Palaeo After Dark

It’s the end of another year, and the Palaeo After Dark team are getting together for another Fiasco. Come join us as James, Amanda, Curt, Ally, and Ants build the characters and the premise for this year’s story of mistaken identity and intrigue in de Medici era Italy.

Direct download: Podcast_227a_-_Building_the_2021_Fiasco.mp3
Category:general -- posted at: 12:22pm EST

The gang discusses two papers that look at the evolutionary history of unique teeth. The first paper looks at the history of tusks and tusk-like structures in synapsids, and the second paper looks at the shape of ancient bird teeth. Meanwhile, James gets to the point, Curt is inspired, and Amanda has a drink.

 

Up-Goer Five (James Edition):

The group looks at two papers that talk about teeth in different groups of animals. The first paper is interested in big teeth that keep growing and don't have a hard cover around them. While these teeth without a hard cover that don't stop growing are usually only found in animals with hair, one group that is part of the same family but much older also has teeth that seem to get big and never stop growing. However it turns out that many of them still have the hard covering, and only some of them lose it to be like the animals with hair today that have long teeth without a cover that doesn't stop growing. The other paper is looking at animals that fly and usually don't have teeth, but that are very old and so do have teeth. They look at the types of these old teeth to see whether they can tell us what these animals ate. It turns out that it is very hard to tell what these animals ate from their teeth, and it seems that other things like the type of face they have may be more important.

 

References:

Zhou, Ya-Chun, et al. "Evolution of tooth crown shape in Mesozoic birds, and its adaptive significance with respect to diet." Palaeoworld (2021).

Whitney, M. R., et al. "The evolution of the synapsid tusk: insights from dicynodont therapsid tusk histology." Proceedings of the Royal Society B 288.1961 (2021): 20211670.

Direct download: Podcast_226_-_Insert_Fleetwood_Mac_Tusk_Joke_Here.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at how trace fossils can give important clues to ancient ecological interactions. The first paper identifies a unique behavior using trace fossils, and the second paper uses bite marks on bone to infer ontogenetic ecological shifts in a large caiman species. Meanwhile, Curt investigates, Amanda collects, and James fixates.

 

Up-Goer Five (Amanda Edition):

This week our friends talk about animals that roll in wet tiny pieces of rock that are really very tiny tiny. We also talk about a very big very slow animal with hair that got bit by a very large animal with no hair but hard skin and lots of big teeth that has a very long face. The animal with hair that rolled in wet tiny very very tiny pieces of rock shows that these animals did this thing a very long time ago; it shows that these animals with hair and two fingers on each leg were in this place at this time, along with animals with stuff that wasn't hair but made of the same stuff as hair and could fly, too. The second paper looks at how we can talk about a hard part of a very big very slow animal with hair could have gotten grabbed by a small one of a very, very, very big animal with no hair but hard skin and lots of big teeth with a very long face. It tells us that these very big animals with no hair but hard skin and lots of big teeth ate different things when they were small than when they were very, very, very big.

 

References:

Abbassi, Nasrollah, et al. "Vertebrate  footprints and a mammal mud-bath trace fossil (Laspichnia) from the  Mukdadiya Formation (Late Miocene–Pliocene), Chamchamal Area, Kurdistan  Region, Northeast Iraq." Ichnos 28.1 (2021): 72-83.

Pujos, François, and Rodolfo  Salas-Gismondi. "Predation of the giant Miocene caiman Purussaurus on a  mylodontid ground sloth in the wetlands of proto-Amazonia." Biology Letters 16.8 (2020): 20200239.

Direct download: Podcast_225_-_Columbo_Meets_the_Caiman.mp3
Category:general -- posted at: 3:00am EST

Random computer glitches are unable to stop the gang from delivering another podcast! This week, they focus on two papers that look at the importance history for understanding trends in our modern biosphere. The first paper discusses how speciation trends are important for planning future conservation efforts, and the second paper looks at the importance of exaptive traits (characters evolved for one purpose but used for another) in the evolutionary history of sea snakes. Meanwhile, Amanda cuts deep, Curt has done this before, and James waits for his time to tell his very good joke.

 

Up-Goer Five (Curt Edition):

Our friends talk about how the past is important. And this is funny because they already did this before but the big boxes with bits that will shock your hand if you touch them lost the talk they did about the past being important so they are doing it again. The first paper they look at is short. It is about how animals living in places that are high up but in warm places make new types of animals that stay at the same high up place, not higher or lower. This means new animals will more often be living the same types of places as the older animals they came from, and this means that as places change we need to make sure the types of places where these animals live can stay open.

The second paper looks at how long animals without legs moved into the water. There are many groups of animals without legs that moved into water, and this paper wants to know the types of places they were in before they moved into water and also if the things they all have that make it easier to be in water were things that appeared before they moved into water (letting them move in there) or after they moved into water (making it better to be in water). They find that most of these groups started in areas with trees before moving into water. They also find that the things which make it easier to be in water appeared in older groups well before these animals moved into water. This means that the things that made it easy to go in water appeared first, and then this made it so these animals could then move into water.

 

References:

Linck, Ethan B., et al. "Evolutionary conservatism will limit responses to climate change in the tropics." Biology Letters 17.10 (2021): 20210363.

Gearty, William, Elsie Carrillo, and  Jonathan L. Payne. "Ecological filtering and exaptation in the evolution  of marine snakes." The American Naturalist 198.4 (2021): 506-521.

Direct download: Podcast_224_-_Second_Times_the_Charm.mp3
Category:general -- posted at: 2:00am EST

The gang discusses two papers that look at the impact of ecological interactions on the evolutionary history of groups. The first looks at potential competitive interactions that could control rabbit body size, and the second paper uses the fossil record to investigate potential clade interactions between two groups of bryozoans. Meanwhile, Curt researches in real time, Amanda gets to talk about a childhood favorite, and James makes future plans.

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at how animals trying to get food and sometimes fighting with each other can change how they live and grow and make more of themselves. The first paper looks at animals that jump and have hair and their name sounds just like hair. These things that sound like hair do not get really big in most cases, even though we know that they could get big if we try and make it happen. This paper looks for reasons why these "hairs" don't get very big. It turns out that "hairs" eat things that a lot of other animals that eat. And while there are a lot of other things in the paper here that help to build this idea, the big idea is that that how big these "hairs" get may be held back by the smallest of the other animals that eat their food. "Hairs" get about as big as the smallest of these other animals in a place.

The second paper looks at animals that grow on top of other things. There are two big groups of these animals, and when we look at how they grow, usually one group will grow over the other group. This means this one group is better at growing in a space and can push out the other group. In the past we used to have more of the group that gets pushed out, but over time we have more of the new group that is better at growing in a place. Some have thought maybe this means that what we see happening in small places may explain this larger change over time. But it is more than just that because it is not just one group going down and another going up. This paper uses a lot of number work to see how these two group may change each other. They find that it is more than just a simple one up one down thing. They find both groups change each other in a few ways. They also don't find that the things happening in the small spaces is causing these bigger changes. It could be because of the type of things we are looking at makes it harder to see these changes, but with what they have it looks like maybe this is not what is causing this change.

 

References:

Tomiya, Susumu, and Lauren K. Miller. "Why aren't rabbits and hares larger?." Evolution 75.4 (2021): 847-860.

Lidgard, Scott, et al. "When fossil clades ‘compete’: local dominance, global diversification dynamics and causation." Proceedings of the Royal Society B 288.1959 (2021): 20211632.

Direct download: Podcast_223_-_Amanda_Loves_Watership_Down.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at evolutionary changes in animal groups after the End Cretaceous Mass Extinction. The first paper looks at morphometric changes in shark teeth, and the second paper studies the evolutionary and biogeographic patterns of snakes. Meanwhile, Amanda “fixes” her audio, Curt goes biblical, and James is missing.

 

Up-Goer Five (Curt Edition):

Our friends talk about things that lived through a real bad time when a huge rock hit the big round place where we all live. The first paper looks at large angry animals that move through water and have pointed things in their mouths and soft bits where things have hard bits. We usually just find the hard pointed bits from the mouth because the rest of the body falls to bits when they die. So this looks at how these old hard bits change from before and after the big rock hit. What they found was that changes happened within groups, where some groups were hit hard and others were not. But if you look at all of the big angry animals, it looks like very little changes. The hard bits are doing things that look the same before and after the rock hit, but its different groups doing that.

The second paper looks at animals with no legs and looked at changes in where they live and how quickly they change over time. The paper finds that after the big rock hit, one group was able to move to a new place. This move seems to happen when they also start making more of themselves. It seems that, for this big group of animals with no legs, the big rock hitting may have helped this group. It seems like a new place opened up after the big rock and the group took over and did well. There are also changes that we see when it gets colder in the time way after the rock hit.

 

References:

Klein, Catherine G., et al. "Evolution and dispersal of snakes across the Cretaceous-Paleogene mass extinction." Nature Communications 12.1 (2021): 1-9.

Bazzi, Mohamad, et al. "Tooth morphology elucidates shark evolution across the end-Cretaceous mass extinction." PLoS biology 19.8 (2021): e3001108.

Direct download: Podcast_222_-_Static_Hiss.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at patterns of speciation and extinction and relate those patterns to shifts in climate. The first paper looks at how both plate tectonics and climatic changes have contributed to shifts in provinciality, and the second paper tests the link between dramatic temperature changes and large scale extinction events. Meanwhile, James cannot remember “that guy”, Curt does not like Oliver Cromwell, Amanda is in an abusive relationship with her cats, and we cannot stay on topic for more than 2 minutes.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about how the change in hot and cold and places where rocks are over a very long time has changed the way things live. Or not lived. The first paper says that while we used to think that changes in the way the big rocks that stick out of the water that we live on is the most important thing for making different animals and green stuff live in different places. But it turns out that it may be changes in hot and cold that take a very long time to happen that is more important. Both things are important, but how it gets colder the more towards the top of the world you go is just a little more important. It really controls how things can live places. The other paper looks at changes in hot and cold and how that makes things die. It turns out that if it gets warmer faster, or colder faster, it makes things die. They have a real number of 5.2 bits, and it is at more than 10 bits every 1,000,000 years. It does not matter if it gets warmer or colder, it is the quick turn that matters, and the big jump in change. They say that we are already getting hot enough fast enough right now to cause lots of things to die, even if we were not killing them, which we are.

 

References:

Kocsis, Ádám T., et al. "Increase in  marine provinciality over the last 250 million years governed more by  climate change than plate tectonics." Proceedings of the Royal Society B 288.1957 (2021): 20211342.

Song, Haijun, et al. "Thresholds of temperature change for mass extinctions." Nature communications 12.1 (2021): 1-8.

Direct download: Podcast_221_-_Ramble_On.mp3
Category:general -- posted at: 3:11pm EST

The gang discusses two papers that look at the fossil record of fishes. The first paper looks at the ontogeny of ancient lampreys, and the second paper investigates the impact genome duplication had on the evolutionary history of teleost fishes. Meanwhile, James finds a gnome, Curt has an adorable ghost problem, Amanda appreciates good music, and we are all back on our b#ll$h!t.

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at animals that live in the water and have hard parts on the inside. The first paper looks at some of these animals which have a round mouth. These animals today are very different as kids then as grown ups. As kids they live in the ground and pull food out of the water. As grown ups they move through the water and eat other animals. This paper looks at old parts of these animals from a long time ago to see if the kids always did this. They find that these very old animals did not have kids and grown ups acting so different. This means that having the kids do something different is a thing that is new, even though people have thought that these animals have always done this.

The second paper looks at the how animals with hard parts that move through the water had the bits inside them that store how to build them get a times two. When there are more bits that store how to build them, it makes the homes in the hard parts bigger. So you can use how big these homes are in the hard parts to learn something about how many bits these animals have. Using old hard parts from old animals and a tree that shows which of the animals are close brothers and sisters to each other, they look at when changes in how big these homes in the hard parts were in the past. And since how big these homes are tells us how many bits that store how to build them they have, we can also see how these bits are changing through time. People have thought that getting more of these bits may be why there are so many of these types of animals. This paper shows that it may not be that simple. The number of bits goes up first, but the number of new animals does not go up at that time. Instead, it happens after big changes in the world. It is possible that these bits may have helped in bringing the number of these animals up, but it alone does not explain it.

 

References:

Miyashita, Tetsuto, et al. "Non-ammocoete larvae of Palaeozoic stem lampreys." Nature 591.7850 (2021): 408-412.

Davesne, Donald, et al. "Fossilized cell structures identify an ancient origin for the teleost whole-genome duplication." Proceedings of the National Academy of Sciences 118.30 (2021).

Direct download: Podcast_220_-_The_Bone_Gnome.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at examples of cohabitation and unique ecological interactions in the Cambrian. The first paper looks at multiple animals living together in a hemichordate living chamber, the and the second looks at a potential example of parasitism on brachiopods. Meanwhile, James flips a coin, Curt has to live with some consequences, and Amanda ranks things from meh to bad.

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at animals which are living together, sometimes not because both animals want that. The first paper looks at these long animals with no legs that live together. There are two different types of these long animals living the in the same spot, which is a home that looks like the ones built by the bigger of the two long animals, but the home seems to be a bit too big. Because the small long things do not have bits that could cut off parts of the bigger long thing, they think that these two animals would have lived in the same spot and been just fine. Since the homes are bigger than either animal, it means we still have to figure out why the homes are so big. It could be that the bigger long animals could be kids and the homes were built by the grown ups for the kids to live in.

The second paper looks at these small long round thing that was found on these animals with hard parts on either side which sit on the ground in the water and pull food out of the water. The animals with hard parts could have these small long round things on them or they could not. The animals with hard parts that had these small long round things were smaller than the ones that did not. The way the small long round things were put onto the animals with hard parts makes it look like they are homes for other small animals that would take the food out of the mouth of the animals with hard parts.

 

References:

Zhang, Zhifei, et al. "An encrusting kleptoparasite-host interaction from the early Cambrian." Nature communications 11.1 (2020): 1-7.

Nanglu, Karma, and Jean-Bernard Caron.  "Symbiosis in the Cambrian: enteropneust tubes from the Burgess Shale  co-inhabited by commensal polychaetes." Proceedings of the Royal Society B 288.1951 (2021): 20210061.

Direct download: Podcast_219_-_Brachiopod_Vape_Bros.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at trackway fossils. The first paper uses a modern study to determine how many tracks are needed to get a reasonable estimate on the trace morphology, and the second paper looks at trackways from an early tetrapod and attempts to determine the likely trace maker. Meanwhile, James has thoughts on Luigi, Amanda gives the birds the bird, Curt regrets a burn, and everyone loves Christopher Walken’s line delivery in Ripper.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about people walking on ground that is wet and animals with four legs that also had a long back end part. The first paper looks at how many people need to walk on ground that is wet before it is enough people to make the numbers good. It also looks at how different kinds of ground and different types of wet also change the way things look. There actually does not need to be too many people walking on ground that is wet before the numbers are good. That means it is easier to do this with things that are not live anymore. The second paper looks at animals with four legs that were walking around a long time ago. The paper does a good job of figuring out just what those animals with four legs probably were, and about how they walked. They also had a long back end that dragged on the ground. That also tells us about how they walked. But there needs to be more stuff done on these animals with four legs and their walking marks, as well as their legs, before we know exactly what the back end marks mean.

 

References:

Logghe, A., et al. "Hyloidichnus  trackways with digit and tail drag traces from the Permian of Gonfaron  (Var, France): New insights on the locomotion of captorhinomorph  eureptiles." Palaeogeography, Palaeoclimatology, Palaeoecology 573 (2021): 110436.

