December 5, 2025 • 38 mins
What dinosaurs and mammals survived the end of the Cretaceous, and why? What can we learn about resilience from survivors of past extinctions? What can we learn about adapting our culture and cities from the story of evolution? Featuring Matt Lamanna, Mary R. Dawson Curator of Vertebrate Paleontology at Carnegie Museum of Natural History, and John Wible, Curator of Mammals at Carnegie Museum of Natural History.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Michael Pisano (00:09):
You're listening to the Anthropocene Archives, a
presentation of We Are Nature.
In this special series ofstories, we're delving deep into
Carnegie Museum of NaturalHistory's 22 million collection
items, raiding cabinets andcases, sifting through objects
and organisms in search ofstories of stewardship,
solutions, and scientificwonder.
On today's episode, mammals ofthe Late Mesozoic, a disastrous
(00:36):
day for dinosaurs, and what wecan learn about resilience from
extinction survivors.
Hop in, we're going to HellCreek.
(00:57):
Welcome to We Are Nature, a show about natural histories and livable futures. I'myour host, a collection of 206
bones, Michael Pisano, and todayI'm joined by two expert bone
collectors.
Friends, would you pleaseintroduce yourselves?
John Wible (01:05):
I'm John Wible, Curator of Mammals, and I study
everything about mammals, theirorigin, their evolution, their
distribution on the planettoday.
Michael Pisano (01:14):
Excellent.
Matt Lamanna (01:14):
And I'm Matt Lamana, Curator of Vertebrate
Paleontology, and I studydinosaurs in particular, and
especially dinosaurs from thesouthern hemisphere continents
at the end of the age ofdinosaurs.
Michael Pisano (01:24):
Excellent.
Thank you both so much forjoining me today and for
bringing us behind the scenes ofyour respective collections
here at the museum.
I wanted to maybe start byhearing a little bit about those
collections.
So could you tell me about thevertebrate paleontology
collection, the scope of it,scale?
Matt Lamanna (01:38):
Sure, sure.
So the VP collection has um wethink about 120,000 specimens in
it.
Um which sounds impressive, butwe're actually quite small
compared to some of the othercollections, at least in terms
of number of specimens.
Michael Pisano (01:50):
Oh sure, we've already talked to insects.
Matt Lamanna (01:52):
Yeah, no, totally.
Michael Pi (01:53):
It's not a contest.
Matt Lamanna (01:54):
Yeah, no, I think we have them on volume, but they
um they have us on number forsure.
Um but yeah, our collectionranges in age from I think the
oldest, so we're fossils ofbackboned animals, so that's
vertebrate paleontology.
So, you know, fishes throughamphibians, through reptiles,
through birds, through mammals.
Um and I think about the oldestfossil we have is in the
(02:14):
ballpark of maybe 450 to 500million years old.
And then the youngest things wehave are, you know, a few
hundred years old, somethinglike that.
Michael Pisano (02:21):
Excellent, excellent.
And I want to hear the samething about the mammal
collection.
John Wible (02:25):
So we have about 130,000 specimens from all over
the world.
Michael Pisano (02:30):
Probably go.
John Wible (02:31):
I know, yeah, from all continents except
Antarctica, because there are nomammals that are native to
Antarctica.
There are some in the waters.
Michael Pisano (02:39):
Sure, whales, I imagine.
Yep, that are hanging outthere.
John Wible (02:43):
Um, and um we have a vast array of diversity, so we
cover an incredible range of uhspecies that are around today,
and a couple of species that areno longer with us, which is one
of the things I'm gonna talkabout today.
Michael Pisano (02:57):
Yes, I'm looking forward to getting into that.
Um you mentioned diversity, andI wonder out there in the
world, what is the diversity ofmammals or the species of
diversity?
John Wible (03:05):
Right.
So there are about um 6,500species today, and uh if you
look at the major groups ofmammals, about half of those
6,500 are rodents, those arethings like uh chip munks and
squirrels and beavers and thingswith ever growing incisors.
A third of the diversity arebats, which usually surprises
(03:28):
people how many different kindsof bats there are.
And the remaining one-sixth iseverything else.
So all those things that youthink of as mammals when you go
to the zoo fit in that one-sixthof the diversity.
Michael Pisano (03:39):
Incredible.
Um about the number of knowndinosaurs.
I know this is a very much anongoing thing, but do you have a
kind of broad tally of speciesdiversity?
Matt Lamanna (03:48):
You know, that's a good question.
Um, well, so what's one figurethat's often quoted, and this
surprises a lot of people, isthat a new dinosaur, a new
dinosaur often at least aspecies, um, usually a genus.
So the the larger group thatthat you know, at least in the
modern world, contains multiplespecies.
A new genus of dinosaursdiscovered um something like
(04:09):
every two weeks.
Um so, like, yeah, in mycareer, I've I've been involved
with the discovery of um, Ithink it's 18 dinosaurs slash
birds from the Cretaceous, um,and birds we think are descended
from dinosaurs.
And I think when people firsthear that, they're like, wow,
that's really cool and awesome.
And then I tell them, oh yeah,well, we discover a new species
(04:30):
every two weeks, so it's reallynot that big of a deal.
Michael Pisano (04:32):
I mean, I've been at this for a long time.
It's quite an accomplishment,I'll say, either way.
I have to imagine, not all ofthat is just, you know,
paleontologists toiling out inthe field digging up new things.
There's also discovery thathappens in places like this.
Matt Lamanna (04:45):
Oh, 100%.
Absolutely.
In fact, we um we likely haveum a colleague of mine uh in
Germany identified what'sprobably may well be a new
species of dinosaur in ourcollection that we've actually
had since 1903 or 1902, andnobody just recognized it, took
the right eyes like coming alongand seeing it to realize what
(05:06):
it was.
So yeah, like, yeah, and howmany dinosaurs have been
discovered thus far?
Um, it depends on how many ofthese genera or species are
valid.
In other words, whether they'retruly distinct from each other.
Sure.
Um, and I should back up alittle bit and say a genus is
like, you know, you can thinklike like our species Homo
sapiens, the genus is homo, thespecies is sapiens, you know,
(05:28):
tyrannosaurus rex, genustyrannosaurus species
tyrannosaurus rex.
Um in the ballpark there,you're talking probably about a
thousand and maybe more validdinosaurs these days.
Um and again, the number isincreasing all the time.
Michael Pisano (05:43):
Which we love to see.
Um, so we've got a bunch ofbeautiful things on the table
that I want to talk about today.
I think we should jump in.
Um, and maybe we could start asa segue with one that I know
you were involved with thediscovery of.
Matt Lamanna (05:56):
Sure.
So um this is uh the fossilthat I brought that's nearest
and dearest to my heart.
Um so I mentioned that I've hadthe privilege to be involved
with the naming of a bunch ofnew species of dinosaurs, and
this is a piece of one of those.
MacKenzie Kimmel (06:21):
Collection item one is four and a half
inches in length and half aninch in thickness.
It tapers from a two-inch widebase to a keen point.
It curves like a menacingblade.
The fossil is a lustrous warmbrown reminiscent of
(06:43):
mineral-rich pottery.
A shallow groove bisects itsgently burnished surface.
Can you identify collectionitem one?
Matt Lamanna (07:03):
So this is a claw from a hand.
Uh it looks something like aum, you know, the blade on a
scythe, like what a reaper, um,you know, the grim reaper is
always shown with, you know,given that we're sort of in the
proximity to Halloween.
Yeah, exactly.
Um but this um uh this clawwould go on the hand of this
dinosaur.
Um uh it would be, and this issuper cool too.
(07:25):
So the when you see a fossilclaw, you're only looking at the
bony part, the bony core of theclaw.
And so just like, you know,just like me with my fingernail
here, or if you have a cat athome and they're on their
scratching post and they'relosing their nails, basically,
uh, this would have been coveredwith the same material,
keratin, that that makes up ourfingernails and and makes up cat
(07:45):
claws and things like that.
So the upshot there is that asbig as this claw is, it would
have been substantially biggerin life.
Um, and so very, veryformidable.
Michael Pisano (07:54):
Um and used for formidable ends.
What what do you think?
And maybe this is a time tointroduce this organism, you
know, who owned this claw?
Matt Lamanna (08:02):
Yeah, so this dinosaur is um a dinosaur called
Anzu wyliei.
It's a dinosaur that that uhagain several friends and I
named back in 2014.
And um it, you know, when youlook at this claw, you think
instantaneously this animal's,you know, grabbing other things
and eating them.
Um and that may well be thecase.
But when we look at the rest ofthe anatomy of Anzu, it's a lot
(08:23):
more like um if you know whatthe bird, like the a bird called
the cassowary is.
So they're you know, they looklike an emu kind of with a crest
on their head, um, sort of umthe males have these bright blue
faces.
This animal, Anzu, looks like agiant cassowary with with
elongate forelimbs tipped withclaws, unlike the modern
cassowary does.
(08:43):
Um we jokingly call this thingthe chicken from hell because it
does look like kind of like agiant chicken.
And so despite these, youknow, sort of raptorial claws, a
lot of the rest of the anatomyof Anzu sort of speaks to an
omnivorous lifestyle, somethingthat's eating both meat and
plants, not unlike cassowarys dotoday.
(09:05):
So cassowarys eat a lot offruit.
I think it's maybe the numberone component of their diet.
Um, but they'll also eat smallvertebrates, so small, small
backboned animals, you know,lizards, mammals, things like
this.
And I think it's probably fairto consider that Anzu may have
done something similar in itsenvironment.
