Past Time

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!

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!

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!

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!

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.