A tooth challenges beliefs about how ancient reptiles lived
At the beginning of the age of dinosaurs, gigantic reptiles—distant relatives of modern crocodiles—ruled the earth. Some lived on land and others in water and it was thought they didn't much interact. But a tooth found by a University of Tennessee, Knoxville, researcher in the thigh of one of these ancient animals is challenging this belief.
This image shows teeth from phytosaurs, a reptile from the Triassic Period, that lived about 210 million years ago in the western United States, in the hand of Virginia Tech research scientist Michelle Stocker. The gray tooth was 3-D printed from CT scans after being digitally extracted from the thigh bone of a large predatory reptile called a rauisuchid.
Credit: Michelle Stocker
Stephanie Drumheller, an earth and planetary sciences lecturer, and her Virginia Tech colleagues Michelle Stocker and Sterling Nesbitt examined 220-million-year-old bite marks in the thigh bones of an old reptile and found evidence that two predators at the top of their respective food chains interacted—with the smaller potentially having eaten the larger animal.
The evidence? A tooth of a semi-aquatic phytosaur lodged in the thigh bone of a terrestrial rauisuchid. The tooth lay broken off and buried about two inches deep in bone and then healed over, indicating that the rauisuchid, a creature about 25 feet long and 4 feet high at the hip, survived the initial attack.
"To find a phytosaur tooth in the bone of a rauisuchid is very surprising. These rauisuchids were the largest predators in their environments. You might expect them to be the top predators as well, but here we have evidence of phytosaurs, who were smaller, semi-aquatic animals, potentially targeting and eating these big carnivores," said Drumheller.
To study the tooth without destroying the bone, the team partnered computed tomographic (CT) data with a 3D printer and printed copies of the tooth. This, along with an examination of the bite marks, revealed a story of multiple struggles. The team found tissue surrounding bite marks illustrating that the rauisuchid was attacked twice and survived. Evidence of crushing, impact and flesh-stripping but no healing showed the team that the animal later died in another attack.
The tooth that was left behind revealed who was guilty of the attacks.
"Finding teeth embedded directly in fossil bone is very, very rare," said Drumheller of the bone obtained from the University of California Museum of Paleontology in Berkeley. "This is the first time it's been identified among phytosaurs, and it gives us a smoking gun for interpreting this set of bite marks."
The findings also suggest previous distinctions between water- and land-based food chains of this time, the Late Triassic Period, might be built upon mistaken assumptions made from fossil remains.
"This research will call for us to go back and look at some of the assumptions we've had in regard to the Late Triassic ecosystems," Stocker said. "The aquatic and terrestrial distinctions made were oversimplified, and I think we've made a case that the two spheres were intimately connected."
The research also calls into question the importance of size in a fight.
"Both of the femora we examined came from some of the physically largest carnivorous species present at both locations. Yet they were targeted by other members of the region—specifically phytosaurs," said Drumheller. "Thus, size cannot be the only factor in determining who is at the top of the food chain."
The research is published online in the German scientific journal Naturwissenschaften, The Science of Nature.
Whitney Heins | Eurek Alert!
More than 100 years of flooding and erosion in 1 event
28.03.2017 | Geological Society of America
Satellites reveal bird habitat loss in California
28.03.2017 | Duke University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy