Past Time

When we think of paleontologists, we think of people hunkered down with bones, teeth, and shells studying the preserved body parts of dead organisms. But animals leave behind more than just their skeletons. As they walk they can leave behind footprints, as they eat they can leave behind bite marks, and as they finish eating they leave behind…well…what comes from the behind. The study of the traces of past behavior is called ichnology and Dr. Tony Martin (@Ichnologist) and author of “Dinosaurs without Bones” is with us to reveal all the amazing insights a paleontologist can learn from the fossil record, even when there aren’t any bones! He takes us through a wandering heard of sauropod dinosaurs, into the burrow of the dinosaur Oryctodromeus, and across the mudflats of an amphibian-dominated Alabama. These animals may be extinct, but their traces bring them back to thundering life in this episode of Past Time!

When we think of iconic dinosaurs, like T. rex with its massive head full of teeth, and Parasaurolophus crowned with a gigantic, tube-like horn, we’re thinking of the features of adult dinosaurs. But we know from looking around today that animals change a lot from birth to adulthood. Did T. rex always have a massive maw and Parasaurolophus a huge crest? How quickly did they grow in? What were they used for? To really understand the biology of these titans, paleontologists need to study baby dinosaurs to connect the dots from tiny hatchling to adult dinosaur. Unfortunately, the fossils of dino-toddlers are few and far between because their skeletons are usually pretty delicate. In this episode we discuss the improbable discovery of a baby Parasaurolophus with Dr. Andy Farke, a paleontologist from the Raymond Alf Museum and Webb Schools in Clermont, California. Dubbed “Dinosaur Joe”, the young dinosaur was found and studied by young, high school scientists from the Webb School. The high school scientists were part of the team that revealed the six-foot-long animal was only one-year-old and had a little nubbin of a what would become that spectacular Parasaurolophus crest. Listen to the episode to learn more about growing up dinosaur!

Marine mammals are fascinating beasts. Whales, manatees, seals, otters...they've all gone back to the water and in the process evolved all kinds of spectacular adaptations to make a living in a soggy setting. Toothed evolved an ability to “see” the underwater world around them using echolocation - basically sonar - to track prey with high-pitched sounds and echoes. A 23 million years old fossil from South Carolina called Cotylocara shows toothed whales could echolocate early in their evolutionary history. A more surprising adaptation to life in the water was preserved with another new whale fossil from California. Called Semirostrum, the new whale has a huge underbite and long chin which was probably used as a sensitive probe to track down buried prey. Whales in the water are interesting, but not unexpected. Our final study examines how SLOTHS adapted to life in the ocean. Thalassocnus was a relative of giant ground sloths, a solidly terrestrial group of animals. A recent study showed how Thalassocnus gradually acquired thickened bones, a trait that has been observed in nearly every mammal that has gone back to the water. Even if it’s a weird animal to imagine clawing through the water, it adapted to that lifestyle in exactly the way paleontologists expect any mammal to get back to the water!

Over 400 million years ago the oceans were teeming with life, but it didn’t look much like what you see at the aquarium or in Finding Nemo. Instead of colorful fish flitting through coral reefs, the ancient seas had giant, shelled squids darting past the icons of the early ocean: The Trilobites! Journey back to the Late Ordovician sea with Dr. Brenda Hunda, Curator of Invertebrates at the Cincinnati Museum Center. Dr. Hunda has spent her career carefully documenting the changes in trilobites in the remarkable rocks near Cincinnati, Ohio. Trilobites were spectacularly diverse early arthropods (the group that includes crustaceous, insects, and arachnids) that adapted to the ever-changing seas, by swimming through the water, scooting along the ocean floor, and burrowing through the mud for their 300 million year reign. Our journey through the ancient Queen City features the musical talents of two great Cincinnati-area bands: The Cincinnati Dancing Pigs and Jake Speed and the Freddies! Take the plunge into invertebrate paleontology with Matt and Adam in this episode of Past Time!

50 million-years ago, the heir to Tyrannosaurus stalked the forests of ancient Europe and North America, snapping up the tiny ancestors of horses, cows, and wolves in its colossal meat-cleaving beak. Gastornis was a six-foot-tall, flightless bird and the king of the food chain...or that’s what we thought. For decades paleontologists looked at the huge, parrot-like head and thought the giant bird must be a carnivore, but a recent, exhaustive study drew on molecular evidence, anatomical evidence, and ecological evidence to show Gastornis was a giant herbivore! The former terror bird likely used that massive beak to crack open the abundant seeds and leaves that would have littered the forest at the beginning of the Age of Mammals. Tune in to Past Time to learn how the fossil Terror Bird became Big Bird!