So it's a um sort of a jack ofall trades, probably eating, you
know, eating fruit, eatingleaves, um, but also eating, you
(09:25):
know, animal protein when ithas the opportunity.
Michael Pisano (09:28):
And speaking of small prey, and this might take
a little bit of context settingabout when this creature uh was
alive and where it was alive,I'm curious about the landscape
and what other organisms wouldhave been there, including
perhaps what mammals were up toat that time.
Matt Lamanna (09:42):
Sure.
Um so this animal comes from arock unit called the Hell Creek
Formation.
It dates to about 68 to 66million years ago and um crops
out um over a broad swath of theRocky Mountain region.
So South Dakota, North Dakota,Montana.
There are equivalent rocks inAlberta and uh and Wyoming, uh,
(10:03):
Colorado, elsewhere.
Um this animal would haveroamed Western North America
sometime between 68 and 66million years ago.
Back then, it was not theenvironment that we have today.
Uh, it's often been ourreconstructions of the
environment have often beencompared to, like, say, the
Louisiana bayou or somethinglike that.
(10:23):
So humid, warm, very rich invegetation, um, uh, you know,
probably with, you know, withwith wetlands in places and
things like that.
Um, as for the other animalsthat were living with this
thing, it's like you look atthis claw and you think, oh,
maybe this thing's at the top ofthe food chain.
Absolutely not the case.
(10:44):
There were a bunch of thingsthat wanted to make chicken
nuggets out of a chicken fromhell.
Um, and uh and the most famousof those is Tyrannosaurus rex.
And so this is what I broughthere is a copy of a T. rex
tooth.
Um, so what I'm holding forpeople that are listening is um
it's large and black, and I wantto say about 10 inches long.
(11:04):
Uh the part um uh the part thatgoes above the jaw, the part
that you would see if you happento be there when the animal
opens its mouth and literallythe last thing you saw.
Michael Pisano (11:14):
Right, unfortunately.
Matt Lamanna (11:15):
Exactly, it would be um, you know, this part about
again, about maybe three and ahalf, four inches long,
something like that.
Um, the rest of this is theroot of the tooth, and so would
have sat inside the massive jawsof this thing.
Um, and so you know, I don'tthink I need to describe a
T. rex for viewers at home, butum, but this animal was
absolutely the top of the foodchain in the Hell Creek
Formation ecosystem.
(11:36):
And when I say formation, uh aformation is a set of rocks
deposited in a specific time ina specific place, but you can
think of it like a fossilizedecosystem, like so a fossil
environment with animals andplants and you know, and and uh
the the land, the wholelandscape uh mixed in.
Michael Pisano (11:53):
You know, uh there's like maybe a common
conception that mammals, theirlifestyle is like scuttling
around under the feet of thesegiant, you know, uh charismatic,
fun animals.
I don't hear a lot aboutmammals in the Cretaceous.
I imagine it has to be a morecomplex picture than that.
Would you give us a little bit?
John Wible (12:09):
So in the Hell Creek Formation, there's quite a
mammal fauna that we alreadyknow about.
Um but most of it is prettysmall.
Uh I would say the largestwould have been maybe a cat
size, maybe a small cat size.
Uh most of the most of themammals that would have been
much smaller than that.
Uh you can think of the mammalsthat were there probably in two
(12:30):
different major groups, thosethat are related to things that
are on the planet today, andthose that have no relations
whatsoever to anything.
Um the proportions of those maybe somewhat equal.
Um so we had some holdoverscoming from ancient uh Mesozoic
groups that survived, and thenwe had these new forms that um
(12:54):
show up uh before the Hell Creekformation, but then it continue
on into the Cenozoic, into theage of mammals, right?
Michael Pisano (13:02):
And I think we'll let's let's wait on that
because we are going to talkabout that transition for sure.
Can you take us back a little?
I I imagine that it willrequire um like an infinite
amount of glossing over, but canyou give us a little bit of the
evolution of mammals?
When did we first start gettingthis you know group that now is
so charismatic and feels sodominant in our culture?
John Wible (13:24):
Well, so it that's actually a kind of a hard
question to answer becauseyou're looking at a continuum of
time and you're just gonna say,okay, where do I draw the line?
So we've got this long lineagethat arose with about the same
time the dinosaurs did.
So mammal ancestors have beenaround for hundreds of millions
of years.
Uh we like to say probably 200million, 220, I mean something,
(13:49):
something in that ballpark.
Uh and then there was a veryslow slog in terms of increasing
mammalness, right?
Taking on features that we thatwe associate with mammals
today.
Now, and one of the problemswith that is that most of the
features that we associate withmammals today are actually soft
tissue features.
(14:10):
So hair is one example.
Um producing milk.
I mean, these are things thatwe can't see.
Well, actually, we can see hairin the fossil record if we're
really lucky with thepreservation.
But most of them we can'treally see.
So um it just, you know, thereare sort of arbitrary lines that
get drawn in terms of talkingabout what those mammals were.
(14:35):
The the bottom line is that formost of the extent of the
Mesozoic mammals were reallysmall.
Michael Pisano (14:40):
All right.
John Wible (14:41):
Um true size really does work.
Uh something that gets up tolike a cat or a small dog is a
giant.
Um most of the mammals weassume were nocturnal.
Michael Pisano (14:54):
Okay.
John Wible (14:55):
Um, and that may be our bias that we think that they
couldn't survive with those bigdinos chasing them around
during the day.
It's a convenient story, theywere hiding during the day, came
out at night.
And but it's interestingbecause um we do have some
reasons to think, at least forcertain things, that they were
nocturnal.
So, for example, we know all abunch of different gliding
(15:17):
mammals were around during theMesozoic, starting in the
Jurassic.
We had these beautifulpreserved specimens that show us
they have wing membranes.
So we know that they weregliders.
It's a thing like a livinggliders are not.
All living gliders arenocturnal.
Right.
So I it's like, is it gonnabuck the trend in the past?
(15:40):
Yeah, maybe it did.
But those are the sorts ofinferences that we can make
based on modern mammals.
Michael Pisano (15:46):
Excellent.
Thank you.
Matt Lamanna (15:49):
And there's there is evidence too, like for
despite the overall small size,especially when you view it
through today's lens of mammals,there's in addition to
morphological diversity, likethe way that you see with a you
know gliding mammal versus a youknow an insectivorous mammal or
something like that, there'sexcellent evidence, and John has
been a part of a bunch of thesediscoveries, um, for lots of
(16:12):
ecological diversity in mammalsas well.
Like so there, we have evidenceof digging mammals in the
Jurassic and Cretaceous.
We have, as John said, glidingmammals, swimming mammals.
Um, of course, the you know,the the the animals that people
think of when they think ofmammals from the age of
dinosaurs, little insectivorousthings that are you know
shrew-like things.
(16:33):
There's uh a the one of thelargest Mesozoic mammals, um,
there's evidence that it preyedon dinosaurs, at least baby
dinosaurs, some of the time.
Um so it is absolutely truethat mammals during the age of
dinosaurs were on average muchsmaller than they are today.
Um, but they do seem to havebeen more diverse than we were
giving them credit for for along time.
John Wible (16:53):
Yeah, one of the big advances that's happened in the
last 50 years is the fact thatwe know so much more about
Mesozoic mammals.
I think in the early discoverydays, when people were looking
in the Mesozoic, they werelooking for dinosaurs.
And dinosaurs were easier tofind than the mammals were.
And now we have people with atotally different search image
(17:14):
looking for tiny things.
So we're discovering all sortsof things about the mammalian
fauna.
And Matt's right.
I mean, the the diversity thatwe know, tree climbers, things
that are terrestrial, I mean, itthey're they're just they're
all over the map.
The only two niches that we wedon't really have in the
Mesozoic that we have todaywould be flyers.
Michael Pisano (17:36):
Sure.
John Wible (17:37):
So there's no dedicated flyers like bats that
we know from the Mesozoic.
And the other thing would belike whale-like things.
So things that are dedicated tobeing aquatic.
We have aquatic-like or whatyou would probably call
semi-aquatic mammals.
Matt Lam (17:53):
Beaver or otter-like.
John Wible (17:53):
Beaver-like, yeah, muskrat, things like that.
But nothing like a whale.
Michael Pisano (17:58):
Very cool.
Well, so something veryimportant happened in the
evolution of mammals anddinosaur and bird lineages about
66 million years ago.
I think most people arefamiliar, but could someone kind
of describe that event veryquickly?
Matt Lamanna (18:12):
Sure, I'll take a stab and John can fill in where
I where I mess up.
Um, but yeah, so uh 66 millionyears ago, uh non-avian
dinosaurs, so we call what wecall non-avian dinosaurs, so so
all dinosaurs, with theexception of birds, um their
descendants, birds, uh disappearfrom the planet seemingly
(18:33):
globally.
And the um the causal mechanismthat most paleontologists and
geo geologists agree on uh goessomething like this.
So a you know a giant, roughlysix-mile-wide asteroid falls out
of the sky, uh hits in what'snow the Yucatan Peninsula.
There's some evidence that thatthere may have been fragments
of it that hit in other placesas well, um, causes basically
(18:58):
global environmentalcatastrophes.
I mean, of course, everythingat ground zero would be
obliterated instantly, but butit was the longer-term um
consequences of this that reallyI think had more profound um
impacts on evolution anddiversity.
Um, so yeah, over the course ofwe're not really sure, you
know, decades, hundreds ofyears, thousands of years,
(19:18):
something, you know, hundreds ofthousands of years, eventually,
as a result of this event andits consequences, non-avian
dinosaurs vanish from theplanet, leaving only their
descendants birds.
Um, so birds are a tiny, uh,there's more than 11,000 species
of birds today, but they are,in evolutionary terms, a tiny
branch of the dinosaurevolutionary tree, and just that
(19:40):
just so happen to be the groupthat we have today.
Anzu, just to be clear, eventhough it has a lot of bird-like
Hell chicken qualities, uh, isnot technically in that group,
right?
No, it's not.
Michael Pisano (19:52):
Can you talk about the distinctions?
Matt Lamanna (19:53):
Yeah, so that's that's an excellent question.
And it's kind of gets to whatJohn said is where do you draw
the line between mammal andnon-mammal?
Where do you draw the linebetween dinosaur and bird?
Um, the line is usually drawnat a famous fossil called
Archaeopteryx.
And this is this is a fossilthat's well known to a lot of
people.
Um it's the it the logo for theArcteryx clothing line of
(20:15):
outdoor gear takes its, youknow, is from the most famous
specimen of Archaeopteryx, theBerlin specimen.
Sure, it's got a yeah, exactly.
It's neck pulled back and avery iconic fossil.
Um, and so most paleontologistsconsider um Archaeopteryx to be
the the what we call theearliest diverging or the most
basal bird.
So in other words, um, we don'tlike to use the word primitive,
but the most sure the firstbird, so to speak.
(20:37):
Um and uh so if you're on theuh the bird side of
Archaeopteryx, you're a bird.
And if you're on the dinosaurside, you're a dinosaur.
And Anzu is um Anzu isextremely bird-like.
In fact, if you could take atime machine back 66 million
years ago to say South Dakotaand see one of these things in
the flesh, your first guesswould be wow, what a big,
(20:58):
weird-looking bird.
Um but it's it's evolutionarilyspeaking, it's not quite a bird
because we don't think it'squite as closely related to
modern birds as isArchaeopteryx, if that makes any
sense whatsoever.
Michael Pisano (21:10):
I mean, we are humans, we strive to have these
definitions, these boxes that,of course, messy.
Matt Lamanna (21:15):
Exactly, totally.
Yeah.
And um that being said, uh, weknow from dinosaurs like Anzu
and its relatives that a lot ofthe features that we associate
with birds did not first evolvein birds.
And so there are numerousspecies of feathered dinosaurs
now.
Um animals that again are lessclosely related to modern birds
than is Archaeopteryx, and yetstill have feathers, still have
(21:35):
hollow bones, still have um uh awishbone.
A lot of the features that weassociate with birds today we
know actually date back tonon-avian dinosaurs.
Michael Pisano (21:57):
I'm curious, and I know this is, you know, maybe
a big question, but I'd love tohear you go back and forth
about it a little bit.
What was it that allowed birdsand mammals to kind of pass
through this long fallout perioduh after the impact in the
Yucatan?
John Wible (22:13):
Well, I can speak to the mammals and maybe I'll let
uh Matt speak to the birds.
So the the mammals, it's it'sinteresting.
Um so the the the 10 millionyears after the uh extinction
event, 66 million years ago, isa uh time that's known as the
Paleocene.
And the mammals that livedduring the Paleocene show some
(22:35):
interesting features thatdistinguish them from both uh
those that went before and thosethat came after.
One of the things that that'scome out uh in the last few
years is that they tend to bemore robust than the mammals
that were before and after.
And so they had heavier bones,heavier features on those bones.
(22:57):
And most of those are featuresthat we associate with uh
digging mammals.
So I like to liken it thatthey're actually the ones that
survived are the ones that coulddig themselves into a den, a
hole, and ride out the eventthat was killing everything
else.
(23:17):
Now that's somewhat fanciful,but it does seem to fit the data
that there's a lot of of thesesort of robust mammals that
first are the first 10 millionyears.
Michael Pisano (23:29):
What does that kind of tell you about the
fallout landscape?
I feel like that might behelpful.
Like if you were above ground,I'm sure globally there were
many different variations, butwhat kind of happened, right?
I mean, this thing hits theearth, I mean we imagine it
kicked up a bunch of dust, plantgrowth was compromised.
Can you guys just kind ofelaborate, paint that scene?
Matt Lamanna (23:48):
Yeah, I mean, I think the picture is, you know,
it sounds odd to say this 66million years later, but I think
the picture of that, of thatday and the weeks that weeks,
months, years that followed isstill developing.
Um but uh but yeah, there's uhfor instance, there's a a good
bit of evidence that they'rebasically the entire Earth
virtually caught on fire due tothese ejecta particles raining
(24:09):
back down onto the planet,heating to ignition, think like
uh, you know, anything likeshooting star entering our
atmosphere, you know, thingslike that.
Um, you know, when that stuffhits the ground, it's gonna set
any vegetate, you know, any dryvegetation at least on fire.
You know, um, so yeah, therewas a lot of um, there seems to
have been a lot of uh, you know,sort of global firestorms.
Uh, there certainly would havebeen, we have good evidence for
(24:31):
this, that at least in theimmediate region of the impact,
there would have been massivetsunamis that were kicked up by
this huge displacement of waterwith this big rock, Mount
Everest sized rock falling intothe water or partly into the
water.
Um so yeah, so um, and then ofcourse, with you know, with with
assuming that the you know,kicking dust into the atmosphere
and having a lot of it staythere for a long time, assuming
(24:52):
that's accurate, um, the thethinking is, as you said,
photosynthesis, so plants,plants are compromised, um, but
also temperatures drop as well.
Um, it's often been likened tothe you know, sort of um uh
nuclear winters that werehypothesized during the Cold
War.
You know, the people that madeit through a hypothetical war
would still have to sufferconsequences for quite a bit a
(25:13):
bit of time afterwards.
So so yeah, big giant rockfalls out of the sky, tsunamis,
you know, in the immediatevicinity at least, global
firestorms, uh, dust in theatmosphere, compromised plants.
Plants form the basis of thefood chain.
So once you knock out plants,you knock out everything else
eventually, or almost everythingelse, as we know, life didn't
completely go away.
But um, but yeah, it would havebeen a really, really crappy
(25:37):
day.
John Wible (25:38):
I liken it to um something that happened during
my lifetime.
You guys might be a little tooyoung to remember this, Mount
St.
Helens.
And I used to spend time in inthat area and um both before and
after.
And it's amazing how quicklyit came back.
Yeah.
So it was totally devastated.
There was at least I don'tknow, six miles, ten miles of
(26:01):
devastation where there was nolife, seemingly no life.
And yet within several years,greenery started to come back.
And I, you know, I mean, so Iliken it to that, that there's
gonna be total devastation, butthen there's a recovery phase
that's that's gonna lead to lifecoming back.
Matt Lamanna (26:20):
And I'm glad, John, I'm glad you brought up
volcanoes too, because I misseda big piece of the puzzle.
Yeah, so there's this, yeah,there's a uh a um volcanic
deposit in what's now India umcalled the Deccan Traps, and
it's thought to have been umdeposited over the course of a
few million years leading up tothe the end of the age of
dinosaurs.
So it's possible that you knowthat dinosaurs in non-avian
(26:43):
dinosaurs and and other animalsthat went extinct uh at the what
we call the CretaceousPaleogene boundary, the KPG
boundary, um endured lots ofcrises over the you know
hundreds of millions of yearsthat, or tens of millions of
years that that they werearound.
Um dinosaurs first evolvedabout 235 million years ago went
extinct 66, so you know, northof a hundred years, 100 million
(27:04):
years.
Um they endured a lot ofdifferent catastrophes.
Um, and so it makes you wonderwhy was this one the one that
did them in?
I mean, obviously it was a avery big deal uh when it
happened, um, but it also mayhave been, you know, they may
have taken some body blows, soto speak, from you know, from
the Deccan eruptions that, aswe've seen, you know, volcanoes
can cause pretty massiveenvironmental disturbances too.
(27:26):
And um-
And the scale of the DeccanTraps isn't it's like not just a
little part of India.
Right.
John Wible (27:31):
It's a big part.
Matt Lamanna (27:32):
And over a vast, vast, vast amount of time.
So, you know, a time a timescale of millions of years, a
time scale that as people wecan't really adequately
comprehend.
John Wible (27:41):
Matt, I have a question for you about birds.
So, what's the thinking todayabout how birds move across the
boundaries?
Matt Lamanna (27:49):
Excellent question.
So there's multiple hypotheses,I guess, and and it could be
that, you know, it could be thatnone of them are right, it
could be that many of them arepartly right.
Um, you know -
John Wible (27:58):
They may all be right.
Matt Lamanna (27:59):
I was gonna say it may not be a one-size fits all
type thing.
Michael Pisano (28:02):
I appreciate the optimism.
Matt Lamanna (28:03):
Yeah.
Um, but uh so one of the one ofthe most important things I
think in this whole thing isthat birds fly.
You know, birds when you knowwhen the going gets tough, they
can get out of a bad situationmaybe a little bit more easily
than you know, something that'suh restricted to walking on a
block two feet or two feet orfour feet.
Exactly.
Yeah, so that's one thing.
(28:24):
So their dispersalcapabilities, their ability to
move around the world is betterthan most other organisms at
that time.
Um, one idea that I have longentertained, I uh one of the
places I work is Antarctica, andum some of the animals that we
find down there from the end ofthe age of dinosaurs are birds
that seem to be members of theof what we call the crown group,
(28:48):
the anatomically modern birdgroup.
