Podcast 194 - Pedals the Crocodile

The gang discusses two papers about the ecological data that we can learn from looking at trace fossils. The first paper looks at a unique ancient crocodilian behavior, and the second paper shows similar shore bird behaviors over the course of tens of millions of years. Meanwhile, James is full of bones, Amanda is honored, and Curt loves Hanna Barbera.

Up-Goer Five (Amanda Edition):

 Today our friends talk about foot marks. They talk about the foot marks of two-legged animals with no hair and no teeth that can usually fly, and also the foot marks of two-legged animals that are usually four-legged, with big teeth and long faces and hard skin. The foot marks of two-legged animals with no hair or teeth that can fly are fun because they look at ones that have been known about for a very long time, but no one has ever done anything with them. They are not so old, and they look at them and some ones that are very very old, and find that they have the same sort of groups of foot marks, even though one is very old and very far away from the other one, which is much less old. They also say that you can see the same sort of groups of foot marks today, too. The other foot marks are from animals that are usually four-legged, but this one is two-legged. That is not so weird, because they were two-legged a long, long time ago. But this one is two-legged after we thought they all were four-legged. That's weird because at the same time there were very large angry animals with big teeth and no hair, which people thought maybe made it so these other usually four-legged animals with big teeth and long faces and hard skin couldn't be two-legged anymore. Maybe that isn't really the case, because it doesn't look like these foot marks were made by something that is only going two-legged for a short time.   

References:

Lockley, Martin, et al. "Bird tracks from the Green River Formation (Eocene) of Utah: ichnotaxonomy, diversity, community structure and convergence." Historical Biology (2020): 1-18. 

 Kim, Kyung Soo, et al. "Trackway evidence for large bipedal crocodylomorphs from the Cretaceous of Korea." Scientific Reports 10.1 (2020): 1-13. 

Podcast 193 - Making Monsters

The gang discuss two papers that describe unique animal fossils which have been known but haven’t (until now) been formally described. The first is “Collins Monster”, a lobopod from the Cambrian, and the second is a fossil dolphin which is similar to an orca. Meanwhile, James rehabilitates some dolphins, Amanda saw a thing, and Curt witnesses true beauty.

Up-Goer Five (Amanda Version):

 Today our friends talk about a strange animal with cute legs and big parts that go to a point, and a really big animal that used to have hair that looks like an animal with no legs but actually does have legs. Both of these things have been known about for a long time, but no one gave them a name. They were used to figure out the family tree of animals, but never had a name. These papers give them a name, which is a very important thing. The strange animal with cute legs and big parts that go to a point is very close to other strange animals with cute legs that we have talked about before. The paper does put them in a different box than we are used to seeing, which we talk about a little and find maybe a little strange. The big animal that used to have hair and looks like an animal that has no legs but it actually has legs looks like it is close to one animal that had hair and looks like it has no legs, which shows that these things show up many times as time goes on. They also show some family trees, but only one is in the paper, the rest are in the other stuff on the space where people store all their stuff today.   

References:

 Caron, Jean‐Bernard, and Cédric Aria. "The Collins’ monster, a spinous suspension‐feeding lobopodian from the Cambrian Burgess Shale of British Columbia." Palaeontology (2020). 

 Boessenecker, Robert W., et al. "Convergent Evolution of Swimming Adaptations in Modern Whales Revealed by a Large Macrophagous Dolphin from the Oligocene of South Carolina." Current Biology (2020). 

Podcast 192 - Egg

Hey now, you’re an all-star, get the game on, go play. Hey now, you’re a rock star, get the show on, get paid! All that glitters is a long discussion about Mesozoic eggs. One of the papers we discuss suggests that the evolution of hard calcification in dinosaur eggs might have evolved independently multiple times. The second paper tries to determine the origins of a cryptic large soft-shelled egg. Meanwhile, James vents on his victims, Curt ruins the fun of Shrek, and Amanda has an egg guy.

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at the things that small baby animals pop out of. Both papers are from a time when there were big angry animals that some people and all children really love. The first paper asks whether or not the things that these babies pop out of were soft or hard. While most of the things which babies pop out of from these angry animals are hard, hard things are also more able to become rocks than soft things. Also, each of the different types of angry animals seem to make their hard things in different ways. This paper looks at the things that babies pop out of from angry animals that are much earlier than the things we usually see. These angry animals all seem to be popping out of soft things, and since they are not close brothers and sisters, this means that angry animals each came up with different ways to make that things babies pop out of hard.

