JACKI LYDEN, HOST:
Now some years ago, road workers in the South American country of Chile discovered something big, really big - whale bones. And not just one or two of them, 40 giant skeletons including those of adult whales cradled together with juveniles. Scientists were called in, including my guest, Nick Pyenson.
Nick is the curator of Fossil Marine Mammals at the Smithsonian. He has to look after these things there. And this past week, he and his colleagues released their most comprehensive review yet of the site in Chile.
Nick Pyenson, we're so excited to talk to you.
NICK PYENSON: Happy to be here.
LYDEN: You've brought a few things with you. What is this?
PYENSON: I did. I did. So, in your hands, you're holding a facsimile - a replica - but it looks a lot like the real thing. Here's a snapshot in deep time of an ecological story. It's the story of how all the skeletons arrived at what we estimate is a graveyard. You can even see - here's another one I'll pass to you. This is kind of more evocative. This is la familia.
LYDEN: The family?
PYENSON: Well, we don't know if it's a real family or not. I'm agnostic about that point. But it is tremendously evocative - two adults and a juvenile. These skeletons are overlapping...
PYENSON: ...and they're complete.
LYDEN: Here you can really, really see it. There's an adult presumably at the top on top of another adult, and then between them a small juvenile. So I just want to ask this is a lot of skeletons at one time? As a paleontologist, what was your reaction to this find?
PYENSON: I was overwhelmed. I was not prepared for what I saw. We were in the area of this part of Chile doing something else. There were many other fossil sites and we were called in by one of our collaborators. And he said: You really have to see the site, I can't describe it. And I underestimated him completely. And when I saw it, I was overwhelmed not only because of the scope than the span of skeleton after skeleton, but it was also the time sensitivity.
PYENSON: I looked at him and I said what are we going to do. And he said: Whatever we do, we need to do it fast.
LYDEN: And what's your speculation about what killed them?
PYENSON: Well, that's the ecological story that we have built an argument around many different lines of evidence. In addition to the incredibly well-preserved whale skeletons, the other important facts about this site are that there's not just whales. There's other marine mammals, some of which are entirely extinct, bizarre forms that we don't have in today's oceans. And there's not just one bone layer - there's four. Whatever happened there happened four times to yield these incredibly well-preserved fossils.
LYDEN: That sounds like it could be something natural like algae.
PYENSON: That's the argument we've put forth is that the best explanation that covers the body effects that we have there; the many different species, their incredibly articulation and the fact that the conditions persistent through time to result in the same kind of what we call a death assemblage. The best explanation for that is something like harmful alga-blooms. And that's a phenomenon we know about in today's world that can produce all those patterns that we see.
LYDEN: So, you don't have very much time to get these things out of there and you have to move them right away because the Chileans are building this highway. So, I understand that that's where this story takes yet another turn. And you have to turn to the...
PYENSON: I call them the laser cowboys.
LYDEN: That's a very good phrase.
PYENSON: These are two guys who are largely responsible for our new initiative at the Smithsonian that involves 3-D documentation.
LYDEN: So, what do they do? Did they use actual lasers to diagram what's in the earth?
PYENSON: We did. And we had very little time. By the time I was able to marshal the resources to bring them down, we had about a week's worth of time before the construction company was going to continue forth.
LYDEN: And they would have. They would have just...
PYENSON: They were compliant with law and saving the bones but, you know, that context was really the crucial thing that we give you the information to answer that question in the way that paleontology could sometimes be like CSI. If you're given the bones at the end of a murder, it's harder to explain how that happened versus having sort of a full-scale reconstruction of what that scene actually looked like.
LYDEN: Why did you call them laser cowboys? So, I presume they're not actually ever, get up on horseback.
PYENSON: One of the things they brought was a laser arm scanner. Actually, it looks like a robotic arm with a laser attached at the end. And the way you use this is much like a paintbrush. And actually one of the laser cowboys talks about it as painting with laser light. And so with a passes of that wand, like a brush, you try to cover the object. And with enough passes, you can actually pull out the 3-D surface of that object. We did this for one of the largest and best skeletons that we saw out at this field site. It took all six days just to do that.
LYDEN: So, you have to be careful and it's not an instant snapshot. It takes time to build that 3-D in the computer...
PYENSON: That's correct.
LYDEN: ...after the scans.
LYDEN: Nick Pyenson is a paleontologist and curator of fossil marine mammals at the Smithsonian. He led the expedition to Chile. Thank you so much for coming in and showing this to us.
PYENSON: Happy to be here. Transcript provided by NPR, Copyright NPR.