Past Time

THE FIRST FROGS OF NORTH AMERICA 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. A SINGLE SPECIMEN. A BIG DISCOVERY. 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! 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! 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

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!

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!   REFERENCES 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.

First Iteration I (Adam) am both proud and nervous to say that this is an atypical Past Time episode, as we’re not talking about a new discovery nor a real scientific topic; it is a recap/review of Jurassic World 2. However, I think it is worth addressing whether or not particular elements of new movies, television, or books adhere to modern science. Dr. Elizabeth Jones taught us that science fiction can have a major impact on scientific advances, as Jurassic Park helped give rise to modern techniques that revealed all sorts of molecules in ancient fossil remains. Although it is far less…science-y…than the original Jurassic Park, Jurassic World Fallen Kingdom may one day have an impact on future paleontologists. This also presented a great opportunity to get some scientific queries from a non-scientist. My partner for this episode is Tommy Dembeck, an old friend from my days as an undergraduate at McDaniel College with whom I discuss sci-fi endlessly. He is also endlessly curious. Of all the laypeople I know who have never worked in a university or museum setting, Tommy has the best questions about biology and prehistory. I would love to have him back for a future episode…there are always shark movies to talk about! I’ve uploaded the full audio of our discussion to this blog post if you want to hear more of our Jurassic World Fallen Kingdom thoughts in two parts! http://www.pasttime.org/wp-content/uploads/2018/08/JurassicWorld_Tommy_Part1.mp3 http://www.pasttime.org/wp-content/uploads/2018/08/JurassicWorld_Tommy_Part2.mp3 FURTHER READING Check out our previous episodes on… “Genes and Jurassic Park“, in which Matt discusses his thoughts about the movie and genetic engineering. …and “New History of Ancient DNA,” which features an interview from Dr. Elizabeth Jones about the history of molecular paleontology and the impacts of science fiction! Visit the Jurassic World website for updates on the movies, games, and other media (for better or for worse). Adam really likes that Jurassic World Alive mobile game…it’s not great, but it actually has Concavenator!

Eighty million years ago, a wildly ornamented species of horned dinosaur roamed the southern half of North America’s western landmass, Laramidia. In 2016, paleontologist Eric Lund and his colleagues named it Machairoceratops cronusi, and we fell in love with this ceratopsian from Utah with hooks over its frill. In 2017, the site where Machairoceratops was found was cut from Grand Staircase-Escalante National Monument, threatening our chances of making new discoveries about dinosaur evolution there. Join us on this episode to meet one of our favorite ceratopsian researchers, marvel at the grandeur of Machairoceratops, and mourn the loss of protections for some incredible vertebrate fossil sites. Hunting Horned Dinosaurs with Eric Lund! We want to thank our guest on this episode, Eric Lund, for clearing up some of our ceratopsian confusion! Although we interviewed him while he was a student at Ohio University, he’ll be finishing up his PhD while he works in his new position in the Paleontology Research Lab at the North Carolina Museum of Natural Sciences. You can follow him on Twitter at @Bwana_Lund. And be sure to check out the scientific article he led about Machairoceratops cronusi in the journal PLOS ONE! Dig Deeper… On this episode, Eric Lund introduces us to the incredibly fossil-rich and scientifically significant Kaiparowits Plateau of Grand Staircase-Escalante National Monument. You can learn more about it in this New York Times article from 2015 and download an awesome poster about the dinosaurs of the monument designed by Blue Aster Studio. Check out the original paper for free in the science journal Plos One! The spectacular paleo-art featured in the promo image was painted by paleoartist Mark Witton. Check out his blog and art gallery. We also touch on the idea of ownership of vertebrate fossils, which tell the story of the evolution of our planet, and the laws surrounding these shared resources in the United States. This How Stuff Works article explains the debate about fossil ownership, and this webpage from the Society of Vertebrate Paleontology explains the Paleontological Resources Preservation Act. It may be confusing for a paleontology podcast to wade into politics, but when you’re talking about a fossil found in a national monument, it is impossible not to. Everyone you hear on this episode is a member of the Society of Vertebrate Paleontology (SVP), and one of the goals of SVP is “To support and encourage the discover, conservation and protection of vertebrate fossils and fossil sites” (SVP Code of Ethics). In line with this Code of Ethics, SVP is taking legal action to prevent the cuts to two national monuments that would endanger significant vertebrate fossil sites. SVP explains its position with useful maps and graphics here, and this interview with Dr. P. David Polly, the outgoing President of SVP

