Past Time

The relationship between predator and prey is a primal one, and one that fires the curiosity of many fossil fans. We love paintings of Tyrannosaurus battling Triceratops or saber-toothed cats leaping onto the backs of ground sloths. And we can be pretty sure that those interactions happened based on TRACE FOSSILS, like tooth marks in Triceratops bones that match closely with tyrannosaur teeth. However, it’s very rare to run across fossils that preserve an animal’s meal still in its rib cage. It’s far rarer for that meal to still have IT’S last meal in IT’S STOMACH! But that’s just the kind of fossil I talk about on Past Time today: a snake skeleton with a lizard in its stomach region, and that lizard with a partial insect still inside! I couldn’t believe the pictures when I saw them, but paleontologists Krister Smith and Augustín Scanferla have a slam-dunk case that the boa-like snake Palaeopython ate a basilisk lizard Geiseltaliellus. And, before being eaten, that lizard ate a tiny insect. That’s a whole lot of ecosystem preserved in a single fossil! Hailing from the Messel Pit fossil site in Germany, this nearly complete snake skeleton suggests that Palaeopython ate its prey in very much the same way as modern snakes. Spectacular fossils like this can reveal amazing truths about ancient ecosystems and just how different they were from the world today! Dig Deeper (Links and References): For more on this discovery, check out the original research paper by Krister Smith of the Department of Palaeoanthropology and Messel Research at the Senckenberg Research Institute in Germany and Augustín Scanferla of the Instituto de Bio y Geociencias del NOA (IBIGEO) in Salta, Argentina. Read it at http://link.springer.com/article/10.1007/s12549-016-0244-1. Past Time covered the Messel fossil site in a classic episode with Matt and Adam! Check it out at http://www.pasttime.org/2013/08/episode-6-field-guide-tiny-horses-galloping-crocs-and-fossilized-jungles/. The Guardian newspaper reported on some of the spectacular fossils of Messel, and published some amazing photos of the crocs, birds, mammals, and insects at https://www.theguardian.com/science/gallery/2009/may/19/fossil-ida-missing-link. And check out a much older case of a three-level trophic interaction involving a shark, amphibians, and an ancient fish at this link: 

Growth is a universal facet of all organisms that have ever lived, but figuring out how old they grow isn’t always easy. A new study examined the growth in one of the biggest predatory fish in all the ocean, the Greenland Shark (Somniosus microcephalus), revealing it to be the vertebrate species with the longest lifespan: nearly 400 years, if not more! Just goes to show that you don’t always need fossils to learn about natural history. Check it out in the latest episode of Past Time!   FURTHER READING: Read about the original study at: http://www.sciencemag.org/news/2016/08/greenland-shark-may-live-400-years-smashing-longevity-record More studies on growth in marine animals use bomb radiocarbon, too, including this study of the Great White. The study linked here was the first to use this method on the age of living sharks. For some awesome pictures of the Greenland Shark in nature, check out ARKIVE.org.  

I tried to google “crocodiles are living fossils,” to see just how commonly that expression was used in popular articles. There were indeed a few articles that referenced this idea, suggesting that croc fossils from 80 million years ago would look identical the skeletons they have today. However, most were news stories reporting various discoveries in the fossil history of crocodiles and their relatives; in these, paleontologists repeatedly debunked the notion of the “living fossil,” each describing some of the strange twists and weird turns taken by crocs over the past 250 million years. I wouldn’t argue that croc history is fraught with more twists than an M. Night Shymalan movie, but there’s ONE place where I think the “living fossil” statement can be used. The body plan of crocodiles, the overall construction of the various parts of the animal, has been maintained for at least 190 million years since the Jurassic Period. The long, flat snout; the low slung body with a sprawled posture; and the coat of armor have held true for all that time. Now, as I note in the episode, the individual species and families of crocodile-relatives that have explored this sit-and-wait aquatic ambush predator role have varied greatly through time. There is a constant pattern of competition, extinction, and dynamic change in the fossil record. But, if we are to use “living fossil” to describe the basic “shape” of the modern croc, I think that is pretty appropriate. The creatures featured in this episode of Past Time are members of the extinct croc-relative family Allodaposuchidae: the short-snouted, big-toothed Lohuecosuchus and the alligator-like Agaresuchus. These two animals co-existed in a single ecosystem in the Late Cretaceous Period of Spain. As illustrated above by Carlos de Miguel (deviant art link below), the two were roughly the same size despite their dramatic differences in anatomy. It is unlikely that these two aquatic predators did not occasionally come to blows (bites?) over the body of a hapless dinosaur plucked from the riverbank. But, we know from today’s crocodile-dominated regions that multiple croc species can coexist just fine, suggesting that they don’t completely overlap in their ecological roles. The major anatomical differences between the new species suggests t

