Palaeo After Dark

The gang discusses two papers about encrusting organisms. The first paper looks at evolutionary patterns of bryozoans to infer environmental triggers for shifts in the ways bryozoans calcify. The second paper uses the distribution of encrusting organisms on spirifd brachiopods to infer the ecology of both the encrusters and the brachiopod they grew on top of. Meanwhile, James discovers new foods, Amanda constructs a worm, and Curt gets confused and makes it everyone's problem. Up-Goer Five (Curt Edition): The friends talk about two papers that look at animals that do not move around much and live stuck to other animals. The first paper looks at a group of animals that grow together with their friends and grow really well on top of other things. This group makes hard parts out of stuff it gets from the water it lives in. When there are changes in ways big rocks move, this changes the types and number of things in the water that can be used to make hard parts, which can make one way of making hard parts easier than others. Most of these animals today make hard parts in the way that is not the way that is easy with how the water is today, but there are some groups that do use the easy way. This paper looks at how these groups changed over time using a family tree for the group, and they find that these groups that make their hard parts the easy way today may have started doing this when the water changed to the way it is today. The second paper looks at a group of animals with hard parts on the top and bottom that lives on the bottom of the water place and eats food by moving water into it to pull the food from the water. These animals do not move around much and they have big hard parts, so they are places where these animals that grow on top of other animals like to grow on top of. This paper looks at how these animals grew on top of these other animals to see if there are anythings that are the same or different between groups of animals that are growing over these animals. This is also used to see if we can learn things about how the animals with hard parts on the top and bottom which are having things grown on top of them are living, because some ways things grow over these animal could only happen if the animal with hard parts on the bottom and top are already dead. This paper shows that a lot of the ideas we had about how this animal with hard parts on the top and bottom lived are wrong. These animals did not change the way they sat at the bottom as they got bigger, and we know this because the parts of the animal that would be in the ground are not covered with animals that would grow on top. The only times we see these parts covered are when the animals that grow over would grow over the parts where the animal with hard parts on the bottom and the top would use to get water into to eat, which means that animal must already be dead. References: Saulsbury, James G., et al. "Evolution of skeletal mineralogy in cheilostome bryozoans from calcite to aragonite seas." Geology 53.11 (2025): 914-918. Vantoorenburg, Haley N., et al. "Palaeoecology of Middle Devonian epizoans and their Paraspirifer hosts." Palaeontology 69.2 (2026): e70050.

The gang discusses two papers that investigate phenotypic plasticity. The first paper reviews the pathways by which phenotype can be plastic, and the second paper looks at plasticity of breeding times in urban vs rural bird populations. Meanwhile, James manages a basement, Amanda names the papers, and Curt makes allegations. Up-Goer Five (James Edition): Today the group look at two papers that are interested in how animals change because of the type of place they live. The first paper is looking at different ways that animals can be changed, either by being changed as they grow or by changing things so that while the animal does not change right now its babies are different. The paper talks about how important the little bits that escape the brain to tell your body how to grow and what to make are and that many of the changes are caused by the different numbers of things escaping the brain because of the different places that the animal lives. The other paper is looking at small angry animals that fly and seeing when they lay small round quiet babies in different places. They look at when the small round quiet babies first appear in places that are built by people and places that are built by trees and also look at how this time has changed over several years during which it has gotten hotter. They find that most small angry animals that fly have their small round quiet babies earlier in places that are built by people, and also that as things have gotten hotter that also makes them have their small round quiet babies earlier. The further up they are though it seems like the time between having small round quiet babies in place built by people and places built by trees is not as much. References: Seebacher, Frank, and Alexander G. Little. "Mechanisms underlying phenotypic plasticity in response to environmental change." Biological Reviews 101.2 (2026): 713-734. Cuchot, Paul, et al. "Facing rising temperatures in urban environments: the role of phenological plasticity in an urban-dwelling passerine, Parus major." Proceedings of the Royal Society B: Biological Sciences 293.2068 (2026).