Big bites come in small skulls This episode tells a story of one of Adam Pritchard’s favorite projects from Yale University, describing the skull of a teeny reptile from the early days of the Age of Reptiles. Hailing from the eastern coast of North America (present-day Connecticut), Colobops noviportensis had a skull only an inch long. However, intensive research and three-dimensional modeling revealed that it possessed cavities for its jaw muscles larger than any other reptile of that size—living OR extinct! Colobops likely nipped at the heels of some of the earliest dinosaurs and crocodile cousins in North America. Dig Deeper The original paper can be read for free in the journal Nature Communications! Adam’s co-author Bhart-Anjan Bhullar, professor of Geology at Yale University, helped produce a great video on the discovery with Yale University’s press office. The brilliant reconstruction of Colobops was hand painted by paleoartist and Geology Ph.D. student at Yale Michael Z. Hanson. Mike will be appearing in an upcoming episode of Past Time on the early days of bird evolution. If you want to see the original Colobops specimen, travel to the Yale Peabody Museum in New Haven, Connecticut!

Masters of horns and teeth Throughout the Jurassic and Cretaceous Periods, dinosaurs were top dogs on every continent and in every sort of environment. The ceratosaurs were some of the classic predators that ruled the tops of the food chains for much of that time. Including classic predators such as Ceratosaurus, Carnotaurus, and Majungasaurus—as well as oddballs like Masiakasaurus, Limusaurus, and Elaphrosaurus—ceratosaurs included top-of-the-food-chain carnivores and slender, fleet-footed herbivores. For this episode, I delve into a cool new paper summing up the current knowledge on these awesome beasts! References Read the original paper by paleontologist Rafael Delcourt for free in the journal Scientific Reports! For some awesome skeletal mounts of ceratosaurs, you can visit museums around the world. See Ceratosaurus at the Natural History Museum of Utah in Salt Lake City and Carnotaurus at the Natural History Museum of Los Angeles and the Museo Argentino de Ciencias Naturales B. Rivadiva in Buenos Aires! The great traveling exhibit Ultimate Dinosaurs-Giants of Gondwana has a number of ceratosaur skeletons too! Please add a comment if you have another ceratosaur museum to suggest!

Egyptian paleontology has a long and storied history, although much of it is focused on discoveries from the Cenozoic Era. Incredible fossils of early whales, primates, and other mammals have been discovered in Egypt since the beginning of the twentieth century, work that continues to this day. However, fossils from the Age of Reptiles are much harder to come by. Indeed, most of the fossils record of Cretaceous dinosaurs and their contemporaries were collected during a small number of expeditions in the early twentieth century by German paleontologist Ernst Stromer. Stromer’s work focused on the “middle” part of the Cretaceous Period: between ~100–90 million years ago. Most of those discoveries—including the original type specimens of dinosaurs like Spinosaurus, Carcharodontosaurus, and Aegyptosaurus—were destroyed in bombings during World War II. For over sixty years, no substantive further discoveries of Mesozoic Egyptian fossils occurred. In the early 2000s, American paleontologists Matthew Lamanna and an international team returned to the Bahariya Oasis and discovered a variety of new dinosaurs, including a supergiant titanosaur Paralititan stromeri now housed in the Cairo Geological Museum. The Mansoura University Vertebrate Paleontology project highlighted in this episode extends those efforts into new fossil deposits into the Quseir Formation of the Western Desert of Egypt, preserving fossils from much later in time than those of the Bahariya Oasis. The Quseir fossils are some of the best records of terrestrial backboned animals from the end of the Cretaceous Period from the whole of Africa. This was also at a time when Africa was an island continent, isolated without land connections with other continents. That makes Africa prime real estate for finding unique fossil ecosystems. Dr. Heham Sallam leads the Mansoura University Vertebrate Paleontology (MUVP) team to the new frontier of vertebrate paleontology in Egypt. Educated at Oxford University, Hesham is one of the first native Egyptians to lead a scientific paleo project. He is training a large number of students in the science of vertebrate paleontology and Mansoura University. His current graduate students include Sana El-Sayed, Eman Abd El Aziz, and Sara Saber. Ms. El-Sayed holds the distinction of being the first woman paleontologist from the Middle East to lead a scientific publication, which described a giant catfish from the early Cenozoic. Sara Saber published the most recent MUVP paper describing the Cretaceous crocodile relative Wahasuchus, which is featured in this paper.

