Palaeo After Dark

The gang discusses two papers that look at how the morphology of tetrapods (animals with four limbs and a backbone) has changed over time. One paper looks at how dinosaur jaws are related to diet preferences, and the other paper looks at how spines have changed as tetrapods diversified through time. Meanwhile, James talks Star Trek, Curt gives some consumer advice, and Amanda would rather not talk about cowboys.

 

Up-Goer Five (James Edition):

This week the group look at two papers that are looking at different ways that animals get more different. The first paper is looking at the mouths of big angry animals with no hair. The big angry animals with no hair that eat other animals and get big have the least different mouths from each other, but those that are small and eat other animals have very different mouths from one another, and those that eat living things that make their own food or both other animals and living things that make their own food have the most different mouths from one another. We see the same thing no matter how we decide how different mouths are.

The other paper is looking at the line of hard bits in the back of animals that do have hair to see if they get more different over time and do different things along the same line of hard bits. We find out that the line of hard bits do get more different over time, and that the reason they get more different may be because the animals with hair start to breathe more air.

 

References:

 Jones, Katrina E., Kenneth D. Angielczyk, and Stephanie E. Pierce. "Stepwise shifts underlie evolutionary trends in morphological complexity of the mammalian vertebral column." Nature communications 10 (2019). 

 Schaeffer, Joep, et al. "Morphological disparity in theropod jaws: comparing discrete characters and geometric morphometrics." Palaeontology (2019). 

Direct download: Podcast_177_-_Grow_a_Spine.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at changes in teeth through time. The first paper looks at the earliest example of heterodont teeth in tetrapods, and the second paper looks at how different mammal groups build sabre tooth morphologies. Meanwhile, James has unique ideas for building worker morale, Amanda accidentally makes a pie faux pas, and Curt is friend to gelfling.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about teeth. Wow, teeth is one of the ten hundred most used words. Cool. So some things have teeth that are all the same kind. Most of the very early things with four feet that go on long have teeth of all the same kind. But there is an early thing with four feet that goes on land that we have known about for a long time that was never really looked at too close and now we see that it has teeth that are big and round and teeth that are small and pointed. It was probably eating things that were very hard and needed to be broken up before it could eat them. What is cool is that there are lots of animals from the same place at the same time that also show this kind of eating thing, where they must have been eating things that were very hard like rock and had to be broken up before they could be eaten. Our friends also talk about animals with hair that had very very long pointed teeth in the front of the mouth. It turns out that these teeth grow in a very different way. Animals with hair only grow teeth two times, and the back teeth only grow in one time. Usually the back teeth grow in last. But these animals had their very very long pointed front teeth grow in last. And they grow in funny. They grow in along the inside of the old teeth, until they are as much as the old teeth, then the old teeth fall out. This might mean that these teeth show up in different animals with hair totally on their own over and over and over again many times, which is cool.


References:

Clack, Jennifer A., et al. "Acherontiscus caledoniae: the earliest heterodont and durophagous tetrapod." Royal Society open science 6.5 (2019): 182087. 

 Wysocki, Matthew Aleksander. "Fossil evidence of evolutionary convergence in juvenile dental morphology and upper canine replacement in sabertooth carnivores." Ecology and Evolution (2019). 

Direct download: Podcast_176_-_Much_Ado_About_Teeth.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that use large data sets to look at big picture patterns in evolution and ecology. Specifically, they look at one paper that explores brachiopod shell thickness in relationship to environmental preferences during the Late Ordovician mass extinction, and another paper that looks at the evolution of using the tail as a weapon in vertebrates. Meanwhile, James is eternally “young”, Curt invents unique ecological roles for Stegosaurus, and Amanda enables the worst type of ASMR (for those who cannot handle food sounds in microphones, skip 47:57-48:54).

 

Up-Goer Five (Curt Edition):

Our friends talk about two papers that bring together a lot of facts about things to say something about how living things have changed over time. The first one looks at hard rock like things that take food out of the water. This paper looks at how thick the hard parts of these things were and it focuses on a time when these things went through a real bad time and a lot of them died. While the paper finds a lot of interesting things, one of the big things they find is that some of the animals that pull food out of the water all made really thicker hard parts than the other types of animals that pull food out of the water. These animals that made really thick hard parts were also the ones that were hurt when a real bad time happened.

The second paper looks at animals that have a long part coming off their bottom. This paper looks at animals which use the long part on their bottom to hit things. There are lots of different ways animals with long parts coming off their bottom can use that long part to hit things, and this paper looks to see what parts need to be in place in order to have these animals be able to hit things. It turns out that there have been many times that life has found a way to hit things with a long part coming out of the bottom.