The gang discusses two papers about the functional morphology of ancient groups of animals. The first paper is a review of how the life position of rangeomorph ediacaran taxa have been reconstructed, and the second paper conducts an actualistic experiment of Oviraptor nesting strategies. Meanwhile, Curt gets activated, James doesn't die, and Amanda relishes in details. Up-Goer Five (James Edition): The group look at two papers that focus of understanding how things are long dead lived. The first paper talks about strange things that might have either lived standing up or lying down at the bottom of the water which is big and you can not drink. It is hard to tell how these things lived because there are not any around today and so instead we need to look at their form and how they are found in the rock. Most of the things seem to have lived how we thought but one actually was lying down rather than standing up. The second paper looks at how big angry animals without hair kept their round babies and helped them grow by making a form in the ground like they used and putting round babies in it. They looked at how the round babies did by themselves and how they did with a warm bag on top like their final big form. They decide that they probably had the final big form covering the round babies when they were growing but that they did not do it the same was a things that fly and do not have hair today. References: McIlroy, Duncan. "Determining the mode of life of Ediacaran rangeomorphs in deep marine settings of Peri-Gondwanan Avalonia." Assemblage 550.538Ma (2022). Su, Chun-Yu, et al. "Heat transfer in a realistic clutch reveals a lower efficiency in incubation of oviraptorid dinosaurs than of modern birds." Frontiers in Ecology and Evolution 14 (2026): 1351288.

The gang discusses two papers that are united by a fin. The first paper uses a computer algorithms to infer the shape of mosasaur tail fins, and the second paper looks at a new species of Spinosaurus with a crest. Meanwhile, James tastes flavor, Amanda tastes drink, and Curt tastes indifference. Up-Goer Five - SERVER NOT FOUND! HELP! References: Song, Yang, and Johan Lindgren. "Convergence in aquatic locomotion: reconstructing mosasaurian (Squamata: Mosasauria) tail fins from osteological correlates and covariation with extant sharks." Paleobiology 52.1 (2026): 121-130. Sereno, Paul C., et al. "Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation." Science 391.6787 (2026): eadx5486.

The gang discuss two papers of odd fossils with exceptional preservation. The first paper looks at some Cambrian vertebrates and shows that soft tissue evidence suggests the presence of two sets of camera eyes (four eyes total), and they interpret the additional set of camera eyes as being a homolog to the modern parietal eye in vertebrates. The second paper uses exceptional preservation of the Rhynie Chert to test hypotheses for the taxonomic placement of the enigmatic Prototaxites and finds evidence that suggests it is not, as previously suggested, a fungus. Meanwhile, James is marooned by weather, Amanda accidentally traumatizes her cat, and Curt imagines the flesh trees. Up-Goer Five (Curt Edition): The friends talk about things that are weird. The first paper looks at a thing that is part of the big group that we are all a part of but is from a long long time ago and lived in the big blue wet thing. This thing has four eyes. Two of those eyes might be the things that become a part of the brain that is not the eyes today. But this shows that, early on, some of these animals could have had four eyes. This also means some animals we see later could have had parts of these other eyes that we have thought were other things. The second paper looks at a thing that is weird that people thought was from a group that is not an animal but has some animal like things like eating other things but has walls in the cells. These weird things are from a long time ago and come from a place where the parts were saved from breaking down by glass getting inside the cells. This means you can see lots of cell stuff, and you can also break down the glass to get at some of the cell bits. This paper looks at a lot of this weird thing and they say that it is not part of the group people thought it was from. In fact, it is so weird that it is not like any group we have today. It is maybe something that is not around today that we did not know about. References: Loron, Corentin C., et al. "Prototaxites fossils are structurally and chemically distinct from extinct and extant Fungi." Science advances 12.4 (2026): eaec6277. Lei, Xiangtong, et al. "Four camera-type eyes in the earliest vertebrates from the Cambrian Period." Nature (2026): 1-6.