The second paper finds a very large soft thing that babies pop out of. Given how big this thing is, they have problems finding out what could have made this thing. They don't have a perfect answer, but they think that maybe it could be from an angry thing that lived in the water. The problem here is that the babies may have died if they were in the water while in the thing. However, it is possible to still have the thing that the babies pop out of be a real thing even if the babies then stay in the mom before they pop out.

References:

 Legendre, Lucas J., et al. "A giant soft-shelled egg from the Late Cretaceous of Antarctica." Nature (2020): 1-4. 

 Norell, Mark A., et al. "The first dinosaur egg was soft." Nature (2020): 1-5. 

Podcast 191 - Turning Points in Plant History

The gang discusses two papers that look at important points in the evolutionary history of land plants. The first paper is a review of the available data for the first time plants moved onto land in the Ordovician, and the second paper looks at the impact that the evolution of herbivory had on plant diversity. Meanwhile, James invents a new insect, Amanda reaches out and touches someone, and Curt is impressed by a brief moment of professionalism.

Up-Goer Five (Curt Edition)

Our friends talk about very old green things that grow in the ground and use the sun. The first paper looks at this very old time when green things move from water to the ground. This was a very very very long time ago, and most of what we have that lets us know about these green things are actually the small bits that the green things let go of. This paper looks at what we know about these first green things move onto land, and says that maybe as these green things go to the ground they may have changed the air. Also, the time that these things move onto land is the same time that things in the water become more different.

The second paper looks at when animals started to first eat these green things. The paper looks at changes in the animals that eat these green things, and tries to see if these animals can change how many green things there are. Big animals eat lots of different types of green things, while small animals often eat just a few types of green things. How big the animals appears to change the number of different green things. This means that animals that eat green things can have a strong control on the number of different types of green things.

References:

 Brocklehurst, Neil, Christian F. Kammerer, and Roger J. Benson. "The origin of tetrapod herbivory: effects on local plant diversity." Proceedings of the Royal Society B 287.1928 (2020): 20200124. 

 Servais, Thomas, et al. "Revisiting the Great Ordovician Diversification of land plants: Recent data and perspectives." Palaeogeography, Palaeoclimatology, Palaeoecology (2019): 109280. 

Podcast 190 - Arthropod Evo Devo

The gang discusses two papers about arthropod evolution and development. One paper focuses on the evolution of arthropod segmentation, and the other summarizes research on the development of the insect wing. Meanwhile, Amanda has a beer with no unintended consequences, Curt makes a shocking discovery about marketing, and James goes from 0 to professional in milliseconds.

As we did last time, here are some organizations you can donate to:

https://blacklivesmatter.com/

https://bailproject.org/

https://www.aclu.org/

Up-Goer Five (Amanda Edition):

 Today our friends look at small things with many legs and many body parts. The first paper is looking at how these small things with many legs and many body parts first grew the parts they needed to fly. The paper says lots of words about this, but there are two big ideas, saying that these body parts that the body parts these animals needed to fly grew from either the up on the side or down on the side. It turns out that maybe the truth is somewhere in the middle. No, really, they probably grew from both up and down on the side, there was another paper that came out while this one was being worked on that says that, and they talk about it in this paper. The second paper looks at how these animals came to have many body parts, and says how it is important that we look at the things that are very very very dead, as well as the very very very very tiny bits of living things that carry the things our bodies need to know to make stuff. 

References:

Chipman, Ariel D., and Gregory D. Edgecombe. "Developing an integrated understanding of the evolution of arthropod segmentation using fossils and evo-devo." Proceedings of the Royal Society B 286.1912 (2019): 20191881. 

 Clark-Hachtel, Courtney M., and Yoshinori Tomoyasu. "Exploring the origin of insect wings from an evo-devo perspective." Current opinion in insect science 13 (2016): 77-85. 

Podcast 189 - Big Bois

(Editor’s Note: This episode was recorded a month ago. Everyone at Palaeo After Dark stands with the protesters fighting for justice. Black Lives Matter!)