In other words, more closelyrelated to, in our case, things
like ducks and geese than theyare to things like, you know,
like Archaeopteryx or moreprimitive Mesozoic birds.
And so um, you know, we've longwondered, and we have very
little evidence to back this up,but we've long wondered if the
prevalence of modern birds ormodern style birds in the at the
(29:11):
end of the age of dinosaurs inAntarctica, where it's already,
comparatively speaking, cold anddark, may have pre-adapted this
group of birds to survive.
And what's interesting, andsomething I didn't mention
before, is that just likeMesozoic mammals, at the KPG
boundary, there are lots ofdifferent kinds of birds around,
including many that go extinctat the KPG boundary.
(29:35):
So it wasn't just non-aviandinosaurs, it was a lot of
different kinds of birds wentextinct as well.
And so what's interesting isAntarctica is one of the only
places, if not the only place,where members of the modern bird
group seem to be dominant atthe end of the age of dinosaurs.
And so, you know, is it is itcoincidence?
It easily could be.
But could it be telling ussomething about, you know, the
(29:56):
sort of pre adaptation to thecold and the dark, you know,
sort of setting them up forsuccess without, of course, them
knowing it.
Michael Pisano (30:03):
I would say that that's another definition of
robustness, certainly.
And I wonder if -
Yeah, it really ties into someof the stuff that John was
talking about.
And I kept ooing and ah-ingwhen John was talking about that
because I'd never I'd neverheard that before.
But this is fairly amazing.
Yeah.
This is recent stuff that's come out.
Matt Lamanna (30:17):
And so the tie that binds with a lot of these
things is, you know, in thecases of mammals, you know,
maybe potentially burrowing,burrowing and waiting things
out, birds potentially flyingand moving, but also potentially
already being adapted tosituations like this.
There's a newer hypothesis,too, and I don't know the
details of it.
It came out, I want to say,about five years ago, about um
(30:38):
birds that were specialized ineating seeds may have done a
little better too.
Um so again, like a food sourcethat will endure for a while.
So the tie that binds is theseanimals that are, you know, kind
of again, without intentionallydoing this, evolution doesn't
work like that.
They're pre-adapted fordisaster conditions, you know,
(30:59):
and then from there, you know,the the groups that squeak
through seem to, in the absenceof or the near absence of
competition from other things,seem to burst into you know
these evolutionary radiations.
John Wible (31:11):
We have this concept of generalists and specialists.
Michael Pisano (31:15):
Yeah.
Please expand on that.
John Wible (31:16):
Specialists, they can be great if the environment
stays the same.
But when the environmentchanges and you've specialized
for one thing and that's nolonger around anymore, these
generalists sometimes went out.
What was the environment likein Antarctica at that time?
Matt Lamanna (31:32):
Well, that's a that's an excellent, another
excellent question, John.
Um, it was undoubtedly muchwarmer than it is today.
Um, we do have evidence for seaice, at least in the winter, so
it was cooler than most peoplethink of the Mesozoic.
Um it is geographically more orless in the same place it is
now, so more or less at thebottom of the world.
Um, the reason it wasn't frozenis um a combination of things,
(31:55):
but it's um partly the overallwarmer climate of the Cretaceous
than we, you know, than we havetoday, but also partly too that
Antarctica was still stuck onAustralia and more or less stuck
on South America, and thatthose continental connections um
kept Antarctica from beingthermally isolated.
So nowadays Antarctica issurrounded by the Antarctic
(32:15):
circumpolar current, and it actslike a Yeti cooler, kind of
keeping the cold air in, um, andled to, you know, um more than,
I can't remember off the top ofmy head when this is thought to
have happened, but uh somewhereballpark 10 to 20 million years
ago, Antarctica goes through adeep freeze where this basically
this goes runaway, and we getthe big massive glaciation in
(32:36):
Antarctica that we have now.
But yeah, so the the to answeryour question, John, uh
Antarctica was much warmer.
It still would have experiencedseveral months of darkness and
several months of light due toits latitudinal position.
Um, we have excellent evidenceof a diversity of non-avian
dinosaurs, um, uh, multiple birdspecies.
It was the rocks that we dig indown there were laid down in a
(32:58):
shallow ocean.
So we mostly find marine thingslike, you know, like um
ammonites, these sort of thingsthat are kind of like a squid
inside a shell, um, sharks, uh,extinct marine reptiles called
mosasaurs and plesiosaurs.
It was a thriving ecosystem atthe end of the age of dinosaurs
down there.
So, yes, absolutely Antarctica,much warmer than today, much
more diverse um terrestrialfauna, uh, and of course marine
(33:22):
fauna as well.
And so, um, but yeah, amongthose were were birds that seem
to be closely related to modernbirds, and it may just may have
been the you know some of theones that squeaked through and
gave ultimately gave rise to thebirds we have today.
Michael Pisano (33:38):
This 66 million year ago boundary, the KPG
boundary, is not the first massextinction event in history of
the Earth, right?
Um, and each time there's kindof this evolutionary bottleneck,
right?
We get pushed through.
Um I guess I wonder what wenow, let's say humans facing
climate change and otherpressures on the environment,
(33:58):
might learn about resiliencefrom examining these mass
extinctions, um, you know, abouthow we might adapt our cities,
our civilization, our culture uhto be resilient now and in the
future based on, you know, theseorganisms that we've talked
about, the the robustness, thequalities of robustness.
Um, what do you what would youthink of that?
John Wible (34:20):
Um so so I guess we could talk about generalists and
specialists in some regards, sothat I could envision perhaps
that you don't want to be tooadapted to your environment
that's right around you, becauseyour environment might be
changing.
Michael Pisano (34:35):
That's true.
John Wible (34:36):
So keep your options open in some regards.
I that's a yeah.
Matt Lamanna (34:43):
I think it's a tough question because the you
know, the key is, and you'veheard me talk about, oh, you
know, in the Cretaceous um, youknow, like Antarctica was warmer
than it is today.
And you know, like when I firsthear that, I'm sort of like,
oh, you know, like maybe modernclimate change isn't so bad, and
things like that.
And so what you have toremember is that we have, as far
(35:04):
as I can remember, there's noevidence of the rate of climatic
change that we're experiencingtoday in the fossil record.
The closest thing we have iswhat's called the
Paleocene-Eocene thermalmaximum, around I want to say
55-ish million years ago,something like that.
Yeah, yeah, yeah.
Again, give or take a fewmillion years, because I'm I'm
good at that.
(35:24):
Um, there's evidence of veryrapid warming um at the PETM.
But as far as I can remember,there's no evidence of even even
the PETM does not approach therate at which we are
accelerating today.
And so there's we certainly canlearn a lot from the past from
deep time when it comes tounderstanding the you know
anthropogenic extinctions thatare happening now, but it does
(35:48):
seem to be in some waysunprecedented.
And so that um, you know, thatlimits our ability to um to I
think predict what's gonnahappen, things like that.
I think um to the to the uhquestion of generalists and
specialists, I mean, you oftenthis sort of gets at like kind
of the you know sort oftongue-in-cheek thing that
people say is you know, likewhen humanity's gone, it's just
gonna be cockroaches andraccoons.
(36:09):
And those two are those two arewonderful examples of
generalists.
That's why that's that's whythat um you know that that uh
sort of cliche has taken hold.
Um but um I mean the bottomline is, you know, I mean, uh
don't need me to tell you, andwe've got to change our our you
know some of the things thatwe're doing.
John Wible (36:28):
Um we really have a hard time predicting what what
any of these events will meandown the road.
So, for example, you as youpointed out, every time there's
been these major climatic thingsin the past, it's shaken up the
planet in terms of what thediversity of life was like.
So at the PETM, we have a bigchangeover from these uh more
(36:51):
primitive uh mammal groups tothe modern groups, and that was
really driven by those climaticchanges.
But the the Earth today is sucha different place because the
human the human species is sodominant over everything.
So it's really hard to predictwhat the next step might be with
(37:13):
similar sorts of climatechange.
Michael Pisano (37:15):
Sure.
I think yeah, that's a reallyexcellent thing to point out.
Um it doesn't stop us fromacting on trying to mitigate
what we do know uh is moreproblematic and is harmful to
changing the climate faster thanit's ever changed.
John Wible (37:29):
But I I should also point out that there's a place
for studying the past.
Yes, of course.
Yeah, because it still isgiving us the only window of
data that we can have.
Matt Lamanna (37:39):
The closest thing we can do to running this
experiment is to look what lookwhat happened when the
experiment was, in a sense, runin the past.
You know.
Michael Pisano (37:48):
Very well put.
250,000 thanks to John and Mattfor inviting us into the
Carnegie's mammal and vertebratepaleontology collections, and
to the many items therein forlessons in robustness,
resilience, and wonder.
(38:09):
We actually talked about awhole additional set of
collection items from the mammalcollection that didn't make it
into this episode.
So we'll be back with a parttwo featuring John, Matt, and
more lessons from a much morerecent extinction.
We Are Nature is produced byNicole Heller and Sloan MacRae.
It's recorded at CarnegieMuseum of Natural History by
(38:31):
Matt Unger and Garrick Schmidt.
DJ Thermos makes the music,Mackenzie Kimmel describes the
collection items, and GarrickSchmidt and Michael Pisano,
that's me, edit the podcast.
Thanks for listening.
You're listening to the Anthropocene Archives, a
presentation of We Are Nature.
In this special series ofstories, we're delving deep into
Carnegie Museum of NaturalHistory's 22 million collection
items, raiding cabinets andcases, sifting through objects
and organisms in search ofstories of stewardship,
solutions, and scientificwonder.