The gang discusses two papers that use fragmentary fossils of animals to investigate the origins of major groups. The first paper describes an Early Ordovician eurypterid, and the second paper looks at mosaic evolutionary patterns in an early squamate. Meanwhile, James has bird opinions, Curt delights in not knowing, and Amanda will definitely be on time. Up-Goer Five (Curt Edition): The friends look at two papers that are using broken bits of things to learn a lot about animals from a long time ago. Both of these papers are looking at old animals that may give us new looks at how big groups of animals changed over time. These animals may be some of the first animals in these groups, or at least let us know what kinds of things those early animals could have been doing. The first paper looks at a group of animals that lived in the big blue wet thing a long time ago and are part of a group that today has animals that make homes that they use to catch food. The new parts this paper finds shows that this group may have come around a lot earlier than we thought. The second paper looks at parts from an animal that is in a group that is cold and has hard skin, some with legs and some without legs. These parts show that the early animals in this group had a lot of changes going on in their hard parts, maybe they changed more early on then they do today. References: Benson, Roger BJ, et al. "Mosaic anatomy in an early fossil squamate." Nature (2025): 1-7. Van Roy, Peter, Jared C. Richards, and Javier Ortega-Hernández. "Early Ordovician sea scorpions from Morocco suggest Cambrian origins and main diversification of Eurypterida." Proceedings of the Royal Society B: Biological Sciences 292.2058 (2025).

The crew of the CS Perry, now trapped in a space station run by multiple hostile AI, work to figure out how best to salvage a mission gone very wrong. "Lightless Dawn" and "Crypto" from Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

The crew of CS Perry were offered the perfect deal, a quick stop at an abandoned spaceport to grab some mothballed tech and they'd be set for life. What could possibly go wrong? "Lightless Dawn" from Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

The gang discusses two papers that are about dinosaurs, and that is all that connects them! The first paper investigates community structure during the Cretaceous, and the second paper describes a well preserved "mummy" of a duck-billed dinosaur. Meanwhile, Amanda is doing well (really she is now), Curt makes an awkward segue, and James has not seen Tremors. Up-Goer Five (Curt Edition): The friends talk about two papers about big angry animals from a long time ago. The first paper looks at how many types of big angry animals were in a place before something bad happened and all the big angry animals died. Lots of people have said that the big angry animals might have been in trouble before the bad thing happen, and lots of other people say that they were probably not in trouble but we just don't have a lot of places that have the big angry animals in them for us to look and see what is happening at that time. This paper looks at a place and shows that it was during the time we want to see and that the types of animals in a place were a lot like the types of animals in a place before, so that means that it does not look like these big angry animals were having a bad time before the bad thing happened. The second paper looks at soft parts of a big angry animal that was dried out so that you can see skin and other bits under the skin. This lets the people find out what the feet look like for this animal, and other bits about how it moved. References: Flynn, Andrew G., et al. "Late-surviving New Mexican dinosaurs illuminate high end-Cretaceous diversity and provinciality." Science 390.6771 (2025): 400-404. Sereno, Paul C., et al. "Duck-billed dinosaur fleshy midline and hooves reveal terrestrial clay-template "mummification"." Science (2025).