The gang discuss two papers about large mammal-like animals. The first is a Triassic synapsid the size of an elephant, and the second is a mammaliaform from the late Cretaceous of Madagascar. Meanwhile, James has a new technology to discuss, Amanda’s cats get involved in some unique business ventures, and Curt appreciates some choice scale-bar decisions.

https://blacklivesmatter.com/

https://action.aclu.org/give/now

Up-Goer Five (Curt Edition)

Our friends talk about big boys. These big boys are great great great great great great brothers and sisters to things that have hair and are warm. The first of these big boys is the oldest and it lived a long time ago when big angry animals were just starting to show up. This big boy is a REALLY big boy. This big boy shows that not just the angry animals, but a lot of other animals, were getting big at this time. This means that maybe something was happening that made it so getting big was a thing lots of different animals could do.

Our second big boy was living just before a rock killed the big angry animals. The second big boy is not nearly as big as the first big boy, but we look at the others boys with hair it was pretty big. This big boy also has lots of weird things in its hard parts that we usually do not see in animals with hair at this time. This big boy lived in a place that was not a part of all the other land and was surrounded by water. This second big boy is another animal that got big when it came to this place. This place has been away from the land for a very very very long time, and so the animals at this place have been different for a long time.

References:

Sulej, Tomasz, and Grzegorz Niedźwiedzki. "An elephant-sized Late Triassic synapsid with erect limbs." Science 363.6422 (2019): 78-80. 

 Krause, David W., et al. "Skeleton of a Cretaceous mammal from Madagascar reflects long-term insularity." Nature (2020): 1-7. 

Podcast 188 - Bird Brains and Propeller Tails

The gang discusses two papers about archosaurs. The first paper looks at the trends in brain size relative to body size in birds over their entire evolutionary history. The second paper revisits the dinosaur Spinosaurus and adds more information to the debate over whether this animal had a semi-aquatic lifestyle. Meanwhile, James has some villagers he needs to “un-person”, Curt gives alternative definitions to slang, and Amanda just disappears (I’m sure she’ll be fine).

Up-Goer Five (Curt Edition):

Our friends talk about thinks they fly and something that moved through the water. The first paper looks at the brains of things that fly. As the body gets bigger, the brain usually gets bigger as well. But sometimes the way in which the brain gets bigger can change. Sometimes the brain gets bigger faster than the body and sometimes it gets bigger slower than the body. When looking at very old things that fly, what they find is that when the body gets smaller, the brain stays larger. This is something that big angry things which are brother and sister to the things that fly did as well. But later things that fly start changing how the brain gets bigger, with some things having their brains get way bigger faster than the body. This is often found in things that fly which are able to talk and use things which can make stuff work.

The second paper looks at an angry animal that some people think may move through the water and other people think those people are wrong. This paper finds more parts of the animal (the part at the end which can be moved up and down or side to side), which can help us better understand what this angry animal might have done. They find that the part at the end can shake to the side really well, which is something we see in animals that can move well through water. They use this to say that this adds more facts that say this thing may have moved through water.

References:

 Ibrahim, Nizar, et al. "Tail-propelled aquatic locomotion in a theropod dinosaur." Nature (2020): 1-4. 

 Ksepka, Daniel T., et al. "Tempo and Pattern of Avian Brain Size Evolution." Current Biology (2020). 

Podcast 187 - Taphonomy Train Wreck

The gang discusses two papers about unique taphonomic conditions. One paper describes how these strange “train wrecks” of crinoid columnals might have formed, and the other paper models how bone jams in Dinosaur National Park could have formed. Meanwhile, James’s computer has a flux capacitor, Amanda mishears the best new BBC crime drama, and Curt enjoys the chance to talk about Nathan Fillion vehicles.

