Featured Research

from universities, journals, and other organizations

Dinosaurs May Have Been Smaller Than Previously Thought

Date:
June 22, 2009
Source:
Wiley - Blackwell
Summary:
The largest animals ever to have walked the face of the earth may not have been as big as previously thought, according to a new article.

Model dinosaur. Scientists have discovered that the original statistical model used to calculate dinosaur mass is flawed, suggesting dinosaurs have been oversized.
Credit: iStockphoto/Klaus Nilkens

The largest animals ever to have walked the face of the earth may not have been as big as previously thought, reveals a paper published June 21 in the Zoological Society of London’s Journal of Zoology.

Scientists have discovered that the original statistical model used to calculate dinosaur mass is flawed, suggesting dinosaurs have been oversized.

Widely cited estimates for the mass of Apatosaurus louisae, one of the largest of the dinosaurs, may be double that of its actual mass (38 tonnes vs. 18 tonnes).

"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs and other extraordinarily large animals in extinct lineages. By re-examining data in the original reference sample, we show that the statistical model is seriously flawed and that the giant dinosaurs probably were only about half as heavy as is generally believed" says Gary Packard from Colorado State University.

"The original equation used by scientists produces fairly accurate results when determining the mass of smaller animals, but when used on larger animals our research shows that many errors have occurred," says Geoffrey Birchard, associate professor of environmental science and policy at George Mason University who was involved with the research. "The new equation shows that dinosaurs are much smaller than we thought, but there is no mistaking that they were indeed huge animals."

Developed in 1985, the results of the original equation have been used by scientists to estimate or evaluate a variety of parameters, including brain size and egg size. The problem occurs as a result of transforming the data, which changes the properties of the original data, and creates biases that can affect the predictive results obtained from the equation.

Birchard and his colleagues realized there was an error when they used the equation to determine the weight of living animals such as a hippopotamus and an elephant and discovered that the equation greatly overestimated the weight of these animals.

The researchers developed a new equation for calculating dinosaur mass based on bone dimensions. This equation doesn't require the transformation of data that the original equation uses.

"The best way to understand the new equation is to think about a building that is built on pillars,"says Birchard. "The bigger the building, the larger the pillars must be to support the weight of the building. In the same way, the legs of an animal are the pillars supporting its body."

According to Birchard, this new research suggests that some dinosaurs were much more slender than had been thought. It also changes many of the factors scientists have already determined about dinosaurs such as the amount of muscle required to use their bodies and how much they ate and breathed.

The new predictions have implications for numerous theories about the biology of dinosaurs, ranging from their energy metabolism to their food requirements and to their modes of locomotion.


Story Source:

The above story is based on materials provided by Wiley - Blackwell. Note: Materials may be edited for content and length.


Journal Reference:

  1. Allometric equations for predicting body mass of dinosaurs. Journal of Zoology, June 21, 2009 DOI: 10.1111/j.1469-7998.2009.00594.x

Cite This Page:

Wiley - Blackwell. "Dinosaurs May Have Been Smaller Than Previously Thought." ScienceDaily. ScienceDaily, 22 June 2009. <www.sciencedaily.com/releases/2009/06/090621195620.htm>.
Wiley - Blackwell. (2009, June 22). Dinosaurs May Have Been Smaller Than Previously Thought. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2009/06/090621195620.htm
Wiley - Blackwell. "Dinosaurs May Have Been Smaller Than Previously Thought." ScienceDaily. www.sciencedaily.com/releases/2009/06/090621195620.htm (accessed October 20, 2014).

Share This



More Fossils & Ruins News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Newsy (Oct. 19, 2014) A 380-million-year-old fish may be the first creature to have copulative sex - and it was side by side with arms linked, like square dancers. Video provided by Newsy
Powered by NewsLook.com
As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

Newsy (Oct. 19, 2014) With Sweden on the look-out for a suspected Russian sub, a lot of people are talking about the Cold War, but is it an apt comparison? Video provided by Newsy
Powered by NewsLook.com
So, Kangaroos Didn't Always Hop

So, Kangaroos Didn't Always Hop

Newsy (Oct. 16, 2014) Researchers believe an extinct kangaroo species weighed 500 pounds or more and couldn't hop. Video provided by Newsy
Powered by NewsLook.com
1000-Year-Old Viking Treasure Hoard Found in Scotland

1000-Year-Old Viking Treasure Hoard Found in Scotland

Reuters - Light News Video Online (Oct. 14, 2014) A hoard of Viking artifacts dating back over 1,000 years is discovered by a treasure hunter with a metal detector in Scotland. Elly Park reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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