Featured Research

from universities, journals, and other organizations

First single-fingered dinosaur discovered

Date:
January 25, 2011
Source:
University College London
Summary:
A new species of parrot-sized dinosaur, the first discovered with only one finger, has been unearthed in Inner Mongolia, China.

Artist's impression of Linhenykus monodactylus.
Credit: © Julius T. Csotonyi

A new species of parrot-sized dinosaur, the first discovered with only one finger, has been unearthed in Inner Mongolia, China.

Related Articles


Scientists named the new dinosaur Linhenykus monodactylus, after the nearby city of Linhe. The work was recently published online in Proceedings of the National Academy of Sciences (PNAS).

The new dinosaur belongs to the Alvarezsauroidea, a branch of the carnivorous dinosaur group Theropoda. Theropods gave rise to modern birds and include such famous dinosaurs as Tyrannosaurus and Velociraptor.

An international team of palaeontologists found the fossil preserved in rocks of the Upper Cretaceous Wulansuhai Formation, which is located near the border between Mongolia and China. The formation dates to 84-75 million years ago and has yielded a rich trove of vertebrate fossils including the recently discovered theropod Linheraptor exquisitus. The authors uncovered a partial skeleton from the site, which included bones of the vertebral column, the forelimb, a partial pelvis and nearly complete hind limbs.

Linhenykus most likely grew to a couple of feet tall and weighed only as much as a large parrot. The new theropod is unusual in having just one large claw, which may have been used to dig into insect nests, on each of its hands. This feature makes the specimen the only known dinosaur with one finger, and highlights the wide variety of evolutionary modifications of the hand that existed in different theropods.

Michael Pittman of the Department of Earth Sciences at University College London, co-author and discoverer of the specimen said: "Non-avian theropods start with five fingers but evolved to have only three fingers in later forms. Tyrannosaurs were unusual in having just two fingers but the one-fingered Linhenykus shows how extensive and complex theropod hand modifications really were."

Most theropod dinosaurs have three fingers on each hand, but in most alvarezsauroids other than Linhenykus the two outer fingers are reduced to tiny, apparently useless structures. The presence of only one finger in Linhenykus, which is hypothesized to be a relatively primitive alvarezsauroid, shows that these vestigial fingers were not present in all members of the group. The reasons for the loss of the two outer fingers in Linhenykus are unclear, and their disappearance may simply reflect the fact that they were no longer being actively maintained by natural selection

Jonah Choiniere, co-author and co-discoverer of the specimen from the Division of Paleontology at the American Museum of Natural History said: "Vestigial structures, like legs in whales and snakes, may appear and disappear seemingly randomly in the course of evolution. Linhenykus highlights the vestigiality of the outer fingers of advanced alvarezsauroids and underscores the complexity in evolution of these vestigial fingers."

Linhenykus lived with closely-related and similarly-sized theropod dinosaurs, but the specializations of its skeleton may reflect differences in behaviour or foraging strategy. Linhenykus also lived alongside small mammals, lizards, clubbed dinosaurs (ankylosaurs) and horned dinosaurs (ceratopsians).

'The first known monodactyl non-avian dinosaur and the complex evolution of the alvarezsauroid hand' is published in Proceedings of the National Academy of Sciences.


Story Source:

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


Journal Reference:

  1. Xing Xu, Corwin Sullivan, Michael Pittman, Jonah N. Choiniere, David Hone, Paul Upchurch, Qingwei Tan, Dong Xiao, Lin Tan, Fenglu Han. A monodactyl nonavian dinosaur and the complex evolution of the alvarezsauroid hand. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1011052108

Cite This Page:

University College London. "First single-fingered dinosaur discovered." ScienceDaily. ScienceDaily, 25 January 2011. <www.sciencedaily.com/releases/2011/01/110124151717.htm>.
University College London. (2011, January 25). First single-fingered dinosaur discovered. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2011/01/110124151717.htm
University College London. "First single-fingered dinosaur discovered." ScienceDaily. www.sciencedaily.com/releases/2011/01/110124151717.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Amphipolis Tomb Architraves Reveal Faces

Amphipolis Tomb Architraves Reveal Faces

AFP (Nov. 22, 2014) — Faces in an area of mosaics is the latest find by archaeologists at a recently discovered tomb dating back to fourth century BC and the time of Alexander the Great in Greece. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
US Returns Looted Artifacts to Thailand

US Returns Looted Artifacts to Thailand

AFP (Nov. 19, 2014) — The United States has returns over 500 vases, bowls, axes, and other ancient artifacts mostly from the Ban Chiang archaeological site which were illegally looted from Thailand decades ago. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
How To Search Through Every Public Tweet Sent Since 2006

How To Search Through Every Public Tweet Sent Since 2006

Newsy (Nov. 19, 2014) — Twitter has announced improvements to its search index that allow users to search through every public tweet sent since its inception in 2006. Video provided by Newsy
Powered by NewsLook.com
Professor Unlocks the Mystery of Paintings

Professor Unlocks the Mystery of Paintings

AP (Nov. 19, 2014) — Richard Johnson, a computer and engineering professor at Cornell University, is using technology to uncover mysteries about the age and authenticity of historic paintings by artists like Johannes Vermeer and Vincent Van Gogh. (Nov. 19) Video provided by AP
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