Antarctica is one of the great frontiers of paleontology. It’s been really far south for a long time, but it hasn’t always been frozen over. In February of 2016, a team of paleontologists and geologists set out on an expedition to the frozen continent in search of fossils from the end of the Age of Dinosaurs. Matt talked with two of the team members, Eric Gorscak and Patrick O’Connor both from Ohio University, about planning the expedition and what they hope to find at the bottom of the world. Follow the entire Antarctic Peninsula Paleontology Project (#AP3) team at www.antarcticdinos.org and @antarcticdinos! Meet the Scientists! Patrick O’Connor is a Professor of Anatomy and Neuroscience at the Ohio University. Here’s a link to his lab’s website. His research is focused on vertebrate evolution on the megacontinent of Gondwana, a giant landmass that broke up through the Mesozoic and beginning of the Cenozoic to become Africa, South America, Australia, Antarctica, Madagascar, and India. In addition to working in Antarctica, he has active field projects in Madagascar, Tanzania, Zimbabwe, and Egypt. He’s worked on weird Gondwanan dinosaurs like Majungasaurus, weird Gondwanan crocodiles like Pakasuchus, and weird Gondwanan mammals like Vintana. Eric Gorscak is a Doctoral Candidate at Ohio University where his research is advised by Dr. O’Connor. Eric’s research is focused on the evolution of sauropod dinosaurs, the gigantic, long-necked, plant-eating dinosaurs that seem to defy the laws of physics and biology. As part of his dissertation, he’s trying to sort out how gigantic titanosaur sauropods found around the world are related to each other. His most recent study described a new Tanzanian titanosaur called Rukwatitian. Antarctica through Time Pat, Eric, and the rest of the Antarctic Peninsula Paleontology Project team want to figure out what was going on in Antarctica during Late Cretaceous, the last slice of time before the extinction of the non-avian dinosaurs. Most of what we kno

If you wander into the basement of the Peabody Museum of Natural History at Yale University, and wander into the fossil collections, you will find a vast array of different dinosaurs dating back over 200 million years. However, just a few feet away from the oldest dinosaurs you will find several drawers filled with the bones of Raphus cucullatus: the dodo. These are not fossilized; the dodo has only been gone from the Earth for four hundred years, after all. Still, placing the dodo among all of the other extinct birds, alongside the dinosaurs seems perfectly appropriate to me. As I mention in the episode, a dodo skeleton is not a common thing in museum collections. There are only a few skeletons that are nearly complete, most of which are preserved in European collections. Only one set of bones at the Oxford Museum of Natural History preserves the soft parts in a mummified state, and only of the head and the foot. As a matter of fact, we likely know less about the dodo than we do about some dinosaur species that have been extinct for more than sixty six million-years longer than the dodo. Moreover, scientists today are applying the same techniques and technologies used to understand the lives of fossil animals to answer questions about the life of the dodo. Eugenia Gold is a scientist uniquely qualified to answer questions about this extinct species. She has engaged in a number of anatomical science projects, examining topics as varied as changes in shape during the life of crocodylians, the anatomy of the brain in the tyrannosaurid dinosaur Alioramus, and the evolution of bird brains! She’s got brains on the brain (I’m sure no one has e

With Past Time, Matt and I tend to focus on the new discoveries in paleontology: the new species that show up in the news, or the important specimens discovered in museum collections. These are the raw materials that feed the fires of paleontology as a science. However, observation is only the first step in the scientific method: a method that paleontologists follow. This week’s episode features the work of Dr. Ali Nabavizadeh, a postdoctoral researcher at the University of Chicago. Ali recently completed a Ph.D. studying the functional anatomy of dinosaur jaws at Johns Hopkins University. His work combines a knowledge of modern reptile jaw muscles and tissues and the skeletons to dinosaurs to make two-dimensional models that can estimate the relative differences in the bite forces of extinct animals. Ali’s research takes those initial observations (the fossils themselves) and uses them to estimate the actual biology of dinosaurs. His research also asks specific questions about the storied history of Ornithischia, the dinosaur group that includes Triceratops, Stegosaurus, the duck-billed hadrosaurs, Iguanodon, and virtually every herbivore that wasn’t a long-necked sauropod. These animals wrote the book on eating plants during the 150+ million year reign of the dinosaurs, and they had a huge variety of different jaw constructions and tooth shapes. Using relative bite force estimates from over 50 ornithischian dinosaur species, Ali estimated where major changes in the force of the bites and the position of the strongest bite within the jaw occurred in dinosaur evolution. Although many paleontologists have sought to understand the jaw muscles of dinosaur groups, Ali’s research is special in the sheer number of species he examined at once! His research therefore proposed a hypothesis, that the bite forces of different groups of ornithischian dinosaurs were very different. Ali then mapped the relative dinosaur bite forces onto a tree of relationships, to see whether or not there were major shifts and where those occurred. He indeed found that some groups had quite different bites than others; the armored dinosaurs (stegosaurs, ankylosaurs) were not strong biters, while the duck-billed hadrosaurs and giant ceratopsians were very strong biters, especially at the backs of their jaws. The data strongly support the hypothesis that major groups of ornithischian dinosaurs experimented with a wide array of different biting strategies in their inexorable search for food. Research like this is a great example of that “next step” that Past Time hasn’t really highlighted as much. The fossils sit in museums for a reason: so that researchers can pick them back up to try and answer their own questions about the past. With research on dinosaur jaw mechanics, we have a chance to not only understand how individual species approached food processing; we can also try to answer questions about how those capabilities evolved over time. Did they maintain the same bite forces? Did they alter their jaw anatomy to effect a stronger bite? Only by taking the fossils to the next step—by using them to ask and answer new questions about ancient biology and evolution—can we truly begin to understand past tim

It’s been a long time coming, but both Matt and I have completed our doctoral degrees at Stony Brook University. This is the end of a journey he and I began over six years ago, when we first moved to Long Island with dreams of becoming paleontologists. Since that time, we have learned a LOT about what exactly it means to be a paleontologist and the many paths that can be taken to reach that goal. In this long-form episode, we do not feature a new discovery in paleontology or a natural history researcher. Instead, we tell a bit of our own stories: specifically, how we came to be at Stony Brook and what we were up to (other than Past Time) while we were there. We hope to give people a bit of guidance in making a decision to follow a career in paleontology. I completed my dissertation research on the evolution of Triassic reptiles and presented it to the Department of Anatomical Sciences in June of 2015. Cathartic does not begin to describe the experience after my adviser told me that I had passed…there were so many times over the preceding years when I was certain it would never end. The dissertation project is so large that it can seem insurmountable at times…but it did come to an end. It comes to an end through persistence, but it also comes to an end because of collaboration. I think collaboration is the primary theme of this episode, which we recorded just an hour and a half after Matt completed his dissertation defense. The goal of a dissertation is to address a scientific question from many different angles. However, addressing a scientific question is not something one can do alone. A student needs to be trained. A researcher needs access to specimens and technology. A person needs support and love from friends and family. Completing a project on this scale

It weighed twice as much as a modern wolf. It had three pairs of meat-slicing teeth. It was the first carnivorous land animal to reach 200 pounds on the entire continent of Europe after the extinction of the dinosaurs. And a team of European scientists and Past Time co-host Matthew Borths just introduced us to it. Ladies and gentlemen: meet Kerberos, monster mammal carnivore! If you’re interested, read the full technical article about the new mammal, Kerberos,in the online journal Plos One There are very few articles on creodonts online, like this one from UC Berkeley, mostly because they remain very mysterious. Matt will have a LOT more to tell the world about creodont mammals after he completes his dissertation this Fall! If you get the chance, wish him luck in the comments, on Facebook, or on Twitter!

