To Cope with Cold Winters, Polar Dinosaurs Burrowed Beneath the Ground

By Allison Bond | July 13, 2009 5:25 pm

ornithopodSome dinosaurs coped with the cold of winter by venturing beneath the Earth’s surface, according to a study to be published in the journal Cretaceous Research. Three fossilized burrows found in southeastern Australia are the second group of such tunnels found on Earth and, dating back 110 million years, are the oldest.

When dinosaurs roamed the Earth, these burrows were within the Antarctic Circle and temperatures dipped below freezing during the winter. Also, periods of little sunlight likely led to cyclical shortages in vegetation. The burrows support the hypothesis that instead of migrating to escape the cold winters of the Cretaceous period, dinosaurs ventured underground, like modern animals such as alligators and coyotes. The only other known dinosaur burrow was discovered in 2005 in Montana, US. Described two years later, this burrow dated from 95 million years ago and contained the bones of an adult and two juveniles of a small new species of dinosaur called Oryctodromeus cubicularis [BBC News]. Burrows that snaked below the ground may have provided a haven offering protection from predators, along with stable temperatures, constant humidity levels and a place to tend to offspring.

Scientists aren‘t sure which dinosaur species made the newly discovered burrows, but they suspect that the Australian tunnel also was once home to Oryctodromeus cubicularis. Previously, researchers theorised that the small dinosaurs in the region survived harsh weather by sheltering beneath large tree roots or in hollows. [This] find, however, indicates that they may have dug into the soft banks of rivers flowing out of the rift valley [Cosmos]. The burrows have not yet been excavated, but analysis of a 2.1-meter, or seven-foot, long burrow indicates that an animal weighing between 4.5 and nine pounds dug the tunnel.

The finding also suggests that dinosaurs in different parts of the globe, millions of years apart during the Cretaceous period, found similar ways to cope with harsh climatic conditions. The burrows were dug in soil deposited in a valley by massive spring floods of meltwater similar to those seen today on the north slopes of Alaska. The dinosaurs could have lived in the burrows in autumn and winter, but would have had to move out before the following year’s spring floods filled them with fresh sediment [New Scientist].

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Image: Wikimedia Commons. The skeleton of a related ornithopod.

CATEGORIZED UNDER: Environment, Living World
  • Sundance

    “Scientists aren‘t sure which dinosaur species made the newly discovered burrows, but they suspect that the Australian tunnel also was once home to Oryctodromeus cubicularis.”

    This makes no sense – I suspect a typo. O. cubicularis was most likely not living in both Montana and south-east Australia. That’s an awfully widespread species, unless it could build boats as well as dig burrows. It would make more sense if it was a species _similar to_ O. cubicularis, for instance an Australian hypsilophodontid like Leaellynasaura amicagraphica. In fact in the article in Cosmos the guy who discovered the burrows in Montana and Australia remarks that they were probably made by different species.

    None-the-less, it’s amazing how much more we know about dinosaur behaviour than we did when I was a kid. I remember books saying that dinosaurs didn’t burrow or climb trees. It’s nifty how we learn new stuff!

  • Nick

    110 million years ago, all the continents were mighty close.

  • debbie

    That just sounds retarded. Do alligators live in Alaska or Antarctica now or even close to either region? Did they even make it as far north as Kansas? No they did not because they cannot survive even that much cold. Alaska is frozen rock solid many feet down for 6 unending months. Antarctica is even worse. Even a burrow just would not do it even if they are hibernating. Why can’t scientists just figure out that we have sudden massive crustal shifts when the poles switch polarity. The magnetic iron core of the planet shifts polarity and abruptly switches direction just like any other electromagnetic motor. After the continental floods clearly described in many ancient stories, the massive earthquakes and hurricane winds for about 7 days we end up with about a 30 degree shift usually. Other things described in ancient times also are seen then such as the illusion of the stars falling and major aurora displays unlike anything seen in recent human history causing the planetwide squatting man images in many ancient petroglyphs. Look it up on google. Recent changes in recent ages have had the North pole at the Yukon, off Norway, near the Hudson and now in the middle of the Arctic. The Arctic shift was particularly devastating causing sea levels to cover many of our important cities under a couple hundred feet of ocean. Why are there tropical fern fossils in Antarctica and the arctic? Why did dinosaurs have a massive population in Northern Alaska, a region now very harsh even for creatures that could also survive on Hoth if they had too? Because those regions used to be much warmer even tropical. When the north pole was off Norway it is easy to see Alaska was much warmer. The dinosaurs were in a much older age. Who knows where the pole was then but since there is glacial evidence even in Madagascar it appears the current north and south pole used to be much warmer.

  • Paardestaart

    Well – maybe they did not go into hibernation to escape the cold; maybe they dug in waiting for rain! Did not a young biologist working in the desert in Egypty recently discover that crocodiles actually survive desert droughts by crawling underground waiting for the rainy-season?

  • JMW

    One wonders, if the dinosaurs burrowed to escape the cold, if they also stockpiled food…it’ll be interesting to see the results of excavating the burrows.

  • dan.versus@gmail

    debbie i hope we can talk, im so curious about this s**t

    i read the other day that every 62 million years (with a 3 million + or -) everything on earth gets wiped out.

    these mayans get cited as predicting 2012, but consider this. what if the mayans call 2012 what we call 2036


    i find this s**t so interesting hahhahaha

    [Moderator’s note: edited the cuss words.]


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