Podcast 169 - Learning about Agnostids

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The gang takes some time to discuss two papers about agnostids, a strange group of trilobite-like arthropods whose evolutionary history has been the subject of considerable debate. First, we discuss a short paper summarizing the history of the agnostid debate, and then we discuss a brand new paper using new material and Bayesian phylogenetics to offer a fresh new hypothesis. Also, James channels frustration into fun, Amanda nearly has her house destroyed by cats, and Curt asks the Star Wars questions no one wanted answered.

Up-Goer Five (Amanda Edition):

Today our friends talk about small animals that have no eyes that might be sisters of animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. The first paper talks about the small animals with no eyes and how hard it is to make one of these animals for people to look at. They talk about the past of the animal and where it lived, and who it might be close sisters to. They say that a very cool area where we find these animals lets us see the legs and that they are different, also that they have a different mouth, and that maybe they actually do have eyes but they are on the mouth? They are weird animals. The second paper also talks about these animals, but does not focus on making the animals for people to look at. It looks at these animals from a different very cool area and shows their legs are sort of like the legs of animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. The paper is different from others, though, because it says that these animals are really either part of or sister to animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. But that is the only part of the tree that really is strong, so maybe who knows still? Our cat friend is writing this and did not really know what was going on that day, and does not know much about these cool animals with maybe no eyes that might really be animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball.

References:

Eriksson, Mats E., and Esben Horn. "Agnostus pisiformis—a half a billion-year old pea-shaped enigma." Earth-Science Reviews 173 (2017): 65-76. 

 Moysiuk, J., and J-B. Caron. "Burgess Shale fossils shed light on the agnostid problem." Proceedings of the Royal Society B286.1894 (2019): 20182314.

Podcast 168 - Alligator Teeth and Too Small Cats

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The gang discusses two papers that look at the diets of past and present crocodylomorphs using patterns in teeth shape and enamel. It turns out, past relatives of crocodiles were likely a lot more experimental in the types of feeding strategies they implemented than we might expect. Meanwhile, Curt comes up with a great name for a Lamsdell lab bowling league, Amanda loves possums, and James has some very strong opinions about the “Cats” trailer.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at the teeth of these big angry animals that hide and eat a lot of animals. It turns out that lots of these big angry animals are sons and daughters of older big angry animals which may have ate other things besides animals. These two papers look at the teeth of the living big angry animals and the older big angry animals to see what we can learn about what they may have ate. The first paper looks at the hardest bits that cover the teeth. In living big angry animals, they find that the teeth furthest back in the mouth have more hard parts covering them than the teeth near the front. This makes sense, because these teeth in the back hold on to animals and so need to be more covered. What they also find is that these big angry animals have way less hard parts covering their teeth than other other animals which are warm, but who do not grow new teeth every time they lose one. The hard parts are the same as some other big angry animals from the past, though some of the big angry animals that might have ate more than just animals have the parts where their teeth are hard being different.

The second paper looks at the ways the teeth look. There is a number that can be looked at which shows if the teeth are simple or if they are very different. Simple teeth usually means that the animal eats other animals. But the more different the teeth are, the more the animal may eat both animals and not animals, or just not eat animals at all. They use this number to study what past big angry animals would eat. What they find is that past big angry animals probably ate way more different things than we see today. While most big angry animals today eat only animals, it seems that not eating animals at all, or eating both animals and not animals, happened way more often in these past big angry animals. It means that maybe these big angry animals have been a lot more different in the past, and our living big angry animals are maybe more "weird" than we think.

References:

 Sellers, K. C., A. B. Schmiegelow, and C. M. Holliday. "The significance of enamel thickness in the teeth of Alligator mississippiensis and its diversity among crocodyliforms." Journal of Zoology

 Melstrom, Keegan M., and Randall B. Irmis. "Repeated Evolution of Herbivorous Crocodyliforms during the Age of Dinosaurs." Current Biology (2019). 

Podcast 167 - Jet Lagged Pterosaur Eggs

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[TRIGGER WARNER: Some dead baby jokes because we were in a very weird mental place, and also way too much rambling conversations about Star Wars]

The gang celebrates their cross continental trip to the 2019 North American Paleontology Convention by immediately getting on microphone the next day to talk about fossil Pterosaur eggs and what they can tell us about Pterosaur reproductive strategies. As expected, this may not have gone well. Witness the horror as barely conscious minds try and keep on topic for more than about 5 minutes! Apologies to the authors of these quite nice papers. [Editor’s note: The scientific discussion on this podcast “starts” around the 10 minute mark]

Up-Goer Five (Amanda Edition):

Today our friends talk about animals with skin arms. We are really talking about the baby animals with skin arms when they live in a small house with a hard outer part. One paper talks about the house of a baby animal with skin arms that is very round and good. You can see all the small bits of this house with a hard outer part. In fact, this house with a hard outer part is very much the same as some of the flying animals with no hair today. That might mean that these animals with skin arms were living like the flying animals with no hair that are around today. We already think they ate the same way, so now we think they might have lived and made their baby small houses in the same way too. The second paper is looking at baby animals with skin arms while they are still living in their house. Different parts of the inside hard pieces of these baby animals with skin arms get hard at different times as they get bigger, but they are still in their small house with a hard outer part, except that not all of the houses really have a hard outer part but that is a story for another time. Anyway some of the babies are still soft but some are very hard and that makes people think that maybe when these baby animals with skin arms come out of their small houses with either hard or soft outer parts they are able to leave the big home right away and go fly away. This is different than almost all living animals that fly and do not have hair except for one group which is big and strange and look kind of like the large big animals that fly (but these ones do not fly) that do not have hair and are good to eat and very stupid, but they do not are not part of that group. So these baby animals with skin arms are very different (maybe) than what is still living today.

References:

Unwin, David Michael, and D. Charles Deeming. "Prenatal development in pterosaurs and its implications for their postnatal locomotory ability." Proceedings of the Royal Society B 286.1904 (2019): 20190409. 

 Grellet-Tinner, Gerald, et al. "The first pterosaur 3-D egg: Implications for Pterodaustro guinazui nesting strategies, an Albian filter feeder pterosaur from central Argentina." Geoscience Frontiers5.6 (2014): 759-765. 

Podcast 165 - Sharks for St. Crispin's Day

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The gang have a “Shark Week” and discuss two papers about the ecology of modern tiger sharks. The first paper talks about a unique feeding strategy for some tiger sharks in which they can consume a fairly large amount of song birds. The second paper discusses how tiger shark populations are distributed around the islands of Hawaii, a place known for fairly high concentrations of tiger sharks. Meanwhile, James informs us of an important holiday, Curt imagines the ultimate battle of goose and shark, and Amanda decides to take charge of the podcast.

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at how these big animals with teeth that move through the water live. The first paper looks at what these big animals in the water are eating. People have been catching these big animals in the water and seeing what is inside of them. During some times in the year, usually the fall, these big animals in the water somehow eat a whole hell of a lot of these very small animals that talk a lot and move through the air. Turns out that most of the big animals in the water eating these small animals from the air that talk a lot are young but not babies. This shows a very interesting case where food comes from the land into the water. Often, food moves from the water into the land but this is the other way around.

The other paper looks at where these big animals live, focusing on a place where a lot of these big animals have had attacks with people. This paper showed that this one place seems to get a lot of these big animals because they like to make babies there. There is a lot of stuff this paper goes through, but the big important point is that this is a place where people play and move in water, and it is also important for these big animals, so this means that people and these big animals are going to come together at some point and the people should be told about this. Another cool thing is that the number of big animals in the area and the number of attacks are not the same, meaning that more of these big animals does not mean more attacks. It shows that making sure people know about these big animals is probably more important, and that scared attempts to kill these big animals do not make the problem better, and ends up very bad for the world.

References:

Meyer, Carl G., et al. "Habitat geography around Hawaii’s oceanic islands influences tiger shark (Galeocerdo cuvier) spatial behaviour and shark bite risk at ocean recreation sites." Scientific reports 8.1 (2018): 4945. 

 Drymon, J. M., et al. "Tiger sharks eat songbirds: scavenging a windfall of nutrients from the sky." Ecology

Podcast 164 - Rails and Snails

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The gang talks about two papers that are interested in iterative evolution, the repeated evolution of the same or similar morphological characteristics within or among species. Specifically, they are focused on iterative evolution in species on islands. The first paper they discuss looks at how being flightless might have evolved multiple times on the same island within the same species of rails. The second paper looks at repeated changes in developmental timing associated with climatic changes on an island. Also, James is an expert, Curt comes up with the best new Blue Sky series for the USA network “Rails and Snails”, and Amanda changes the podcast’s format.

Up-Goer Five (Curt Edition):

Our friends talks about two times that weird things happen when animals get on an piece of land that is surrounded on all sides by water. The first paper looks at small light flying things. When these flying things get onto a piece of land surrounded by water, they seem to stop flying. However, they find these remains of these light flying things on this one piece of land so they can see how the way these remains look change, because the way these remains look will tell us if these light flying things had decided to stop flying. The cool thing is that many different flying groups of this same flying thing landed on this pieces of land surrounded by water and all decided to stop flying on their own. So the story for these light flying things is that they land on this piece of land surrounded by water, they stop flying, and then they die from breathing water when the land goes under, and then when the land is above the water, they repeat.

The second paper looks at how these things that sit there, have a rock around them, and pull food out of water change over time. What the paper finds is that these little things with a rock around them look very different when the water goes up and down. The paper says that this is because of changes in how these little animals with a rock around them grow up. Do they take longer to grow up, do they look more like grown ups or do they look more like babies? The changes they see in how these things grow up happen at the same time as changes in where the water is, as well as how hot or cold it is.

References:

Hume, Julian P., and David Martill. "Repeated evolution of flightlessness in Dryolimnas rails (Aves: Rallidae) after extinction and recolonization on Aldabra." Zoological Journal of the Linnean Society (2019). 

 Hearty, Paul J., and Storrs L. Olson. "Environmental Stress and Iterative Paedomorphism in Shells of Poecilozonites (Gastropoda: Gastrodontidae) from Bermuda." Palaios 34.1 (2019): 32-42. 

Podcast 163 - Triassic Fish Questions

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The gang discusses two papers that look at the extinction and survivorship patterns of clades across the Triassic mass extinction event. Specifically, they look at changes in morphospace in ray-finned fishes as well as phylogenetic patterns of extinction in early archosaurs. Interestingly enough, both studies suggest very low ecological selection (at least in the characteristics we can study in the fossil record), but the archosaur study shows clear phylogenetic clustering of extinction. Meanwhile, James works on his social media engagement, Amanda perfects the concept of a joke, and Curt discovers this podcast’s theme far too late.

Up-Goer Five (Curt Edition):

The friends talk about two papers which look at a time that was really bad when nearly anything died. But this time is slightly different from the other, more well known ones. Its not the biggest, and its not the one everyone thinks of. Instead, this bad time when everything dies happens just a little after the worst of the bad times where everything dies, and may have been important for the angry animals with no hair and large teeth.

The friends talk about how two different types of animals that were changed by this really bad time. The first are things living in the water who can move through the water and have a flipper where their legs and arms should be. This first paper looks at how the form of these flipper animals changed before and after the bad time. What they found was that the form of these flipper animals didn't get changed by the both the really bad time, and the bad time very few people think about. They think this might mean that the bad time focused on hurting flipper animals that liked it to be warm or cold wet or dry. It also could be that these animals had a single job in their home. This is because form often changes when animals take on new jobs or move to a new home with different things the animals have to deal with. This might mean that these flipper animals just were not changed in any way but these big bad times of death.

But the other paper looks at animals on land who are aunt and uncle to the big angry animals with no hair and large teeth. This paper did not look at the form of these aunts and uncles, but it did look at the sons and daughters and brothers and sisters that these animals had. It also looked at how these aunts and uncles of big angry animals lived; what was their job and how did they like it (warm, cold, wet, dry)? What the paper found was the bad time of death did not kill these aunts and uncles of big angry animals because of their jobs or how they liked to live. So this seems pretty much the same as the paper about the flipper animals. However, the paper also found that if a close brother or sister died during the bad time, their closest brothers and sisters were also going to die. This makes things hard to understand, because close brothers and sisters usually live in places that are almost or very much the same and/or have jobs that are almost or very much the same. The bad time seems to be killing close families, but not because of how they like to live or their job. This could mean that we are missing important things about how this animals liked to live which we just aren't looking for, or maybe we can't look for. It also makes us wonder if more animals might show something very much the same to these flipper animals and these aunts and uncles of big angry animals.

References:

Smithwick, Fiann M., and Thomas L. Stubbs. "Phanerozoic survivors: Actinopterygian evolution through the Permo‐Triassic and Triassic‐Jurassic mass extinction events." Evolution 72.2 (2018): 348-362. 

 Allen, Bethany J., et al. "Archosauromorph extinction selectivity during the Triassic–Jurassic mass extinction." Palaeontology 62.2 (2019): 211-224. 

Podcast 162 - Turtle Power

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The gang discusses a few papers that look at the evolutionary history, biogeography, and life habit of Mesozoic turtles. Specifically, they look at a paper about a stem turtle with interesting information about the evolutionary history of turtle morphology, a paper on a special fossil of a marine turtle with exceptionally preserved eggs, and a paper that investigates the biogeographic history of turtles. Basically, its a whole lotta turtles! Meanwhile, James resurrects some old arguments, Curt revisits cherished film scenes, and Amanda has a new obsession.

Up-Goer Five (James Edition):

The group look at two papers that are looking at animals with four legs and hard parts on the outside that they can hide in. These things are found on land with legs and in the water with water legs that they use for being not on land. This is a very long set of words, so we will call them hard boys.

The first paper is looking at a hard boy that was full of little round things that would become babies. This is the second hard boy to be found with almost babies and can tell us whether hard boys had lots of babies or not a lot of babies. Hard boys that are in the water usually have a lot of babies that are not expected to live very long; this long dead hard boy actually had not many babies, so although it lived in the water it expected its babies to live.

The second paper is looking at where hard boys lived in the past and how they got to be where they are today. The paper shows that hard boys started in one place that was very big and that they stayed on it as it broke up over time. As it broke up they also moved between the bits, so the hard boys were able to move between the bits even though they are usually slow. They keep doing this until the bits get too far from each other to let the hard boys move across.

References:

 Li, Chun, et al. "A Triassic stem turtle with an edentulous beak." Nature560.7719 (2018): 476. 

 Ferreira, Gabriel S., et al. "Phylogeny, biogeography and diversification patterns of side-necked turtles (Testudines: Pleurodira)." Royal Society open science 5.3 (2018): 171773. 

 Cadena, Edwin‐Alberto, et al. "A gravid fossil turtle from the Early Cretaceous reveals a different egg development strategy to that of extant marine turtles." Palaeontology (2018). 

Podcast 161 - Whales Not Whales

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The gang discusses two papers that look at how various animals associated with whales have reacted to environmental shifts over the last several hundred thousand years. The first paper looks at polar bears and reviews data on the potential utility of whale carcasses on polar bear survival during warmer periods in recent Earth history. The second paper investigates how changes in the shell chemistry of barnacles attached to whales may preserve important information on whale migratory patterns. Meanwhile, James has ideas about Final Fantasy and all Square Enix protagonists, Curt thinks James is the Kuja of the podcast, and Amanda finds her ideal Nobody name. Somehow we got on a real theme this episode.

Up-Goer Five (Amanda Edition):

 Today our friends do not talk about very large big heavy things that had hair once. Instead our friends talk about small weird hard things that don't move that do not look like tiny things with many legs but are actually very close to tiny things with many legs. These things that do not look like tiny things with many legs but are actually very close to the tiny things with many legs are hard and live on the very large big heavy things that had hair once, but do not hurt them. They are friends, but the large big heavy things that had hair once don't actually care about the small weird hard things that don't move. But the small weird hard things that don't move can help us see if the big large heavy things that had hair once move around when it goes from warm to cold or not. It turns out that maybe even very old big large heavy things that had hair once might have moved around just like today's do. Our friends also talk about large white angry things with hair that want food that eat the large big heavy things that had hair once. These large white angry things with hair are in trouble because their home is going away. Their home has gone away in the past, and maybe they ate the big large heavy things that had hair once when they died and came on land. One big large heavy thing that had hair once can be food for lots and lots of large angry white things with hair. But people have killed a lot of the big large heavy things that had hair once, and that might be a problem. Maybe the big white angry things with hair won't be able to eat the large big heavy things that had hair once anymore, and they will all die.   

References:

Taylor, Larry D., et al. "Isotopes from fossil coronulid barnacle shells record evidence of migration in multiple Pleistocene whale populations." Proceedings of the National Academy of Sciences (2019): 201808759. 

 Laidre, Kristin L., et al. "Historical and potential future importance of large whales as food for polar bears." Frontiers in Ecology and the Environment 16.9 (2018): 515-524. 

Podcast 160 - Weasel Time

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The gang finds two papers that discuss the ecology of fossil mustelids, the objectively best group of mammals. Both of these papers look at creative solutions to try and interpret past life habits for some very complex and debated fossil organisms. Meanwhile, James becomes passionate about food, Amanda wonders what sitcom the podcast must be, Curt discusses the true American Dream, and everyone is very sorry about how off track we get in this podcast. (Editor’s Note: We sort of get to talking about the papers around 7:45)

Up-Goer Five (Curt Edition):

Our friends talk about cute long animals with hair that pretty much everyone of them loves. They find two papers that look at how some of the long animals from very very long again may have lived. They look at the hard parts of the head to see what these long animals could have eaten. Some of these long animal heads are really weird and have big raised edges on the top of the head. One of these papers look at using lot of numbers to try and figure out what one of these very old and weird looking long animals may have eaten. They find that there is a lot of things we need to look at and consider if we want to try and figure out what these very old animals ate. They find that its actually very hard to do, but that's a cool and good thing. We need to use lots of different numbers and study lots of different parts if we want to get a good understand of these very very old animals.

References:

Valenciano, Alberto, et al. "Megalictis, the bone-crushing giant mustelid (Carnivora, Mustelidae, Oligobuninae) from the Early Miocene of North America." PloS one 11.4 (2016): e0152430. 

 Prybyla, Alixandra N., Zhijie Jack Tseng, and John J. Flynn. "Biomechanical simulations of Leptarctus primus (Leptarctinae, Carnivora), and new evidence for a badger-like feeding capability." Journal of Vertebrate Paleontology (2019): e1531290.