Featured Research

from universities, journals, and other organizations

Oldest dinosaur embryos give insights into infancy and growth

Date:
November 12, 2010
Source:
Society of Vertebrate Paleontology
Summary:
After sitting in collections for nearly 30 years, some remarkably well-preserved dinosaur eggs and their contents are offering new insights into the infancy and growth of early dinosaurs. They represent the oldest embryos of any land-dwelling vertebrate ever found. The eggs, found in 1976 in South Africa, date from the early part of the Jurassic Period, 190 million years ago. They belong to Massospondylus, a member of a group of dinosaurs known as prosauropods that are the ancestors to the later sauropods -- the large, four-legged dinosaurs with long necks, typified by the popular ' Brontosaurus' and Diplodocus.

Top: Artist's reconstruction of a Massospondylus embryo. Bottom: Photograph of skeleton of the first embryo of Massospondylus. White materials represent eggshell that remained around the embryonic skeleton after they had been exposed.
Credit: Top image courtesy of Heidi Richter / Bottom image courtesy of Diane Scott, University of Toronto at Mississauga

After sitting in collections for nearly 30 years, some remarkably well-preserved dinosaur eggs and their contents are offering new insights into the infancy and growth of early dinosaurs. They represent the oldest embryos of any land-dwelling vertebrate ever found.

The eggs, found in 1976 in South Africa, date from the early part of the Jurassic Period, 190 million years ago. They belong to Massospondylus (măs-ō-spŏn-dīl-ŭs), a member of a group of dinosaurs known as prosauropods that are the ancestors to the later sauropods -- the large, four-legged dinosaurs with long necks, typified by the popular ' Brontosaurus' and Diplodocus.

Dr. Robert Reisz of the University of Toronto and his colleagues worked on these fossils, and it was only through modern preparation techniques that these findings were brought to light. One of Dr. Reisz's co-authors, research assistant Diane Scott, prepared the delicate fossils under high-powered microscopes and compiled the illustrations. "I don't think anybody else could have done this job," says Dr. Reisz.

These eggs contain the oldest known embryos of dinosaurs. In fact, they are the oldest of any land-dwelling backboned animal. The preservation of the embryos is exquisite, permitting a complete reconstruction of the skeleton and detailed interpretations of the anatomy.

The level of ossification -- how much of the skeleton has turned to bone -- reveals that the embryos were close to hatching. The fossils also reveal that the future hatchlings would have been oddly proportioned and would have looked very different from the adults of the species.

The 20 cm (8 in.) embryos were quadrupedal (they walked on all four legs), with relatively long front limbs and disproportionately large heads. In contrast, the 5 m (16.5 ft) long adults had relatively tiny heads and long necks; they mostly likely were bipedal, given that their forelimbs are much shorter than their hind limbs. This implies that as the dinosaurs matured, their necks and hind limbs grew much faster than their forelimbs and head. Later dinosaurs in this group, the sauropods, had body proportions more similar to those of the Massospondylus embryos.

In at least one way, Massospondylus development resembles that of humans; infancy is awkward, and a more erect stance and evenly proportioned body only come later.

There may be another way that Massospondylus infancy was similar to that of humans. The embryos lack teeth and this, combined with the awkward body proportions, suggests that the hatchlings may have required parental care. If true, these fossils also document the oldest record of parental care.

"This project opens an exciting window into the early history and evolution of dinosaurs," says Reisz. "Prosauropods are the first dinosaurs to diversify extensively, and they quickly became the most widely spread group, so their biology is particularly interesting as they represent in many ways the dawn of the age of dinosaurs."

The eggs and embryos are on display at the Royal Ontario Museum in an exhibit entitled, "Dinosaur Eggs and Babies: Remarkable Fossils from South Africa." Dr. David Evans, one of the co-authors of this research, is curator at that museum.


Story Source:

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


Journal Reference:

  1. Reisz, R.R., D.C. Evans, H.-D. Sues, D. Scott. Embryonic skeletal anatomy of the sauropodomorph dinosaur Massospondylus from the Lower Jurassic of South Africa. Journal of Vertebrate Paleontology, 2010; 30 (6)

Cite This Page:

Society of Vertebrate Paleontology. "Oldest dinosaur embryos give insights into infancy and growth." ScienceDaily. ScienceDaily, 12 November 2010. <www.sciencedaily.com/releases/2010/11/101111163339.htm>.
Society of Vertebrate Paleontology. (2010, November 12). Oldest dinosaur embryos give insights into infancy and growth. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2010/11/101111163339.htm
Society of Vertebrate Paleontology. "Oldest dinosaur embryos give insights into infancy and growth." ScienceDaily. www.sciencedaily.com/releases/2010/11/101111163339.htm (accessed July 26, 2014).

Share This




More Fossils & Ruins News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did ISIS Destroy Jonah's Tomb?

Did ISIS Destroy Jonah's Tomb?

Newsy (July 25, 2014) Unverified footage posted to YouTube purportedly shows ISIS militants destroying a shrine widely believed to be the tomb of the prophet Jonah. Video provided by Newsy
Powered by NewsLook.com
Richard III's Car Park Burial Site Opens to Public

Richard III's Car Park Burial Site Opens to Public

AFP (July 25, 2014) Visitors will be able to look down from a glass walkway on the grave of King Richard III when a new centre opens in the English cathedral city of Leicester, where the infamous hunchback was found under a car park in 2012. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Mobile App Gives Tour of Battle of Atlanta Sites

Mobile App Gives Tour of Battle of Atlanta Sites

AP (July 25, 2014) Emory University's Center for Digital Scholarship has launched a self-guided mobile tour app to coincide with the 150th anniversary of the Civil War's Battle of Atlanta. (July 25) Video provided by AP
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. 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