Featured Research

from universities, journals, and other organizations

New research throws doubt on earlier 'killer walrus' claims

Date:
January 17, 2013
Source:
University of Otago
Summary:
Palaeontologists who examined a new fossil found in southern California have thrown doubt on earlier claims that a "killer walrus" once existed.

Palaeontologists who examined a new fossil found in southern California have thrown doubt on earlier claims that a “killer walrus” once existed.
Credit: Copyright Robert W. Boessenecker

Palaeontologists who examined a new fossil found in southern California have thrown doubt on earlier claims that a "killer walrus" once existed.

A University of Otago geology PhD student Robert Boessenecker and co-author Morgan Churchill from the University of Wyoming have just published their paper about the fossil in the online scientific journal PLOS One.

The paper reports that the new fossil-find, of the extinct walrus Pelagiarctos from southern California, prompts a different hypothesis to an earlier one that a "killer walrus" existed, preying on other marine mammals and/or birds.

Fossils of the walrus were originally found in the 1980s. The large, robust size of the jaw bone, along with the sharp pointed cusps of the teeth similar to modern bone-cracking carnivores like hyenas, suggested that Pelagiarctos fed upon other marine mammals rather than the typical diet of fish as in modern walruses.

However the new fossil, a lower jaw with teeth, and more complete than the original fossil, suggests to the Otago and Wyoming palaeontologists that the Pelagiarctos was more of a fish eater as it lacked adaptations for being a "killer walrus."

The evidence pointed to the tooth shape being unlikely to have been adapted for feeding upon large prey; instead it was an example of primitively retained tooth shape.

"This new find indicates that this enigmatic walrus would have appeared similar in life to modern sea lions, with a deep snout and large canines," says Mr Boessenecker.

The researchers estimated Pelagiarctos to be similar in size to some modern male sea lions (about 350 kg or 770 lbs).

"However, modern pinnipeds (seals, sea lions, and walruses) of small and large body sizes are dietary generalists, and tend to have diets rich in fish -- including sea lions similar in body size to Pelagiarctos, which means that its large body size alone doesn't make Pelagiarctos an apex predator."

The new study also analysed the evolutionary relationships of Pelagiarctos for the first time, and found it to be an early sea lion-like walrus that was most closely related to another sea lion-like walrus, Imagotaria downsi, also from California.

The study was supported by a University of Otago Doctoral Scholarship, and grants from the Geological Society of America, The Palaeontological Society, and a National Science Foundation EAPSI Fellowship.


Story Source:

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


Journal Reference:

  1. Robert W. Boessenecker, Morgan Churchill. A Reevaluation of the Morphology, Paleoecology, and Phylogenetic Relationships of the Enigmatic Walrus Pelagiarctos. PLoS ONE, 2013; 8 (1): e54311 DOI: 10.1371/journal.pone.0054311

Cite This Page:

University of Otago. "New research throws doubt on earlier 'killer walrus' claims." ScienceDaily. ScienceDaily, 17 January 2013. <www.sciencedaily.com/releases/2013/01/130117105903.htm>.
University of Otago. (2013, January 17). New research throws doubt on earlier 'killer walrus' claims. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2013/01/130117105903.htm
University of Otago. "New research throws doubt on earlier 'killer walrus' claims." ScienceDaily. www.sciencedaily.com/releases/2013/01/130117105903.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
What's To Blame For Worst Ebola Outbreak In History?

What's To Blame For Worst Ebola Outbreak In History?

Newsy (July 27, 2014) A U.S. doctor has tested positive for the deadly Ebola virus, as the worst-ever outbreak continues to grow. Video provided by Newsy
Powered by NewsLook.com
The New York Times Backs Pot Legalization

The New York Times Backs Pot Legalization

Newsy (July 27, 2014) The New York Times has officially endorsed the legalization of marijuana, but why now, and to what end? 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:
from the past week

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