Click Here
ad info

 Headline News brief
 news quiz
 daily almanac

 video archive
 multimedia showcase
 more services

Subscribe to one of our news e-mail lists.
Enter your address:
Get a free e-mail account

 message boards

CNN Websites
 En Español
 Em Português


Networks image
 more networks

 ad info



Snakes hold thread of evolution evidence

thread snake
The threadsnake is small enough to coil itself on a dime.  

January 3, 2000
Web posted at: 2:39 p.m. EST (1939 GMT)

By Environmental News Network staff

Only six to eight inches long, the diminutive threadsnake boasts a unique feeding system that may have great evolutionary and ecological importance, according to a recent study.

"Typically when we think of snakes feeding, we think of pythons and boas eating large animals," said Nate Kley, an evolutionary biologist and herpetologist at the University of Massachusetts at Amherst. "The snakes are able to do this because they have very flexible hinged jaws. Most snakes savor their infrequent feasts, taking anywhere from several minutes to several hours to consume a meal."

Unlike most of their cousins, threadsnakes survive on a daintier diet that consists principally of the pupae and larvae of ants. Instead of consuming their meals in one big gulp, threadsnakes eat at a rate of three or four bites each second. They are the only known vertebrates to use only their lower jaw to devour prey.
Dinner for this threadsnake is an ant pupa often found under rocks or inside rotting logs.  

The front parts of the threadsnake's triple-jointed lower jaw swing in and out of the mouth "like a pair of saloon doors," dragging prey quickly into the esophagus, Kley explains.

Scientists generally agree that lizards are the evolutionary forefathers of snakes. Kley views the foraging strategy of threadsnakes as a link between snakes and lizards. Like lizards, threadsnakes eat small prey; like other snakes, they gorge themselves on huge meals, eating thousands of ants or termites at a time. These patterns lead Kley to believe that threadsnakes may be among the most primitive groups of snakes.

The rapid-fire eating habit of the threadsnake may be the result of its hazardous foraging strategy, Kley said. When threadsnakes invade ants' nests to find sufficient food, they have to eat very quickly to avoid being attacked or even killed by large and powerful worker ants guarding the nests.

"The evolutionary origin of snakes has been contentious," Kley said. [Among other uncertainties,] people do not know from which lizards snakes evolved. Learning more about the feeding mechanisms of snakes may shed light on how they evolved."

Little research has been conducted on threadsnakes, in part because their small size makes them difficult to handle and study. The tendency of the threadsnake to burrow also makes it extremely difficult to find, Kley said.

Copyright 1999, Environmental News Network, All Rights Reserved

Tracking lizard history by the tail
Study suggests rapid lizard evolution
U.S. imports fire ant enemies
ENN Multimedia: Uncoding dangerous bites
ENN Multimedia: Africa is an evolutionists mecca

University of Massachusettes
Society for the study of amphibians and reptiles
American Society for Ichthyologists and Heprtologists
Threadsnake Feeding Videos
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.


Israeli president: 'Stop cooperation' with Arafat
El Salvador relief effort hampered
Okinawa town demands U.S withdrawal
Civilians say they didn't distract sub crew
California braced for weekend of power scrounging
Nancy Reagan says she was 'terrified' when Reagan broke hip
Court order averts strike against Union Pacific railroad
U.S. warning at Davos forum
Microsoft concedes it had bad week, says ordeal over now
Christa McAuliffe's home town quiet on eve of Challenger anniversary
Consumer group: Online privacy protections fall short
Guide to a wired Super Bowl
Commercials remain a big Super Bowl draw
Indiana beats Bond in heroes poll
Musician re-tunes, re-tools for next 'Survivor
Celine Dion's son is 'gorgeous,' says Florida doctor at delivery

Launch CNN's Desktop Ticker and get the latest news, delivered right on your desktop!

Today on CNN
Enter keyword(s)   go    help

Back to the top   © 2001 Cable News Network. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.