Wedel noted. Herds of cowlike plant-eaters called Tenontosaurus would have dotted the plains.
