Featured Research

from universities, journals, and other organizations

It’s All In The Hips: Early Whales Used Well Developed Back Legs For Swimming, Fossils Show

Date:
September 18, 2008
Source:
Society of Vertebrate Paleontology
Summary:
The crashing of the enormous fluked tail on the surface of the ocean is a "calling card" of modern whales. Living whales have no back legs, and their front legs take the form of flippers that allow them to steer. Their special tails provide the powerful thrust necessary to move their huge bulk. Yet this has not always been the case. Now newly found fossils from Alabama and Mississippi that pinpoint where tail flukes developed in the evolution of whales.

The tail-powered swimming of modern baleen (Mysticeti) and toothed (Odontoceti) whales evolved from the hip wiggling style of the ancient whale Georgiacetus.
Credit: Illustration by Mary Parrish, Smithsonian Institution

The crashing of the enormous fluked tail on the surface of the ocean is a “calling card” of modern whales. Living whales have no back legs, and their front legs take the form of flippers that allow them to steer. Their special tails provide the powerful thrust necessary to move their huge bulk. Yet this has not always been the case.

Reporting in the latest issue of the Journal of Vertebrate Paleontology, paleontologist Mark D. Uhen of the Alabama Museum of Natural History describes new fossils from Alabama and Mississippi that pinpoint where tail flukes developed in the evolution of whales.

“We know that the earliest whales were four-footed, semi-aquatic animals, and we knew that some later early whales had tail flukes, but we didn’t know exactly when the flukes first arose,” said Uhen. “Now we do.”

The most complete fossil described in the study is a species called Georgiacetus vogtlensis. Although not new to science, the new fossils provide some very significant new information. In particular, previously unknown bones from the tail show that it lacked a tail fluke. On the other hand, it did have large back feet and Uhen suggests that it used them as hydrofoils. Undulating the body in the hip region was the key factor in the evolution of swimming.

The very different body forms seen in the lineage of whales point to very different methods of swimming underwater. Previous studies have proposed a possible process to evolve from the ancestral form, paddling with all four legs, to the modern-day whale in which the tail oscillates up and down. Living vertebrates that are capable swimmers employ a whole range of different techniques, including five particularly well defined methods: quadrupedal paddling, paddling only using the back legs, undulation of the hips, tail undulation, and tail oscillation.

Interestingly, it had been suggested that during whale evolution each of these steps occurred in turn, but that the hip undulation stage might have been by-passed. The new discoveries indicate that the complete opposite was true, and as Uhen says “wiggling hips were a significant step in the evolution of underwater swimming in whales.”

So now we know that Elvis was not the first to owe success to undulating hips!


Story Source:

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


Cite This Page:

Society of Vertebrate Paleontology. "It’s All In The Hips: Early Whales Used Well Developed Back Legs For Swimming, Fossils Show." ScienceDaily. ScienceDaily, 18 September 2008. <www.sciencedaily.com/releases/2008/09/080917210028.htm>.
Society of Vertebrate Paleontology. (2008, September 18). It’s All In The Hips: Early Whales Used Well Developed Back Legs For Swimming, Fossils Show. ScienceDaily. Retrieved September 15, 2014 from www.sciencedaily.com/releases/2008/09/080917210028.htm
Society of Vertebrate Paleontology. "It’s All In The Hips: Early Whales Used Well Developed Back Legs For Swimming, Fossils Show." ScienceDaily. www.sciencedaily.com/releases/2008/09/080917210028.htm (accessed September 15, 2014).

Share This



More Plants & Animals News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. 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