Featured Research

from universities, journals, and other organizations

Skull Study Sheds Light On Dinosaur Diversity

Date:
September 16, 2005
Source:
University of Michigan
Summary:
With their long necks and tails, sauropod dinosaurs -- famous as the Sinclair gasoline logo and Fred Flintstone's gravel pit tractor -- are easy to recognize, in part because they all seem to look alike. The largest animals known to have walked the earth, sauropods were common in North America during the middle of the dinosaur era but were thought to have been pushed to extinction by more specialized plant-eaters at the end of that era. New discoveries, however, are showing that one lineage of sauropods diversified at the end of the dinosaur era, University of Michigan paleontologist Jeffrey Wilson says.

The largest animals known to have walked the earth, sauropods were common in North America during the middle of the dinosaur era but were thought to have been pushed to extinction by more specialized plant-eaters at the end of that era. New discoveries, however, are showing that one lineage of sauropods diversified at the end of the dinosaur era, University of Michigan paleontologist Jeffrey Wilson says.
Credit: Image courtesy of University of Michigan

ANN ARBOR, Mich.—With their long necks and tails, sauropoddinosaurs—famous as the Sinclair gasoline logo and Fred Flintstone'sgravel pit tractor—are easy to recognize, in part because they all seemto look alike.

Related Articles


The largest animals known to have walked theearth, sauropods were common in North America during the middle of thedinosaur era but were thought to have been pushed to extinction by morespecialized plant-eaters at the end of that era. New discoveries,however, are showing that one lineage of sauropods diversified at theend of the dinosaur era, University of Michigan paleontologist JeffreyWilson says.

Wilson's recent restudy and reconstruction of theskull of a Mongolian sauropod adds to a growing body of evidence forsauropod diversity at the end of the dinosaur era. Wilson described thereconstruction and the conclusions he drew from it in a paper publishedAug. 24 in the Journal of Systematic Palaeontology.

He based thereconstruction on two nearly complete skulls that were found in theGobi Desert in the 1950s and 1960s but whose evolutionary relationshipshave remained enigmatic. In the 1990s and early 2000s, Wilson restudiedthe skulls and found characteristics identifying them as skulls oftitanosaurs, a late surviving sauropod lineage.

"Titanosaurs,which were surprisingly common at the end of the dinosaur era, werereally the only sauropod lineage that flourished. All the others wentextinct," said Wilson, an assistant professor of geological sciencesand an assistant curator at the University of Michigan Museum ofPaleontology. But as prevalent as titanosaurs were, they left behindsurprisingly few skulls. Paleontologists have found plenty of othertitanosaur bones, providing a picture of a group of sauropods withspecialized limb bones.

Wilson began to appreciate the finerpoints of titanosaurs as a graduate student, when he and anotherstudent studied fossilized sauropod tracks and titanosaur limb anatomy.From those studies, Wilson concluded that unlike other sauropods,titanosaurs walked with their feet planted far from the middles oftheir bodies, an unusual style of "wide gauge" locomotion.

"Mostanimals walk with a narrow gauge, with their feet close to the midline,because it's energetically more efficient to walk that way. But somesauropod trackways tell us that a group of sauropods were walking witha new wide-gauge stance. We can identify characteristics of titanosaursthat would have allowed that stance, and we can tie the appearance ofthose features with the proliferation of wide gauge tracks everywherein the fossil record at the end of the dinosaur era." Wilson wonders ifthe change in locomotion—from typical sauropod narrow-gauge walking totitanosaur wide-gauge walking—corresponded to lifestyle changes, suchas different feeding habits. But without skulls to study, it has beenhard to draw conclusions about how and what titanosaurs ate.

Withhis work and that of researchers at the State University of New York,Stony Brook who announced the discovery of a complete titanosaurskeleton in 2001, sauropod specialists finally can start piecingtogether a clearer picture of the dinosaurs' lives.

One featureof the skulls is particularly intriguing. "They have elongate, sort ofhorse-like skulls with many openings and grooves on the outer surfaceof their snouts," said Wilson, who worked closely with U-M Museum ofPaleontology artist Bonnie Miljour over the course of a year preparingthe paper's many illustrations of the skull reconstruction. "Bloodvessels and nerves passed through these holes and may suggest anespecially sensitive snout. This probably had some role in feeding, butwe haven't investigated it at all."

Oddly, a group of distantlyrelated sauropods evolved a similarly grooved snout. "Apparently, thesetwo different branches of sauropods gravitated toward similaranatomical structures, perhaps because they were specialized for eatingcertain types of vegetation."


Story Source:

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


Cite This Page:

University of Michigan. "Skull Study Sheds Light On Dinosaur Diversity." ScienceDaily. ScienceDaily, 16 September 2005. <www.sciencedaily.com/releases/2005/09/050916074135.htm>.
University of Michigan. (2005, September 16). Skull Study Sheds Light On Dinosaur Diversity. ScienceDaily. Retrieved November 1, 2014 from www.sciencedaily.com/releases/2005/09/050916074135.htm
University of Michigan. "Skull Study Sheds Light On Dinosaur Diversity." ScienceDaily. www.sciencedaily.com/releases/2005/09/050916074135.htm (accessed November 1, 2014).

Share This



More Fossils & Ruins News

Saturday, November 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer History on Display at Museum of Death

Killer History on Display at Museum of Death

AP (Oct. 30, 2014) Visitors take a trip down murderer memory lane at the Museum of Death located in the heart of Hollywood. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Major Clue Found In Amelia Earhart Mystery

Major Clue Found In Amelia Earhart Mystery

Newsy (Oct. 29, 2014) Researchers believe they have identified a fragment from Amelia Earhart's plane. Video provided by Newsy
Powered by NewsLook.com
Dracula's Dungeon May Have Been Found in Turkey

Dracula's Dungeon May Have Been Found in Turkey

AP (Oct. 29, 2014) Historians think they may have discovered a dungeon in Turkey where the Romanian prince who inspired Count Dracula was once held captive. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Study Doesn't Prove Megalodons Are Extinct, Never Needed To

Study Doesn't Prove Megalodons Are Extinct, Never Needed To

Newsy (Oct. 27, 2014) How and why a study about when the giant prehistoric shark Megalodon went extinct got picked up as "proof" that it is. 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