Featured Research

from universities, journals, and other organizations

Fossilized pregnant plesiosaur: 78-million-year-old fossils of adult and its embryo provide first evidence of live birth

Date:
August 12, 2011
Source:
Natural History Museum of Los Angeles County
Summary:
Archeologists have determined that a unique specimen now displayed in a museum is the fossil of an embryonic marine reptile contained within the fossil of its mother.

Scientists have determined that a unique specimen now displayed in NHM's Dinosaur Hall is the fossil of an embryonic marine reptile contained within the fossil of its mother.
Credit: Image courtesy of Natural History Museum of Los Angeles County

A paper to be published on August 12, 2011 in the the journal Science reveals that Dr. F. Robin O'Keefe of Marshall University in Huntington, W.Va. and Dr. Luis Chiappe, Director of the Natural History Museum's Dinosaur Institute, have determined that a unique specimen now displayed in NHM's Dinosaur Hall is the fossil of an embryonic marine reptile contained within the fossil of its mother.

The 78-million-year-old, 15.4-foot-long adult specimen is a Polycotylus latippinus, one of the giant, carnivorous, four-flippered reptiles known as plesiosaurs that lived during the Mesozoic Era. The embryonic skeleton contained within shows much of the developing body, including ribs, 20 vertebrae, shoulders, hips, and paddle bones. The research by Dr. O'Keefe and Dr. Chiappe establishes that these dual fossils are the first evidence that plesiosaurs gave birth to live young, rather than hatching their offspring from eggs on land.

Although live birth (or viviparity) has been documented in several other groups of Mesozoic aquatic reptiles, no previous evidence of it has been found in the important order of plesiosaurs. Drs. O'Keefe and Chiappe have also determined that plesiosaurs were unique among aquatic reptiles in giving birth to a single, large offspring, and that they may have lived in social groups and engaged in parental care.

"Scientists have long known that the bodies of plesiosaurs were not well suited to climbing onto land and laying eggs in a nest," Dr. O'Keefe stated. "So the lack of evidence of live birth in plesiosaurs has been puzzling. This fossil documents live birth in plesiosaurs for the first time, and so finally resolves this mystery. Also, the embryo is very large in comparison to the mother, much larger than one would expect in comparison with other reptiles. Many of the animals alive today that give birth to large, single young are social and have maternal care. We speculate that plesiosaurs may have exhibited similar behaviors, making their social lives more similar to those of modern dolphins than other reptiles."

Plesiosaurs have no known living relatives, but were common in the world's oceans during the Age of Dinosaurs. They were among the top predators in the Western Interior Seaway, the vast, tropical body of water that split North America during the Cretaceous when waters from the Arctic Ocean and the Gulf of Mexico flooded onto the continent and met.

The remarkable NHM specimen was discovered in 1987 by Charles Bonner on the Bonner Ranch in Logan County, Kansas. Virtually complete except for parts of the adult's neck and skull, the "mother" specimen and her baby were given extensive conservation by NHM and then mounted for display by Phil Fraley Productions (Patterson, NJ) with the supervision of Drs. O'Keefe and Chiappe. The specimen is currently on display in the Dinosaur Hall, the new 14,000-square-foot exhibition at NHM featuring more than 300 fossils and 20 complete mounts of dinosaurs and sea creatures.

"Like many other specimens on display and in our collection, this extremely important specimen is among the significant fossils that can be admired and studied only here in Los Angeles," Dr. Chiappe stated. "We're very proud that at NHM, these irreplaceable materials are accessible not only to research scientists but to the public, giving people the opportunity to connect the quest for knowledge with the wonder of seeing the remains of these ancient and mysterious animals."


Story Source:

The above story is based on materials provided by Natural History Museum of Los Angeles County. Note: Materials may be edited for content and length.


Journal Reference:

  1. F. R. O'Keefe, L. M. Chiappe. Viviparity and K-Selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia). Science, 2011; 333 (6044): 870 DOI: 10.1126/science.1205689

Cite This Page:

Natural History Museum of Los Angeles County. "Fossilized pregnant plesiosaur: 78-million-year-old fossils of adult and its embryo provide first evidence of live birth." ScienceDaily. ScienceDaily, 12 August 2011. <www.sciencedaily.com/releases/2011/08/110811142806.htm>.
Natural History Museum of Los Angeles County. (2011, August 12). Fossilized pregnant plesiosaur: 78-million-year-old fossils of adult and its embryo provide first evidence of live birth. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2011/08/110811142806.htm
Natural History Museum of Los Angeles County. "Fossilized pregnant plesiosaur: 78-million-year-old fossils of adult and its embryo provide first evidence of live birth." ScienceDaily. www.sciencedaily.com/releases/2011/08/110811142806.htm (accessed August 22, 2014).

Share This




More Fossils & Ruins News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Neanderthals Probably Died Out Earlier Than We Thought

Neanderthals Probably Died Out Earlier Than We Thought

Newsy (Aug. 21, 2014) — A new study is packed with interesting Neanderthal-related findings, including a "definitive answer" to when they went extinct. Video provided by Newsy
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Newsy (Aug. 15, 2014) — A mother and son in Alaska uncovered woolly mammoth tusks in the same river more than two decades apart. Video provided by Newsy
Powered by NewsLook.com
Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Newsy (Aug. 14, 2014) — Newly found fossils reveal a previously unknown species of flying reptile with a really weird head, which some say looks like a butterfly. 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