Featured Research

from universities, journals, and other organizations

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

Date:
July 1, 2013
Source:
University of New South Wales
Summary:
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. To achieve a kill Thylacosmilus atrox must have secured and immobilized 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.

This shows cut away views through the skulls of (A) the sabre-toothed 'tiger' (Smilodon) and (B) the bizarre pouched sabre-tooth (Thylacosmilus). Note the incredibly wide gape and huge canine teeth with roots extending almost into the braincase of Thylacosmilus.
Credit: S. Wroe

A bizarre, pouched super-predator that terrorised 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 UNSW 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.


Story Source:

The above story is based on materials provided by University of New South Wales. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stephen Wroe, Uphar Chamoli, William C. H. Parr, Philip Clausen, Ryan Ridgely, Lawrence Witmer. Comparative Biomechanical Modeling of Metatherian and Placental Saber-Tooths: A Different Kind of Bite for an Extreme Pouched Predator. PLoS ONE, 2013; 8 (6): e66888 DOI: 10.1371/journal.pone.0066888

Cite This Page:

University of New South Wales. "Curious mix of precision and brawn in a pouched super-predator." ScienceDaily. ScienceDaily, 1 July 2013. <www.sciencedaily.com/releases/2013/07/130701100804.htm>.
University of New South Wales. (2013, July 1). Curious mix of precision and brawn in a pouched super-predator. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/07/130701100804.htm
University of New South Wales. "Curious mix of precision and brawn in a pouched super-predator." ScienceDaily. www.sciencedaily.com/releases/2013/07/130701100804.htm (accessed October 1, 2014).

Share This



More Plants & Animals News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) — A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) — Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins