News / Science & Technology

Dinosaurs May Have Sat on Eggs Like Chickens

Darla Zelenitsky, assistant professor in the Department of Geoscience at the University of Calgary, explored the unusual nesting habits of the small meat-eating Troodon dinosaur by studying the shells of fossil eggs.(Photo:Jay Im)Darla Zelenitsky, assistant professor in the Department of Geoscience at the University of Calgary, explored the unusual nesting habits of the small meat-eating Troodon dinosaur by studying the shells of fossil eggs.(Photo:Jay Im)
x
Darla Zelenitsky, assistant professor in the Department of Geoscience at the University of Calgary, explored the unusual nesting habits of the small meat-eating Troodon dinosaur by studying the shells of fossil eggs.(Photo:Jay Im)
Darla Zelenitsky, assistant professor in the Department of Geoscience at the University of Calgary, explored the unusual nesting habits of the small meat-eating Troodon dinosaur by studying the shells of fossil eggs.(Photo:Jay Im)
VOA News
The theory that dinosaurs and birds share an evolutionary link just got stronger as scientists have discovered that a bird-like dinosaur may have incubated its eggs much like a brooding chicken.

The study done by researchers at the University of Calgary and Montana State University examined fossilized groups of eggs from a small, meat-eating dinosaur called Troodon. The eggs were found in Alberta, Canada and Montana.

Due to the scarce amount of evidence, paleontologists have long searched for answers about how dinosaurs hatched their young. Crocodiles, a close relative of dinosaurs, bury their eggs in nesting material, usually sand or dirt, while birds lay their eggs in the open or non-covered nests. 

The Troodon appears to have laid its eggs vertically, with only the bottoms of the eggs buried in mud, concluded researchers in a finding that was published in the spring issue of Paleobiology.

“Based on our calculations, the eggshells of Troodon were very similar to those of brooding birds, which tells us that this dinosaur did not completely bury its eggs in nesting materials like crocodiles do,” says study co-author Darla Zelenitsky, assistant professor of geoscience at the University of Calgary.

The bird-like Troodon lived in North America 77 million years ago. Illustration by Julius Csotony, University of CalgaryThe bird-like Troodon lived in North America 77 million years ago. Illustration by Julius Csotony, University of Calgary
x
The bird-like Troodon lived in North America 77 million years ago. Illustration by Julius Csotony, University of Calgary
The bird-like Troodon lived in North America 77 million years ago. Illustration by Julius Csotony, University of Calgary
Researcher David Varricchio of Montana State University added that the eggs studied indicated only a “partial burial,” meaning “an adult would have directly contacted the exposed parts of the eggs during incubation.”

The bird-like Troodon lived in North America 77 million years ago.

A key to the finding was comparing the number of pores in the Troodon’s eggs to those of crocodiles and other birds that completely bury their eggs. Pores allow for respiration, and crocodile eggs have more pores than those of a brooding bird. In the case of the Troodon eggs, there were relatively fewer pores indicating the eggs may not have been completely buried.

“For now, this particular study helps substantiate that some bird-like nesting behaviors evolved in meat-eating dinosaurs prior to the origin of birds. It also adds to the growing body of evidence that shows a close evolutionary relationship between birds and dinosaurs,” Zelenitsky says.

The study in Paleobiology is available here.

You May Like

Video One Year After Thai Coup, No End in Sight for Military Rule

Since carrying out the May 22, 2014 coup, the general has retired from the military but is still firmly in charge More

Goodbye, New York

This is what the fastest-growing big cities in America have in common More

Job-Seeking Bangladeshis Risk Lives to Find Work

The number of Bangladeshi migrants on smugglers’ boats bound for Southeast Asian countries has soared in the past two years More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Turkey's Main Opposition Party Hopes for Election Breakthroughi
X
May 22, 2015 10:23 AM
Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Turkey's Main Opposition Party Hopes for Election Breakthrough

Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Europe Follows US Lead in Tackling ‘Conflict Minerals’

Metals mined from conflict zones in places like the Democratic Republic of Congo are often sold by warlords to buy weapons. This week European lawmakers voted to force manufacturers to prove that their supply chains are not inadvertently fueling conflicts and human rights abuses. Henry Ridgwell reports from London.
Video

Video Class Tackles Questions of Race, Discrimination

Unrest in some U.S. cities is more than just a trending news item at Ladue Middle School in St. Louis, Missouri. As VOA’s Kane Farabaugh reports, it’s a focus of a multicultural studies class engaging students in wide-ranging discussions about racial tensions and police aggression.
Video

Video Mind-Controlled Prosthetics Are Getting Closer

Scientists and engineers are making substantial advances towards the ultimate goal in prosthetics – creation of limbs that can be controlled by the wearer’s mind. Thanks to sophisticated sensors capable of picking up the brain’s signals, an amputee in Iceland is literally bringing us one step closer to that goal. VOA’s George Putic reports.
Video

Video Afghan Economy Sinks As Foreign Troops Depart

As international troops prepare to leave Afghanistan, and many foreign aid groups follow, Afghans are grappling with how the exodus will affect the country's fragile economy. Ayesha Tanzeem reports from the Afghan capital, Kabul.
Video

Video Poverty, Ignorance Force Underage Girls Into Marriage

The recent marriage of a 17-year old Chechen girl to a local police chief who was 30 years older and already had a wife caused an outcry in Russia and beyond. The bride was reportedly forced to marry and her parents were intimidated into giving their consent. The union spotlighted yet again the plight of many underage girls in developing countries. Zlatica Hoke reports poverty, ignorance and fear are behind the practice, especially in Asia and Africa.
Video

Video South Korea Marks Gwangju Uprising Anniversary

South Korea this week marked the 35th anniversary of a protest that turned deadly. The Gwangju Uprising is credited with starting the country’s democratic revolution after it was violently quelled by South Korea’s former military rulers. But as Jason Strother reports, some observers worry that democracy has recently been eroded.
Video

Video California’s Water System Not Created To Handle Current Drought

The drought in California is moving into its fourth year. While the state's governor is mandating a reduction in urban water use, most of the water used in California is for agriculture. But both city dwellers and farmers are feeling the impact of the drought. Some experts say the state’s water system was not created to handle long periods of drought. Elizabeth Lee reports from Ventura County, an agricultural region just northwest of Los Angeles.
Video

Video How to Clone a Mammoth: The Science of De-Extinction

An international team of scientists has sequenced the complete genome of the woolly mammoth. Led by the Swedish Museum of Natural History in Stockholm, the work opens the door to recreate the huge herbivore, which last roamed the Earth 4,000 years ago. VOA’s Rosanne Skirble considers the science of de-extinction and its place on the planet
Video

Video Blind Boy Defines His Life with Music

Cole Moran was born blind. He also has cognitive delays and other birth defects. He has to learn everything by ear. Nevertheless, the 12-year-old has had an insatiable love for music since he was born. VOA’s June Soh introduces us to the young phenomenal harmonica player.

VOA Blogs