On today's episode, mammals ofthe Late Mesozoic, a disastrous
(00:36):
day for dinosaurs, and what wecan learn about resilience from
extinction survivors.
Hop in, we're going to HellCreek.
(00:57):
Welcome to We Are Nature, a show about natural histories and livable futures. I'myour host, a collection of 206
bones, Michael Pisano, and todayI'm joined by two expert bone
collectors.
Friends, would you pleaseintroduce yourselves?
John Wible (01:05):
I'm John Wible, Curator of Mammals, and I study
everything about mammals, theirorigin, their evolution, their
distribution on the planettoday.
Michael Pisano (01:14):
Excellent.
Matt Lamanna (01:14):
And I'm Matt Lamana, Curator of Vertebrate
Paleontology, and I studydinosaurs in particular, and
especially dinosaurs from thesouthern hemisphere continents
at the end of the age ofdinosaurs.
Michael Pisano (01:24):
Excellent.
Thank you both so much forjoining me today and for
bringing us behind the scenes ofyour respective collections
here at the museum.
I wanted to maybe start byhearing a little bit about those
collections.
So could you tell me about thevertebrate paleontology
collection, the scope of it,scale?
Matt Lamanna (01:38):
Sure, sure.
So the VP collection has um wethink about 120,000 specimens in
it.
Um which sounds impressive, butwe're actually quite small
compared to some of the othercollections, at least in terms
of number of specimens.
Michael Pisano (01:50):
Oh sure, we've already talked to insects.
Matt Lamanna (01:52):
Yeah, no, totally.
Michael Pi (01:53):
It's not a contest.
Matt Lamanna (01:54):
Yeah, no, I think we have them on volume, but they
um they have us on number forsure.
Um but yeah, our collectionranges in age from I think the
oldest, so we're fossils ofbackboned animals, so that's
vertebrate paleontology.
So, you know, fishes throughamphibians, through reptiles,
through birds, through mammals.
Um and I think about the oldestfossil we have is in the
(02:14):
ballpark of maybe 450 to 500million years old.
And then the youngest things wehave are, you know, a few
hundred years old, somethinglike that.
Michael Pisano (02:21):
Excellent, excellent.
And I want to hear the samething about the mammal
collection.
John Wible (02:25):
So we have about 130,000 specimens from all over
the world.
Michael Pisano (02:30):
Probably go.
John Wible (02:31):
I know, yeah, from all continents except
Antarctica, because there are nomammals that are native to
Antarctica.
There are some in the waters.
Michael Pisano (02:39):
Sure, whales, I imagine.
Yep, that are hanging outthere.
John Wible (02:43):
Um, and um we have a vast array of diversity, so we
cover an incredible range of uhspecies that are around today,
and a couple of species that areno longer with us, which is one
of the things I'm gonna talkabout today.
Michael Pisano (02:57):
Yes, I'm looking forward to getting into that.
Um you mentioned diversity, andI wonder out there in the
world, what is the diversity ofmammals or the species of
diversity?
John Wible (03:05):
Right.
So there are about um 6,500species today, and uh if you
look at the major groups ofmammals, about half of those
6,500 are rodents, those arethings like uh chip munks and
squirrels and beavers and thingswith ever growing incisors.
A third of the diversity arebats, which usually surprises
(03:28):
people how many different kindsof bats there are.
And the remaining one-sixth iseverything else.
So all those things that youthink of as mammals when you go
to the zoo fit in that one-sixthof the diversity.
Michael Pisano (03:39):
Incredible.
Um about the number of knowndinosaurs.
I know this is a very much anongoing thing, but do you have a
kind of broad tally of speciesdiversity?
Matt Lamanna (03:48):
You know, that's a good question.
Um, well, so what's one figurethat's often quoted, and this
surprises a lot of people, isthat a new dinosaur, a new
dinosaur often at least aspecies, um, usually a genus.
So the the larger group thatthat you know, at least in the
modern world, contains multiplespecies.
A new genus of dinosaursdiscovered um something like
(04:09):
every two weeks.
Um so, like, yeah, in mycareer, I've I've been involved
with the discovery of um, Ithink it's 18 dinosaurs slash
birds from the Cretaceous, um,and birds we think are descended
from dinosaurs.
And I think when people firsthear that, they're like, wow,
that's really cool and awesome.
And then I tell them, oh yeah,well, we discover a new species
(04:30):
every two weeks, so it's reallynot that big of a deal.
Michael Pisano (04:32):
I mean, I've been at this for a long time.
It's quite an accomplishment,I'll say, either way.
I have to imagine, not all ofthat is just, you know,
paleontologists toiling out inthe field digging up new things.
There's also discovery thathappens in places like this.
Matt Lamanna (04:45):
Oh, 100%.
Absolutely.
In fact, we um we likely haveum a colleague of mine uh in
Germany identified what'sprobably may well be a new
species of dinosaur in ourcollection that we've actually
had since 1903 or 1902, andnobody just recognized it, took
the right eyes like coming alongand seeing it to realize what
(05:06):
it was.
So yeah, like, yeah, and howmany dinosaurs have been
discovered thus far?
Um, it depends on how many ofthese genera or species are
valid.
In other words, whether they'retruly distinct from each other.
Sure.
Um, and I should back up alittle bit and say a genus is
like, you know, you can thinklike like our species Homo
sapiens, the genus is homo, thespecies is sapiens, you know,
(05:28):
tyrannosaurus rex, genustyrannosaurus species
tyrannosaurus rex.
Um in the ballpark there,you're talking probably about a
thousand and maybe more validdinosaurs these days.
Um and again, the number isincreasing all the time.
Michael Pisano (05:43):
Which we love to see.
Um, so we've got a bunch ofbeautiful things on the table
that I want to talk about today.
I think we should jump in.
Um, and maybe we could start asa segue with one that I know
you were involved with thediscovery of.
Matt Lamanna (05:56):
Sure.
So um this is uh the fossilthat I brought that's nearest
and dearest to my heart.
Um so I mentioned that I've hadthe privilege to be involved
with the naming of a bunch ofnew species of dinosaurs, and
this is a piece of one of those.
MacKenzie Kimmel (06:21):
Collection item one is four and a half
inches in length and half aninch in thickness.
It tapers from a two-inch widebase to a keen point.
It curves like a menacingblade.
The fossil is a lustrous warmbrown reminiscent of
(06:43):
mineral-rich pottery.
A shallow groove bisects itsgently burnished surface.
Can you identify collectionitem one?
Matt Lamanna (07:03):
So this is a claw from a hand.
Uh it looks something like aum, you know, the blade on a
scythe, like what a reaper, um,you know, the grim reaper is
always shown with, you know,given that we're sort of in the
proximity to Halloween.
Yeah, exactly.
Um but this um uh this clawwould go on the hand of this
dinosaur.
Um uh it would be, and this issuper cool too.
(07:25):
So the when you see a fossilclaw, you're only looking at the
bony part, the bony core of theclaw.
And so just like, you know,just like me with my fingernail
here, or if you have a cat athome and they're on their
scratching post and they'relosing their nails, basically,
uh, this would have been coveredwith the same material,
keratin, that that makes up ourfingernails and and makes up cat
(07:45):
claws and things like that.
So the upshot there is that asbig as this claw is, it would
have been substantially biggerin life.
Um, and so very, veryformidable.
Michael Pisano (07:54):
Um and used for formidable ends.
What what do you think?
And maybe this is a time tointroduce this organism, you
know, who owned this claw?
Matt Lamanna (08:02):
Yeah, so this dinosaur is um a dinosaur called
Anzu wyliei.
It's a dinosaur that that uhagain several friends and I
named back in 2014.
And um it, you know, when youlook at this claw, you think
instantaneously this animal's,you know, grabbing other things
and eating them.
Um and that may well be thecase.
But when we look at the rest ofthe anatomy of Anzu, it's a lot
(08:23):
more like um if you know whatthe bird, like the a bird called
the cassowary is.
So they're you know, they looklike an emu kind of with a crest
on their head, um, sort of umthe males have these bright blue
faces.
This animal, Anzu, looks like agiant cassowary with with
elongate forelimbs tipped withclaws, unlike the modern
cassowary does.
(08:43):
Um we jokingly call this thingthe chicken from hell because it
does look like kind of like agiant chicken.
And so despite these, youknow, sort of raptorial claws, a
lot of the rest of the anatomyof Anzu sort of speaks to an
omnivorous lifestyle, somethingthat's eating both meat and
plants, not unlike cassowarys dotoday.
(09:05):
So cassowarys eat a lot offruit.
I think it's maybe the numberone component of their diet.
Um, but they'll also eat smallvertebrates, so small, small
backboned animals, you know,lizards, mammals, things like
this.
And I think it's probably fairto consider that Anzu may have
done something similar in itsenvironment.
So it's a um sort of a jack ofall trades, probably eating, you
know, eating fruit, eatingleaves, um, but also eating, you
(09:25):
know, animal protein when ithas the opportunity.
Michael Pisano (09:28):
And speaking of small prey, and this might take
a little bit of context settingabout when this creature uh was
alive and where it was alive,I'm curious about the landscape
and what other organisms wouldhave been there, including
perhaps what mammals were up toat that time.
Matt Lamanna (09:42):
Sure.
Um so this animal comes from arock unit called the Hell Creek
Formation.
It dates to about 68 to 66million years ago and um crops
out um over a broad swath of theRocky Mountain region.
So South Dakota, North Dakota,Montana.
