WEBVTT - BrainStuff Classics: What Can a Cache of Pterosaur Eggs Teach Us?

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<v Speaker 1>Welcome to brain Stuff production of I Heart Radio. Hey

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<v Speaker 1>brain Stuff, I'm Lauren vogel Bomb and this is another

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<v Speaker 1>classic episode from our archive. Every time a new cash

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<v Speaker 1>of the remains of incredible prehistoric animals crops up, it's

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<v Speaker 1>cause for celebration. In this episode, we dig into the

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<v Speaker 1>amazing find of hundreds of parasaur eggs. Hey there, brain Stuff,

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<v Speaker 1>Lauren vogel Bomb. Here. Flight is a hard thing to master.

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<v Speaker 1>The vast majority of vertebrates can walk, swim, or do both,

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<v Speaker 1>but in the history of life on this planet, only

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<v Speaker 1>three groups of backboned animals have ever evolved the ability

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<v Speaker 1>to fly. Early bats acquired the skill roughly fifty two

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<v Speaker 1>million years ago. Feathered dinosaurs began to experiment with flight

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<v Speaker 1>back in the Jurassic period. Incidentally, you probably know of

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<v Speaker 1>their descendants today as birds. Yet while birds and bats

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<v Speaker 1>are still around, the animals that first pioneered vertebrate flight

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<v Speaker 1>are long gone. That's because hundred and twenty eight million

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<v Speaker 1>years ago, a flying plade of reptiles evolved. These were

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<v Speaker 1>the pterosaurs. Though Hollywood often mislabels them as dinosaurs, they

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<v Speaker 1>actually represented a separate, contemporaneous group for more than a

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<v Speaker 1>hundred and sixty million years, dinosaurs and pterosaurs lived side

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<v Speaker 1>by side. It was an exciting time to be an aeronaut.

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<v Speaker 1>During their reign, the pterosaurs diversified like crazy. Some species

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<v Speaker 1>would be comparable to sparrows in size. Others had wingspans

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<v Speaker 1>of thirty six feet that's eleven meters or more, making

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<v Speaker 1>them the largest flying animals of all time. Then, sixty

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<v Speaker 1>six million years ago, the pterosaurs succumbed to the same

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<v Speaker 1>mass extinction that wiped out all non avian dinosaurs. In

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<v Speaker 1>four Italian naturalist Cosmo Collini became the first person to

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<v Speaker 1>write a formal scientific description of a pterosaur skeleton. At

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<v Speaker 1>the time, he thought this strange looking animal was some

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<v Speaker 1>kind of deep sea creature. But thanks to hard working paleontologists,

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<v Speaker 1>we've learned a great deal about these winged wonders. Nonetheless,

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<v Speaker 1>there are still some large gaps in our knowledge. One

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<v Speaker 1>big mystery involves the early lives of young pterosaurs. The

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<v Speaker 1>first confirmed dinosaur and nest was unearthed in nineteen twenty three.

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<v Speaker 1>Since then, fossil hunters have excavated thousands of dino eggs

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<v Speaker 1>sites all over the world. Yet terrasaur eggs are considerably rarer.

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<v Speaker 1>None whatsoever were discovered until two thousand four, when two

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<v Speaker 1>appeared in China and a third showed up in Argentina.

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<v Speaker 1>In twenty eleven, a fourth egg was found next to

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<v Speaker 1>the skeleton of its presumed mother, an adult animal from

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<v Speaker 1>the genus Darwin a terrace. Three years later and another

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<v Speaker 1>Argentinian egg emerged, along with five additional Chinese specimens. So

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<v Speaker 1>until very recently, the global scientific community hadn't found enough

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<v Speaker 1>terosaur eggs to fill as standard egg carton, but paleontologists

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<v Speaker 1>just hit the motherload. In the December twenty seventeen issue

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<v Speaker 1>of the journal Science, a Chinese research team announced the

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<v Speaker 1>discovery of a new site in China's Globi Desert containing

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<v Speaker 1>at least two hundred and fifteen pterosaur eggs. Sixteen preserved

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<v Speaker 1>embryos were found there as well, along with some skeletons

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<v Speaker 1>from hatchling, juvenile and adult pterosaurs. These eggs are roughly

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<v Speaker 1>a hundred and twenty million years old and were laid

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<v Speaker 1>by Hamateus tiensnsis a crusted toothy species with an eleven

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<v Speaker 1>foot wingspan that's about three point three meters. Terrasaur experts

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<v Speaker 1>are still trying to assess where it belongs on the

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<v Speaker 1>family tree. One such authority is paleontologist David Hohne, who

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<v Speaker 1>told us in an email that Hamateus' closest relatives were

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<v Speaker 1>most likely various groups of terrasaurs known for being ocean

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<v Speaker 1>going or at least coastal foragers. In terms of lifestyle,

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<v Speaker 1>he says these animals would have behaved like today's gulls

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<v Speaker 1>and albatrosses. The newfound bounty of eggs was recovered by

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<v Speaker 1>a team representing the Beijing based Chinese Academy of Sciences.

