Plants and the Dinosaur Extinction


is this how you can I got your samples
how we do it Hey everybody! Welcome back to the valley of the last dinosaurs Today I’m sitting with my colleague Dr.
Antoine Bercovici. Hi everyone Antoine is a postdoctoral fellow at the
Smithsonian Institute and he’s here collecting samples for his paleo
botanical research so break that big word for me down what’s paleobotany all
about? so paleontology is the study of
animal life on Earth, fossil animal life and paleobotany is the study of fossil
plant life ok fossil plants got it. so do you
actually find lots of fossil plants out here? well actually for the past 30 years
people have been finding a tremendous amount of fossil plants, beautiful leave
impressions from all over those rocks and I there is also wood that you can
find. So leaves and wood. i think I’ve seen seen a few leave fossils but i don’t
really have a trained eye yet what else we’re gonna plant bottles you stumble
upon out here well there is that kind of plan fossil
thats everywhere here that we cannot see because it’s microscopic its fossil
pollen oh really. Tiny pollen and actually makes
a fossil? that’s so cool so i don’t think i’ve
ever seen any of that. How would i know if I’d seen that? well as I said it’s everywhere in
microscopic so you cannot see it in the field that you can take sample here back
to the lab. Process it and then look at it under a microscope all that’s so cool that must be why
you’re doing this huge trench every time I see you, you ha’ve got a spade in your hand and you’re out here riffing these huge tall holes Absolutely. So the problem here is that
we are working in soft rock and are not very hard rock like granite, so we can
basically remove it with your hand it just crumbles and erosion actually smear
all those contact and we actually need to to sample some very fresh rock in
order to avoid any sort of contamination I see, so you are actually cutting in
here to look for the actual layers of sediment that were laid down in the
order that they were laid down So Tyler told me a little bit
about your research and said that actually the fossil pollen is very
important for finding the KT boundary how does that work? so it is because just like the dinosaurs
went extinct and other animals when extinct to plant suffered the mass
extinction at the end of the cretaceous plants produce pollen and
spores, so by looking at the pollen record you can track this extinction as
well now the great thing about pollen and spores I
said that their makeup microscopic they’re very small so you can find
millions of them in this outcrop and sample them at a centimeter scale every
centimeter by centimeter and find a point where i actually you see this
changing floor that correspond to the mass extinction event oh wow so when the
ecosystem change with the ex with the extinction you can see that record and all the tiny
little pollen grains in a little piece of rock this big that’s right you just
flip the switch plans getting extinct and in a chip off rock like this one
that you just picked up I can find probably 100,000 pull
ingredients for so there’s a lot of data right there oh man so I guess the resolution is a
lot better when you’re dealing with tiny little microscopic fossils of dinosaur
is a huge thing meters and meters in length but with the pollen you’re able
to pick I guess what precision level you have a
centimeter that’s yeah if you can get down to one centimeter and pick out the
boundaries you can find the actual boundary and then we have a time line
across all those those holes it’s been digging out that indicates this this
point of extinction and all the entire field area that’s what we’re tracking
gosh that’s so cool so if you haven’t sampled all this yet but do you have a
guess where you might think the KT boundary is in the section that were
sitting in right now yes well we actually doing a lot of
those trenches all across and in some of those of you – actually I have actually
process that and it seems like you’re actually sitting right on the KT Boundary right there so wait right here underneath here yeah no way that’s so cool all that
crazy destruction of mass extinction right here in a fine layer and we
wouldn’t know what to make it out you have to use those microscopes backing
off they do that yes so you’ll take bags of this sample
material back to the lab and you’ll be looking at my guess all winter yes trying to make sense of this. how many of these trenches have you dug out here in this little area that we’ve been
in all summer? probably a dozen — yeah so a lot of
microscope slides to look at hundreds of thousands of individual pollen grains
that check out and it sounds like a big project but we really appreciate you
taking a minute to tell us about your research today and you guys at home check back in with this this week we’re
going to show you some of the images that and want to share with us from his
lab through the microscope looking at what looks like dirt right here too naked eye there’s a whole universe of
tiny plant fossils right here right yeah and the good thing is that you’re not
running out of dirt here it’s all over the place so that’s good you have
another shortage of dirt here i think i’ve got plenty on my pair of jeans back
probably sample but anyway thanks for tuning in guys ok I’ll come on back at the end of the
week and we’ll check back in with Antoine here in the valuable last
dinosaurs later yeah