Up-Goer Five (Amanda Edition):

 Today our friends talk about animals with hard parts on their insides. Some of these animals have long arms with lots of parts and look like they sit on sticks. Others have many inside hard parts in place along their backs, and that is where they get their names. The animals with the long arms with lots of parts sometimes break into small pieces when they die. Usually they break into lots of little single round things, or they are very quickly covered up and are found all put together. But sometimes they break into big pieces that look like a train ran into another train. This paper talks about why they do that. They have long, strong bits of stuff like what is found on your knee. This stuff does not break down so easy and sometimes that is why you get these bigger pieces. The other paper looks at animals with hard parts inside their bodies put in a place along their backs, and what happens when these animals die and their hard parts come together in a moving water place. This paper does this by making tiny ones of the hard parts and putting them in a not-real moving water place. They find that these hard parts easily stick together and it explains why some of the these hard parts look the different ways they do once the animals are dead.  

References:

 Donovan, Stephen K. "Train crash crinoids revisited." Lethaia. 

 Carpenter, Kenneth. "Use of scaled dinosaur bones in taphonomic water flume experiments." Die Naturwissenschaften 107.3 (2020): 15-15. 

Podcast 186 - Fish Fingers and Mammal Fins

The gang discusses two papers that look at modifications of the vertebrate hand. The first looks at how the lobe fin evolved into the vertebrate hand, and the second paper looks at the early limb transformations of early whales as hands became fins. Meanwhile, James’s computer is a time traveler, Amanda is upset that everyone is upset about Bunny Day, and Curt wonders about numbers higher than 10.

Up-Goer Five (Curt Edition):

Our friends talk about how hands got started, and also how hands can become things that let animals move through the water. When this happens, we don't have a lot of remains because lots of the hard parts for these animals that are moving into or out of the water aren't there for us to look at. These two papers talk about new remains that have been found which give us more hard parts to look at so we can better understand how this happens. The first paper looks at new remains of old animals that let us know what the first animals which would have arms and legs and a back and lived on land looked like. This also lets us learn more about how hands first started. Big hard parts that used to be used to go through the water had some of those hard parts change to make fingers. While these first fingers started to form, the rest of the animal looked like it lived in the water.

The second paper looks at another type of animal that later on moved off the land and back into the water. When that happened, the hands become more like things that are used to move through the water. This animal is just starting to move into the water, but its great great great great children would be large animals with warm blood who move through the water. This animal that is just starting to move into the water shows changes in the hand that we usually see with things in water, but also has some hard parts that we see on land.

References:

Cloutier, Richard, et al. "Elpistostege and the origin of the vertebrate hand." Nature 579.7800 (2020): 549-554. 

 Vautrin, Quentin, et al. "From limb to fin: an Eocene protocetid forelimb from Senegal sheds new light on the early locomotor evolution of cetaceans." Palaeontology 63.1 (2020): 51-66. 

Podcast 185 - As the Worm Turns

That gang discusses two papers about fossil soft-bodied Cambrian organisms; one of which is a unique lobopod and the other is a fossil worm. Meanwhile, Amanda could go for some fish, Curt can’t stop the puns, James is going to be a cowboy.

Up-Goer Five (James Edition):

This week the group looks at two papers that are looking at two very old animals that have long bodies with no legs. One of these is a true animal with a long body and no legs, but the other is actually an animal that would usually have a short body and lots of legs but has grown a long body with very few legs and live in a long hard home that they make. This animal is actually part of the group that is the parents of animals with many legs and hard outer skin. This animal seems to have grabbed small bits of food with the legs that it has left and live inside the hard home it made, a very different way of living to the rest of its family. The other animal is a true animal with long body and no legs. It has been known for a long time but we did not know what the head looked like and now we do. As well as the head, the paper looks at the very small hard parts on its long body to show that it is not the animal that people thought it was, but a new animal! In total, things with long bodies and no legs are very good.  

References:

 Howard, Richard J., et al. "A Tube-Dwelling Early Cambrian Lobopodian." Current Biology (2020). 

 Whitaker, Anna F., et al. "Re-description of the Spence Shale palaeoscolecids in light of new morphological features with comments on palaeoscolecid taxonomy and taphonomy." PalZ (2020): 1-14. 

Podcast 184 - Lockdown Baby

The gang talks about two papers which look at the ecology of the Ediacaran. One paper uses trace fossils to infer how ecological systems change as we move from the Ediacaran to the Cambrian, and the second paper identifies some interesting features previously undocumented in Ediacaran fossils. Meanwhile, Curt has ideas about sponges, the internet destroys James’s comedic timing, and Amanda is happy to finally put those years of teaching physiology to good use.

