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Past Time is a podcast that explores how we know what we know about the past. There's a special focus on the fossil record - it is hosted by two paleontologists - but delving into the story of the past isn't limited to dry bones. Today's paleontologists use techniques drawn from other sciences including Physics, Chemistry, Geology, and Biology to figure out what extinct animals were like and how they lived.

Whether you are just starting to learn about the amazing animals that have called this planet home, or you have been fascinated by fossils for a long time, we hope you will join us as we dig into past times.

Keywords: Paleontology, Dinosaurs, Mammals, Reptiles, Birds, Animals, Fossils, Extinction

Past Time Matt Borths, Adam Pritchard, Catherine Early

    • Naturvetenskap

Past Time is a podcast that explores how we know what we know about the past. There's a special focus on the fossil record - it is hosted by two paleontologists - but delving into the story of the past isn't limited to dry bones. Today's paleontologists use techniques drawn from other sciences including Physics, Chemistry, Geology, and Biology to figure out what extinct animals were like and how they lived.

Whether you are just starting to learn about the amazing animals that have called this planet home, or you have been fascinated by fossils for a long time, we hope you will join us as we dig into past times.

Keywords: Paleontology, Dinosaurs, Mammals, Reptiles, Birds, Animals, Fossils, Extinction

    Episode 34 – March of the Trilobites

    Episode 34 – March of the Trilobites

    Of Collective Behavior and Trilobites
    Reading scientific papers can be a daunting prospect. Even the titles can contain layers of jargon. On Past Time, we work diligently to break down the barriers of science to make the discoveries of science for audiences of all ages. In this episode, we experiment with a new method: breaking down every word in the title of a scientific paper. It might seem like a little task, but it is a way to introduce people to big ideas! This time, we introduce big ideas about trilobites!
    For this episode, we delve into the journal Scientific Reports and the article “Collective behaviour in 480-million-year-old trilobite arthropods from Morocco.” by Jean Vannier of the Université de Lyon and his colleagues. This title doesn’t have a ton of jargon, but it presents a great chance to look at INVERTEBRATE animals…gathering into a conga line.
    Two examples of Ampyx priscus lines from the Fezouata Shale of Morocco. Image modified from Figure 2 of Vannier et al. (2019).
    Well, not an actual conga line…but the fossil trilobite fossils in this paper are definitely situated in a single-file lines. These specimens of the species Ampyx priscus come from an amazing fossil deposit in Morocco. They teach us about the anatomy of trilobites, but they preserve important clues about the behaviors of ancient animals. Join us as we learn how and why trilobites—and living invertebrates—gather together in collective behaviors.
    Dig Deeper…

    To read the original open-access paper, check out this link!
    This popular article by LiveScience details the discovery.
    For a classic Past Time episode about trilobites, check out our interview with paleontologist Brenda Hunda!
    To learn more about trilobites, check out this laboratory exercise from an undergraduate paleontology course at Kansas University by Drs. Michelle Casey and Bruce Lieberman.
    To see some modern invertebrate conga lines, join Jacques Cousteau in this classic documentary about the spiny lobster! Conga lines begin around the 33:00 mark.