There are equivalent rocks inAlberta and uh and Wyoming, uh,
(10:03):
Colorado, elsewhere.
Um this animal would haveroamed Western North America
sometime between 68 and 66million years ago.
Back then, it was not theenvironment that we have today.
Uh, it's often been ourreconstructions of the
environment have often beencompared to, like, say, the
Louisiana bayou or somethinglike that.
(10:23):
So humid, warm, very rich invegetation, um, uh, you know,
probably with, you know, withwith wetlands in places and
things like that.
Um, as for the other animalsthat were living with this
thing, it's like you look atthis claw and you think, oh,
maybe this thing's at the top ofthe food chain.
Absolutely not the case.
(10:44):
There were a bunch of thingsthat wanted to make chicken
nuggets out of a chicken fromhell.
Um, and uh and the most famousof those is Tyrannosaurus rex.
And so this is what I broughthere is a copy of a T. rex
tooth.
Um, so what I'm holding forpeople that are listening is um
it's large and black, and I wantto say about 10 inches long.
(11:04):
Uh the part um uh the part thatgoes above the jaw, the part
that you would see if you happento be there when the animal
opens its mouth and literallythe last thing you saw.
Michael Pisano (11:14):
Right, unfortunately.
Matt Lamanna (11:15):
Exactly, it would be um, you know, this part about
again, about maybe three and ahalf, four inches long,
something like that.
Um, the rest of this is theroot of the tooth, and so would
have sat inside the massive jawsof this thing.
Um, and so you know, I don'tthink I need to describe a
T. rex for viewers at home, butum, but this animal was
absolutely the top of the foodchain in the Hell Creek
Formation ecosystem.
(11:36):
And when I say formation, uh aformation is a set of rocks
deposited in a specific time ina specific place, but you can
think of it like a fossilizedecosystem, like so a fossil
environment with animals andplants and you know, and and uh
the the land, the wholelandscape uh mixed in.
Michael Pisano (11:53):
You know, uh there's like maybe a common
conception that mammals, theirlifestyle is like scuttling
around under the feet of thesegiant, you know, uh charismatic,
fun animals.
I don't hear a lot aboutmammals in the Cretaceous.
I imagine it has to be a morecomplex picture than that.
Would you give us a little bit?
John Wible (12:09):
So in the Hell Creek Formation, there's quite a
mammal fauna that we alreadyknow about.
Um but most of it is prettysmall.
Uh I would say the largestwould have been maybe a cat
size, maybe a small cat size.
Uh most of the most of themammals that would have been
much smaller than that.
Uh you can think of the mammalsthat were there probably in two
(12:30):
different major groups, thosethat are related to things that
are on the planet today, andthose that have no relations
whatsoever to anything.
Um the proportions of those maybe somewhat equal.
Um so we had some holdoverscoming from ancient uh Mesozoic
groups that survived, and thenwe had these new forms that um
(12:54):
show up uh before the Hell Creekformation, but then it continue
on into the Cenozoic, into theage of mammals, right?
Michael Pisano (13:02):
And I think we'll let's let's wait on that
because we are going to talkabout that transition for sure.
Can you take us back a little?
I I imagine that it willrequire um like an infinite
amount of glossing over, but canyou give us a little bit of the
evolution of mammals?
When did we first start gettingthis you know group that now is
so charismatic and feels sodominant in our culture?
John Wible (13:24):
Well, so it that's actually a kind of a hard
question to answer becauseyou're looking at a continuum of
time and you're just gonna say,okay, where do I draw the line?
So we've got this long lineagethat arose with about the same
time the dinosaurs did.
So mammal ancestors have beenaround for hundreds of millions
of years.
Uh we like to say probably 200million, 220, I mean something,
(13:49):
something in that ballpark.
Uh and then there was a veryslow slog in terms of increasing
mammalness, right?
Taking on features that we thatwe associate with mammals
today.
Now, and one of the problemswith that is that most of the
features that we associate withmammals today are actually soft
tissue features.
(14:10):
So hair is one example.
Um producing milk.
I mean, these are things thatwe can't see.
Well, actually, we can see hairin the fossil record if we're
really lucky with thepreservation.
But most of them we can'treally see.
So um it just, you know, thereare sort of arbitrary lines that
get drawn in terms of talkingabout what those mammals were.
(14:35):
The the bottom line is that formost of the extent of the
Mesozoic mammals were reallysmall.
Michael Pisano (14:40):
All right.
John Wible (14:41):
Um true size really does work.
Uh something that gets up tolike a cat or a small dog is a
giant.
Um most of the mammals weassume were nocturnal.
Michael Pisano (14:54):
Okay.
John Wible (14:55):
Um, and that may be our bias that we think that they
couldn't survive with those bigdinos chasing them around
during the day.
It's a convenient story, theywere hiding during the day, came
out at night.
And but it's interestingbecause um we do have some
reasons to think, at least forcertain things, that they were
nocturnal.
So, for example, we know all abunch of different gliding
(15:17):
mammals were around during theMesozoic, starting in the
Jurassic.
We had these beautifulpreserved specimens that show us
they have wing membranes.
So we know that they weregliders.
It's a thing like a livinggliders are not.
All living gliders arenocturnal.
Right.
So I it's like, is it gonnabuck the trend in the past?
(15:40):
Yeah, maybe it did.
But those are the sorts ofinferences that we can make
based on modern mammals.
Michael Pisano (15:46):
Excellent.
Thank you.
Matt Lamanna (15:49):
And there's there is evidence too, like for
despite the overall small size,especially when you view it
through today's lens of mammals,there's in addition to
morphological diversity, likethe way that you see with a you
know gliding mammal versus a youknow an insectivorous mammal or
something like that, there'sexcellent evidence, and John has
been a part of a bunch of thesediscoveries, um, for lots of
(16:12):
ecological diversity in mammalsas well.
Like so there, we have evidenceof digging mammals in the
Jurassic and Cretaceous.
We have, as John said, glidingmammals, swimming mammals.
Um, of course, the you know,the the the animals that people
think of when they think ofmammals from the age of
dinosaurs, little insectivorousthings that are you know
shrew-like things.
(16:33):
There's uh a the one of thelargest Mesozoic mammals, um,
there's evidence that it preyedon dinosaurs, at least baby
dinosaurs, some of the time.
Um so it is absolutely truethat mammals during the age of
dinosaurs were on average muchsmaller than they are today.
Um, but they do seem to havebeen more diverse than we were
giving them credit for for along time.
John Wible (16:53):
Yeah, one of the big advances that's happened in the
last 50 years is the fact thatwe know so much more about
Mesozoic mammals.
I think in the early discoverydays, when people were looking
in the Mesozoic, they werelooking for dinosaurs.
And dinosaurs were easier tofind than the mammals were.
And now we have people with atotally different search image
(17:14):
looking for tiny things.
So we're discovering all sortsof things about the mammalian
fauna.
And Matt's right.
I mean, the the diversity thatwe know, tree climbers, things
that are terrestrial, I mean, itthey're they're just they're
all over the map.
The only two niches that we wedon't really have in the
Mesozoic that we have todaywould be flyers.
Michael Pisano (17:36):
Sure.
John Wible (17:37):
So there's no dedicated flyers like bats that
we know from the Mesozoic.
And the other thing would belike whale-like things.
So things that are dedicated tobeing aquatic.
We have aquatic-like or whatyou would probably call
semi-aquatic mammals.
Matt Lam (17:53):
Beaver or otter-like.
John Wible (17:53):
Beaver-like, yeah, muskrat, things like that.
But nothing like a whale.
Michael Pisano (17:58):
Very cool.
Well, so something veryimportant happened in the
evolution of mammals anddinosaur and bird lineages about
66 million years ago.
I think most people arefamiliar, but could someone kind
of describe that event veryquickly?
Matt Lamanna (18:12):
Sure, I'll take a stab and John can fill in where
I where I mess up.
Um, but yeah, so uh 66 millionyears ago, uh non-avian
dinosaurs, so we call what wecall non-avian dinosaurs, so so
all dinosaurs, with theexception of birds, um their
descendants, birds, uh disappearfrom the planet seemingly
(18:33):
globally.
And the um the causal mechanismthat most paleontologists and
geo geologists agree on uh goessomething like this.
So a you know a giant, roughlysix-mile-wide asteroid falls out
of the sky, uh hits in what'snow the Yucatan Peninsula.
There's some evidence that thatthere may have been fragments
of it that hit in other placesas well, um, causes basically
(18:58):
global environmentalcatastrophes.
I mean, of course, everythingat ground zero would be
obliterated instantly, but butit was the longer-term um
consequences of this that reallyI think had more profound um
impacts on evolution anddiversity.
Um, so yeah, over the course ofwe're not really sure, you
know, decades, hundreds ofyears, thousands of years,
(19:18):
something, you know, hundreds ofthousands of years, eventually,
as a result of this event andits consequences, non-avian
dinosaurs vanish from theplanet, leaving only their
descendants birds.
Um, so birds are a tiny, uh,there's more than 11,000 species
of birds today, but they are,in evolutionary terms, a tiny
branch of the dinosaurevolutionary tree, and just that
(19:40):
just so happen to be the groupthat we have today.
Anzu, just to be clear, eventhough it has a lot of bird-like
Hell chicken qualities, uh, isnot technically in that group,
right?
No, it's not.
Michael Pisano (19:52):
Can you talk about the distinctions?
Matt Lamanna (19:53):
Yeah, so that's that's an excellent question.
And it's kind of gets to whatJohn said is where do you draw
the line between mammal andnon-mammal?