Up-Goer Five (Curt Edition):

Our friends talk about the time just before we have a lot of dead things that can appear in rocks. The first paper looks at the tracks left behind by animals and other things as they change through time. In the time before when we have a lot of dead things in rocks, there are still tracks. As we study these tracks, it turns out that there are lots of changes in these tracks that we didn't know about. It turns out that tracks show life was doing lots of things that we didn't see because the dead things themselves didn't get into rocks. This means the big changes we see as soon as dead things appear in the rocks might have been happening earlier.

The next paper looks at a group of weird things that were around a lot before we had a lot of dead things in the rocks. These weird things are like sticks with bits on either side. There used to be lots of these stick things, and it turns out that these stick things had small lines that goes to each of these sticks. These lines are very small, which is why it was so hard to find them. The paper thinks that these lines might mean that all of these sticks are a repeat of the same stick over and over again. This is something that some things that make their own food from the sun do today, meaning that making more of themselves by repeating over and over again might be something that first happened a long time ago.

References:

 Liu, Alexander G., and Frances S. Dunn. "Filamentous Connections between Ediacaran Fronds." Current Biology (2020). 

Laing, Brittany A., et al. "A protracted Ediacaran–Cambrian transition: an ichnologic ecospace analysis of the Fortunian in Newfoundland, Canada." Geological Magazine 156.9 (2019): 1623-1630.

Podcast 183 - Nobody Wins; The Human Impact on Our Future Fossil Record

The gang discusses two papers that look at the human impact on the fossil record. The first paper runs multiple model studies to try and determine when hominines (the group that includes all of our ancestors) first began significantly impacting the biosphere. The second paper estimates what our future fossil record may look like by using the state of Michigan as a model system (much to Amanda’s delight). Meanwhile, Amanda attempts to train a cat, Curt and James invent the best machine, James has his mind blown, and everyone wonders what the “prepper layer” of the Anthropocene will look like in a few million years.

Up-Goer Five (Curt Edition):

Our friends talk about how people have changed the world. First, they talk about how big brains might have led to lost of animals dying. This first paper looks at how brains got larger in the great great great great parents of people over time. They run a lot of numbers in a computer in order to find out if the real big animals that died went away because of people or because of changes in the places where these animals live. They look at how big the brains of these people were, as well as how much rain fell and if there were trees. What they find is that, after running all the numbers, is that the best answer out of all the things they looked at was that these animals started to die when the brains of people got bigger. They think this could mean that the people with bigger brains started to take food from some of these big animals, and that made it harder for these big animals to stay living.

The second paper looks at what we will leave behind after people are gone in the rocks. It uses a state that looks like a hand (and which one of our friends really really likes) as a way to look into this. Turns out, people cover things in ground a lot more than would usually happen without people. But people only cover in ground a small number of animals, like people, dogs, cats, and animals that we use on places where we make food. This means that the rocks after we are gone will look very different from the rocks before us. These rocks will be filled with just a few things, and most of those things will probably be in the same position. Also, a lot of the animals will all be men and all will have died for the same reasons.

References:

Faurby, Søren, et al. "Brain expansion in early hominins predicts carnivore extinctions in East Africa." Ecology Letters.

Plotnick, Roy E., and Karen A. Koy. "The Anthropocene Fossil Record of Terrestrial Mammals." Anthropocene (2019): 100233.

Podcast 182 - The Pain; Happy Birthday

The gang celebrates their 7th anniversary by inflicting pain on themselves for your amusement by discussing a classic paper, Gould's "Paradox of the First Tier". They discuss the paper in its historical context, and also how our knowledge of mass extinctions has changed and evolved from this paper. Meanwhile, James comes up with unconventional ways to communicate, Amanda may need some more whiskey to get through this, and Curt is all smiles.

Up-Goer Five (Curt Edition):

Our friends have fun on the day that comes around every year which is when they first started doing this thing. They talk about a paper that is old but looking to the time ahead. This paper is interested in how things die, especially when a lot of things die. There are bad times in the past when lots of things have died all at once. This paper points out that these bad times might be really important. These bad times when lots of things die all at once might act to change the direction of how life is changing through time. Life might be changing in one way and doing just fine, but when one of these bad times happens the things that were doing well might do bad but the things that were doing bad might do really well. Our friends talk about how the ideas brought up in this old paper have changed over time.