Arrr, ye mateys! Pour out some grog, and I’ll tell ye a tale of mines, beaches, and death in ancient jungles. I of course be talkin’…about salamanders! Okay, not going to do that voice the whole time (though maybe it should be in the episode), but I will briefly present Palaeoplethodon hispaniolae, the first salamander in amber and the first ever found in the Caribbean! This discovery was spearheaded by George Poinar, Jr of Oregon State University (http://oregonstate.edu/ua/ncs/archives/2015/aug/first-ever-discovery-salamander-amber-sheds-light-evolution-caribbean-islands) and David Wake of University of California Berkeley. The Caribbean is home to many fossil sites that preserve amber, and Palaeoplethodon comes from a mine on the island of Hispaniola. Its age is a mystery, unfortunately, but it confirms without doubt that salamanders did live in the Caribbean some time in the past…a place where they do not exist today. We still have many mysteries to solve about how salamanders got to these islands and why they are not there any more… Check out the scientific paper in the journal Palaeodiversity at http://www.palaeodiversity.org/pdf/08/03Palaeodiversity_8-15_Poinar-Wake_4.pdf for more pictures and data!

The oldest basilisk lizard from North America, described by Jack Conrad from NYIT College of Osteopathic Medicine, shows the 48 million year old animal was part of an ancient lush jungle ecosystem…in the middle of Wyoming. The beautifully preserved skull has important stories to tell about the evolution of the lizards most famous for their ability to scamper across the water, but it also reveals what North America was like during a greenhouse world that wasn’t all that different from what our planet’s future may look like. Here’s the link to the original article. And here’s what some modern basilisks can do when they get near the water’s edge: And here’s what the beautiful skull looks like!  

Genes were the stars of Jurassic Park and the movie taught us what the near genetic future might be. (more…)

Dating fossils might sound like Saturday night for a paleontologist, but it’s serious science! In a new study, a group of physicists and paleontologists teamed up to re-date one of the most complete skeletons of a human relative ever discovered. The skeleton was discovered in a cave in South Africa twenty years ago, but the geology of the cave made it tough to figure out how long ago the animal, nicknamed “Little Foot” was washed in an buried. The date paleontologists were working with was 2 million years old, making this specimen that belongs to the genus Australopithecus a much younger animal than its cousin Lucy (Australopithecus afarensis). Using a new technique that looks at how the atoms in the sand grains around the specimen changed after being sealed in the cave, away from cosmic ray bombardment, the team discovered the specimen is 3.67 million years old! That put the South African animal on the landscape at the same time as Lucy. That means two species of Australopithecus were wandering around at the same time. How did they share the landscape? Which species is more closely related to us? The paleontologists working on Little Foot are still getting it ready for a full anatomical description, but this new study presents a new way to date fossils once thought impossible to get an age from and makes us even more eager to know more about the anatomy of this ancient cousin of ours! Check out this video if you want to learn more about the machine used by the physicists to date the sand around the Little Foot specimen: The study: Darryl E. Granger, Ryan J. Gibbon, Kathleen Kuman, Ronald J. Clarke, Laurent Bruxelles, and Marc W. Caffee. 2015. New cosmogenic burial ages for Sterkfontein Member 2 Australopithecus and Member 5 Oldowan. Nature. DOI:10.1038/nature14268  

Brontosaurus was an extinct name for an extinct animal, but a new study brings the “Thunder Lizard” title roaring back to life! But how does a name get dropped, and how does it get brought back again? Follow us into the winding world of paleontology taxonomy, the study of names. In the 1870s two giant hip bones were found and named by one of the great paleontologists of the age: Othniel Marsh. He thought there were a few differences and called one Apatosaurus ajax and the other, named a few years later, Brontosaurus excelsus. The Brontosaurus and Apatosaurus parts of those names are the genus, and the second part – excelsus and ajax – are the species. In 1903 another paleontologist, Elmer Riggs, decided they weren’t different enough to be different genera. Apatosaurs was the older genus, so Brontosaurus excelsus became Apatosaurus excelsus to show other scientists how closely related it was to Apatosaurus ajax. They were two species in the same genus. Infographic created by 4.0 PeerJ A new study looked at every specimen from the family that includes Apatosaurus that has ever been collected: Diplodocidae. The family Diplodocidae includes long-necked dinosaurs with horse-like faces and whip-like tails. Some of the specimens were collected 150 years ago but were never really scrutinized before. In the new analysis, the specimens once called Brontosaurus  were found to be related to different specimens from Apatosaurus ajax. They aren’t each other’s closest relatives anymore, so the name Brotosaurus was brought back to describe this newly discovered cluster of specimens that are united by newly discovered anatomical features such as Brontosaurus’s narrower neck. This is just one more hypothesis for dinosaur relationships. There are more fossils to discover in the field and in museum collections and paleontologists will keep hunting for more relatives of the Thunder lizard and its kin! The study: Emanuel Tschopp, Octávio Mateus, and Roger B.J. Benson. 2015. A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda). PeerJ 3:e857 https://dx.doi.org/10.7717/peerj.857

In a study published in the Proceedings of the Royal Society B, Rodolfo Salas-Gismondi and other paleontontologists described the crocodiles from a gigantic wetland that predated the Amazon. Ten million years ago there was the giant Purussarus, the duck-billed Mourasuchus, the tube-snouted gharial-like croc, a coyote-like croc similar to Paleosuchus, and three new crocs with broad teeth perfect for crushing shells: Kuttanacaiman, Caiman wannlangstoni, and Gnatusuchus pebasensuis. This is the largest number of croc species living in the same place at the same time that the Earth has ever known. How did they find room for each other in the ecosystem? These new animals from Peru shed light on the South American croc ecosystem before the Amazon River started to flow and tell us we have a lot to learn about the ways crocs can make a living. The crocodiles from the Pebas Formation were a diverse bunch. The fossil new species are shown on the left drawn by Javier Herbozo, the giant Purussaurus was drawn by Nobu Tamura, Mourasuchus-like Stomatosuchus (they look similar, but are distantly related) by Dmitry Bogdanov. Drawing of the new croc species from the Pebas Formation in northeastern Peru by Javier Herbozo. All three are closely related to caimans, a group of crocodilians closely related to alligators. Gnatusuchus has blunted teeth that would have made it a formidable shellfish eater. Citation: Rudolfo Salas-Gismondi, John J. Flynn, Patrice Baby, Julia V. Tejada-Lara, Frank P. Wesselingh, Pierre-Olivier Antoine. 2015. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands. Proceedings of the Royal Society B.

Under the canopy of an ancient fern forest near the border of Arizona and New Mexico a colossal crocodile-like reptile took a bite out of an even larger, toothy giant. The attack failed and the victim limped on to fight another day, until its carcass was finally pillaged by another scaly monster and smaller, pickier scavengers. Studying bones collected over a century ago, scientists are now able to reconstruct these scenes from the ancient Wild West using new digital tools familiar to fans of C.S.I. Stephanie Drumheller, from the University of Tennessee, and her team first noticed the fossils, collected in 1913, in museum collections. They observed deep bite marks in two separate thigh bone specimens that would have belonged to two rauisuchians (row-ay-soo-keeans), wolf-like reptiles with the head of Tyrannosaurus rex. These 30-foot-long carnivores were supposed to be at the top of the food chain 218 million years ago in the Chinle Formation, an ancient ecosystem preserved in flame-red rock that gives the Painted Desert its name. Who took the bite out of these meat-eating giants? Fortunately, the attacker left a weapon at the scene of the crime. Deeply embedded near the hip joint in one of the bones is a massive, curved tooth. Using the same CT-scanning technology doctors use to create 3D images of their patients, Drumheller and her team digitally extracted the tooth, identifying the powerful predator as a 25-foot long phytosaur (fight-o-sore). Scientists thought the slender-snouted, crocodile-like reptile was a fish specialist, but this new evidence shows it fought one of the largest carnivores on the planet. CT-scanners are a new, important part of the fossil hunting toolkit, allowing scientists to digitally dissect rare and delicate fossils to expose the secrets locked inside. Around the embedded tooth, Drumheller and her team digitally extracted healed bone, evidence that the rauisuchian escaped the phyotosaur’s attack and the wound had time to heal. Near the tooth are deep, unhealed bite marks, showing another large phytosaur attacked the same rauisuchian later, but there wasn’t time for that wound to heal. Closer to the knee are shallower, smaller tooth scratches, evidence of scavengers that picked over what was left behind by the phytosaur, just as modern vultures pick at a carcass once the lions have eaten their fill. There are a lot of gigantic reptiles in the Chinle Formation and the hypothesis was that the large rauisuchians were the top of the land-based food chain, and phytosaurs were at the top of the aquatic fo