Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dinosaur fossil record compiled, analyzed

10.02.2004


500 or more dinosaurs possible yet to be discovered


Julia Heathcote, graduate student in earth and planetary sciences in Arts & Sciences, holds a dinosaur model in a McDonnell building laboratory. Heathcote has done an inventory of the complete dinosaur fossil record to determine the quality and congruence of the record. She calls the record, known as the Dinosauria, "moderately good," and says her results indicate that there might be 500 or more dinosaurs yet to be discovered.
David Kilper/WUSTL Photo



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.

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 fit 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."

Tony Fitzpatrick | WUSTL

More articles from Earth Sciences:

nachricht A promising target in the quest for a 1-million-year-old Antarctic ice core
24.05.2018 | University of Washington

nachricht Tropical Peat Swamps: Restoration of Endangered Carbon Reservoirs
24.05.2018 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>