Featured Research

from universities, journals, and other organizations

World's oldest dinosaur embryo bonebed yields organic remains

Date:
April 10, 2013
Source:
University of Toronto
Summary:
A 190-million-year-old dinosaur bonebed near the city of Lufeng, in Yunnan, China has revealed for the first time how dinosaur embryos grew and developed in their eggs.

This is a flesh reconstruction of embryonic dinosaur inside egg.
Credit: Artwork by D. Mazierski

The great age of the embryos is unusual because almost all known dinosaur embryos are from the Cretaceous Period. The Cretaceous ended some 125 million years after the bones at the Lufeng site were buried and fossilized.

Related Articles


Led by University of Toronto Mississauga paleontologist Robert Reisz, an international team of scientists from Canada, Taiwan, the People's Republic of China, Australia, and Germany excavated and analyzed over 200 bones from individuals at different stages of embryonic development.

"We are opening a new window into the lives of dinosaurs," says Reisz. "This is the first time we've been able to track the growth of embryonic dinosaurs as they developed. Our findings will have a major impact on our understanding of the biology of these animals."

The bones represent about 20 embryonic individuals of the long-necked sauropodomorph Lufengosaurus, the most common dinosaur in the region during the Early Jurassic period. An adult Lufengosaurus was approximately eight metres long.

The disarticulated bones probably came from several nests containing dinosaurs at various embryonic stages, giving Reisz's team the rare opportunity to study ongoing growth patterns. Dinosaur embryos are more commonly found in single nests or partial nests, which offer only a snapshot of one developmental stage.

To investigate the dinosaurs' development, the team concentrated on the largest embryonic bone, the femur. This bone showed a consistently rapid growth rate, doubling in length from 12 to 24 mm as the dinosaurs grew inside their eggs. Reisz says this very fast growth may indicate that sauropodomorphs like Lufengosaurus had a short incubation period.

Reisz's team found the femurs were being reshaped even as they were in the egg. Examination of the bones' anatomy and internal structure showed that as they contracted and pulled on the hard bone tissue, the dinosaurs' muscles played an active role in changing the shape of the developing femur. "This suggests that dinosaurs, like modern birds, moved around inside their eggs," says Reisz. "It represents the first evidence of such movement in a dinosaur."

The Taiwanese members of the team also discovered organic material inside the embryonic bones. Using precisely targeted infrared spectroscopy, they conducted chemical analyses of the dinosaur bone and found evidence of what Reisz says may be collagen fibres. Collagen is a protein characteristically found in bone.

"The bones of ancient animals are transformed to rock during the fossilization process," says Reisz. "To find remnants of proteins in the embryos is really remarkable, particularly since these specimens are over 100 million years older than other fossils containing similar organic material."

Only about one square metre of the bonebed has been excavated to date, but this small area also yielded pieces of eggshell, the oldest known for any terrestrial vertebrate. Reisz says this is the first time that even fragments of such delicate dinosaur eggshells, less than 100 microns thick, have been found in good condition.

"A find such as the Lufeng bonebed is extraordinarily rare in the fossil record, and is valuable for both its great age and the opportunity it offers to study dinosaur embryology," says Reisz. "It greatly enhances our knowledge of how these remarkable animals from the beginning of the Age of Dinosaurs grew."


Story Source:

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


Journal Reference:

  1. Robert R. Reisz, Timothy D. Huang, Eric M. Roberts, ShinRung Peng, Corwin Sullivan, Koen Stein, Aaron R. H. LeBlanc, DarBin Shieh, RongSeng Chang, ChengCheng Chiang, Chuanwei Yang, Shiming Zhong. Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains. Nature, 2013; 496 (7444): 210 DOI: 10.1038/nature11978

Cite This Page:

University of Toronto. "World's oldest dinosaur embryo bonebed yields organic remains." ScienceDaily. ScienceDaily, 10 April 2013. <www.sciencedaily.com/releases/2013/04/130410131216.htm>.
University of Toronto. (2013, April 10). World's oldest dinosaur embryo bonebed yields organic remains. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2013/04/130410131216.htm
University of Toronto. "World's oldest dinosaur embryo bonebed yields organic remains." ScienceDaily. www.sciencedaily.com/releases/2013/04/130410131216.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Fossils & Ruins News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Discovery Of 'Dragon' Dinosaur In China Could Explain Myths

Discovery Of 'Dragon' Dinosaur In China Could Explain Myths

Newsy (Jan. 30, 2015) A long-necked dinosaur from the Jurassic Period was discovered in China. Researchers think it could answer mythology questions. Video provided by Newsy
Powered by NewsLook.com
Battle of Waterloo Artefacts Go on Display at Windsor Castle

Battle of Waterloo Artefacts Go on Display at Windsor Castle

AFP (Jan. 29, 2015) Artefacts from the Battle of Waterloo go on display at Windsor Castle to mark the 200th anniversary of the momentous battle. The exhibition includes contemporary prints, drawings and personal belongings of French Emperor Napoleon. Duration: 00:31 Video provided by AFP
Powered by NewsLook.com
Mideast Skull Find Sheds Light on Human Ancestors' Trek

Mideast Skull Find Sheds Light on Human Ancestors' Trek

AFP (Jan. 29, 2015) A 55,000-year-old partial skull found in the Middle East gives clues to when our ancestors left their African homeland, and strengthens theories that they co-habited with Neanderthals. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Newsy (Jan. 28, 2015) Wrongly categorized as lizard fossils, snake fossils now show the reptile could have developed earlier than we thought — 70 million years earlier. 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