Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New research on sauropod gigantism summarized in publicly available collection

14.01.2014
Giants of Earth's history still pose a wealth of riddles / Publication in PLOS ONE

Sauropods, the largest land animals in Earth's history, are still mightily puzzling the scientists. These plant-eating dinosaurs with their long necks and small heads could reach a height of 10 meters or more and dominated all other land vertebrates in terms of size. They could weigh up to 80 tons, more than any other known land vertebrate.


Replica of the reconstructed skeleton of Argentinosaurus huinculensis, on display as part of a special exhibition at the Senckenberg Natural History Museum, Frankfurt am Main. The fossil remains of this titanosaur that lived in the Early Cretaceous period were discovered in Neuquén province, Argentina. Argentinosaurus huinculensis is currently the largest known sauropod with a total length of 38 meters and an estimated total body weight of 75 tons.
photo: Eva Maria Griebeler

One question that has been intensely debated is how these giants of the animal kingdom regulated their own body temperature. Dr. Eva Maria Griebeler of Johannes Gutenberg University Mainz has now shown that the hypothesis is inaccurate that their body size was limited only because the associated rise in body temperature could have resulted in potential overheating.

According to the calculations of the Mainz-based ecologist, the body temperature of these animals did not increase with body weight. Her estimates indicate that sauropods may have had an average body temperature of some 28 degrees Celsius. The upper limit for the body temperature that can be tolerated by vertebrate species living today is 45 degrees Celsius. The body temperatures that Griebeler postulates for the sauropods are thus well below those of today’s endothermic vertebrates but consistent with those of ectothermic monitor lizards. Her calculations of sauropod body temperature take into account the relationship between the maximum rate of growth and the basal metabolic rate of an animal, whereby the latter is largely determined by body temperature.

Griebeler's work is part of a collection that brings together the results of recent research into sauropod gigantism. The gigantism of these vertebrates, unique in the history of the Earth, raises many questions, such as why no other land creatures have ever achieved this size and what their bauplan, physiology, and life cycle would have been like. The collection put together by the leading open access journal PLOS ONE consists of 14 contributions from the fields of ecology, morphology, animal nutrition, and paleontology that all address the fundamental question of how the sauropods managed to become so extraordinarily massive. "We are pleased that this new research is freely accessible not only to other scientists, but also to sauropod fans," said PD Dr. Eva Maria Griebeler. She and Dr. Jan Werner are members of the research group "Biology of the Sauropod Dinosaurs: The Evolution of Gigantism (FOR 533)," funded by the German Research Foundation (DFG). The collection was initiated as a result of a related international conference on this subject. Both scientists from the Ecology division at the Institute of Zoology at Mainz University have been working for more than six years within this research group. They have written three of the 14 contributions in the collection.

In one article, Jan Werner and his colleague Koen Stein of the University of Bonn describe a new method of determining the density of bone tissue and juxtapose sauropod data and results extrapolated for comparable endothermic mammals. Although the bone structure and the density of certain tissues of sauropods were similar to those of today's mammals, the results do not conclusively demonstrate that sauropods were also endothermic animals. Other functional aspects, such as similar weight-bearing stresses, could have resulted in the development of convergent forms of bone tissue.

Another article looks at the reproductive biology of sauropods. Here Werner and Griebeler discuss the hypothesis that a high rate of reproduction contributed to the gigantism of the large dinosaurs. They discovered that the reproductive pattern of most dinosaurs was similar to that of modern reptiles and birds. The reproductive pattern of theropods, i.e., ancestors of the modern birds, turned out to be comparable with that of birds, prosauropods, and sauropods rather than reptiles. However, contrary to the assumptions of previous studies, the calculations of the Mainz scientists did not corroborate the hypothesis that the large dinosaurs would have laid a particularly large number of eggs. In terms of total eggs produced annually, this number could not have exceeded 200 to 400 eggs for a sauropod weighing 75 tons. Today's large sea turtles are known to lay clutches in this range.

All 14 contributions in the collection 'Sauropod Gigantism: A Cross-Disciplinary Approach' are available online at the PLOS ONE website:

www.ploscollections.org/sauropodgigantism.

Photos:
http://www.uni-mainz.de/bilder_presse/10_zoologie_sauropoden_01.jpg
Replica of the reconstructed skeleton of Argentinosaurus huinculensis, on display as part of a special exhibition at the Senckenberg Natural History Museum, Frankfurt am Main. The fossil remains of this titanosaur that lived in the Early Cretaceous period were discovered in Neuquén province, Argentina. Argentinosaurus huinculensis is currently the largest known sauropod with a total length of 38 meters and an estimated total body weight of 75 tons.

photo: Eva Maria Griebeler

http://www.uni-mainz.de/bilder_presse/10_zoologie_sauropoden_02.jpg
Egg containing a titanosaur embryo, on display as part of a special exhibition at the Senckenberg Natural History Museum, Frankfurt am Main. This fossilized egg was discovered in Neuquén province, Argentina, and has an approximate diameter of 15 centimeters.

photo: Eva Maria Griebeler

http://www.uni-mainz.de/bilder_presse/10_zoologie_sauropoden_03.jpg
Titanosaur egg, on display as part of a special exhibition at the Senckenberg Natural History Museum, Frankfurt am Main. This fossil was discovered in Neuquén province, Argentina.

photo: Eva Maria Griebeler

Publications:
Eva Maria Griebeler
Body Temperatures in Dinosaurs: What Can Growth Curves Tell Us?
PLOS ONE, 30 October 2013
DOI: 10.1371/journal.pone.0074317
Koen W. H. Stein, Jan Werner
Preliminary Analysis of Osteocyte Lacunar Density in Long Bones of Tetrapods: All Measures Are Bigger in Sauropod Dinosaurs
PLOS ONE, 30 October 2013
DOI: 10.1371/journal.pone.0077109
Jan Werner, Eva Maria Griebeler
New Insights into Non-Avian Dinosaur Reproduction and Their Evolutionary and Ecological Implications: Linking Fossil Evidence to Allometries of Extant Close Relatives
PLOS ONE, 21 August 2013
DOI: 10.1371/journal.pone.0072862
Further information:
PD Dr. Eva Maria Griebeler
Ecology division
Institute of Zoology
Johannes Gutenberg University Mainz (JGU)
D 55099 Mainz, GERMANY
phone +49 6131 39-26621
fax +49 6131 39-23731
e-mail: em.griebeler@uni-mainz.de
http://www.oekologie.biologie.uni-mainz.de/people/evi/home.htm

Petra Giegerich | idw
Further information:
http://www.oekologie.biologie.uni-mainz.de/
http://www.ploscollections.org/sauropodgigantism

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>