Featured Research

from universities, journals, and other organizations

Chicken-hearted Tyrants: Predatory Dinosaurs As Baby Killers

Date:
August 7, 2009
Source:
Ludwig-Maximilians-Universität München
Summary:
Tyrannosaurus rex and other predatory dinosaurs might not have been fearless hunters after all. Using new fossil evidence, researchers in Germany propose that the large carnivores hunted mainly juvenile dinosaurs instead of giant herbivorous adults.

Fossil evidence suggests that the large carnivores hunted mainly juvenile dinosaurs instead of giant herbivorous adults.
Credit: iStockphoto/David Coder

Two titans fighting a bloody battle – one that often turns fatal for both of them. This is how big predatory dinosaurs like Tyrannosaurus are often depicted while hunting down their supposed prey, even larger herbivorous dinosaurs. The fossils, though, do not account for that kind of hunting behavior but indicate that theropods, the large predatory dinosaurs, were hunting much smaller prey.

Dr. Oliver Rauhut, paleontologist at Ludwig-Maximilians-Universität (LMU) in Munich, and his collegue Dr. David Hone surmise that giant carnivores like Tyrannosaurus preyed mainly on juvenile dinosaurs. "Unlike their adult and well-armed relatives these young animals hardly posed any risk to the predators," says Rauhut. "And their tender bones would have added important minerals to a theropod's diet. Now we hope for more fossils to be found that add new evidence to our hypothesis."

King of tyrants, Tyrannosaurus rex is by far the most famous dinosaur. Not even recent finds of slightly bigger – and maybe even more terrifying – species like Giganotosaurus could dent the aura of "T-Rex". But what would happen if the king turned out a baby killer instead of fearless hunter of much bigger prey? "Animals such as Tyrannosaurus are often seen as the perfect 'killing machines' with extremely powerful bites, which were able to bring down even the largest possible prey," says Rauhut of the Bayerische Staatssammlung für Paläontologie und Geologie and LMU Munich. "But the very few fossils that reflect the hunt of predatory dinosaurs on large herbivores tell a tale of failure – the prey either got away, or both prey and predator were killed."

On the other hand, the also extremely sparse cases of direct evidence for the diet of predatory dinosaurs – stomach contents and coprolites – show that juveniles or much smaller prey species were ingested and the latter were swallowed whole. Rauhut and Hone, who is now at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, therefore propose as a hypothesis that large predatory dinosaurs only as an exception attacked other large dinosaurs, but mainly fed on juveniles. "Even modern predators prefer old and sick animals or unexperienced young individuals," states Hone. "These are an easy prey to bring down and the risk of injury for the predator is much lower. This strategy was probably the same in dinosaurs."

Another look at recent predators reveals an additional benefit of young prey: Crocodiles, the closest living relatives of dinosaurs, have extremely strong acids in their stomachs. They can completely dissolve the poorly ossified bones of young animals which adds important nutrients to the reptiles' diet. The fossil finds of juvenile dinosaurs that have been swallowed whole by theropods support the idea that dinosaurs might have profited from this as well.

Missing fossils, though, lend even more plausibility: "Finds of dinosaur nesting sites indicate that they contained large numbers of eggs which should have resulted in a high number of offspring," says Rauhut. "But little of this is reflected in the fossil record: Juvenile dinosaurs are surprisingly rare – maybe because many of them have been eaten by predators. Hopefully there will soon be more evidence to help us really understand the theropods' hunting behavior."


Story Source:

The above story is based on materials provided by Ludwig-Maximilians-Universität München. Note: Materials may be edited for content and length.


Journal Reference:

  1. David W. E. Hone and Oliver W. M. Rauhut. Feeding behaviour and bone utilization by theropod dinosaurs. Lethaia, 2009; DOI: 10.1111/j.1502-3931.2009.00187.x

Cite This Page:

Ludwig-Maximilians-Universität München. "Chicken-hearted Tyrants: Predatory Dinosaurs As Baby Killers." ScienceDaily. ScienceDaily, 7 August 2009. <www.sciencedaily.com/releases/2009/08/090806112357.htm>.
Ludwig-Maximilians-Universität München. (2009, August 7). Chicken-hearted Tyrants: Predatory Dinosaurs As Baby Killers. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2009/08/090806112357.htm
Ludwig-Maximilians-Universität München. "Chicken-hearted Tyrants: Predatory Dinosaurs As Baby Killers." ScienceDaily. www.sciencedaily.com/releases/2009/08/090806112357.htm (accessed September 19, 2014).

Share This



More Fossils & Ruins News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Egypt Denies Claims Oldest Pyramid Damaged in Restoration

Egypt Denies Claims Oldest Pyramid Damaged in Restoration

AFP (Sep. 17, 2014) — Egypt's antiquities minister denied Tuesday claims that the Djoser pyramid, the country's first, had been damaged during restoration work by a company accused of being unqualified to do such work. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
King Richard III's Painful Cause Of Death Revealed

King Richard III's Painful Cause Of Death Revealed

Newsy (Sep. 17, 2014) — King Richard III died in the Battle of Bosworth in 1485, and now researchers examining his skull think they know how. Video provided by Newsy
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) — Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Museum Traces Fragments of Star-Spangled Banner

Museum Traces Fragments of Star-Spangled Banner

AP (Sep. 12, 2014) — As the Star-Spangled Banner celebrates its bicentennial, Smithsonian curators are still uncovering fragments of the original flag that inspired Francis Scott Key's poem. (Sept. 12) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins