Palaeo After Dark

The gang discusses two papers that study ecological changes in the evolutionary history of some charismatic ancient animal groups. The first paper uses geographic data to infer the timing of the evolution of homeothermy in non-avian dinosaur groups, and the second paper looks at the mechanisms by which cats (and cat-like animals) developed saber teeth. Meanwhile, Curt makes some plans for Amanda, James muddles things over, and Amanda could use another.   Up-Goer Five (Curt Edition): The friends talk about two papers that look at how where animals live can change how they look and also maybe how they look can change where they can live. The first paper looks at old big angry animals and where they live to see if they can find when these animals were able to make themselves warm inside. We have other things that make us think that some of these big angry animals may have been able to get warm inside, but that this might have happened a few times in this group. By looking at where these animals were found in the past, they see that there are times when these animals move into places that are colder. They use this to say that these times may be because these animals now being able to make themselves warm inside. The second paper looks at animals that are cats and cat like animals. Some of these cats and cat like animals have very long teeth. This paper does a lot of things to study how these cats and cat like animals change their heads when they get these big teeth. They find that some of these cat like groups do this in a different way than cats, but also that cats start to change their heads to be a bit more like the cat like things when they get bigger teeth but also not in the same way.   References: Chiarenza, Alfio Alessandro, et al. "Early Jurassic origin of avian endothermy and thermophysiological diversity in Dinosauria." bioRxiv (2023): 2023-12. Chatar, Narimane, et al. "Evolutionary patterns of cat-like carnivorans unveil drivers of the sabertooth morphology." Current Biology (2024).

The gang discusses two papers that look into long term trends in body size over time. The first paper looks at body size trends in corals, and the second looks at body size and ecology of terror birds. Meanwhile, James loses a bit of himself, Amanda is bad at transitions, and Curt goes places no one wants to go.   Up-Goer Five (Curt Edition): The friends talk about two papers that look at how big things are and how that changes over time. The first paper looks at tiny animals that live together in a group and share their homes with even smaller living things that help give them food. It turns out that being small makes it good for the smaller things living with them. So this paper wants to see if these animals have been getting smaller over time. Turns out that it is not that easy, and that some of these earlier animals were bigger than today but probably did have even smaller living things with them helping them. But it seems like there is some bit of these animals getting smaller, so maybe these animals have gotten better at building homes for these even smaller living things. The second paper looks at big angry animals that are close to things that can fly but these big angry animals could not fly. This paper looks to see if these animals lived at the same time and did the same things and were as big as each other, or do we see these animals doing different things at the same time or with one of them being bigger than the other. They find that most of the time, when there are two of these animals living at the same time, they are either doing different things or one of them is much bigger than the other. The paper says this shows that these animals were trying not to fight each other for the same stuff, but the friends have other questions about what could be going on.   References: LaBarge, Thomas W., Jacob D. Gardner, and Chris L. Organ. "The evolution and ecology of gigantism in terror birds (Aves, Phorusrhacidae)." Proceedings of the Royal Society B 291.2021 (2024): 20240235. Dimitrijević, Danijela, Nussaïbah B. Raja, and Wolfgang Kiessling. "Corallite sizes of reef corals: decoupling of evolutionary and ecological trends." Paleobiology 50.1 (2024): 43-53.

The gang discusses two papers that look at the shark fossil record. The first paper looks into the completeness of the record, and the second paper discusses the ecological implications of an exceptionally preserved specimen. Meanwhile, James has ideas of what is normal, Curt has a hard out, and Amanda shows her specific history interests.   Up-Goer Five (Curt Edition): The friends talk about two papers that look at animals with lots of soft parts that move through the water and have lots and lots of teeth. The first paper is looking at how well we know these animals in the past, since most of the time we may only know them by their teeth. They do a lot of things to see how much of the animals we have at any time. What they find is that, most of the time, we do not have many parts of these animals. However, there are some times in the past when we do see more parts that are not just teeth, so there might be times in the past that were better and making sure the soft parts were able to stick around and be found later. But most of the time, we really only have teeth or a few other parts, and that this makes these animals different from most other animals that are close to them and that makes sense because the rest of these animals have hard parts where these animals have soft parts. The second paper looks at one of these animals with soft parts where those soft parts were found today. This is the first time this type of animal has been found with its soft parts. Most of the time, we just find the teeth, which look like they were good at breaking hard things. With the soft parts, we can get an idea of how it would move through the water and if it was slow or fast. We can also find out what its brothers and sisters were. What they find is that the soft parts show that this animal looked like a lot of the animals in this group we see today that are not breaking hard things but are catching fast moving food in the water. This is not something we would think would happen, because today animals that have teeth like the ones this animal had don't need to move very fast to catch their food. This shows that this animal was doing something that we don't see today. This might be because there were lots of animals with hard parts on the outside that were moving in the water really fast at that time, which this one animal would have tried to catch for food.   References: Schnetz, Lisa, et al. "The skeletal completeness of the Palaeozoic chondrichthyan fossil record." Royal Society Open Science 11.1 (2024): 231451. Vullo, Romain, et al. "Exceptionally preserved shark fossils from Mexico elucidate the long-standing enigma of the Cretaceous elasmobranch Ptychodus." Proceedings of the Royal Society B 291.2021 (2024): 20240262.

The gang discusses two papers about an interesting locality in South America and the various body fossils and ichnofossils found in this locality. This podcast originally started as a patreon request to podcast about fossil procyonids… but it ended up like this… ooops! Meanwhile, James has a vocal doppelganger, Amanda deals with being human, Curt deals with scams, and everyone talks way too much about visuals on an audio podcast.   Up-Goer Five: (Curt Edition) The friends talk about a place that has rocks from a long time ago that give us an idea of the types of animals that were around in the land areas under where the friends are today. The land where our friends are one used to not be touching the land that is under them like it is now. Once these two lands touched, then the animals from each land moved into the other lands. This place is from a time before these two lands had finished touching, so some animals moved over but others had not yet. The first paper looks at some parts of a type of animals that is brother/sister to animals that grab food out of our place we put food that we can not eat anymore. These animals had moved onto the land under the land our friends are on before the two lands had stopped touching. The place where these parts are found is interesting because it seems like it is under water for some time but there are some bits that are not under water. The first paper shows some marks in the ground that are interesting, but the second paper goes in on these marks to show that they are homes and marks from food searches from other animals. These marks show that the animals in this area were doing a lot of things to make homes and look for food under the ground. This shows that even before other animals moved from the other land, animals in this area were doing cool things in the ground.   References: Soibelzon, Leopoldo H., et al. "First record of fossil procyonid (Mammalia, Carnivora) from Uruguay." Journal of South American Earth Sciences 92 (2019): 368-373. Varela, Luciano, et al. "Late Miocene mammalian burrows in the Camacho Formation of Uruguay reveal a complex community of ecosystem engineers." Evolving Earth 1 (2023): 100023.

The gang discusses two papers that look at the morphology and ecology of early fishes. The first paper investigates a hypothesis for how the pectoral girdle could have evolved, and the second paper looks at the functional morphology of a Paleozoic jawless fish. Meanwhile, Amanda missed some context, James throws some shade, and Curt is annoyed by AI.   Up-Goer Five (Curt Edition): The friends talk about two papers that look at animals from a long time ago that live in water. The first paper looks at how part of the shoulder in people may have first started as a part of another part of the animal in these animals that lived in water a long long time ago. They find these parts of this animals from a long long time ago that they can use to see how the parts around the head grew. They use this to say that the shoulder parts may have started as a part of the thing these animals use to breath. The second paper looks at the mouth of a type of animal that lived in water a long long time ago that did not have a hard part in the mouth to move up and down and eat food. They use an animal they found with a lot of parts to see how these animals may have lived and what they could have eaten. They find that this animal could have been picking up food from ground at the bottom of the water or they could have been of taking food out of the water. This shows that even animals without a hard part to move up and down to eat food were finding ways to eat a lot of different things.   References: Brazeau, Martin D., et al. "Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle." Nature 623.7987 (2023): 550-554. Dearden, Richard P., et al. "The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes." Proceedings of the Royal Society B 291.2019 (2024): 20232258.

The gang discusses two papers that look at the correlation between climate change and extinction risk in the fossil record. The first paper uses climate modeling to simulate extinction risk during past periods of climate change, and the second paper uses new radiometric age dates to infer diachronous extinction between marine and terrestrial environments during the Permian mass extinction. Meanwhile, James orders food, Curt stirs the pot, and Amanda lives with her choices.   Up-Goer Five (Curt Edition): The friends look at two papers that look at times when a lot of things died. The first paper uses computers and numbers to see how things could die during times when things get real hot or real cold. They look at real times in the past when lots of things die during these cold and hot times, and then they use their computers and numbers to make those things happen in the world of a computer to see if they can find out what may or may not make that happen. They find that lots of things can cause animals to die during these times when things get hot or cold, but how big the space animals live in and how many different types of places these animals can live in are big for knowing if they will or will not die. The second paper looks at a time in the past when almost everything died. This is a time when it got real hot. Things die on the land and in the water. A lot of what we study is in the water because those things are able to get covered in ground faster than the things that live on the land. But this paper finds some rocks from the land and does some work with the matter that makes up these rocks to see how old the rocks are. These rocks have animals in them that would die because of this big bad time when everything died. But the time that they found was after when everything in the water died. So this could mean that animals may have died first in the water and then died after on the land. This could be because the way the world changes when things get hot is going to be different in the water and on land.   References: Malanoski, Cooper M., et al. "Climate change is an important predictor of extinction risk on macroevolutionary timescales." Science 383.6687 (2024): 1130-1134. Wu, Qiong, et al. "The terrestrial end-Permian mass extinction in the paleotropics postdates the marine extinction." Science Advances 10.5 (2024): eadi7284.

The gang talks about two papers that look through existing museum collections to discover some fascinating new discoveries. Meanwhile, Curt may be haunted, James may be losing energy, and Amanda may not be real.   Up-Goer Five (Curt Edition): The friends look at two papers about new things that found when going through the stuff stored in a big building where you keep things so that people can look at them later. The first paper finds some really cool new small things that live in water that had been found before and put in a big building to keep things, but no one saw that these small things were not the same as the other small things. These small things are part of a group that lives in fast moving water that we usually do not get a lot of them in the ground. The second paper finds that a thing that was put in a big building a long time ago was actually a lie. This thing is not what everyone thinks it is and the paper looks into what it really is, which is that it is a painting on rock. The paper talks about how it could have ended up this way.   References: Godunko, Roman J., and Pavel Sroka. "A  new mayfly subfamily sheds light on the early evolution and Pangean  origin of Baetiscidae (Insecta: Ephemeroptera)." Scientific Reports 14.1 (2024): 1599. Rossi, Valentina, et al. "Forged soft tissues revealed in the oldest fossil reptile from the early Permian of the Alps." Palaeontology 67.1 (2024): e12690.

The gang discusses two papers that look at the fossil frog record. The first paper identifies fossil frogs from Antarctica, and the second paper looks at some exceptional soft-tissue preservation. Meanwhile, James has ideas for expanding the brand, Amanda asks for clarification on an important topic, and Curt makes some executive decisions.   Up-Goer Five (James Edition): The group looks at two papers that are interested in animals that are wrong and good at jumping and live in the water but some can walk on land and climb trees. The first paper is looking at one from the very cold land in the bottom of the round thing we live on, where we do not find any of them today because it is too cold. The animal is known by two small bits but we can tell what type of jumping thing it is and so we know it is part of a group that is found in two areas that do not touch today, but the place at the bottom of the round thing we live on is between them, so that makes sense! But it is very cold today, so that is strange, but the animal being there and the things we find with it seems to show that is must have been a little hotter then. The second paper is looking at one of the animals that is good at jumping that is found with lots of round things that become babies in it. This is very cool because the animal is also still soft in places in it that means it was not the most grown it could be and so was making babies when it was still young. There is also a thought that the animal may have died while trying to make babies which is interesting.   References: Mörs, Thomas, Marcelo Reguero, and  Davit Vasilyan. "First fossil frog from Antarctica: implications for  Eocene high latitude climate conditions and Gondwanan cosmopolitanism of  Australobatrachia." Scientific Reports 10.1 (2020): 5051. Du, Baoxia, et al. "A cretaceous frog  with eggs from northwestern China provides fossil evidence for sexual  maturity preceding skeletal maturity in anurans." Proceedings of the Royal Society B 291.2016 (2024): 20232320.

The gang discusses two papers that investigate evidence of symbiosis in the fossil record. The first paper looks at wormy organisms living inside Cambrian vetulicolians, and the second paper shows potential evidence of hydroids growing in mollusc shells. Meanwhile, Amanda is haunted, James’s computer is totally cooperating, and Curt may or may not have had to stitch this podcast together from other sources.   Up-Goer Five (Curt Edition): The friends look at two papers that look at animals that live inside of other animals. Sometimes these things live inside other things and both of the things do well because of it. Sometimes, these things live inside other things and they cause problems for the thing they live in. These two papers look at the ways we can see old bits of things that used to live in other things and how we can try and figure out why they might have lived inside other things. The first paper looks long animals living inside a weird animal from a long long time ago. These long animals are all in a small part of these animals that looks like where these weird animals would breathe. Many long animals live inside one of these weird animals. The second paper looks at how hard parts of animals grow over things trying to live on them and we can use use the way these things grow to get an idea of what could have been living on them.   References: Li, Yujing, et al. "Symbiotic fouling of Vetulicola, an early Cambrian nektonic animal." Communications Biology 3.1 (2020): 517. Wisshak, Max, et al. "Putative hydroid  symbionts recorded by bioclaustrations in fossil molluscan shells: a  revision and reinterpretation of the cecidogenus Rodocanalis." Papers in Palaeontology 9.2 (2023): e1484.

The gang discusses two papers that look at Mesozoic tracks that may or may not have been made by an avian archosaur. Meanwhile, Curt becomes activated, Amanda has to deal with harsh truths, James gets creative with taxon names, and everyone get distracted very quickly. (Editor’s Note: If you want to just “get to the science” skip to 11 minutes in. We hadn’t talked in 2 months and it shows. I just didn’t have the heart to cut all of it)   Up-Goer Five (Curt Edition): The friends look at two papers that look at foot falls in the ground from a very very long time ago which may or may not be made by animals that can fly through the sky, or may have been made by big angry animals. The problem is that big angry animals and the animals that can fly are very close to each other, and their foot falls can look a lot like each other. The first paper looks at some very old foot falls and some of these foot falls do look like they were made by animals that can fly, but that would be very very strange because it would need a lot of other things to be true if that were true. They say that there was something moving like these animals today that can fly but were probably not those types of animals, but it shows how hard it can be to see if these foot falls were made by these animals that can fly. The second paper uses numbers to try and see if we can really see if some of these foot falls were made by animals that fly. What they find is that we have used how big these foot falls are as a reason why we think some are from big angry animals and some are from animals that can fly. This is maybe a problem because we know there are small big angry animals, and that today there are some big animals that are from the group that can fly. If you use numbers to take how big they are out of the running, it seem like some of these foot falls could be from big animals part of the group that can fly.   References: Abrahams, Miengah, and Emese M. Bordy. "The oldest fossil bird-like footprints from the upper Triassic of southern Africa." Plos one 18.11 (2023): e0293021. Hong, Sung-Yoon, et al. "The discovery  of Wupus agilis in South Korea and a new quantitative analysis of  intermediate ichnospecies between non-avian theropods and birds." Cretaceous Research 155 (2024): 105785.