 

References:

 Arbour, Victoria M., and Lindsay E. Zanno. "The evolution of tail weaponization in amniotes." Proceedings of the Royal Society B: Biological Sciences 285.1871 (2018): 20172299. 

 Balthasar, Uwe, et al. "Brachiopod shell thickness links environment and evolution." Palaeontology (2019). 

Direct download: Podcast_175_-_Big_Data_Studies.mp3
Category:general -- posted at: 3:00am EST

The gang talks about two papers that look at potential examples of parasitism in the fossil record. One paper finds possible parasites attaching to ancient ostracods, and another paper details potential parasitic isopods on electric ray fossils. Meanwhile, James practices his spidey sense, Curt is suspicious that things are going too well, and Amanda’s internet has amazing timing.

 

Up-Goer Five (Amanda and James Edition):

 Today our friends talk about animals that eat other animals without killing them. First our friends talk about a paper that talks about an animal that has big teeth but no hard inside parts even though it is in a group that has hard inside parts and lives in the water. This animal has a number of smaller animals that have sort of hard outer parts, that may have been living on its skin by sticking its head inside its skin and living there. It is very hard to tell if this thing had its head in the animal with big teeth and no inside hard parts when it lived, or if it was just maybe eating the animal after it was dead. It is very hard to tell if things ate other things while they were still living or if they were there after it died.

Our friends also talk little animals that have five arms that today live in animals without legs that breath water. The animals with five arms first became animals with five arms that ate other animals without killing before the animals without legs that breath water came to be, so we did not know what the animals with five arms used to eat. Now we know that they would eat animals with lots of legs and a hard head, and that they would eat the animals with lots of legs and a hard head from lots of places, not just inside like they eat the animals with no legs that breath water.

 

References:

 Siveter, David J., et al. "A 425-million-year-old Silurian pentastomid parasitic on ostracods." Current Biology 25.12 (2015): 1632-1637. 

 Robin, Ninon, et al. "Eocene isopods on electric rays: tracking ancient biological interactions from a complex fossil record." Palaeontology 62.2 (2019): 287-303. 

Direct download: Podcast_174_-_Feeling_Drained_Parasites_in_the_Fossil_Record.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look into early plant evolution and ecology. The first paper looks at some evidence from fossil spores to determine where the earliest vascular plants on land may have evolved. The second paper looks at a unique Devonian forest ecology from China. Meanwhile, James accidentally hoists himself, Amanda is more heard than she thinks, Curt fails as acting like everything’s ok, and everyone has a good old time working around Amanda’s computer deciding to die.

 

Up-Goer Five (Curt Edition):

Our friends talk about old things that can make their own food from the sun. First, they talk about some of the oldest things that make their food from the sun which also have ways of moving water from the bottom of the thing to the top. Before this paper, it was thought that things which make their food and live on the land probably first started in the big piece of land that used to be made up of most of the other land pieces put together. With this paper, they found parts of these things which are used for making babies in the rocks of a different piece of land. This makes the people who wrote the paper think that, maybe, a lot of the changes in these early things on the land that make food may have actually happened in this other place.

The second paper looks at some very early trees. These trees are not the same as trees today, because they are not quite doing the same thing as trees today. But these early trees still act a bit like trees today. This paper finds a very interesting type of group of trees which seems to be in a place close to the big blue wet thing. This group of trees has the trees way more close together than we have seen before. It is a lot earlier than when we usually see trees that are grouped very close together. This means that trees got very close together with a lot of trees in one area very early on. This means that the big groups of trees we see a bit later on had their start earlier than we had first thought. This group of trees is also very cool is that the way the trees are grouped together is very different from what we see today, and even in the past. The trees are all the same type of tree and there are big, not so big but not so small, and small trees all grouped together. This means that lots of trees grouped together could really pull down some clear things in the air that control how hot the air is.

 

References:

 Wang, Deming, et al. "The Most Extensive Devonian Fossil Forest with Small Lycopsid Trees Bearing the Earliest Stigmarian Roots." Current Biology 29.16 (2019): 2604-2615. 

 Rubinstein, Claudia V., and Vivi Vajda. "Baltica cradle of early land plants? Oldest record of trilete spores and diverse cryptospore assemblages; evidence from Ordovician successions of Sweden." GFF (2019): 1-10. 

 

Direct download: Podcast_173_-_Early_Plants.mp3
Category:general -- posted at: 3:00am EST

James, Brendan, Aly, Carlie, Anna, and Curt gather together at the 2019 Geological Society of America Meeting in Phoenix and discuss the various paleontology talks they saw at the event.

