 |
|
Duck-billed dinosaurs outgrew predators to survive
August 06, 2008With long limbs and a soft body, the duck-billed hadrosaur had few defenses against predators such as tyrannosaurs. But new research on the bones of this plant-eating dinosaur suggests that it had at least one advantage: It grew to adulthood much faster than its predators, giving it superiority in size.
In a study published online today in the Proceedings of the Royal Society of London B: Biological Sciences, scientists compared growth rate data from the hadrosaur, Hypacrosaurus, to three predators: the tyrannosaurs Albertosaurus and its gigantic relative Tyrannosaurus rex, as well as the small Velociraptor-like Troodon.
The research suggests that it took 10 to 12 years for Hypacrosaurus to become fully grown. Tyrannosaurs, however, reached adulthood after 20 to 30 years, said Drew Lee, a postdoctoral fellow in Ohio University's College of Osteopathic Medicine who co-authored the paper with Lisa Noelle Cooper, a doctoral student at Kent State University and a researcher with the Northeastern Ohio Universities College of Medicine.
"Our duck-billed dinosaur grew three to five times faster than any potential predators that lived alongside it," Lee said. "By the time the duck-billed dinosaur was fully grown, the tyrannosaurs were only half grown - it was a huge size difference."
Hypacrosaurus also reached sexual maturity early, at only two or three years of age, Cooper said.
"That's another added bonus when facing predators - if you can keep reproducing, you're set," she said. "It's the stuff of evolution."
Cooper conducted the original analysis of the hadrosaur while an undergraduate student at Montana State University. Working with scientists Jack Horner and Mark Taper, Cooper looked at thin sections of the long leg bones of a specimen of Hypacrosaurus and counted and measured the growth rings, which each represent one year of life.
"We were shocked at how fast they grew. If you look at a cross section of the bone of a nestling or even from within the egg, there are huge spaces in which blood supply was going through the bone, which means they were growing like crazy," she said.
Hypacrosaurus was one of three common prey for the meat-eating tyrannosaurs, but was the most vulnerable, Lee said. He described the animal, which lived 67 million to 80 million years ago, as the "Thomson's gazelle of the Late Cretaceous." The other two had horns or had stout, tank-like bodies that would have provided some physical protection from their enemies. But even those creatures show faster growth rates than the predators, Lee noted, with the hadrosaur boasting the quickest growth spurt.
At least one study suggests that living animals employ this survival strategy as well, Lee said. Scientists have found that killifish, a tiny freshwater fish found mainly in the Americas, mature faster when predators lurk. Anecdotal evidence suggests that creatures such as African ungulates grow big to create an advantage over lions, cheetahs and hyenas, he said. And researchers also see signs of this phenomenon in butterflies, toads, salamanders, guppies and some birds, Cooper added.
"Over evolutionary history, this pattern seems to be prevalent," she said.
Though scientists are careful to preserve dinosaur fossils, they've also learned much more about growth rates, life spans, behavior and sexual reproduction of dinosaurs in the past decade by cutting up the bones and taking a closer look at the clues they contain, Lee and Cooper noted. Such research has offered a much more detailed picture of the relationships between different dinosaur species, including predator and prey. Cooper also has used the same bone analysis techniques to confirm the ancestor of whales, a study she co-authored last year in Nature.
Lee, who recently published a study in the Proceedings of the National Academy of Sciences on the sexual maturity rates of dinosaurs, hopes to conduct more research on communities of dinosaurs, such as those of Allosaurus, Stegosaurus and Apatosaurus, to draw further conclusions on the fast growth survival strategy.
"This study is a stepping stone to a larger comparative study on community changes that impacted dinosaur evolution," Lee said.
Ohio University
"Our duck-billed dinosaur grew three to five times faster than any potential predators that lived alongside it," Lee said. "By the time the duck-billed dinosaur was fully grown, the tyrannosaurs were only half grown - it was a huge size difference."
Hypacrosaurus also reached sexual maturity early, at only two or three years of age, Cooper said.
"That's another added bonus when facing predators - if you can keep reproducing, you're set," she said. "It's the stuff of evolution."
Cooper conducted the original analysis of the hadrosaur while an undergraduate student at Montana State University. Working with scientists Jack Horner and Mark Taper, Cooper looked at thin sections of the long leg bones of a specimen of Hypacrosaurus and counted and measured the growth rings, which each represent one year of life.
