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Paleontologists today look at more than just fossil evidence to learn about organisms that lived millions of years ago. For this episode we visited Dr. Katrina Jones at Harvard's Museum of Comparative Zoology to learn how she dissects and examines animals living today in the search for answers about the movements and evolution of early synapsids!

The specimens in this episode were found dead in the wild, and legally obtained with government-issued salvage permits. Do not touch, pick up, or otherwise attempt to obtain parts of or entire animals you may find dead without properly authorized permits.

This is part two in a three-part series supported in part by The Field Museum, the Museum of Comparative Zoology at Harvard University, and The National Science Foundation (!!!!). Watch Part 1 here:

Big thanks to Drs. Ken Angielczyk, Stephanie Pierce, and Katrina Jones for their immense help and accommodation during the creation of this series.

Want to learn more about this research? Here's the gist:

Mammals are known for their great range of locomotor behaviors, including unique gaits such as galloping and bounding. These gaits are made possible by the subdivision of the backbone into two distinct regions: the thoracic region, which bears ribs and aids in breathing; and the lumbar region, which is ribless, highly mobile and functions in locomotion. Combined, these two sections of the backbone allow mammals to breathe and move simultaneously, permitting the use of high speed gaits for prolonged periods of time. But, how did this key mammalian trait evolve? Using cutting-edge 3D technology, along with the rich fossil record of mammals and their ancestors, this research will trace the origin and evolution of the mammalian backbone and its link with the development of mammal-specific locomotor behaviors. The work will deepen our understanding of the history of a key characteristic of mammals and part of the skeleton that is of great medical importance.
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"Dimetrodon is Not a Dinosaur"

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Producer, Writer, Creator, Host:
Emily Graslie

Producer, Editor, Camera, Graphics:
Brandon Brungard
This episode is supported in part by:
The Field Museum in Chicago, IL

And filmed on location at:
The Museum of Comparative Zoology at Harvard University

The National Science Foundation:
Grants NSF EAR-1524938 and EAR-1524523
This series of episodes is brought to you by The Field Museum, the Harvard Museum of Comparative Zoology, and the National Science Foundation.

Hey! We're here at Harvard's Museum of Comparative Zoology with Dr. Ken Angielczyk-

Ken: And I am the associate curator of fossil mammals at The Field Museum of Natural History

E: And we're here today to do some experimenting' on some dead animals, to learn more about those fossil mammals, it's gonna be great.  Let's go.


K: In the episodes that we've been doing so far we've talked a lot about synapsids, but you might not know what those are.  So a synapsid is a member of a group of animals that includes living mammals as their sort of living, but also a number of fossil forms that, in some cases, look very different.  And all of our different synapsids are characterized by one feature, this opening back here in the back of the skull, just behind the eye socket.  That's an area where jaw muscles attach to the skull, and all synapsids have those.  So if you compare an animal like this, this is eyothyrus, one of the most primitive synapsids that we know about, to a living mammal, you can see the skull looks very different, but we have that same synapsid temporal opening back here in the skull the way we did with eyothyrus.

Um, so this is an animal called Massetognathus which is a more derived or a more advanced kind of synapsid, you can see that it has a skull much more similar to our living mammel.  Synapsids have undergone a massive amount of evolutionary change over the course of their history, so there's actually very few features other than that that you can point to  in all synapsid specimens.

E: And this is kind of why we're here today, right? So we're going to be looking at some of the changes and the other parts of the skeletons of these animals, and primarily what is it that we're going to be looking at?

K: Yeah, so we're interested in looking at the backbone of synapsids.  So living mammals have very distinct vertebral columns or backbones that have lots of different regions and they have very specific functions in those regions.  And if we look at more primitive synapsids, they have a much more uniform backbone or vertebral column.  We can only get so much information out of the fossils, we need to get some living mammals with their soft tissues like muscles attached to their backbone or vertebral column, and what we can do is learn about how the backbone functions in those animals and then go back to our fossils and, um, essentially model how those vertebral columns would have been working when they had all of their soft tissues attached.

E: So, we're going to the prep lab.


E: We are here in the prep lab at Harvard's Museum of Comparative Zoology with Dr. Katrina Jones.  Katrina, what is is that you do?

Katrina: Hi Emily, I'm a researcher here at the museum and I study the anatomy and evolution of mammals.

E: And that is what we have in this bag here in front of us.

K: Exactly, yeah.  So, this is a fisher cat and today we're gonna be dissecting out its vertebral column so that we can do experiments on it.

E: But it's not, it's not a fish, kind of.  It's a derived fish.  And it's not a cat.  It's like a big ferret.

K: Yeah, kinda like a giant ferret, otter. So the skin was taken off and its gone to be used in our collections, and all of the organs have been taken out, but now we need to remove the head, the limbs, and get down to the vertebral column, which is what we're interested in.

E: Let's do it!  Should I grab this end?

K: Yep, you can grab it and pull it out.

E: Oooh, oh boy.  You can kind of already, if I'm gonna hold this guy up, you can already sort of see-whoops, now it's bleeding on the table