References:

Gould, Stephen Jay. "The paradox of the first tier: an agenda for paleobiology." Paleobiology 11.1 (1985): 2-12.

Podcast 181 - Before the Pain; The Root of the Problem

The gang discusses two papers about unique fossil preservation. One paper looks at how fossil root systems can inform our understanding of early Devonian forests, and the other paper shows how slime molds can be preserved in the fossil record. Meanwhile, Amanda is excited for questionable reasons, James prepares for the pain, and Curt learns his role in the friendship.

Up-Goer Five (Amanda Edition):

Today our friends talk about weird cool things that have only one piece but can get very big, and the tall green things with many pieces above and under ground, that is trees. Because trees is a word we can use. We focus on the pieces under ground. The weird cool things that have only one piece are found in old tree blood. The part of the weird cool things that have only one piece look kind of like things that are good to eat but might also kill you that grow on the ground. They are where the weird cool things that have only one piece make more of themselves. They are very very old but look just like pieces around today. The paper says maybe this is a sign that things stay the same for a very long time because the world around things makes it so, but it is important to remember that sometimes two things that are not close brothers and sisters can look very very much like close brothers and sisters. The tree paper finds very very old tree parts under ground and says that groups of trees a very very long time ago were even more like groups of trees today than maybe we thought. This would make the ground safer for things to live on.   

References:

 Stein, William E., et al. "Mid-Devonian Archaeopteris Roots Signal Revolutionary Change in Earliest Fossil Forests." Current Biology (2019). 

 Rikkinen, Jouko, David A. Grimaldi, and Alexander R. Schmidt. "Morphological stasis in the first myxomycete from the Mesozoic, and the likely role of cryptobiosis." Scientific Reports 9.1 (2019): 1-8. 

Podcast 180 - Worms and Snails

The gang returns back from their winter break to discuss two papers that look at the important information we can glean from soft-bodied organisms in the fossil record. First, we take a look at a paper that shows some incredible preservation of Cretaceous snails in amber and how we can use that exceptionally preserved material to infer important information about the evolutionary history of these groups. Second, we talk about a cool example where hypotheses pulled from trace fossils can inform the distribution of modern worm species. Meanwhile, Amanda was not content with being driven mad by just TWO cats, James somehow manages to complain about being good at things, Curt spills the secrets on his friends, the internet TOTALLY doesn’t mess up our recording, SpaceX should probably paint their satellites, and we completely stay on topic this entire time….. believe me…..

Up-Goer Five (Curt Edition)

The friends talk about two papers about things that have soft bodies. First, the friends talk about a paper where a soft animal who makes a hard home out of rock that it carries around with it was stuck in some stuff that comes off of trees. This stuff that comes off of trees made it so that things we usually do not see got saved in the rocks. This allows us to see all of these different soft things that don't show up in rocks. People used these bits of tree stuff with soft things in them to find out that some of the soft things we see today in these animals that make a home for themselves out of rock may have first showed up very very long ago. They use this to try to find out when these groups of animals may have first showed up.

Next, our friends look at the changes in broken up bits of rock that form from soft and long animals live in the ground. As these animals move through the ground, they leave behind remains of where they were that can be seen in the broken up bits of rock they live in. These remains are usually very much the same when they are made by soft and long animals which live in very much the same way. One type of remain is usually found in places that are cold, but some people think they have found some of these remains in places that are usually pretty hot. This might be because there are ways that water moves which can cause areas that are usually very hot to have very cold water in them. That might make it just right for these soft and long animals which form these remains to live and be happy. To figure out if this is true, people went to a very warm place where in one side of the land the water was very cold and on the other side it was very warm. What they found was that the cold side had these remains, but the warm side did not. This means that these animals can live in warm places if the changes in the water allow for places with cold water.

References:

Hirano, Takahiro, et al. "Cretaceous amber fossils highlight the evolutionary history and morphological conservatism of land snails." Scientific reports 9.1 (2019): 1-16. 

 Quiroz, Luis I., et al. "the search for an elusive worm in the tropics, the past as a key to the present, and reverse uniformitarianism." Scientific Reports 9.1 (2019): 1-8.