Belvedere, Matteo, et al. "When is enough, enough? Questions of sampling in vertebrate ichnology." Palaeontology (2021).

Direct download: Podcast_218_-_Dem_Feet.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers with… honestly a pretty flimsy link connecting them together. The first paper looks at size shifts in the dinosaur group, Alvarezsauridae, and the other paper looks at beetle fossils preserved in a dinosauromorph coprolite deposit. Meanwhile, James finds that the third time is the charm, Curt struggles to segue, and Amanda has thoughts on ham.

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that are not as much the same as they had hoped. The first paper looks at a group of angry animals wear most of these animals got really big a long time ago. A few of these animals start getting small, and this paper looks at one of those groups of angry animals that gets small to try and see when and why they got small. This paper uses a study of how these different animals are sister and brother to each other and then looks at how the big these animals are and tries to see if there is a time when things start to get small. They find that these things start to get small at a time pretty late in the life of the group. This is also around the time that a lot of small animals who wear their hard parts on the outside and live in big groups first appeared. Since the angry animals have weird hands that look like they could move through the ground, it is possible that these animals got smaller and started eating these even small animals who live in big groups.

The second paper looks at a small animal that wears its hard parts on the outside that was found in shit. I have to use the word shit because it is the only word in the ten hundred most used words that can be used to tell you what this animal was found in. It was found in shit. The animal is broken up so it seems that the animal was eaten by a bigger animal who then pushed it out when that animal had a shit. This small animal is one of the best remains of one of these animals from so long ago, because the shit kept the animal parts from breaking down. Shit is a really great way to find parts of other animals because it keeps some of those parts from breaking down really well. Also, the small animals in this shit are found with other bits of green things that live in water and use sun to make food. This means that the animal which ate the small animals might have been trying to eat the green things and happened to grab a lot of those small animals who were also on the green things.

 

References:

Qvarnström, Martin, et al. "Exceptionally preserved beetles in a Triassic coprolite of putative dinosauriform origin." Current Biology (2021).

Qin, Zichuan, et al. "Growth and miniaturization among alvarezsauroid dinosaurs." Current Biology (2021).

Direct download: Podcast_217_-_In_the_Thick_of_It.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at ecological patterns in the Mesozoic. The first paper looks at ecomorphic trends in Triassic herbivorous tetrapods, while the second paper uses morphological and chemical evidence to estimate the behavioral patterns of Cretaceous mosasaurs. Meanwhile, James has ideas about electrolites, Curt has a 99% average, and Amanda manages to record an entire podcast while having vertigo (that last bit isn’t a joke).

 

Up-Goer Five (Amanda Edition):

Today our friends talk about where and how things live. The first paper looks at all kinds of animals with four feet that eat green things from the first part of the age of big angry animals with lots of teeth and no hair. This paper is trying to use the parts of the animal's face to see how they eat. There are different kinds of ways to eat green things, and some ways of doing things have more types of these animals with four feet than others. They also find that there are big changes that happen at some times in different groups of these animals. The second paper is really cool and looks at big angry animals with hard skin that go back to the water. This paper shows that these big angry animals, which live in water that isn't good to drink, sometimes go to places where there is more water that is good to drink. Some go back to water that is good to drink every 4 to 7 days if they live in one place, or 12 to 20 days if they live in the other place. It is possible that these big angry animals with hard skin that go back to the water might have also gone from top of the world towards the middle of the world over longer times, and back again, like animals with light bodies and no teeth and no hair, but they are not sure here, they need to look more.

 

References:

Taylor, Leah Travis, et al. "Oxygen  isotopes from the teeth of Cretaceous marine lizards reveal their  migration and consumption of freshwater in the Western Interior Seaway,  North America." Palaeogeography, Palaeoclimatology, Palaeoecology 573 (2021): 110406.

Singh, Suresh A., et al. "Niche partitioning shaped herbivore macroevolution through the early Mesozoic." Nature communications 12.1 (2021): 1-13.

Direct download: Podcast_216_-_Salty_Tooth.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that are loosely connected by the fact that they include mammals. The first paper looks at the biomechanics of a type of sabre tooth cat. The second paper analyzes the stability of mammal communities in deep time. Meanwhile, James loves the fans, Amanda is hemmed in by sound, Curt tries to avoid a lawsuit, and everyone really bungles explaining a paper on what is supposedly a scientific podcast.

 

Up-Goer Five (Curt Edition):

Our friends talk about two very different papers that are still about things with hair that are warm. The first paper looks at some of these animals with hair that had a set of very long teeth in their mouth that look like things we use to cut people. These animals all had many different types of long teeth, but we usually thought that they might be doing a lot of the same things just because so few other animals with hair get sets of teeth that long. This paper looks at the other parts of one of these animals with long teeth and finds that it is very different from many of the other animals with long teeth. A lot of animals with long teeth could run quick for a short time, while this animal looks like it could run for long times. This animal looks like it could chase things for a longer time, while the other animals with long teeth may have surprised their food. This is cool because it means that animals may have got long teeth for different reasons.

The second paper looks at groups of animals living together and sees how those groups change over time. They are looking to see if those groups can stay more or less the same across a long time, and also what helps these groups to not change. What they find is that in the area they are looking, there are three different groups that form and more or less stay the same until they suddenly change. These sudden changes happen when the world around them changes a lot. The groups remain more or less the same though before these really big changes in the world. Also, the groups can remain more or less the same even if the animals in those groups change over time. The thing that seems to be important in keeping these groups more or less the same is how the groups are built. Groups with a lot of different jobs for animals to do seem to be better at staying more or less the same over a long time.