    Episode 33 – The Story of the Sloth

    Episode 33 – The Story of the Sloth

    After three and a half months of discovering how insanely busy a museum curator can be, I (Adam) am back to past times with a brand new episode of Past Time! Join me on a journey back to the Smithsonian Institution to learn about the whole history of sloths. We’ll also meet RYAN HAUPT, an ally in sloth paleontology and science podcasting!
    Ryan Haupt: Master of Sloth
    A Ph. D. candidate at the University of Wyoming, a fellow with the Geological Society of America, a researcher at the Smithsonian Institution, AND a podcaster…Ryan Haupt is a busy guy. His research focuses on the roles of sloths in both ancient and modern ecosystems. Balancing studies of sloth biology in the jungles of Panama and laboratory work on ground sloth bones and teeth, Ryan was the perfect guest to teach us in this episode of Past Time. He might even throw in some sloth coprolites (fossil feces) for the heck of it! Together, Ryan and I explore over thirty million years of sloth history and HOW we know what we know about extinct sloth species.
    Ryan studied sloths in the jungles of Panama. This photo shows him holding a mother sloth complete with a baby gripping her chest!
    Science…Sort Of
    Ryan helps lead the team on the popular science podcast Science…Sort Of! He is one a huge team of ‘paleo-pals’ that produce the series, which focuses on scientists from all fields: from physics to chemistry to geology to biology! Science…Sort Of presents scientific ideas to a broad audience in a free-form conversational format. The series has featured noted science communicators like astrophysicist Neil deGrasse Tyson, science writer Carl Zimmer, and yours truly! But Ryan and his friends what scientists of all backgrounds on the podcast, to get their stories out to the largest possible audience!
    Science…Sort of.

    Explore the podcast at their website: https://sciencesortof.com/
    Follow them on Facebook and Twitter!
    If you like what you hear, you can support the podcast on Patreon and receive updates and special rewards!

    Sloth Conservation and Research

    Check out the Sloth Conservation Foundation. Ryan is a member of the board for the foundation.
    Visit your closest museum. If you are in North OR South America, it almost certainly has some fossils of a ground sloth!

    For the best of ground sloth fossils, visit the American Museum of Natural History (New York, NY). SO MANY SLOTHS!

    The sloth display at the Hall of Mammals at the American Museum of Natural History includes several giant ground sloths! Photograph by Wikimedia user Dallas Krentzel (CC License 2.0).
    Click here for a classic Past Time episode featuring Thalassocnus, the sloths that swam in the Pacific Ocean off the coast of Peru. For the episode field guide, click here.

    To check out the giant ground sloth model that gave its likeness to our cover image, visit the Virginia Museum of Natural History in Martinsville, Virginia.
    Jungle background image from Wikimedia user Dirk Vander Made (Creative Commons 1.0 license).

    Episode 32 – The Changing Face of Crocodiles

    Episode 32 – The Changing Face of Crocodiles

    Episode 32 – The Changing Face of Crocodiles
    Every living thing grows up, and this episode of “Past Time” explores the evolution of the growing process. Specifically, we explore the evolution of growth in crocodiles, and how changes to the growing process at the earliest stages of crocodile development help produce the wide array of crocodile snout shapes we see today and in the fossil record. Increase the rate of snout growth in an embryonic croc, and you can produce an adult with a narrow, tubular snout like an Indian gharial or an African slender-snouted crocodile. Slow that process down, and you can produce an adult with a short, rounded snout like a broad-snouted caiman or an African dwarf crocodile.
    Paleontologist/Developmental biologist Zachary Morris spritzes water over an incubator filled with Alligator eggs.
    Our guest this week is Zachary Morris, a Ph.D. student at Harvard University who studies growth in crocodylians. He wields both the fossil record and the skeletons of modern crocodylians—from tiny embryos to giant adults—to study that very topic. To examine the shape changes in the skull of crocodylians through the growth process, Zach has traveled the world to collect eggs, embryos, juveniles, and adults to build 3D models of skull anatomy. He delved into the collections of museums around the world to find nests and eggs of rare crocodiles that were collected by explorers hundreds of years ago. Zoos were also a critical resource for eggs of breeding species.
    Further reading and links –

    The original paper by Zach and his research team was published in the journal Proceedings of the Royal Society B in Spring 2019.
    To learn more about Zach and his research, visit his research site.
    To see all the snout shapes that exist in modern crocodylians and their fossil cousins, check out this amazing review by crocodylian expert Dr. Christopher Brochu.
    If you’re interested in visiting ALL the crocodylian species in the world, travel to Florida for a visit to the St. Augustine Alligator Farm. It’s not so much a farm as a glorious reptile zoo with a deep dedication to the research and conservation of endangered reptile species.
    For more information on reproduction in modern crocodylians—from mating rituals to nesting to parenting strategies—the IUCN Crocodylian Specialist Group produced this amazing summary.

    Media Credits –

    Image of a hatching baby crocodile from an etching by Heath. Used under CC 4.0 license courtesy of Wellcome Images


    Image of African Dwarf Crocodile from Wikimedia and a photograph by Charlie Marshall. Used under a CC 2.0 license.


    Image of African Slender-Snouted Crocodile from Wikimedia and a photograph by Tim Strater. Used under a CC 2.0 license.



    • 24 min
    Episode 31 – The First Frogs of the Age of Dinosaurs!

    Episode 31 – The First Frogs of the Age of Dinosaurs!

    Every discovery we make in natural history happens thanks to specimens. Fossil bones, shells, footprints, coprolites, tissue samples—even field notes and photograms—are the building blocks scientists use to tell the story of life on our planet. On Past Time, we talk a LOT about the contributions of museums and scientists to the story of life. However, we don’t often address the specific specimens that help tell that story. Even one little bone can reveal great truths.
    Meet DMNH 2018-05-0002, an eyelash-sized bone from the 213-million-year-old Chinle Formation of eastern Arizona. The bone is housed in the fossil collections of the Perot Museum of Nature and Science in Dallas, Texas. DMNH 2018-05-0002 (I refuse to abbreviate!) is a right ilium (pelvic bone) of a frog that was likely only a few centimeters long in life. This fragile treasure is the oldest evidence for a frog on the entire North American continent, predating the next fossil by 30 million years! One little bone leads to a huge expansion in the story of frogs, the most abundant group of amphibians on Earth!
    Dr. Michelle Stocker holds up DMNH 2018-05-0002 embedded in matrix and wax. It’s THAT small. Image from vt.edu
    These amazing frogs were published in Biology Letters by Virginia Tech paleontologist Michelle Stocker, a world-renowned expert on Triassic ecosystems. Dr. Stocker and her team have done a lot of recent work on MICROVERTEBRATES, the bones and teeth of tiny animals. Microvertebrate fossil sites are those that preserve large quantities of tiny (~1 centimeter and smaller) bits, and they can tell us a lot about the smaller animals in an environment. Some paleontologists use sifting and fine-mesh screens to collect bones out of these sediments. In this case, Dr. Stocker and her team prepared bones out of blocks of sediment using microscopes and extremely fine tools. Hat-tip specifically to Ben Kligman, a Virginia Ph.D. student who is pioneering these refined preparation techniques!
    Images of the Chinle frog fossils described by Stocker et al. (2019). DMNH 2018-05-0002 is featured in the top row. The lower images include other frog ilia and jaw fragments found in the collections of Petrified Forest National Park and the Museum of Northern Arizona.

    DIG DEEPER (Links and Reading)

    The Perot Museum of Nature and Science in Dallas, Texas is a world-class museum with incredible collections of Cretaceous vertebrates from Texas, Alaska, and across the western United States. Obviously, there are some Triassic treasures in the collection, too! The exhibits include classic American dinosaurs like Alamosaurus, Tyrannosaurus, and Tenontosaurus and some newcomers like Convolosaurus, Nanuqsaurus, and Ugrunaaluk.
    The original scientific paper in Biology Letters by Dr. Michelle Stocker and her colleagues describes the Chinle frogs, including DMNH 2018-05-0002 and a series of other tiny frog fragments from Triassic Arizona.
    For general audiences, Virginia Tech put out a press release describing the discovery, including a video featuring Dr. Stocker.
    Petrified Forest National Park (PEFO) is an amazing park in eastern Arizona. Named for the fossilized remains of ancient forests from the Triassic Period, PEFO contains some of the largest fossil exposures from the Triassic Period of North America. DMNH 2018-05-0002 was found just to the south of the park, but some additional Triassic frog bits have been found in the PEFO fossil collections! Seriously, go to PEFO if you like beautiful and desolate vistas!
    VT Paleobiology is a collaborative effort of all of the Virginia Tech paleontologists, including Dr. Stocker. Their research ranges from Cambrian invertebrates, to Triassic ecosystems, to Cretaceous tyrannosaurs, and beyond!


    The amazing artwork used for the promo image is a painting by

    • 11 min
    Episode 30 – SVP Recap, guest-starring I KNOW DINO

    Episode 30 – SVP Recap, guest-starring I KNOW DINO

    Meeting of the Minds
    There is no bigger paleontology conference for fans of dinosaurs, prehistoric mammals, birds, fishes, and reptiles than the Society of Vertebrate Paleontology Annual Meeting. The 78th annual meeting just took place this October in Albuquerque, New Mexico, USA and Matt, Adam, and Catherine were in attendance. They learned about a lot of exciting new discoveries in natural history, and they also made friends with another pair of paleo-podcasters: Garrett and Sabrina of I Know Dino!
    Dig Deeper
    For more about the SVP meeting, visit the society website at www.vertpaleo.org. Anyone can attend, provided they register for the meeting.
    To learn more about (and subscribe to!) I Know Dino, check out their official website at www.iknowdino.com. You can subscribe to their podcast on iTunes, like them on Facebook, and follow them on Twitter!
    To read all about real dinosaur lungs, you can read the original paper by Xiaoli Wang and colleagues in the journal Proceedings of the National Academy of Sciences!
    Be sure to subscribe to Past Time on iTunes, follow us on Twitter, like us on Facebook, and subscribe to our revitalized YouTube channel!

    • 26 min
    Episode 29 – First of the Four-Footed Giant Dinosaurs!

    Episode 29 – First of the Four-Footed Giant Dinosaurs!

    Ledumahadi and the first dinosaur giants
    The sauropod dinosaurs—the classic long-necks—included the largest land animal species that have ever lived. Throughout the Jurassic and Cretaceous, multiple families of sauropods achieved body masses over 50 tons: greater than any modern elephant and even exceeding the colossal indricothere rhinoceroses. Despite their incredible sizes, the sauropod dinosaurs have a murky early history…
    This Past Time episode features a brand new species of sauropod cousin from the Early Jurassic of South Africa: Ledumahadi mafube. Described in a new paper in the journal Current Biology, Ledumahadi is part of a group of dinosaurs traditionally called “prosauropods.” Unlike the straight, column-like legs of true sauropods, Ledumahadi has strong but flexed arms and legs that lacked weight-bearing adaptations of its later cousin. Despite these anatomical differences, this new colossus achieved a mass over 12 tons, upending our classic understanding of the evolution of gigantic size!
    The original paper on Ledumahaadi mafube was published in the journal Current Biology and is available at this link. The University of the Witwatersrand put out a great press release and Youtube video about this awesome find, so check those out too!
    For more great research on the early days of the giants, check out lead author Dr. Blair McPhee’s research profile. To check out some great sauropod cousin specimens, check out the specimens on display at the Evolutionary Studies Institute in Johannesburg, South Africa.
    For more general information on sauropod cousins and the true sauropods, I recommend Dr. Tom Holtz’s overview of the group on his University of Maryland website. You can also check out a classic Past Time episode on growth in the super-giant sauropods featuring friend of the show Dr. Mike D’Emic.
    The awesome art used for our promo image is work by Viktor Radermache, an up-and-coming paleoartist who has also worked on other finds out of the Evolutionary Studies Institute. Check out this cool interview with him for some more science and artwork. I added myself to the artwork in the front under Creative Commons 4.0.
    Sound effects from this episode are used under Creative Commons 3.0 licenses and were produced by AlexTriceratops123 (‘Elephant Growls’), Souchav (‘kid-playing-in-a-swimming-pool’), sonicport (‘stream6’), and maj061785 (‘stomp.’). These are available through freesound.org.

    • 12 min

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