"We were shocked at how fast they grew. If you look at a cross section of the bone of a nestling or even from within the egg, there are huge spaces in which blood supply was going through the bone, which means they were growing like crazy," she said.
Hypacrosaurus was one of three common prey for the meat-eating tyrannosaurs, but was the most vulnerable, Lee said. He described the animal, which lived 67 million to 80 million years ago, as the "Thomson's gazelle of the Late Cretaceous." The other two had horns or had stout, tank-like bodies that would have provided some physical protection from their enemies. But even those creatures show faster growth rates than the predators, Lee noted, with the hadrosaur boasting the quickest growth spurt.
At least one study suggests that living animals employ this survival strategy as well, Lee said. Scientists have found that killifish, a tiny freshwater fish found mainly in the Americas, mature faster when predators lurk. Anecdotal evidence suggests that creatures such as African ungulates grow big to create an advantage over lions, cheetahs and hyenas, he said. And researchers also see signs of this phenomenon in butterflies, toads, salamanders, guppies and some birds, Cooper added.
"Over evolutionary history, this pattern seems to be prevalent," she said.
Though scientists are careful to preserve dinosaur fossils, they've also learned much more about growth rates, life spans, behavior and sexual reproduction of dinosaurs in the past decade by cutting up the bones and taking a closer look at the clues they contain, Lee and Cooper noted. Such research has offered a much more detailed picture of the relationships between different dinosaur species, including predator and prey. Cooper also has used the same bone analysis techniques to confirm the ancestor of whales, a study she co-authored last year in Nature.
Lee, who recently published a study in the Proceedings of the National Academy of Sciences on the sexual maturity rates of dinosaurs, hopes to conduct more research on communities of dinosaurs, such as those of Allosaurus, Stegosaurus and Apatosaurus, to draw further conclusions on the fast growth survival strategy.
"This study is a stepping stone to a larger comparative study on community changes that impacted dinosaur evolution," Lee said.
Ohio University
Predators Current Events and Predators News RSSRed-eyed treefrog embryos actively avoid asphyxiation inside their eggs
Boston University undergraduate Jessica Rogge and associate professor Karen Warkentin, working at the Smithsonian Tropical Research Institute's laboratories in Gamboa, Panama, discovered that frog embryos at a very early developmental stage actively respond to oxygen levels in the egg-as reported in the Nov. 7, 2008 issue of the Journal of Experimental Biology.
In mice, anxiety is linked to immune system
In the first study ever to genetically link the immune system to normal behavior, scientists at Rockefeller and Columbia universities show that mast cells, known as the pharmacologic bombshells of the immune system, directly influence how mice respond to stressful situations.
New CU-Boulder study shows diversity decreases chances of parasitic disease
A new University of Colorado at Boulder study showing that American toads who pal around with gray tree frogs reduce their chances of parasitic infections known to cause limb malformations has strong implications for the benefits of biodiversity on emerging wildlife diseases.
Study sheds new light on dolphin coordination during predation
Spinner dolphins have long been known for their teamwork in capturing prey but a new study using high-tech acoustics has found that their synchronization is even more complex than scientists realized and likely evolved as a strategy to maximize their energy intake.
Brain structure provides key to unraveling function of bizarre dinosaur crests
Paleontologists have long debated the function of the strange, bony crests on the heads of the duck-billed dinosaurs known as lambeosaurs. The structures contain incredibly long, convoluted nasal passages that loop up over the tops of their skulls.
'Plant-eating predator to fight superweed is not magic bullet'
Plans to introduce plant-eating predators to fight a superweed spreading throughout Britain should not be seen as a 'magic bullet', says a world expert on Japanese knotweed at the University of Leicester.
Brown Scientist Finds Coastal Dead Zones May Benefit Some Species
Coastal dead zones, an increasing concern to ecologists, the fishing industry and the public, may not be as devoid of life after all. A Brown scientist has found that dead zones do indeed support marine life, and that at least one commercially valuable clam actually benefits from oxygen-depleted waters.
Fitness in a Changing World
The stickleback fish, Gasterosteus aculeatus, is one of the most thoroughly studied organisms in the wild, and has been a particularly useful model for understanding variation in physiology, behavior, life history and morphology caused by different ecological situations in the wild.
Researchers Turning Freshwater Farm Ponds into Crab Farms
Work by researchers at North Carolina State University is leading to a new kind of crab harvest - blue crabs grown and harvested from freshwater ponds, instead of from the sea.