 

References:

DeSantis, Larisa RG, et al. "Dietary ecology of the scimitar-toothed cat Homotherium serum." Current Biology (2021).

Blanco, Fernando, et al. "Punctuated ecological equilibrium in mammal communities over evolutionary time scales." Science 372.6539 (2021): 300-303.

Direct download: Podcast_215_-_Ostensibly_a_Science_Podcast.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two examples where extinction may have been very important in directing the evolution of mammals through time. The first paper looks at the impact of other mammals groups on the morphology of earlier therians, and the second paper looks at how extinction could explain some of the patterns observed in the Great American Interchange. Meanwhile, James learns some things, Curt steps out, Amanda imagines the end.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about animals with hair. The first paper talks about animals with hair, and that ideas were had a while ago about how old kinds of animals with hair just weren't as good as new kinds of animals with hair, and that the very big angry animals with lots of teeth and no hair made the animals with hair from the same time stay small and not good. But it turns out that even after the very big angry animals with lots of teeth and no hair went away the animals with hair were still all very much the same and didn't do anything fun until much longer after the very big angry animals with lots of teeth and no hair were gone. That means that the very big angry animals with lots of teeth and no hair didn't really keep the animals with hair from being any good. The other paper talks about animals with hair from the upper part of the colder area of land in the "new" half of the world (which is not new but that's the only word we can use in this stupid word thing) moved into the usually warmer lower area of land in the "new" half of the world. It talks about how upper animals with hair moved into lower areas of land, and how lower animals with hair moved into upper areas of land. However, more upper animals moved into lower areas of land. And they wanted to know why. It turns out that more animals with hair that lived in the lower part of the "new" half of the world were dying as the places changed and got colder. We used to think just that it was upper animals with hair were better at living than lower ones, but that isn't true. It's just that there was space for upper animals to move in, and they could use the area better than lower animals with hair that moved to the upper part of the "new" half of the world.

 

References:

Carrillo, Juan D., et al.  "Disproportionate extinction of South American mammals drove the  asymmetry of the Great American Biotic Interchange." Proceedings of the National Academy of Sciences 117.42 (2020): 26281-26287.

Brocklehurst, Neil, et al. "Mammaliaform extinctions as a driver of the morphological radiation of Cenozoic mammals." Current Biology (2021).

Direct download: Podcast_214_-_Dead_Mammals.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers about unique adaptations in the fossil record, the first is a paper about pterosaurs that have opposable thumbs and the second paper talks about burrowing synapsids. Meanwhile, Discord is silencing James, Amanda fact checks, and Curt messes everything up…. like EVERYTHING.

 

Up-Goer Five (Amanda Edition):

Today our friends look at some things that make very old animals that are not close to other animals look like those other animals. First our friends talk about an animal that had a very long ring finger with long skin on it and could fly. This is a pretty early animal that had a very long ring finger with long skin on it. People have thought that maybe animals that had a very long ring finger with long skin on it lived in trees. A new animal was found that had a first finger that can move across from the others, like people have on their hands. This means that this animal that had a very long ring finger with long skin on it could grab onto trees and hold them, which means they probably did live in trees. The second paper our friends look at looked at very old animals that had hair. Some of these are not even really animals that have hair like the ones that live today, because the three hard pieces inside the ear are not all the way in there yet. But these animals that had hair had some things that are like each other, because they had very big hands with heavy hard pieces in them that means they move in the ground. They push the ground around and are found under it. These are the oldest kinds of animals with hair that do this, and they also do some strange things with their hard bits that make up their back. This might be a thing that animals with hair living under the ground just do.

 

References:

Zhou, Xuanyu, et al. "A new darwinopteran pterosaur reveals arborealism and an opposed thumb." Current Biology (2021).

Mao, Fangyuan, et al. "Fossoriality and evolutionary development in two Cretaceous mammaliamorphs." Nature (2021): 1-6.

Direct download: Podcast_213_-_Bringing_our_C_Game.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that talk about T-Rex, and also the interesting way that these papers were discussed in popular culture. The first paper looks at the walking speed of T-Rex, and the second paper estimates how many T-Rex could have lived on Earth at any given time. Meanwhile, James is so very tired, Amanda loves soap, and Curt picks the worst transitions.

 

Up-Goer Five (Curt Edition):

The friends talk about a big angry animal that a lot of people know about. The first paper looks at how quickly that big angry animal could walk. Most animals with four legs / arms all walk about as fast as each other, even if the animals are big or small. Early work had made it seem that the big angry animal may have walked faster than the animals today. These early papers were looking at the foot falls of these big angry animals. This new paper looks at the big long part that comes off the end of these angry animals. The paper says that these big angry animals walked about as fast as any animal today even though they were big and angry and walked in a funny way.

The second paper tries to use the parts of these big angry animals that have turned into rocks to try and figure out how many of these big angry animals may have been living at any given time. It looks at how many animals we see around today to do this, and sees that the number of animals may be controlled by how much food the animals need to keep eating. Some animals burn a lot of food which means there can not be as many of them in an area. This means you can use how much food an animal burns to try and figure out how many animals could have been living in an area at any time. So they use this and some other numbers to try and figure out how many of these big animals were around in the past. This also allows them to figure out how many of the big angry animals may have been covered in ground and have their parts turned to rocks and how many were not.

 

References:

Marshall, Charles R., et al. "Absolute abundance and preservation rate of Tyrannosaurus rex." Science 372.6539 (2021): 284-287.

van Bijlert, Pasha A., AJ ‘Knoek van  Soest, and Anne S. Schulp. "Natural Frequency Method: estimating the  preferred walking speed of Tyrannosaurus rex based on tail natural  frequency." Royal Society Open Science 8.4 (2021): 201441.

Direct download: Podcast_212_-_Ruining_T-Rex.mp3
Category:general -- posted at: 3:00am EST

The gang talks about two papers that look at changes in ecological interactions through deep time. The first paper looks at how ecological networks changed from the Permian into the Triassic, and the second paper looks at how echinoid diversity patterns compare to echinoid predation patterns. Meanwhile, James has some choice words about Elon Musk, Amanda’s stream is torn “into pieces”, and Curt once again would really like to start the second half of the podcast…

 

Up-Goer Five (Curt Edition):

Our friends talk about how animals and things that are not animals can build a place to live together, and how that changes over time. The first paper looks at how the places these animals and not animals build can change when things get really bad. It looks at two places in the past and uses numbers to see how these places change by getting more busy or less busy. They find that before most of the times when lots of stuff died, the places built by these animals and not animals were getting easy to fall to pieces. This is not true for this one time where things go really bad though, which is interesting and means that what was happening when things got really bad must be different.

The second paper looks at how a round animal in the water with hard hurt causing parts have changed over time and tries to see if being eaten caused some change. The paper finds that there are some changes that happen when we see these things get eaten, but also a lot of the changes are happening before we see these things get eaten.

 

References:

Petsios, Elizabeth, et al. "An  asynchronous Mesozoic marine revolution: the Cenozoic intensification of  predation on echinoids." Proceedings of the Royal Society B 288.1947 (2021): 20210400.

Huang, Yuangeng, et al. "Ecological  dynamics of terrestrial and freshwater ecosystems across three  mid-Phanerozoic mass extinctions from northwest China." Proceedings of the Royal Society B 288.1947 (2021): 20210148.

Direct download: Podcast_211_-_Fossil_Ecological_Networks.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at the ecology of the ancient shark Megalodon. One paper uses our knowledge of modern sharks to fill in the missing data on what Megalodon could have looked like, and the other looks for evidence of Megalodon nurseries in the fossil record. Meanwhile, Amanda cares too much, James spreads “facts”, and Curt would really like to find a segue.

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that are about a really big angry animal with large teeth that moved through the water and is known by a lot of people. This animal with big teeth lived a long time ago and would have eaten other really big animals. But because most of this animal is made of soft parts, we do not know a lot about what it would have looked like. So the first paper uses other animals which are very close to this big animal (but not as big) and see how they all look to see if bigger things look the same. They find that they can guess what parts of these animals should look like just by looking at their teeth, which is cool! They then use this to guess what this really big old animal could have looked like.

The second paper looks at how these big animals would have raised their babies. Some places where we get teeth from these big animals do not have a lot of big teeth, while other places do not have a lot of small teeth. This paper looks at these places to see if the change in how big the teeth are is important. They find that some areas really do have more small than big teeth. Some areas also have more teeth that are between being big or small. It seems that smaller animals (babies) lived in some areas, and then when they get bigger they move out.

 

References:

Herraiz, Jose L., et al. "Use of nursery areas by the extinct megatooth shark Otodus megalodon (Chondrichthyes: Lamniformes)." Biology letters 16.11 (2020): 20200746.

Cooper, Jack A., et al. "Body dimensions of the extinct giant shark Otodus megalodon: a 2D reconstruction." Scientific reports 10.1 (2020): 1-9.

Direct download: Podcast_210_-_Mega_Shark_Doot_Do_Do_Do.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at how animals take up space in a community. The first paper looks at ancient reef systems and uses spatial analysis to infer ecological interactions between corals. The second paper looks at the impact that lions have on other predators in South African reserves. Meanwhile, Amanda loves a number, James is an adult, and Curt has some strange ideas about pizza.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about space. Not the cool space, with stars, but the space between animals. The first paper looks at tiny animals that form big groups that look like rocks. There are two kinds of tiny animals that formed big groups that look like rocks from a long time ago. In the first paper, it turns out that some of the tiny animals that formed big groups that look like rocks settle in a space and then make it better for other types of tiny animals that formed big groups that look like rocks. Sometimes we would think that these animals would fight and would not want to help each other, but it turns out that actually they might really need each other to live in a place. This paper uses new ways of doing things, so their stuff is really cool, but is also really new; it's never been done on tiny animals that formed big groups that look like rocks before, only on big tall green trees. So more stuff needs to be done with this new way of doing things. The second paper looks at large animals where boys have lots of hair around their heads and necks and the girls do all the work. The short of it is that when these large animals where boys have lots of hair around their heads are around, there aren't as many smaller things that eat other animals. But there seem to be more kinds of smaller things that eat other animals when large animals where boys have lots of hair around their heads and necks are around. So it is kind of weird.

 

References:

Dhungana, Alavya, and Emily Mitchell. "Facilitating corals in an early Silurian deep-water assemblage." (2020).

Curveira-Santos, Gonçalo, et al. "Mesocarnivore community structuring in the presence of Africa's apex predator." Proceedings of the Royal Society B 288.1946 (2021): 20202379.

Direct download: Podcast_209_-_Spacing_Out.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that look at community structure in fossil and modern biota. The first paper looks at the size distribution of dinosaur communities and finds an interesting lack of mid-sized predators. The second paper looks at a modern kelp forest community to determine if fishing refugia results in ecological cascades in this system. Meanwhile, James is a magician, Amanda would rather be playing D&D, and Curt remembers Dino Riders.

 

Up-Goer Five (Curt Edition):

Our friends look at two papers that look at how animals live together in a place. The first looks at some very old and angry animals. When people look at how big these old angry animals are, they find something weird. If we look at all the angry things, we have a lot of big things, some small things, but not that much in the middle. When we look at that only eat things that get their food from the sun and see how they are different from the things that eat other animals, they find that this missing middle is because there are no middle animals in the things that eat other animals. One thought for why this could be is that some of the real big animals that eat other animals might have kids that fill the middle when they start to grow up.

The second paper looks at these places in the water that you can't drink where there are things that move through the water, things that move on the ground and have big hard things on them that come to points, and things that make food from the sun which are big and green. In a lot of places like this, if there are not some animals that eat a lot, the things with the points can eat all of the big green things. This place doesn't have one of those animals that eats a lot, but it was a place where people can not go in and grab some of the animals that move in the water. Since there are still big green things here, the people who wrote this paper wanted to see if the animals in the water were good at eating the animals with points. It seems that, while the animals in the water are doing better, so are the animals with points. This means that other things must be going on to let the big green things still be there.

 

References:

Malakhoff, Katrina D., and Robert J. Miller. "After 15 years, no evidence for trophic cascades in marine protected areas." Proceedings of the Royal Society B 288.1945 (2021): 20203061.

Schroeder, Katlin, S. Kathleen Lyons,  and Felisa A. Smith. "The influence of juvenile dinosaurs on community  structure and diversity." Science 371.6532 (2021): 941-944.

Direct download: Podcast_208_-_Stable_States.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at snake evolution and ecology. The first paper looks at the evolutionary steps required for venom spitting behavior in cobras, and the second paper looks at how snake populations in the tropics are being impacted by mass amphibian die offs. Meanwhile, James likes the Resident Evil Lady, Curt meets big Bowser, and Amanda has a BIIIIG beer.

 

Up-Goer Fiver (Curt Edition):

Our friends talk about long animals with no legs. Some of these long animals have bad stuff that they can put into your body. The long animals that can make the bad stuff and also make their neck really wide are a group of long animals that have some animals that can push the bad stuff out of their body a great way away from their body. The first paper our friends talk about is trying to find out how these long animals that can push bad stuff a far way out of their body were able to do this. Did they get it from their moms and dads a long long time ago. The paper looks at what the bad stuff is made of, and finds that the things that are close family with the long things that can push bad stuff far away have bad stuff that looks the same. But there is one part of the bad stuff that there is more of in the things that push bad stuff far away that isn't in all of the long animals. The cool thing is, the moms and dads of these animals had this other bad stuff even though they do not push bad stuff far away from their bodies. This means that the other bad stuff changed first, and then the long animals started pushing bad stuff far away from their bodies.

The second paper looks at how long animals are hurt when their food goes away. Another group of animals that breathe through their skin has been having a real hard time because they keep getting sick. This paper looks at how the sick animals that breathe through the skin are causing some of the long animals to die because they can no longer get as much food (from the animals that breathe through their skin). Some long animals are doing really well, but most of the long animals are not doing well. This means that something that hurts one group of animals can and will hurt a lot of other animals over time.

 

References:

Zipkin, Elise F., et al. "Tropical snake diversity collapses after widespread amphibian loss." Science 367.6479 (2020): 814-816.

Kazandjian, Taline D., et al. "Convergent evolution of pain-inducing defensive venom components in spitting cobras." Science 371.6527 (2021): 386-390.

Direct download: Podcast_207_-_Sneks_and_the_Toad_Wars.mp3
Category:general -- posted at: 4:00am EST

The gang discusses two papers that look at evidence for past behavior in the fossil record using both fossil and modern data. The first looks at the evolution of vibration sensing organs in bird beaks, and the second paper looks at how shark teeth within the genus Otodus changed through time. Meanwhile, the gang spends the first 11 minutes arguing about bagels.

 

Up-Goer Five (James Edition):

The group look at two papers that look at how different types of face have come about in different groups in order to do or eat different things. The first paper looks at the hard face of animals that fly, especially some that have lots of little spaces inside the hard face that allow them to feel things without touching them. The paper shows that the flying animals that can feel things without touching them are not close family, but that when they do begin to feel things without touching them they end up doing it the same way every time. Also some of the earliest things that could fly could feel things without touching them, so all the different ones that feel things without feeling them may be able to do it because it is something that deep down they have because their oldest family did. The other paper looks at big angry animals that breathe water that are more big and angry. It looks at the teeth to see if as these animals got bigger their teeth changed so that they could eat bigger food. The study actually shows that the teeth did not get better at eating big food, but that the way the teeth change might be because they are growing for longer as the animal gets bigger, and that this same thing might explain why those around today eat such a wide type of foods.

