Palaeo After Dark – Détails, épisodes et analyse

The gang discusses two papers that have very little in common with each except for the word "stem". The first paper uses birth death models to simulate the fossil record in order investigate if neutral models can produce patterns similar to the "crown"/"stem" evolutionary dynamics that have been observed in real data. The second paper investigates stem mandibulate fossils to investigate the timing of major key innovations in the evolutionary history of this arthropod group. Meanwhile, Amanda decides, James bullies, and Curt explains.

Up-Goer Five (Curt Edition):

The friends talk about two papers that have very little to do with each other, other than the fact that they have one of the same words in them. The first paper looks at the ways in which animals change over time and how they make more of each other and how the ways things live and die can make it look like there are some groups that do better than others. The paper shows that some of this is something we should see even if it is just because of how things make more things and the fact that we care more about the things that live today than the things that do not live today.

The second paper looks at how animals that have many parts that repeat make their arms and legs. This paper looks at very very old animals from groups that are not around today but maybe could be close to those groups. The group of animals today that this group is close to has a lot of things that all of them share, like that they make mouths from a lot of arms, and also they have things on the front they use to feel things, and that they are three parts. This paper is using these old animals that are close to this group to try and see which things today in this group appeared first, and which things may have taken some time before they appeared.

References:

Budd, Graham E., and Richard P. Mann. "The dynamics of stem and crown groups." Science Advances 6.8 (2020): eaaz1626.

Liu, Yao, et al. "A tiny Cambrian stem-mandibulate reveals independent evolution of limb tagmatization and specialization in early euarthropods." Scientific Reports 15.1 (2025): 19115.

The gang discusses two papers that investigate injuries in fossil bones. The first paper tests hypotheses about the causes of facial injuries in herrarasaurids, and the second paper tests if inferred hunting strategies map onto injury patterns in predators from the La Brea Tar Pits. Meanwhile, Curt provides some hypotheses, Amanda gets spiritual, and James is photogenic.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at why animals from a long time ago got hurt. The first paper looks at some very old and angry animals with no hair that all got hurt in the face. They try to see why these animals got hurt in the face. They look at all the ways that they could have got hurt in the face and find that it was probably other animals just like them that they lived with that probably hurt them in the face.

The second paper looks at two groups of animals that eat other animals. One group of animals is man's best friend, and the other group of animals is from a group that does not care if man lives or dies. Since these two groups of animals are old and from a long time ago we don't know really what they ate but we use other things to come up with thoughts on how they could eat. We look to animals today that are like these animals and think that maybe these old animals ate the same way. But, trying to eat other animals is hard and can get you hurt, and you can get hurt in a lot of the same ways if you jump or run. This paper looks at how they got hurt to see if this fits with how we think they would eat. Turns out that the ways they were hurt makes sense if they ate way we think they ate, with man's best friend running and man's not best friend running.

References:

Garcia, Mauricio S., Ricardo N. Martínez, and Rodrigo T. Müller. "Craniofacial lesions in the earliest predatory dinosaurs indicate intraspecific agonistic behaviour at the dawn of the dinosaur era." The Science of Nature 112.2 (2025): 1-12.

Brown, Caitlin, et al. "Skeletal trauma reflects hunting behaviour in extinct sabre-tooth cats and dire wolves." Nature Ecology & Evolution 1.5 (2017): 0131.

The gang continues "Wet Hot Archosaur Summer" with a discussion about pterosaur trace fossils. The first paper tests a method for assigning pterosaur traces to potential trace makers, and the second paper is a case study of actually assigning traces to a species. Meanwhile, Amanda herds cats (figuratively and literally), James can only accomplish three things, Curt keeps it light, and everyone upholds their "journalistic integrity".

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at the marks that animals leave on the ground. These marks are made by animals that fly from a long time ago and are no longer around today. The first paper is asking if we can look at these marks and try to better figure out what kinds of these animals could have made those marks. They do a lot of work to look at the marks and some parts of these animals that we have that are really good in order to see if there are parts of the animal that would also be the same as these marks, and then they use numbers like how long these parts are on the marks and the animal parts are to try and see if we can put the marks into groups of animals. They find that maybe we can, and that there are some places where it might be best to see how well this works.

The second paper is one of those places where we can go see if this thing the first paper did works. They have these marks and there are two different types of marks. This place also has parts from two different groups of these animals, and those animals are in the same beds so they can be pretty sure that the animals were in the same spot as the marks at around the same time. They look at the numbers and how these marks look and they are able to point to each of these marks and say which of the two animals they have would have made those marks.

References:

Smyth, Robert SH, et al. "Identifying pterosaur trackmakers provides critical insights into mid-Mesozoic ground invasion." Current Biology 35.10 (2025): 2337-2353.

Li, Yang, et al. "First deciphering of large pterosaur footprints and their trackmaker in the Junggar Basin, China." Cretaceous Research 167 (2025): 106036.

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

What was that you were saying? Oh, no, I am sorry, sir; I do not accept returns. All sales are final!

Well it seems you must not have been using the sacred artifact properly, then! All of my wares are completely authentic. I can assure you of that!

Look, I simply do not have any time to argue with you about this. I am a very busy man and I need to organize a trip north to secure more sacred objects! In fact, I have already arranged my trip. I am leaving Florence tonight…

Oh, fine, I suppose I can help you out. I do happen to have a small sliver of wood from the true cross. I guess I could part with it… for a small price.

"The Priest and the Peddler" is a story of secrets, faith, mistaken identity, and the elusive search for redemption.

Grand Dark Waltz Allegretto by Kevin MacLeod

Link: https://incompetech.filmmusic.io/song/7920-grand-dark-waltz-allegretto

License: https://filmmusic.io/standard-license

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

Have you heard about Father Valentine? Strange things happening in that church, I heard. Did you know he recently hired a mercenary? For what? An armed guard? I heard from a friend, who heard from a friend, that the father has some secret plans he doesn't want us to know about. Anyways, I have a lovely item for sale today that I think would be perfect for you; a finger bone from St. Raphael himself. Keep it close and that cough is sure to go away! Oh of course it will work! Would I lie?

"The Priest and the Peddler" is a story of secrets, faith, mistaken identity, and the elusive search for redemption.

Grand Dark Waltz Allegretto by Kevin MacLeod

Link: https://incompetech.filmmusic.io/song/7920-grand-dark-waltz-allegretto

License: https://filmmusic.io/standard-license

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.

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.

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.

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.

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.