Featured Research

from universities, journals, and other organizations

Dinosaur Fossil Record Compiled, Analyzed; 500 Or More Dinosaurs Possible Yet To Be Discovered

Date:
February 10, 2004
Source:
Washington University In St. Louis
Summary:
A graduate student in earth and planetary sciences in Arts and Sciences at Washington University in St. Louis has combed the dinosaur fossil record from T Rex to songbirds and has compiled the first quantitative analysis of the quality and congruence of that record.

A graduate student in earth and planetary sciences in Arts & Sciences at Washington University in St. Louis has combed the dinosaur fossil record from T Rex to songbirds and has compiled the first quantitative analysis of the quality and congruence of that record.

Related Articles


Julia Heathcote, whose advisor is Josh Smith, Ph.D., Washington University assistant professor of earth and planetary sciences, examined data of more than 250 dinosaur genera, or classes, as well as various clades, or family tree branches, of dinosaur classes.

Heathcote found that existing data is between one-half and two-thirds complete, or of high quality, for dinosaur data. As template, she used two published whole dinosaur studies and compared them with smaller family trees within the context of the whole dinosaur data, commonly known as the Dinosauria. She also analyzed for congruence – the correlation between the fossil record and family tree relationships. Heathcote found some of the clades both complete and congruent, while others are poor in both ways.

"The whole Dinosauria fossil record I would say is moderately good, which was a surprise, because I thought it would be much worse," Heathcote said. "It generally shows a low degree of completeness but a high degree of congruence with the existing phylogenies, or family trees, studied."

Her results are important for paleontologists who are especially focused on the evolution of dinosaurs. It is to the paleontologist what Beckett's Baseball Card Price guide is to the baseball card collector, and more -– Heathcote's analysis provides information on the relationships between classes and groups, whereas the Beckett guide draws no lineages for players, for instance.

Heathcote said that there have been many attempts to analyze evolutionary patterns using the fossil record, but that the patterns can only be interpreted usefully in the context of stratigraphy -- essentially how old the fossils are. It's important to know the quality of the fossil record to better assess whether an apparently large number of genera at any one time – say, the late Jurassic period – is due to genuine species diversity or just exceptionally good preservation. Congruence matters, too, to provide information on the adequacy of data and confidence to construct evolutionary relationships.

Heathcote presented her results at the annual meeting of the Geological Society of America, held Nov. 2-5, 2003, in Seattle.

Heathcote used three different calculations to achieve her results: the Stratigraphic Consistency Index, the Relative Completeness Index and the Gap Excess Ratio. The first is a measure of how well the relationships that have been proposed for dinosaurs fits in with the stratigraphic data, which contributes to a timeline for evolution. The Relative Completeness index measures the percentage of how much missing data there might be to how much researchers actually have. And the Gap Excess Ratio measures how much missing data there actually is to the minimum missing data possible if the genera were arranged in the family tree in order of age.

Heathcote said that the known number of dinosaurs now stands at slightly more than 250. But because her results give a maximum possible completeness value, there might be 500 or more yet to be discovered, and she hopes that with each discovery, the researchers will enter their data into her program so that all paleontologists can benefit by seeing how the new discovery relates to previous ones.

She called the work "a new tool that draws together all of the data of the past 150 years, all plotted out accurately for the first time. You can see how far back these dinosaurs go, see their relationships with each other."


Story Source:

The above story is based on materials provided by Washington University In St. Louis. Note: Materials may be edited for content and length.


Cite This Page:

Washington University In St. Louis. "Dinosaur Fossil Record Compiled, Analyzed; 500 Or More Dinosaurs Possible Yet To Be Discovered." ScienceDaily. ScienceDaily, 10 February 2004. <www.sciencedaily.com/releases/2004/02/040210074742.htm>.
Washington University In St. Louis. (2004, February 10). Dinosaur Fossil Record Compiled, Analyzed; 500 Or More Dinosaurs Possible Yet To Be Discovered. ScienceDaily. Retrieved March 2, 2015 from www.sciencedaily.com/releases/2004/02/040210074742.htm
Washington University In St. Louis. "Dinosaur Fossil Record Compiled, Analyzed; 500 Or More Dinosaurs Possible Yet To Be Discovered." ScienceDaily. www.sciencedaily.com/releases/2004/02/040210074742.htm (accessed March 2, 2015).

Share This


More From ScienceDaily



More Fossils & Ruins News

Monday, March 2, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gerbils, Not Rats, Might Be To Blame For The Black Death

Gerbils, Not Rats, Might Be To Blame For The Black Death

Newsy (Feb. 24, 2015) The "black death" that killed tens of millions of people has been blamed on rats for years, but now researchers say they may have gotten a bad rap. Video provided by Newsy
Powered by NewsLook.com
Timbuktu Manuscripts Face an Uncertain Future

Timbuktu Manuscripts Face an Uncertain Future

AFP (Feb. 23, 2015) Two years ago a large number of manuscripts were taken from Timbuktu for safe keeping. Now the question is whether to return them. Duration: 02:50 Video provided by AFP
Powered by NewsLook.com
How Did A Mummy End Up In A 1,000-Year-Old Buddha Statue?

How Did A Mummy End Up In A 1,000-Year-Old Buddha Statue?

Newsy (Feb. 23, 2015) A CT scan has revealed a mummified Chinese monk inside a Buddha statue. The remains date back about 1,000 years. Video provided by Newsy
Powered by NewsLook.com
Rare First Folio Arrives at Shakespeare's Globe Theatre

Rare First Folio Arrives at Shakespeare's Globe Theatre

Reuters - Light News Video Online (Feb. 23, 2015) A rare First Folio discovered in a French library arrives at the Shakespeare&apos;s Globe Theatre in London, where the Bard&apos;s plays were first performed. 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