 

References:

du Toit, C. J., A. Chinsamy, and S. J. Cunningham. "Cretaceous origins of the vibrotactile bill-tip organ in birds." Proceedings of the Royal Society B 287.1940 (2020): 20202322.

Ballell, Antonio, and Humberto G.  Ferrón. "Biomechanical insights into the dentition of megatooth sharks  (Lamniformes: Otodontidae)." Scientific reports 11.1 (2021): 1-9.

Direct download: Podcast_206_-_In_The_Face.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at how competition, environment, and biogeography affect macroevolutionary patterns. The first paper looks at the evolution of bird beaks, and the second paper looks at patterns in horse evolution. Meanwhile, James has “some” gin, Amanda practices her “reviewer” skills, and Curt enjoys some last minute “honesty”.

 

Up-Goer Five (James Edition):

Today the group look at two papers that are interested in what causes animals to change their form over time. The first paper looks at animals with hard noses that fly to see what causes the nose to change, especially whether close friends wanting to eat the same food makes them change. The paper studies many different groups of animals with hard noses that fly and found that while some groups do show some sign of changing because close friends want to eat the same food, it is not all parts of the animal that changes and most groups do not show any sign of changing because of it at all. The second paper looks at scared animals that run on one finger to see what caused their legs to change over time. It shows that the scared animals that run on one finger living on different big bits of land had different legs, and that their legs changed when they moved into new places so that they could walk across the different types of land they found.

 

References:

MacLaren, Jamie A. "Biogeography a key influence on distal forelimb variation in horses through the Cenozoic." Proceedings of the Royal Society B 288.1942 (2021): 20202465.

Chira, A. M., et al. "The signature of competition in ecomorphological traits across the avian radiation." Proceedings of the Royal Society B 287.1938 (2020): 20201585.

Direct download: Podcast_205_-_Horse_Couture.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at interesting new arthropod fossil finds. The first paper is the discovery of a new early arthropod which complicates our understanding of their evolution, and the second paper is a large deposit of trace fossils which could be caused by mass arthropod molting. Meanwhile, James has issues with formatting, Amanda’s cat is a butt, and Curt has some important legal disclaimers to share.

 

Up-Goer Five (Curt Edition):

Our friends talk about some animals with many legs that lived in the water and lose their hard skin a long time ago. The first paper is talking about a new type of these animals from a very long time ago which has a lot of different parts on it which look like parts that are found in different animals from around that same time. It has really long arms and also five eyes. These very different parts that don't look like they go together means that it can tell us a lot about how these animals with many legs that lose their hard skin have changed over time. And then our friends run out of things to talk about.

The second paper looks at marks left in the broken up bits of rock. These marks were probably made by one of these animals with many legs that was in the middle of breaking out of its hard skin. The marks look the animals put their bottoms in the ground as they broke out of their skin. Also, the type of broken up bits of rock leads the people who wrote the paper to think that these animals might be moving to place that is not great to live in in order for them to be safe when they break out of their skin. They find lots of marks in the broken up its of rock all at the same time. This might mean that the animals that made these marks were able to move into these places just to break out of their skin.

 

References:

Mángano, M. Gabriela, et al.  "Paleoecologic and paleoenvironmental implications of a new trace fossil  recording infaunal molting in Devonian marginal-marine settings." Palaeogeography, Palaeoclimatology, Palaeoecology 561 (2021): 110043.

Zeng, Han, et al. "An early Cambrian euarthropod with radiodont-like raptorial appendages." Nature 588.7836 (2020): 101-105.

Direct download: Podcast_204_-_Cool_Arthropod_Bro.mp3
Category:general -- posted at: 3:00am EST

The gang celebrates the end of the year by taking another break to play Fiasco, a crime/noir storytelling game by Bully Pit Games.

 

Thank you for subscribing to our Mars Inc. weekly newsletter. We value your continued engagement with the Mars Inc. brand. Currently, Mars Inc. is undergoing an aggressive restructuring campaign that will improve efficiency and ensure larger shares for our top job creators. While we are unfortunately still in the planning process, we look forward to sharing our future for the company at our next shareholders meeting next month.

 

“Mars Inc.” is a story of greed, chaos, and unlikely revolutionaries.

 

Music from Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/

Direct download: Podcast_203c_-_Mars_Inc_Part_2.mp3
Category:general -- posted at: 3:00am EST

The gang celebrates the end of the year by taking another break to play Fiasco, a crime/noir storytelling game by Bully Pit Games.

 

Congratulations, your application to relocate to the Mars Incorporated Colony has been approved! Mars Incorporated is the premiere future forward, ever-expanding, corporate city state in the Milky Way Galaxy. We only employ experts whose work is on the cutting edge of future technologies. And we pride ourselves on always pushing against the outer limits of the possible, and we are excited to have you joining our team. When you arrive, a sophisticated group of artificial intelligence units and computationally intensive algorithms will assign you to the position best suited for your skills. Then you will enjoy the true splendor and standard of living that is only possible because of Mars Incorporated.

Welcome to Mars Inc., where the future is now!™

 

“Mars Inc.” is a story of greed, chaos, and unlikely revolutionaries.

 

Music from Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/

Direct download: Podcast_203b_-_Mars_Inc_Part_1.mp3
Category:general -- posted at: 3:00am EST

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