Featured Research

from universities, journals, and other organizations

Pterygotid sea scorpions: No terror of the ancient seas?

Date:
December 24, 2010
Source:
Buffalo Museum of Science
Summary:
New experiments have generated evidence that questions the common belief that the pterygotid eurypterids ("sea scorpions") were high-level predators in the Paleozoic oceans.

Top: Acutiramus capturing prey (soft-bodied and relatively weak in this case) by pinning it against the sea floor. Bottom: Detailed drawing of its claw.
Credit: Illustrations by William L. Parsons / Buffalo Museum of Science

Experiments by a team of researchers in New York and New Jersey have generated evidence that questions the common belief that the pterygotid eurypterids ("sea scorpions") were high-level predators in the Paleozoic oceans. This group, which ranged the seas from about 470 to 370 million years ago (long before the dinosaurs appeared), included the largest and, arguably, scariest-looking arthropods known to have evolved on planet Earth.

Related Articles


Reaching lengths of 2 meters with a body supported by well-developed legs, and armed with a pair of forward-facing claws laden with sharp projecting spines, they seem like the Tyrannosaurus rex among the invertebrates.

But in a new study, published in volume 39 of the Bulletin of the Buffalo Society of Natural Sciences, Richard Laub (Buffalo Museum of Science) and his colleagues Victor Tollerton (Research Associate, New York State Museum) and Richard Berkof (Stevens Institute of Technology) show that the mechanical constraints on the claw of the pterygotid sea scorpion Acutiramus made it incapable of penetrating the external shell of a medium-sized horseshoe crab without danger of rupturing.

They suggest that these imposing sea scorpions, and by extension others of their family who lived in the seas about 470 to 370 million years ago, were not necessarily the voracious predators they are commonly believed to have been. The practical operational force that could be safely applied by the claw of Acutiramus without causing damage to it was no more than about 5 Newtons, whereas a force of 8-17 Newtons was required to penetrate the horseshoe crab's armor.

Laub's team also noted that the absence of an 'elbow joint' between the claws and the body of Acutiramus limited claw movement, making them more effective in grasping prey on the sea floor than capturing actively fleeing fish or other swimming animals. Armed with serrated spines, the claws may have been used together to both capture and shred the prey, but the predatory capabilities of Acutiramus would appear to lack the force necessary for this animal to operate as a major predator.

"I have long been suspicious of prevailing popular interpretations" said Dr. Roy Plotnick, Department of Earth and Environmental Sciences at the University of Illinois at Chicago, who was not involved in the study. "This is a welcome contribution that strongly supports an alternative interpretation of claw function" he said.

"Our results derail the image of these imposing-looking animals, the largest arthropods yet known to have existed, as fearsome predators, or at least as predators of other eurypterids and of the armored fishes of the time" said team leader Richard Laub, who noted that "it opens the possibility that they were scavengers or even vegetarians."


Story Source:

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


Journal Reference:

  1. Laub, R.S., Tollerton, Jr. V.P. and Berkof, R.S. The cheliceral claw of Acutiramus (Arthropoda: Eurypterida): Functional analysis based on morphology and engineering principles. Bulletin of the Buffalo Society of Natural Sciences, 2010; 39: 29

Cite This Page:

Buffalo Museum of Science. "Pterygotid sea scorpions: No terror of the ancient seas?." ScienceDaily. ScienceDaily, 24 December 2010. <www.sciencedaily.com/releases/2010/12/101222173039.htm>.
Buffalo Museum of Science. (2010, December 24). Pterygotid sea scorpions: No terror of the ancient seas?. ScienceDaily. Retrieved February 26, 2015 from www.sciencedaily.com/releases/2010/12/101222173039.htm
Buffalo Museum of Science. "Pterygotid sea scorpions: No terror of the ancient seas?." ScienceDaily. www.sciencedaily.com/releases/2010/12/101222173039.htm (accessed February 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, February 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Amazon Keeps Its Green Thanks To The Sahara Desert

The Amazon Keeps Its Green Thanks To The Sahara Desert

Newsy (Feb. 25, 2015) Satellite data shows the Amazon rainforest supports its lush flora with a little help from Sahara Desert dust. Video provided by Newsy
Powered by NewsLook.com
Mayor Says District of Columbia to Go Ahead With Pot Legalization

Mayor Says District of Columbia to Go Ahead With Pot Legalization

Reuters - News Video Online (Feb. 25, 2015) Washington&apos;s mayor says the District of Columbia will move forward with marijuana legalization, despite pushback from Congress. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Marijuana Nowhere Near As Deadly As Alcohol: Study

Marijuana Nowhere Near As Deadly As Alcohol: Study

Newsy (Feb. 25, 2015) A new study says marijuana is about 114 times less deadly than alcohol. Video provided by Newsy
Powered by NewsLook.com
Fox With Horrifying Injury Rescued and Released Back Into the Wild

Fox With Horrifying Injury Rescued and Released Back Into the Wild

RightThisMinute (Feb. 25, 2015) This wounded fox knew what she was doing when she wandered into the yard of a nature photographer. The photographer got "Scamp" immediately in the hands of Wildlife Aid and she was released back into the wild in no time. Video provided by RightThisMinute
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