Day 1 (Anna, James, Curt, Brendan): 0:00 - 1:05

Day 2 (James, Aly, Carlie, Brendan, Curt): 1:05 - 2:37

Day 3 (James, Anna, Curt): 2:37 - 3:54

Day 4 (James, Carlie, Brendan): 3:54 - 5:17

Direct download: Podcast_172_-_GSA_2019.mp3
Category:general -- posted at: 6:53pm EST

The gang discusses some very interesting papers about bird fossils in New Zealand. These papers describe how many different types of birds ended up on New Zealand throughout the Cenozoic, and each time they experienced significant increases in their size. Sadly, since this was a very straightforward topic, no one could quite manage to focus on anything. So meanwhile, Curt remembers childhood animations that no one cares about, James makes it “fun” for himself and no one else, Amanda drinks the unholy combination of bourbon and rye (brye?), and everything just kind of gets way too 2019 near the end (EDITOR’S NOTE: Apologies for the inconsistent audio on this episode. The wrong inputs were used for some of the audio due to some last minute changes, but this should not happen in the future).

 

Up-Goer Five (Amanda Edition):

Today our friends talk about things with no teeth that can fly that can't actually fly and live on land that has water all around it. One of these things with no teeth that can fly but can't actually fly does sort of fly, but under the water instead of in the air. The other is a very large thing with no teeth that can fly but can't fly that people will have as an animal in their house a lot of the time. These things with no teeth that can fly that people keep in their house yell a lot and can also learn to talk. The one our friends talk about is just a leg, but it was very large and probably as big as a small child. The whole animal was that big, not the leg. The other thing with no teeth that can fly but can't fly but does sort of fly under the water is very big and very old and maybe is one of the oldest ones of these things with no teeth that can't fly anymore. It seems like maybe this land with water all around it was a good place for these early things with no teeth that can fly but now can't fly but sort of fly under water, because there are many of them there at this time. And they are very old, some of the oldest ones, and very big, so maybe being big is an old thing that this group of animals does.

 

References:

 Worthy, Trevor H., et al. "Evidence for a giant parrot from the Early Miocene of New Zealand." Biology letters 15.8 (2019): 20190467. 

 Mayr, Gerald, et al. "Leg bones of a new penguin species from the Waipara Greensand add to the diversity of very large-sized Sphenisciformes in the Paleocene of New Zealand." Alcheringa: An Australasian Journal of Palaeontology (2019): 1-18. 

Direct download: Podcast_171_-_Birds_Get_Swole_in_New_Zealand.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two very different papers that are sort of united together based upon the importance of taphonomy. First, they look at a paper about how the ways in which conodont elements are preserved can affect our understanding of their evolution. Second, they talk about the recent finding of exceptionally preserved therizinosaur dinosaur nesting sites. Meanwhile, Amanda finds herself dealing with a failing webcam, Curt enjoys burying the lede, and James is never wrong unless he wants to be.

 

Up-Goer Five (Curt Edition):

Our friends talk about how the ways that things wear down can really change how we understand our past. First, they look at these things that are like teeth but are not and are part of this very old group of animals that are aunt or uncle to a lot of animals that have hard parts in their backs which live today. Some of these old animals that have not teeth have changes through time in their not teeth. The bottom of these not teeth appears to disappear in the animals we find which are closer to today. However, this paper finds new animals that show maybe the bottom of these teeth have not actually disappeared, but instead it turns out that this bottom part is very easy to break off. This is important because it means that the not teeth may still have some deep relationship to how actual teeth teeth form.

Next, our friends look at the places where big angry animals would lay bag like things that hold babies, here after we will call them sit places. A big question has been if these big angry animals liked to find sit places close to each other or far away. It is hard to tell this in the past because we can't always be sure all of the sit places were used at the same time. This paper find a single red line that runs across all of the sit places, which allows the people who wrote the paper to say that all of the sit places were probably used at the same time. Also, the number of babies that didn't die is a lot like the number of babies that don't die in animals who also find sit places together today. So it looks like these big angry animals probably shared sit places.

 

References:

Tanaka, Kohei, et al. "Exceptional preservation of a Late Cretaceous dinosaur nesting site from Mongolia reveals colonial nesting behavior in a non-avian theropod." Geology(2019). 

 Souquet, Louise, and Nicolas Goudemand. "Exceptional basal-body preservation in some Early Triassic conodont elements from Oman." Palaeogeography, Palaeoclimatology, Palaeoecology (2019). 


