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 GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>