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 discusses two papers that provide nuanced information to test when key innovations in vertebrate evolution occurred. The first paper looks at unique semi-terrestrial trace fossils in the early Devonian in order to determine the trace maker, and the second paper looks at fossils that could provide information about the origins of teeth. Meanwhile, Curt has theme park ambitions, James provides Amanda with new anxieties, and Amanda leaves it all to chance. Up-Goer Five (James Edition): The group talk about two papers that are looking at the earliest time things have been seen in the rocks. The first paper looks at some tracks in the rock left by animals with no legs that live in the water but can gasp air. We have looked at tracks from the same place before where the animals stuck their faces into the ground. The new tracks come in two forms. The first is where the animal took a rest and its bits that it uses to move in the water stuck in the ground. The other track is where it had to come out of the water and moved around on land. It used its head to pull it along as it moved. The track made by this is the same as tracks made by the same type of animal that still lives today. This is the oldest case of this type of animal moving on land and shows that animals with hard parts inside them began to move onto land in lots of different ways. The other paper looks at the supposed earliest time we find teeth growing on skin. This is interesting because there are several ideas about why the teeth began to grow on the skin, so when it first started could help tell which of these reasons is true. The skin teeth bit has been considered the same as an animal with no legs that lived in the water that was found in younger rocks from a different place, but when studied up close it does not look like the thing it is named as. By using lights to look inside the rock and seeing whether it looks the same as skin teeth on living animals it is shown that the old skin teeth are not skin teeth at all but actually are parts of the skin of a different animal with no hard parts inside that has legs that move in many places. References: Haridy, Yara, et al. "The origin of vertebrate teeth and evolution of sensory exoskeletons." Nature (2025): 1-6. Szrek, P., et al. "Traces of dipnoan fish document the earliest adaptations of vertebrates to move on land." Scientific Reports 15.1 (2025): 28808. Falkingham, Peter L., and Angela M. Horner. "Trackways produced by lungfish during terrestrial locomotion." Scientific Reports 6.1 (2016): 33734.

The gang discusses two papers about skin preservation in fossil tetrapods. The first paper describes skin impressions from a Permian synapsid, and the second paper identifies feather-like structures in an early Triassic diapsid. Meanwhile, James considers the horse, Amanda shames extinct animals, and Curt quotes "philosophy". Up-Goer Five (Amanda Edition): Today our friends talk about things that are sort of close to things with hair but not that close to things with hair. They are closer to things with hair than to things with dry skin with no hair or long many-part skin things. Anyway for a long time we did not know what the skin of the animals that are sort of close to things with hair looked like. Did they have dry skin with no hair like the things today? Or did they maybe have hair? We didn't know, but now we have found marks in the ground that show that they had dry skin with no hair, but it looks different than the animals with dry skin and no hair today. So hair comes around after the dry skin with no hair does. Then our friends talk about a very weird little animal that is sort of somewhere close to animals with dry skin and no hair, but it has these really weird things that come off of its back that look kind of like the many-part skin things on the most flying animals that are around today. But it's really not the same many-part skin things, because all the parts are not really same. And also there is only one of them and not one on each side. So it might be that many-part skin things come earlier than people thought they might have. References: Marchetti, Lorenzo, et al. "Early Permian synapsid impressions illuminate the origin of epidermal scales and aggregation behavior." Current Biology 35.11 (2025): 2752-2759. Spiekman, Stephan NF, et al. "Triassic diapsid shows early diversification of skin appendages in reptiles." Nature (2025): 1-7.

The gang is all back together in one place again as they unite in an undisclosed cabin in the woods to record the last two podcasts for Wet Hot Archosaur Summer. For this episode, the gang talks about herbivorous pterosaurs and wadding T-rex. Meanwhile, James experiences relative sobriety, Curt welcomes everyone to the Great Northern, Amanda is fueled by spite, and we all get completely off track. Up-Goer Five (Curt Edition): The friends are together for the first time in a long time and so they have a lot of fun together and sometimes they talk about a paper or two. The first paper that they sort of talk about is about big angry animals that fly and are no longer around. This paper looks at one group of these big angry animals and finds that they have bits and pieces of things that are found in green things that make their own food from the sun. They do a lot of things to make sure that these bits are found inside these animals and they use this to say that this one group of big angry animals probably ate these green things. The second paper looks at how big angry animals moved and how fast they could move in air or in water. This is because some big angry animals that are in all of the movies are said to maybe not be as fast as the things they would eat. This paper says maybe they chased food into water where they would be faster. The friends point out that other animals today do not have to be faster than the animals they eat, but sure... go off. References: Blanco, R. Ernesto. "Tyrannosaurus rex runs again: a theoretical analysis of the hypothesis that full-grown large theropods had a locomotory advantage to hunt in a shallow-water environment." Zoological Journal of the Linnean Society 198.1 (2023): 202-219. Jiang, Shunxing, et al. "First occurrence of phytoliths in pterosaurs-evidence for herbivory." Science bulletin (2025): S2095-9273.