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.

Direct download: Podcast_169_-_Learning_about_Agnostids.mp3
Category:general -- posted at: 3:00am EST

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). 

Direct download: Podcast_168_-_Alligator_Teeth_and_Too_Small_Cats.mp3
Category:general -- posted at: 3:00pm EST

[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. 

Direct download: Podcast_167_-_Jet_Lagged_Pterosaur_Eggs.mp3
Category:general -- posted at: 3:00am EST

We all just got back from the 2019 North American Paleontological Conference at UC Riverside with an extra long (over 5 hours) episode. Join James, Carlie, Curt, and Brendan as they discuss the talks they saw each day of the conference. Time stamps for each day: Day 2 talks ~ 54 min.; Day 4 talks ~2 hr, 36 min; Day 5 talks ~3 hr, 49 min.

Direct download: Podcast_166_-_NAPC_2019.mp3
Category:general -- posted at: 12:00pm EST

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

Direct download: Podcast_165_-_Sharks_for_St_Crispins_Day.mp3
Category:general -- posted at: 3:00am EST

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. 

Direct download: Podcast_164_-_Rails_and_Snails.mp3
Category:general -- posted at: 3:00am EST

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. 

Direct download: Podcast_163_-_Triassic_Fish_Questions.mp3
Category:general -- posted at: 3:00am EST

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). 

Direct download: Podcast_162_-_Turtle_Power.mp3
Category:general -- posted at: 3:00am EST

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. 

Direct download: Podcast_161_-_Whales_Not_Whales.mp3
Category:general -- posted at: 3:00am EST

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. 

Direct download: Podcast_160_-_Weasel_Time.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers about the Cretaceous mass extinction event (i.e. the time that the non-avian dinosaurs died). Specifically, they talk about the Deccan Traps, a widespread volcanic province that was active during the extinction event. The first paper studies the timing of the volcanic activity to determine if the onset of volcanism can be explained by the large bollide impact (Editors Note: Apologies to all igneous petrologists who will likely be yelling at our ignorance of hard rock geology). The second paper uses ecological niche modeling to see if dinosaurs were experiencing significant reduction in their geographic range before the extinction event. Also, James is in a “good” mood, so please enjoy as we bounce between topics like Sinclair oil, the French Revolution, “training” children, and experiences at paleo festivals. Its definitely one of those podcasts.

 

Up-Goer Five (Amanda Edition):

 Today our friends talk about the time when the big angry animals with no hair and large teeth all died. One of the ideas is that a very big rock hit and killed everything. Another idea is that rock that acts like water came out of the ground and changed the air and that killed everything by making things too warm or too cold. Many people are starting to think the rock that acts like water that came out of the ground killed the big angry animals with no hair and large teeth, because it seems like they died more slowly that maybe they should have if a big rock hit the ground and killed everything. That would be very fast. But then maybe the big rock that hit the ground really did kill everything, because it turns out that the rock that acts like water that came out of the ground maybe didn't happen at the same time that the big angry animals with no hair and large teeth died. It might also be that big angry animals with no hair and large teeth were maybe around in more places and maybe there were more big angry animals with no hair and large teeth than we think because we only have rocks in some places from some times and that makes it look like the big angry animals with no hair and large teeth died slowly, but maybe they actually died fast.

 

References:

 Sprain, Courtney J., et al. "The eruptive tempo of Deccan volcanism in relation to the Cretaceous-Paleogene boundary." Science 363.6429 (2019): 866-870. 

 Chiarenza, Alfio Alessandro, et al. "Ecological niche modelling does not support climatically-driven dinosaur diversity decline before the Cretaceous/Paleogene mass extinction." Nature communications 10 (2019). 

Direct download: Podcast_159_-_Rocks_Fall_Everyone_Dies_The_Cretaceous_Mass_Extinction.mp3
Category:general -- posted at: 3:00am EST

The gang celebrates their 6th anniversary by taking some time to talk about two papers about early mammal ecology. The first paper looks at some unique traces left by Mesozoic mammals, while the second paper attempts to determine how early mammals might have chewed their food. Meanwhile, James has made friends with his new Eevee named DMX, Amanda finds the fuel to sustain herself, and Curt imagines some tactical mammal stealth action.