This episode was a blast to produce for a vertebrate scientist. I learned a ton about the echinoderms, the group of invertebrate animals to which sea stars, brittle stars, sea cucumbers, sea urchins, and crinoids belong. Be prepared for more adventures with invertebrate animals in the future. Engineering Echinoderms with Elizabeth Clark! This episode would not have happened with Elizabeth Clark, graduate student in the Geology Department at Yale University and my gateway to echinoderms. As a part of the lab of Derek Briggs, Liz has studied a wide range of topics on echinoderm paleontology and biology. You can check out the original scientific paper on her Ordovician asteroid in Biology Letters and the Yale News story about the discovery. The original specimen of Protasterina flexuosa featured in the study is pictured below. It actually lived alongside the Flexicalymene trilobites featured in our previous invertebrate episode. You can see their fossils (and hundreds of thousands of others) at the Cincinnati Museum Center in Cincinnati, Ohio. Scurrying with Sea Stars, Crawling with Crinoids, and Battling with Brittle Stars! I had a lot of fun watching echinoderms locomote while making this podcast. I really cannot believe the diversity of movement styles they adopted throughout their history. A lot of this system is built on the water vascular system and associated tube feet, but many species explore different methods for motion. Check ‘em out below! Sea star (Asteroidea) strande

Matheronodon is certainly a dinosaur worthy of a bigger bite. With proportionally giant teeth strikingly different from the standard-issue ornithopod dinosaur, it is certainly one of the most important dino discoveries out of Europe this year. Better yet, the original scientific paper by Pascal Godefroit and colleagues is free to read in the journal Scientific Reports! If you’d like to learn more about Rhabdodontidae, the small but successful family of dinosaurs to which Matheronodon belongs, check out the papers in the reference list below. Museum of Matheronodon The original specimen (pictured below) is housed at the Musée du Moulin Seigneurial in Velaux, France. I looked up the museum online, and it looks really cool. Built in an old olive mill, the exhibits include Cretaceous in Provence displays. The displays include specimens of Matheronodon contemporaries, including the sauropod Atsinganosaurus velauciensis, the crocodile Allodaposuchus, and ancient turtles. If I get a chance to visit, I’m hoping the Matheronodon teeth and jaws will be there too! Ali Nabavizadeh and his biting dinosaur commentary Our guest this episode was Dr. Ali Nabavizadeh, who was not actually involved in the study. But, he is one of the most knowledgable scientists working on dinosaur jaws! His work focuses on the evolution of eating in herbivorous animals. His early work focused entirely on dinosaurs, but he has branched out into other plant-eating reptiles and mammals. Ali’s work was featured on a classic episode of Past Time on j

The quest to recover ancient genetic material from extinct animals had its blockbuster moment when Jurassic Park came out. But where did the idea come from and who is trying to figure out if the science fiction of Jurassic Park can be science reality? We talk to Dr. Elizabeth Jones, a science historian at University College London, about her work digging through the murky early history of ancient DNA and the dynamic scientists who are trying to figure out how fossils sometimes preserve more than bone.   One of Dr. Jones’s amazing contributions to the history of science is her work interviewing the people who have been thinking about and trying to recover ancient DNA. As a historian of science, she can put look at larger trends in how ideas get passed around between scientists, and how media and public interest affects the scientific process. One key distinction to remember is there is a difference between researchers who are interested in recovering ancient DNA to study what it might tell us about ancient populations or the relationships of ancient animals to modern animals. There’s a whole separate field of researchers who are trying to figure out how to resurrect extinct animals using ancient DNA and cloning technology. These fields feed interest in each other, but they involve different techniques, different philosophical questions, and different research questions. Dr. Jones calls Ancient DNA research a “celebrity science” because each new revelation gets tons of media attention. Listen to our discussion to learn more about where the field started and what might be on the horizon! Dig Deeper! An article summarizing all the amazing insights Neanderthal DNA has revealed: https://www.theverge.com/2017/10/9/16448412/neanderthal-stone-age-human-genes-dna-schizophrenia-cholesterol-hair-skin-loneliness An article covering Dr. Mary Schweitzer’s work on dinosaur proteins: http://www.sciencemag.org/news/2017/09/i-don-t-care-what-they-say-about-me-paleontologist-stares-down-critics-her-hunt  