Where do you draw the linebetween dinosaur and bird?
Um, the line is usually drawnat a famous fossil called
Archaeopteryx.
And this is this is a fossilthat's well known to a lot of
people.
Um it's the it the logo for theArcteryx clothing line of
(20:15):
outdoor gear takes its, youknow, is from the most famous
specimen of Archaeopteryx, theBerlin specimen.
Sure, it's got a yeah, exactly.
It's neck pulled back and avery iconic fossil.
Um, and so most paleontologistsconsider um Archaeopteryx to be
the the what we call theearliest diverging or the most
basal bird.
So in other words, um, we don'tlike to use the word primitive,
but the most sure the firstbird, so to speak.
(20:37):
Um and uh so if you're on theuh the bird side of
Archaeopteryx, you're a bird.
And if you're on the dinosaurside, you're a dinosaur.
And Anzu is um Anzu isextremely bird-like.
In fact, if you could take atime machine back 66 million
years ago to say South Dakotaand see one of these things in
the flesh, your first guesswould be wow, what a big,
(20:58):
weird-looking bird.
Um but it's it's evolutionarilyspeaking, it's not quite a bird
because we don't think it'squite as closely related to
modern birds as isArchaeopteryx, if that makes any
sense whatsoever.
Michael Pisano (21:10):
I mean, we are humans, we strive to have these
definitions, these boxes that,of course, messy.
Matt Lamanna (21:15):
Exactly, totally.
Yeah.
And um that being said, uh, weknow from dinosaurs like Anzu
and its relatives that a lot ofthe features that we associate
with birds did not first evolvein birds.
And so there are numerousspecies of feathered dinosaurs
now.
Um animals that again are lessclosely related to modern birds
than is Archaeopteryx, and yetstill have feathers, still have
(21:35):
hollow bones, still have um uh awishbone.
A lot of the features that weassociate with birds today we
know actually date back tonon-avian dinosaurs.
Michael Pisano (21:57):
I'm curious, and I know this is, you know, maybe
a big question, but I'd love tohear you go back and forth
about it a little bit.
What was it that allowed birdsand mammals to kind of pass
through this long fallout perioduh after the impact in the
Yucatan?
John Wible (22:13):
Well, I can speak to the mammals and maybe I'll let
uh Matt speak to the birds.
So the the mammals, it's it'sinteresting.
Um so the the the 10 millionyears after the uh extinction
event, 66 million years ago, isa uh time that's known as the
Paleocene.
And the mammals that livedduring the Paleocene show some
(22:35):
interesting features thatdistinguish them from both uh
those that went before and thosethat came after.
One of the things that that'scome out uh in the last few
years is that they tend to bemore robust than the mammals
that were before and after.
And so they had heavier bones,heavier features on those bones.
(22:57):
And most of those are featuresthat we associate with uh
digging mammals.
So I like to liken it thatthey're actually the ones that
survived are the ones that coulddig themselves into a den, a
hole, and ride out the eventthat was killing everything
else.
(23:17):
Now that's somewhat fanciful,but it does seem to fit the data
that there's a lot of of thesesort of robust mammals that
first are the first 10 millionyears.
Michael Pisano (23:29):
What does that kind of tell you about the
fallout landscape?
I feel like that might behelpful.
Like if you were above ground,I'm sure globally there were
many different variations, butwhat kind of happened, right?
I mean, this thing hits theearth, I mean we imagine it
kicked up a bunch of dust, plantgrowth was compromised.
Can you guys just kind ofelaborate, paint that scene?
Matt Lamanna (23:48):
Yeah, I mean, I think the picture is, you know,
it sounds odd to say this 66million years later, but I think
the picture of that, of thatday and the weeks that weeks,
months, years that followed isstill developing.
Um but uh but yeah, there's uhfor instance, there's a a good
bit of evidence that they'rebasically the entire Earth
virtually caught on fire due tothese ejecta particles raining
(24:09):
back down onto the planet,heating to ignition, think like
uh, you know, anything likeshooting star entering our
atmosphere, you know, thingslike that.
Um, you know, when that stuffhits the ground, it's gonna set
any vegetate, you know, any dryvegetation at least on fire.
You know, um, so yeah, therewas a lot of um, there seems to
have been a lot of uh, you know,sort of global firestorms.
Uh, there certainly would havebeen, we have good evidence for
(24:31):
this, that at least in theimmediate region of the impact,
there would have been massivetsunamis that were kicked up by
this huge displacement of waterwith this big rock, Mount
Everest sized rock falling intothe water or partly into the
water.
Um so yeah, so um, and then ofcourse, with you know, with with
assuming that the you know,kicking dust into the atmosphere
and having a lot of it staythere for a long time, assuming
(24:52):
that's accurate, um, the thethinking is, as you said,
photosynthesis, so plants,plants are compromised, um, but
also temperatures drop as well.
Um, it's often been likened tothe you know, sort of um uh
nuclear winters that werehypothesized during the Cold
War.
You know, the people that madeit through a hypothetical war
would still have to sufferconsequences for quite a bit a
(25:13):
bit of time afterwards.
So so yeah, big giant rockfalls out of the sky, tsunamis,
you know, in the immediatevicinity at least, global
firestorms, uh, dust in theatmosphere, compromised plants.
Plants form the basis of thefood chain.
So once you knock out plants,you knock out everything else
eventually, or almost everythingelse, as we know, life didn't
completely go away.
But um, but yeah, it would havebeen a really, really crappy
(25:37):
day.
John Wible (25:38):
I liken it to um something that happened during
my lifetime.
You guys might be a little tooyoung to remember this, Mount
St.
Helens.
And I used to spend time in inthat area and um both before and
after.
And it's amazing how quicklyit came back.
Yeah.
So it was totally devastated.
There was at least I don'tknow, six miles, ten miles of
(26:01):
devastation where there was nolife, seemingly no life.
And yet within several years,greenery started to come back.
And I, you know, I mean, so Iliken it to that, that there's
gonna be total devastation, butthen there's a recovery phase
that's that's gonna lead to lifecoming back.
Matt Lamanna (26:20):
And I'm glad, John, I'm glad you brought up
volcanoes too, because I misseda big piece of the puzzle.
Yeah, so there's this, yeah,there's a uh a um volcanic
deposit in what's now India umcalled the Deccan Traps, and
it's thought to have been umdeposited over the course of a
few million years leading up tothe the end of the age of
dinosaurs.
So it's possible that you knowthat dinosaurs in non-avian
(26:43):
dinosaurs and and other animalsthat went extinct uh at the what
we call the CretaceousPaleogene boundary, the KPG
boundary, um endured lots ofcrises over the you know
hundreds of millions of yearsthat, or tens of millions of
years that that they werearound.
Um dinosaurs first evolvedabout 235 million years ago went
extinct 66, so you know, northof a hundred years, 100 million
(27:04):
years.
Um they endured a lot ofdifferent catastrophes.
Um, and so it makes you wonderwhy was this one the one that
did them in?
I mean, obviously it was a avery big deal uh when it
happened, um, but it also mayhave been, you know, they may
have taken some body blows, soto speak, from you know, from
the Deccan eruptions that, aswe've seen, you know, volcanoes
can cause pretty massiveenvironmental disturbances too.
(27:26):
And um-
And the scale of the DeccanTraps isn't it's like not just a
little part of India.
Right.
John Wible (27:31):
It's a big part.
Matt Lamanna (27:32):
And over a vast, vast, vast amount of time.
So, you know, a time a timescale of millions of years, a
time scale that as people wecan't really adequately
comprehend.
John Wible (27:41):
Matt, I have a question for you about birds.
So, what's the thinking todayabout how birds move across the
boundaries?
Matt Lamanna (27:49):
Excellent question.
So there's multiple hypotheses,I guess, and and it could be
that, you know, it could be thatnone of them are right, it
could be that many of them arepartly right.
Um, you know -
John Wible (27:58):
They may all be right.
Matt Lamanna (27:59):
I was gonna say it may not be a one-size fits all
type thing.
Michael Pisano (28:02):
I appreciate the optimism.
Matt Lamanna (28:03):
Yeah.
Um, but uh so one of the one ofthe most important things I
think in this whole thing isthat birds fly.
You know, birds when you knowwhen the going gets tough, they
can get out of a bad situationmaybe a little bit more easily
than you know, something that'suh restricted to walking on a
block two feet or two feet orfour feet.
Exactly.
Yeah, so that's one thing.
(28:24):
So their dispersalcapabilities, their ability to
move around the world is betterthan most other organisms at
that time.
Um, one idea that I have longentertained, I uh one of the
places I work is Antarctica, andum some of the animals that we
find down there from the end ofthe age of dinosaurs are birds
that seem to be members of theof what we call the crown group,
(28:48):
the anatomically modern birdgroup.
In other words, more closelyrelated to, in our case, things
like ducks and geese than theyare to things like, you know,
like Archaeopteryx or moreprimitive Mesozoic birds.
And so um, you know, we've longwondered, and we have very
little evidence to back this up,but we've long wondered if the
prevalence of modern birds ormodern style birds in the at the
(29:11):
end of the age of dinosaurs inAntarctica, where it's already,
comparatively speaking, cold anddark, may have pre-adapted this
group of birds to survive.
And what's interesting, andsomething I didn't mention
before, is that just likeMesozoic mammals, at the KPG
boundary, there are lots ofdifferent kinds of birds around,
including many that go extinctat the KPG boundary.
(29:35):
So it wasn't just non-aviandinosaurs, it was a lot of
different kinds of birds wentextinct as well.
