PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Curious mix of precision and brawn in a pouched super-predator

2013-07-01
(Press-News.org) SYDNEY: A bizarre, pouched super-predator that terrorized South America millions of years ago had huge sabre-like teeth but its bite was weaker than that of a domestic cat, new research shows.

Australian and American marsupials are among the closest living relatives of the extinct Thylacosmilus atrox, which had tooth roots extending rearwards almost into its small braincase. "Thylacosmilus looked and behaved like nothing alive today," says University of New South Wales palaeontologist, Dr Stephen Wroe, leader of the research team.

"To achieve a kill the animal must have secured and immobilised large prey using its extremely powerful forearms, before inserting the sabre-teeth into the windpipe or major arteries of the neck – a mix of brute force and delicate precision." The iconic North American sabre-toothed 'tiger', Smilodon fatalis, is often regarded as the archetypal mammalian super-predator.

However, Smilodon - a true cat - was just the end point in one of at least five independent 'experiments' in sabre-tooth evolution through the Age of Mammals, which spanned some 65 million years.

Thylacosmilus atrox is the best preserved species of one of these evolutionary lines - pouched sabre-tooths that terrorised South America until around 3.5 million years ago.

For its size, its huge canine teeth were larger than those of any other known sabre-tooth.

Smilodon's killing behaviour has long attracted controversy, but scientists now mostly agree that powerful neck muscles, as well as jaw muscles, played an important role in driving the sabre-teeth into the necks of large prey.

Little was known about the predatory behaviour in the pouched Thylacosmilus.

To shed light on this super-predator mystery, Dr Wroe's team of Australian and US scientists constructed and compared sophisticated computer models of Smilodon and Thylacosmilus, as well as a living conical-toothed cat, the leopard. These models were digitally 'crash-tested' in simulations of biting and killing behaviour. The results are published in the journal PLoS ONE.

"We found that both sabre-tooth species were similar in possessing weak jaw-muscle-driven bites compared to the leopard, but the mechanical performance of the sabre-tooths skulls showed that they were both well-adapted to resist forces generated by very powerful neck muscles," says Dr Wroe.

"But compared to the placental Smilodon, Thylacosmilus was even more extreme."

"Frankly, the jaw muscles of Thylacosmilus were embarrassing. With its jaws wide open this 80-100 kg 'super-predator' had a bite less powerful than a domestic cat. On the other hand - its skull easily outperformed that of the placental Smilodon in response to strong forces from hypothetical neck muscles."

"Bottom line is that the huge sabres of Thylacosmilus were driven home by the neck muscles alone and - because the sabre-teeth were actually quite fragile - this must have been achieved with surprising precision."

"For Thylacosmilus - and other sabre-tooths - it was all about a quick kill."

"Big prey are dangerous – even to super-predators – and the faster the kill the less likely it is that the predator will get hurt – or for that matter attract unwanted attention from other predators."

"It may not have been the smartest of mammalian super-predators – but in terms of specialisation – Thylacosmilus took the already extreme sabre-tooth lifestyle to a whole new level," says Dr Wroe.



INFORMATION:

Media Contacts:

Dr Stephen Wroe: +61 (2) 4969 3006, s.wroe@unsw.edu.au

UNSW Science media: Deborah Smith: +61 (2) 9385 7307, +61 (0) 478 492, deborah.smith@unsw.edu.au



ELSE PRESS RELEASES FROM THIS DATE:

A calculator to estimate the likelihood of antidepressant response

2013-07-01
Philadelphia, PA-- As in any other field of medicine, when a depressed person visits a psychiatrist for treatment of depression, they like to be informed of the odds that they will respond to the medication they are prescribed. Unfortunately, there has been no precise way to predict antidepressant response in individual patients. It would be very nice to have an equation that would enable doctors to predict the likelihood that individual patients would respond to specific treatments. Accurate predictions are likely to be challenging. The ability to accurately predict ...

Teaching a computer to play concentration advances security, understanding of the mind

2013-07-01
Computer science researchers have programmed a computer to play the game Concentration (also known as Memory). The work could help improve computer security – and improve our understanding of how the human mind works. The researchers developed a program to get the software system called ACT-R, a computer simulation that attempts to replicate human thought processes, to play Concentration. In the game, multiple matching pairs of cards are placed face down in a random order, and players are asked to flip over two cards, one at a time, to find the matching pairs. If a player ...

Too much of a good thing? Too many 'healing' cells delays wound healing

2013-07-01
Bethesda, MD -- Like most other things, you can have too much of a good thing when it comes to wound healing, and new research proves it. According to an article published in the July 2013 issue of the Journal of Leukocyte Biology, wound healing can be delayed because the body produces too many mast cells, which normally promote healing. An overabundance of these cells, however, also causes harm by leading to the overproduction of IL-10, which prevents certain white blood cells from reaching the wounded area. The work was conducted in mice with lymphedematous skin, and ...