Decline in Alaskan sea otters affects bald eagles' diet
Sea otters are known as a keystone species, filling such an important niche in ocean communities that without them, entire ecosystems can collapse.
More Predators Current Events and Predators News Articles
 | The Predator State: How Conservatives Abandoned the Free Market and Why Liberals Should Too by James Galbraith The cult of the free market has dominated economic policy-talk since the Reagan revolution of nearly thirty years ago. Tax cuts and small government, monetarism, balanced budgets, deregulation, and free trade are the core elements of this dogma, a dogma so successful that even many liberals accept it. But a funny thing happened on the bridge to the twenty-first century. While liberals continue to... |
 | Predators: A Pop-up Book with Revolutionary Technology by Lucio and Meera Santoro Get up close and personal with some of the world's most terrifying and dangerous predators! Amazing 3-D pop-ups swing off the page, bringing to life spiders, polar bears, crocodiles, and more! Filled with interesting facts and vibrant artwork, Predators! takes readers on an interactive and imaginative journey into the wild!This paper-over-board book has innovative, swinging pop-ups. Packaged in a... |
 | The Predators' Ball: The Inside Story of Drexel Burnham and the Rise of the Junk Bond Raiders by Connie Bruck During the '80s, Michael Milken at Drexel Burnham created the corporate raiders. He was the billionaire Junk Bond King. But, in the corner stood the U.S. District Attorney waiting to file criminal and racketeering... |
 | Predator (Kay Scarpetta Mysteries) by Patricia Cornwell The exhilarating new Dr. Kay Scarpetta novel from America's number-one-bestselling crime writer. Unabridged CDs - 11 CDs, 12 1/2... |
 | Predator: South China Sea (Predator) by Jeff VanderMeer On a remote South China Sea island, a deadly hunt is underway... but not the kind of expedition the participants expected. In this remote, jungle-covered island somewhere between Thailand and Indonesia some of the most exotic animals in the world have been gathered as the prizes in a challenge of human against nature. The hunters come from all walks of life. Each has come to the island for... |
 | Predator: Turnabout (Predator) by Steve Perry Deep in the Alaskan forest, ranger Sloan comes across the torn and bloody carcasses of Grizzly bears. Searching a human cause for the massacres, he discovers a team of poachers hunkered within the Alaska wilderness, waiting for the chance to score a big kill. He also finds evidence of the most fearsome killers in the universe: the... |
 | Aliens vs. Predator Omnibus, Vol. 1 by Various Mankind's two ultimate nightmares come together in mortal combat, and whoever wins - we lose. On the remote planet Ryushi, a small ranching community becomes an unwilling participant in a deadly ritual: extraterrestrial Predators have seeded Ryushi with Alien eggs in order to create the ultimate hunt. But what the Predators don't know is that an Alien queen egg is amongst those they've sent as... |
 | Predators: Pedophiles, Rapists, And Other Sex Offenders by Anna Salter What motivates sexual abusers? Why are so few caught? Drawing on the stories of abusers, Anna C. Salter shows that sexual predators use sophisticated deception techniques and rely on misconceptions surrounding them to evade discovery. Arguing that even the most knowledgeable among us can be fooled, Salter dispels the myths about sexual predators and gives us the tools to protect our families and... |
 | Predator Omnibus Volume 4 (Predator Omnibus) by Kevin J. Anderson, Gordon Rennie, James Vance, Others, Scott Kolins, Colin MacNeil, Toby Cypress Across the centuries, humanity's capacity for violence has marked time as surely as the movement of the stars. And from those very stars have come an invisible participant in our history, the extraterrestrial Predator, who has used mankind's own penchant for murder and mayhem as a shadow to cover its own bloody tracks. But the Predator has not passed through the ages unnoticed, and despite the... |
 | Predator Omnibus Volume 1 (Predator) by Mark Verheiden, Dan Barry, Others, Christopher S. Warner, Ron Randall Dark Horse set the comics industry on its ear with its comics expansion of the Predator mythos, a comics series so true to the spirit of the original 20th Century Fox film blockbuster that concepts from the first Predator comics series were incorporated into the Predator screen universe. Now, the three core Dark Horse Predator graphic novels - Concrete Jungle, Cold War and Dark River - and... |
| © 2008 BrightSurf.com |