And so what's interesting isAntarctica is one of the only
places, if not the only place,where members of the modern bird
group seem to be dominant atthe end of the age of dinosaurs.
And so, you know, is it is itcoincidence?
It easily could be.
But could it be telling ussomething about, you know, the
(29:56):
sort of pre adaptation to thecold and the dark, you know,
sort of setting them up forsuccess without, of course, them
knowing it.
Michael Pisano (30:03):
I would say that that's another definition of
robustness, certainly.
And I wonder if -
Yeah, it really ties into someof the stuff that John was
talking about.
And I kept ooing and ah-ingwhen John was talking about that
because I'd never I'd neverheard that before.
But this is fairly amazing.
Yeah.
This is recent stuff that's come out.
Matt Lamanna (30:17):
And so the tie that binds with a lot of these
things is, you know, in thecases of mammals, you know,
maybe potentially burrowing,burrowing and waiting things
out, birds potentially flyingand moving, but also potentially
already being adapted tosituations like this.
There's a newer hypothesis,too, and I don't know the
details of it.
It came out, I want to say,about five years ago, about um
(30:38):
birds that were specialized ineating seeds may have done a
little better too.
Um so again, like a food sourcethat will endure for a while.
So the tie that binds is theseanimals that are, you know, kind
of again, without intentionallydoing this, evolution doesn't
work like that.
They're pre-adapted fordisaster conditions, you know,
(30:59):
and then from there, you know,the the groups that squeak
through seem to, in the absenceof or the near absence of
competition from other things,seem to burst into you know
these evolutionary radiations.
John Wible (31:11):
We have this concept of generalists and specialists.
Michael Pisano (31:15):
Yeah.
Please expand on that.
John Wible (31:16):
Specialists, they can be great if the environment
stays the same.
But when the environmentchanges and you've specialized
for one thing and that's nolonger around anymore, these
generalists sometimes went out.
What was the environment likein Antarctica at that time?
Matt Lamanna (31:32):
Well, that's a that's an excellent, another
excellent question, John.
Um, it was undoubtedly muchwarmer than it is today.
Um, we do have evidence for seaice, at least in the winter, so
it was cooler than most peoplethink of the Mesozoic.
Um it is geographically more orless in the same place it is
now, so more or less at thebottom of the world.
Um, the reason it wasn't frozenis um a combination of things,
(31:55):
but it's um partly the overallwarmer climate of the Cretaceous
than we, you know, than we havetoday, but also partly too that
Antarctica was still stuck onAustralia and more or less stuck
on South America, and thatthose continental connections um
kept Antarctica from beingthermally isolated.
So nowadays Antarctica issurrounded by the Antarctic
(32:15):
circumpolar current, and it actslike a Yeti cooler, kind of
keeping the cold air in, um, andled to, you know, um more than,
I can't remember off the top ofmy head when this is thought to
have happened, but uh somewhereballpark 10 to 20 million years
ago, Antarctica goes through adeep freeze where this basically
this goes runaway, and we getthe big massive glaciation in
(32:36):
Antarctica that we have now.
But yeah, so the the to answeryour question, John, uh
Antarctica was much warmer.
It still would have experiencedseveral months of darkness and
several months of light due toits latitudinal position.
Um, we have excellent evidenceof a diversity of non-avian
dinosaurs, um, uh, multiple birdspecies.
It was the rocks that we dig indown there were laid down in a
(32:58):
shallow ocean.
So we mostly find marine thingslike, you know, like um
ammonites, these sort of thingsthat are kind of like a squid
inside a shell, um, sharks, uh,extinct marine reptiles called
mosasaurs and plesiosaurs.
It was a thriving ecosystem atthe end of the age of dinosaurs
down there.
So, yes, absolutely Antarctica,much warmer than today, much
more diverse um terrestrialfauna, uh, and of course marine
(33:22):
fauna as well.
And so, um, but yeah, amongthose were were birds that seem
to be closely related to modernbirds, and it may just may have
been the you know some of theones that squeaked through and
gave ultimately gave rise to thebirds we have today.
Michael Pisano (33:38):
This 66 million year ago boundary, the KPG
boundary, is not the first massextinction event in history of
the Earth, right?
Um, and each time there's kindof this evolutionary bottleneck,
right?
We get pushed through.
Um I guess I wonder what wenow, let's say humans facing
climate change and otherpressures on the environment,
(33:58):
might learn about resiliencefrom examining these mass
extinctions, um, you know, abouthow we might adapt our cities,
our civilization, our culture uhto be resilient now and in the
future based on, you know, theseorganisms that we've talked
about, the the robustness, thequalities of robustness.
Um, what do you what would youthink of that?
John Wible (34:20):
Um so so I guess we could talk about generalists and
specialists in some regards, sothat I could envision perhaps
that you don't want to be tooadapted to your environment
that's right around you, becauseyour environment might be
changing.
Michael Pisano (34:35):
That's true.
John Wible (34:36):
So keep your options open in some regards.
I that's a yeah.
Matt Lamanna (34:43):
I think it's a tough question because the you
know, the key is, and you'veheard me talk about, oh, you
know, in the Cretaceous um, youknow, like Antarctica was warmer
than it is today.
And you know, like when I firsthear that, I'm sort of like,
oh, you know, like maybe modernclimate change isn't so bad, and
things like that.
And so what you have toremember is that we have, as far
(35:04):
as I can remember, there's noevidence of the rate of climatic
change that we're experiencingtoday in the fossil record.
The closest thing we have iswhat's called the
Paleocene-Eocene thermalmaximum, around I want to say
55-ish million years ago,something like that.
Yeah, yeah, yeah.
Again, give or take a fewmillion years, because I'm I'm
good at that.
(35:24):
Um, there's evidence of veryrapid warming um at the PETM.
But as far as I can remember,there's no evidence of even even
the PETM does not approach therate at which we are
accelerating today.
And so there's we certainly canlearn a lot from the past from
deep time when it comes tounderstanding the you know
anthropogenic extinctions thatare happening now, but it does
(35:48):
seem to be in some waysunprecedented.
And so that um, you know, thatlimits our ability to um to I
think predict what's gonnahappen, things like that.
I think um to the to the uhquestion of generalists and
specialists, I mean, you oftenthis sort of gets at like kind
of the you know sort oftongue-in-cheek thing that
people say is you know, likewhen humanity's gone, it's just
gonna be cockroaches andraccoons.
(36:09):
And those two are those two arewonderful examples of
generalists.
That's why that's that's whythat um you know that that uh
sort of cliche has taken hold.
Um but um I mean the bottomline is, you know, I mean, uh
don't need me to tell you, andwe've got to change our our you
know some of the things thatwe're doing.
John Wible (36:28):
Um we really have a hard time predicting what what
any of these events will meandown the road.
So, for example, you as youpointed out, every time there's
been these major climatic thingsin the past, it's shaken up the
planet in terms of what thediversity of life was like.
So at the PETM, we have a bigchangeover from these uh more
(36:51):
primitive uh mammal groups tothe modern groups, and that was
really driven by those climaticchanges.
But the the Earth today is sucha different place because the
human the human species is sodominant over everything.
So it's really hard to predictwhat the next step might be with
(37:13):
similar sorts of climatechange.
Michael Pisano (37:15):
Sure.
I think yeah, that's a reallyexcellent thing to point out.
Um it doesn't stop us fromacting on trying to mitigate
what we do know uh is moreproblematic and is harmful to
changing the climate faster thanit's ever changed.
John Wible (37:29):
But I I should also point out that there's a place
for studying the past.
Yes, of course.
Yeah, because it still isgiving us the only window of
data that we can have.
Matt Lamanna (37:39):
The closest thing we can do to running this
experiment is to look what lookwhat happened when the
experiment was, in a sense, runin the past.
You know.
Michael Pisano (37:48):
Very well put.
250,000 thanks to John and Mattfor inviting us into the
Carnegie's mammal and vertebratepaleontology collections, and
to the many items therein forlessons in robustness,
resilience, and wonder.
(38:09):
We actually talked about awhole additional set of
collection items from the mammalcollection that didn't make it
into this episode.
So we'll be back with a parttwo featuring John, Matt, and
more lessons from a much morerecent extinction.
We Are Nature is produced byNicole Heller and Sloan MacRae.
It's recorded at CarnegieMuseum of Natural History by
(38:31):
Matt Unger and Garrick Schmidt.
DJ Thermos makes the music,Mackenzie Kimmel describes the
collection items, and GarrickSchmidt and Michael Pisano,
that's me, edit the podcast.
Thanks for listening.
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If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
My Favorite Murder with Karen Kilgariff and Georgia Hardstark
My Favorite Murder is a true crime comedy podcast hosted by Karen Kilgariff and Georgia Hardstark. Each week, Karen and Georgia share compelling true crimes and hometown stories from friends and listeners. Since MFM launched in January of 2016, Karen and Georgia have shared their lifelong interest in true crime and have covered stories of infamous serial killers like the Night Stalker, mysterious cold cases, captivating cults, incredible survivor stories and important events from history like the Tulsa race massacre of 1921. My Favorite Murder is part of the Exactly Right podcast network that provides a platform for bold, creative voices to bring to life provocative, entertaining and relatable stories for audiences everywhere. The Exactly Right roster of podcasts covers a variety of topics including historic true crime, comedic interviews and news, science, pop culture and more. Podcasts on the network include Buried Bones with Kate Winkler Dawson and Paul Holes, That's Messed Up: An SVU Podcast, This Podcast Will Kill You, Bananas and more.