World's Oldest Embryo Fossils Shed Light on Dinosaur Parenting

By Jennifer Welsh | November 12, 2010 12:05 pm

dinobabyFossilized dinosaur embryos, found still in their eggshells, have claimed the title of the oldest vertebrate embryos ever seen–they were fossilized in the early Jurassic Period, around 190 million years ago, researchers say. The embryos are from the species Massospondylus, a prosauropod, the family of dinosaurs which gave rise to iconic sauropods like the Brachiosaurus.

Robert Reisz and his team found the embryos when analyzing a clutch of fossilized eggs collected in South America in 1976. The find was just published in the Journal of Vertebrate Paleontology.

“This project opens an exciting window into the early history and evolution of dinosaurs,” said Professor 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.” [BBC News]

dino-embryoThe well-preserved embryos are about 8 inches long and are detailed enough to give researchers a good look at what the juvenile Massospondylus looked like. What they found wasn’t exactly elegant. The juveniles looked similar to adult sauropods like Brachiosaurus, with an oversized head and four-legged strut (unlike the adult Massospondylus, which walked on two legs).

To some extent, these dinosaurs then developed as humans do today. The infancy is “awkward,” as the researchers put it, and a more erect stance and evenly-proportioned body only comes later. Additionally, the embryos lack teeth. With the awkward body proportions, it’s then likely that the hatchlings would have required parental care. If that’s the case, these fossils also document the oldest record of parental care, according to the paleontologists. [Discovery]

Related content:
80beats: Stay-at-Home Dinosaur Dads May Have Hatched Eggs and Cared for Young
80beats: The Dilemma of the Dinosaur Stance: How Did They Hold Their Heads?
80beats: Dinosaur “Mummy” Reveals a Creature With Bird-Like Skin
80beats: How Dinosaur Feet Evolved Into Bird Wings: New Fossil Provides Clues
80beats: New Fossil Suggests Dinosaur World Domination Started in S. America
Not Exactly Rocket Science: Dramatic restructuring of dinosaur feathers revealed by two youngsters of same species

Images: Heidi Richter, Diane Scott

  • megan

    For the absent freaks who are posting more often at science blogs.
    “Thems just God’s creation destroyed during the flood and encased in mud. You’ve no proof they’re millions of years old. Neanderthals ate them for lunch and died out too at the same time. “

  • Felix Rocha Martinez

    To Megan and those interested in fresh options of evolution:
    Please read Richard Dawkin’s article “The Angry Evolutionist” and my reply to him in three parts in
    Among so many other things you will find that the oversized head is more common to many species than what most people believe and you will also find a new pattern of evolution in which big heads are integral part of it.
    There are many articles, take time to read them. You will find them interesting.
    Felix Rocha Martinez

  • aj

    190 million years old ?!? That is so ridiculous that it is almost frightening to think that some people believe it. Get with the program. Evolution is dead and has been proved dead over and over again. It is way past the time for humanity to start thinking about other ways that we may have gotten here. And it sure as feck ain’t evolution. Find me one scientist that truly, 100%, without a shadow of a doubt, believes in evolution and I will show you a complete stubborn non-thinking-clearly idiot. Richard Dawkins Whatever His Name Is is on the top of that list.

  • Dante The Canadian

    aj, why so angry? Evolution, in some way, shape or form, IS HOW WE ALL GOT HERE. It’s the ONLY EVIDENCE THERE IS. Fossil records, current DNA studies, and observation of adaptations occurring in current flora and fauna all show that EVOLUTION is still active. What is YOUR idea? Aliens? Have any PROOF???? What about God? Want to PROVE THAT ONE FOR ME? Not with theological gobbledy gook or passages from a book WRITTEN BY MEN FOR MEN, but with actual EVIDENCE!!!

    See, the problem for me with other ‘theories’ regarding life and how we got here, is that there IS NO PROOF from those other theories. The only theory to be able to explain the fossil record and the distinct specialization of certain species is??? TAH DA!!!!!! EVOLUTION!!!!

  • Dante The Canadian

    Oh and one more thing, your inability and the inability of people being able to comprehend the vast amounts of time (190 Million years old for example) that REAL HISTORY has happened in, tells me how narrow your paradigms are and how misguided you are on the age of the planet, the solar system, and the universe. If you think humans, life, the planet, the solar system, or the universe were created in a matter of thousands of years, then I have some penny stocks you should invest in. Don’t worry, God told me they would grow exponentially and make us rich!!!!

  • Adam

    As a kid, I was fascinated by dinosaurs (like many children) and read as much as I could about them. It amazes me how much our perceptions have changed about these creatures in the last 20 or so years. Dinos with feathers, endothermic metabolism and now……considerable parental investment? I’m more fascinated than ever. I can only imagine what we will discover next.

  • http://Discover Terri

    The internet is truly amazing, and thank goodness we can access the latest information. Its sad that often our schools don’t keep up. IE; Electronics still being taught using 100 year old technology. School books ie: Science out of date. I think we all have to think out of the box somewhat when dealing with such issues above. All life adapts, it must overcome to insure survival. Quickly to Adam, I always hoped i’d see the day when we had “visual” phones like the Jetson’s cartoon when I was a kid, sure enough… Our planet is truly amazing, every creature specifically designed to do its part in keeping things balanced, I can’t imagine that everything just “miraculously” came together. When I was in Hawaii I saw some huge rainbow gum trees known for its multicolored bark. Light green, dark green, tans, almost florescent , about 7 shades. The lines of color ran up and down but somewhat twisted I thought of its creator, like a child with play dough, twisting and pulling until perfect. So it took a while.

  • aj

    Thanks Dante for your enlightening comments. I am glad there are people around like you that have it all figured out. Fossils explain evolution. Thank you again for enlightening me. Is there any way I can become a member of your fan club?And that life on this planet is millions and millions of years old. Cheers again. God? Aliens? Anger? You lost me there. If you do ever decide to pull your head out of your evolutionary arse then TA DA!!! You might realize the fossil record does not prove anything. How we got here? Feck knows….

  • Ganzjahresreifen



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