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<v Speaker 1>Most of the shelled treasures were embedded in a sandstone

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<v Speaker 1>block that may be hiding even more clutches that have

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<v Speaker 1>yet to be revealed. One reason why this find is

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<v Speaker 1>so spectacular has to do with the fragility of terrasaur eggshells.

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<v Speaker 1>Like modern chickens, extinct dinosaurs laid hard shelled eggs. Contrast

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<v Speaker 1>these with the eggs of present day snakes, whose shells

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<v Speaker 1>are thin, soft, pliable, and have the xture of old parchment.

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<v Speaker 1>Terrasaur eggs resembled the ladder, a fact confirmed by previous discoveries.

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<v Speaker 1>Because their shells were so soft, these rare eggs tend

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<v Speaker 1>to get squitched flat by the forces of fossilization, Yet

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<v Speaker 1>the ones that this new Chinese site were preserved in

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<v Speaker 1>three dimensions. The discoveries implications are still open to debate.

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<v Speaker 1>Chinese Academy of Sciences paleontologist Shallon Wang was the lead

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<v Speaker 1>author of the paper in the journal Science which announced

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<v Speaker 1>this big find. In it, he and his co authors

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<v Speaker 1>suggest the site may have a lot to say about

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<v Speaker 1>terrasaur parenting. As Whang and his colleagues point out, some

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<v Speaker 1>of the embryo's lack teeth and their wingbones seem underdeveloped.

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<v Speaker 1>The paleontologists think this could mean that newly hatched Hamma

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<v Speaker 1>terrists could neither fly nor eat solid food. Thus they

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<v Speaker 1>would have had to depend on their parents for protection

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<v Speaker 1>and sustenance. Other scientists have disagreed with that conclusion. In

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<v Speaker 1>present day reptiles, teeth are one of the last things

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<v Speaker 1>embryos developed, so while these developing terosaurs were toothless, they

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<v Speaker 1>might still have grown some choppers before had ching. Also,

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<v Speaker 1>according to Michael Habib, a pterosaur specialist at the University

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<v Speaker 1>of California, the fetal wings appeared quite robust, meaning the

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<v Speaker 1>newborns might have been able to start flying right away.

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<v Speaker 1>A point of consensus among paleontologists, though, is that pterosaurs

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<v Speaker 1>probably didn't brood their eggs like present day birds. For

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<v Speaker 1>one thing, as Homee told us, the extinct reptiles simply

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<v Speaker 1>could not sit like birds due to the anatomical differences. Also,

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<v Speaker 1>while terrasaurs were coated with fuzzy stuff, they lacked feathers,

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<v Speaker 1>which roosting avians used to keep their clutches nice and warm.

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<v Speaker 1>Another leading expert in modern terrasaur science one S Christopher

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<v Speaker 1>Bennett of Fort Hayes State University in Kansas, agrees. He

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<v Speaker 1>said via email, there's no evidence and no reason to

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<v Speaker 1>think that terosaurs incubated their eggs. Rather, they probably deposited

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<v Speaker 1>them in sands, soils, or vegetable matter, like modern reptiles.

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<v Speaker 1>In the past, Bennett has championed the idea that at

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<v Speaker 1>least some terrasaurs formed nesting groups near environments suitable for

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<v Speaker 1>the hatchlings to feed and grow safely. He feels the

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<v Speaker 1>new Hemiates site may lend some credence to that notion,

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<v Speaker 1>a sentiment shared by Weighing and his co authors, but

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<v Speaker 1>it added careful excavation of terrasaur egg deposits could certainly

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<v Speaker 1>provide evidence as to whether eggs were buried and whether

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<v Speaker 1>terrasaurs reused desting sites year after year. Today's episode was

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<v Speaker 1>written by Mark Mancini and produced by Tristan McNeil and

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<v Speaker 1>Tyler Playing. For more on this and lots of other

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<v Speaker 1>terrorific topics, visit housetuffworks dot com. Brain Stuff is production

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<v Speaker 1>of I Heart Radio. For more podcasts my heart Radio,

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