Hi all. Adam Pritchard here. I’ve been thinking about telling the story of my field experience in the Triassic-aged Chinle Formation of northern New Mexico for many years. The Hayden Quarry fossil site at Ghost Ranch has produced the best-preserved and most diverse record of American dinosaurs from the Triassic of North America, plus some of the strangest reptiles that ever lived. I’ve been proud to be a part of the Ghost Ranch field crew for nearly a decade now!   First off, here are some links to exhibits and museum experiences relating to the Ghost Ranch project, including the recent Hayden Quarry discoveries:   The Ruth Hall Museum of Paleontology at Ghost Ranch https://www.ghostranch.org/explore/museums/museum-of-paleontology/ Check out the Ghost Ranch exhibit in the heart of it all, filled with the awesome fossils from the Triassic Period. Includes links for school groups and to join tours of the local fossil sites led by Ghost Ranch staffers!   Paleontology at Ghost Ranch Jan-Term courses https://www.ghostranch.org/retreats/category/retreats/archaeology-geology-paleontology/ In addition to summer classes, there is a winter paleontology experience at Ghost Ranch that runs through January. Members of the classes have discovered some amazing, valuable fossils from the Hayden Quarry site!   Shelf Life episode about the Ghost Ranch area and dinosaur evolution. https://www.youtube.com/watch?v=567bv6xmuss A video from the American Museum of Natural History on its role in uncovering the amazing discoveries at the Coelophysis   I thought it’d also be good to add some links to the MANY books scientific

A few weeks ago Past Time co-host Matt Borths published a study that identified a new species of now-extinct carnivorous mammal from Egypt. The animal was near the top of the African food chain when Africa was cut off from the other continents. It lived in the same swampy ecosystem that was home to our earliest monkey-like relatives! Here’s a link to the original paper in the open access journal PLOS ONE <http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173527> if you want to take a look at the original fossils. You can even see them in 3D at www.morphosource.org Masrasector means “The Egyptian slicer” because the meat-eater was found in the deserts of Egypt, near the Fayum Oasis southwest of Cairo. The species name, nananubis, means “tiny Anubis,” because the small, fox-sized carnivore resembles the jackal-headed Ancient Egyptian god of embalming and guide through the afterlife. “Tiny Anubis” likely scrambled on the ground, chasing large rodents and small hyraxes through the Fayum wetland. It probably didn’t spend a lot of time weighing the hearts of the dead, but such behaviors don’t fossilize very well. Masrasector nananubis was part of an extinct group of carnivorous mammals called hyaenodonts. If you think of a meat-eating mammal today, like a wolf, tiger, or hyena, you’re thinking of a species from the mammalian order Carnivora. Carnivorans are united by having one pair of specialized meat-slicing teeth on each side of their face. Next time you see a dog or cat yawn, look in the back of their mouth for the scissor-like blades. Hyaenodonts had three pairs of these meat-slicers on each side of their mouths instead of just one, making it easy to recognize them in the fossil record. Hyaenodonts were the only meat-eating mammals in Africa for over forty million years between the extinction of the dinosaurs and the arrival of the first African carnivorans. Carnivorous mammals are rare in modern ecosystems, and this was also true in the past. Fossilization itself is a rare event, which means the chances of a rare carnivore becoming a rare fossil are very low. This means African hyaenodonts are a rare find, and most are only known from a few isolated teeth and jaws. But, Masrasector is known from several nearly complete skulls, dozens of jaws, and pieces of arm bone. With all this material it’s possible to really dig into what Masrasector ate, and how it moved through its environment. African carnivores like lions and hyenas are fascinating, endangered creatures. Hyaenodonts were a separate experiment in how to be a carnivorous African mammal, and they did it successfully for millions of years.Masrasector offers a detailed view of how African hyaenodonts pursued their prey and what their diet was like. The specimens were discovered in a quarry called Locality-41, one of the most fossil-rich places from the beginning of the Age of M

Past Time is BACK! Matt and Adam have been traveling the world independently for some time, delving deeply into the history of life on the planet, but now they’re back to tell you all about what they’ve discovered!   In this episode, Matt interviews Adam about his research into the early days of the Age of Reptiles and the strange non-dinosaurs living 212 million years ago in New Mexico. Come face-to-face with Drepanosaurus, one of the strangest reptiles that ever lived on Earth, and one that has presented an anatomical mystery for over thirty years! Nicknamed “the monkey lizard,”iIt had arms like no other animal, a claw on the end of its tail, and likely lived like a modern anteater! For more information on this project, you can check out Adam’s original article and the news article produced by Yale University!