Social responsibility, the main motivation of minority-language radio journalism

2013-07-01
This news release is available in Spanish. The UPV/EHU researcher Irati Agirreazkuenaga-Onaindia has developed a new methodology for studying the profiles, working habits and perceptions of Basque and Scottish Gaelic-speaking radio journalists. The study confirms that social responsibility is the main motivation for the EITB and BBC journalists. Euskadi Irratia was 30 years old last year, and the study covers what the journalists who work in minority languages are like and how they go about their work. So the UPV/EHU researcher Irati Agirreazkuenaga has compared ...

Breakthrough discovery into the regulation of a key cancer drug target

2013-07-01
There's not much difference between what makes a man and what makes his beer - at least at the molecular level - according to a new study led by Professor John Schwabe at the University of Leicester. Scientists used a powerful technique called protein crystallography to look at 3D structures of protein complexes purified from cultured human cells. They discovered that a family of complexes, that switch off gene expression, is regulated by small signalling molecules called inositol phosphates. This latest study shows that this mode of regulation is conserved from yeast ...

Neuroblastoma: Autophagy protects from chemotherapy

2013-07-01
Neuroblastomas are pediatric tumors that originate from cells of the embryonic nervous system. The disease can take widely varying clinical courses that range from spontaneous regression to fatal outcomes. Highly aggressive neuroblastomas rarely respond well to chemotherapy. Understanding and overcoming the resistance mechanisms of highly aggressive neuroblastomas are considered essential to the development of effective treatments. Scientists from the department headed by Professor Dr. Olaf Witt at the German Cancer Research Center (Deutsches Krebsforschungszentrum, ...

Long-term cannabis use may blunt the brain's motivation system

2013-07-01
Researchers found that dopamine levels in a part of the brain called the striatum were lower in people who smoke more cannabis and those who began taking the drug at a younger age. They suggest this finding could explain why some cannabis users appear to lack motivation to work or pursue their normal interests. The study, by scientists at Imperial College London, UCL and King's College London, was funded by the Medical Research Council and published in the journal Biological Psychiatry. The researchers used PET brain imaging to look at dopamine production in the striatum ...

Researchers discover new way to block inflammation

2013-07-01
Researchers at NYU Langone Medical Center have discovered a mechanism that triggers chronic inflammation in Alzheimer's, atherosclerosis and type-2 diabetes. The results, published today in Nature Immunology, suggest a common biochemical thread to multiple diseases and point the way to a new class of therapies that could treat chronic inflammation in these non-infectious diseases without crippling the immune system. Alzheimer's, atherosclerosis and type-2 diabetes—diseases associated with aging and inflammation—affect more than 100 million Americans. When the body encounters ...

Study finds biochemical role of crucial TonB protein in bacterial iron transport and pathogenesis

2013-07-01
MANHATTAN, Kan. -- A Kansas State University-led study has discovered the role of a protein in bacteria that cause a wide variety of diseases, including typhoid fever, plague, meningitis and dysentery. The results may lead to new and improved antibiotics for humans and animals. Phillip E. Klebba, professor and head of the department of biochemistry and molecular biophysics, made the findings with two colleagues in the department: Lorne D. Jordan, doctoral candidate, Manhattan, and Salete M. Newton, research professor. The collaboration included other biophysicists at ...

After the shooting, political violence lives on in kids' behavior problems

2013-07-01
DURHAM, N.C. -- Even short-term exposure to political violence may have long-lasting effects on children's adjustment and behavior, says a new study by a team of researchers from Kenya, Italy and the United States. Intense violence followed the contested Kenyan presidential election of December 2007. More than a year later, children who were exposed to the violence showed increased delinquent and aggressive behaviors, including such problem behaviors as bullying, vandalism, stealing and skipping school, said study author Ann T. Skinner of the Duke University Center for ...

LAST 30 PRESS RELEASES:

KAIST Develops Retinal Therapy to Restore Lost Vision​

Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response

Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid

Low LDL cholesterol levels linked to reduced risk of dementia

Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients

Almost one in ten people surveyed report having been harmed by the NHS in the last three years

Enhancing light control with complex frequency excitations

New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients

New insight into factors associated with a common disease among dogs and humans

Illuminating single atoms for sustainable propylene production

New study finds Rocky Mountain snow contamination

Study examines lactation in critically ill patients

UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award

Doubling down on metasurfaces

New Cedars-Sinai study shows how specialized diet can improve gut disorders

Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana

PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation

ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy

How VR technology is changing the game for Alzheimer’s disease

A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet

Balance between two competing nerve proteins deters symptoms of autism in mice

Use of antifungals in agriculture may increase resistance in an infectious yeast

Awareness grows of cancer risk from alcohol consumption, survey finds

The experts that can outsmart optical illusions

Pregnancy may reduce long COVID risk

Scientists uncover novel immune mechanism in wheat tandem kinase

Three University of Virginia Engineering faculty elected as AAAS Fellows

Unintentional drug overdoses take a toll across the U.S. unequally, study finds

A step toward plant-based gelatin

ECMWF unveils groundbreaking ML tool for enhanced fire prediction

[Press-News.org] Curious mix of precision and brawn in a pouched super-predator