(EDITOR’S NOTE: If you’re wondering if Curt went all the way into making a complete edit on that song near the end….. of course he did: https://www.youtube.com/watch?v=d-fs-Qx8W18 )

 

Up-Goer Five (James Edition):

Today the group looks at two papers dealing with animals with warm blood and hair and looking at how they lived a long time ago. The first paper is looking at tracks of animals with hair that look a bit weird, with one side pushing down more than the other. The people studying the tracks think that they could have been made by an animal with hair carrying babies on it. This would be interesting as it would suggest that the animals with hair looked after their babies and let them drink warm white wet stuff from their bodies even this long ago. In order to see whether the tracks were made by an animal with hair that carried babies, the people writing the paper took an animal with hair that eats things people throw out but people also keep as animal friends and stuck things to it to make it carry them as if it was carrying babies to see if when it tried to walk it made tracks like they see in the rocks. It really just wanted to lie down but when it did walk it made tracks just like they see in the rock from a long time ago! The second paper is looking at how animals with hair that are around today eat their food and seeing how much it is the same or different to how animals with hair a long time ago ate. They show that they eat a way that we were not thinking they would and actually roll their mouth when biting, and that some of our strangest animals with hair that are part of an older group than most of our other animals with hair actually eat the same was as animals with hair from a very long time ago ate.

 

References:

Kuznetsov, Alexander N., and Aleksandra A. Panyutina. "First Paleoichnological Evidence for Baby–Riding in Early Mammals." Ameghiniana 55.6 (2018): 668-677. 

 Bhullar, Bhart-Anjan S., et al. "Rolling of the jaw is essential for mammalian chewing and tribosphenic molar function." Nature (2019): 1. 

 

 

Pokemon and "Pokemon: Let's Go Eevee" are the properties of Nintendo, Creatures, and Game Freak ; "X Gonna Give It To Ya" by DMX owned by Def Jam and the Universal Music Group.

Direct download: Podcast_158_-_Is_DMX_Eevee_a_Mammal.mp3
Category:general -- posted at: 3:00am EST

<EDITORS NOTE: As discussed in the very beginning of the episode, we had some serious audio issues which meant that the recording quality is not up to our usual quality. We apologize for the degraded audio quality in this episode, but future episodes should not have this issue.>

The gang discusses two papers about the interesting vertebrate remains in Myanmar amber, including a neonate snake and an Enantiornithean bird, and discuss the ecological and evolutionary implications of these fossils. Meanwhile, Curt starts a terrible “theory”, James measures his hands, and Amanda might be responsible for some collusion.

 

Up-Goer Five (Curt Edition):

Our friends talk about very thick stuff that sticks together and comes off of trees and often living things end up inside of it and dying. Most of the time, old tree stuff just has small animals who have their hard parts on the outside. This very old tree stuff is very is not like a lot of other old tree stuff because it also has a lot of big animals in it who have hard parts on the inside. Our friends talk about the animals that ended up inside this old tree stuff. One of the animals in the old tree stuff is a baby long animal without legs. This baby long animal with no legs gives us a look at a type of animal we often do not get to see in old rocks and lets us know that some of these old long animals without legs may have lived in trees. The other parts that ended up in this old tree stuff were from an animal who could fly. One of these animals who could fly ended up in the tree stuff, and all we have left are a foot and part of the arm like thing they use to fly. This animal that can fly shows is very different from the animals that can fly today that are brothers and sisters to it. The foot has things coming off of it that are weird. In both of these papers, we can see how this old tree stuff gives us very important facts about how animals that used to be in the world a long long time ago.

 

References:

 Xing, Lida, et al. "A mid-Cretaceous embryonic-to-neonate snake in amber from Myanmar." Science advances 4.7 (2018): eaat5042. 

 Xing, Lida, et al. "A fully feathered enantiornithine foot and wing fragment preserved in mid-Cretaceous Burmese amber." Scientific reports 9.1 (2019): 927. 

 

"Hep Cats" Kevin MacLeod (incompetech.com)

Licensed by Creative Commons: By Attribution 3.0

http://creativecommons.org/licenses/by/3.0/

Direct download: Podcast_157_-_A_Sticky_Situation_More_Talk_of_Vertebrates_in_Amber.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that look at the links between morphology and ecology. Specifically, they discuss a fossil marine reptile with a very unique looking skull that gives clues to a possible “platypus” like life-habit. However, they also discuss a modern ecological study of crustacean-eating snakes which shows that sometimes unique behaviors can greatly expand the potential prey species available to a predator. Meanwhile, James regales us with tales of an epic battle, Amanda is good at social interactions, and Curt ponders anime betrayals.

<FYI: The second paper has a video supplemental information showing snake feeding strategies. This is exactly what it sounds like. It is interesting, but you have been warned. https://www.youtube.com/watch?v=JtMR7I38s1U >

 

Up-Goer Five (Curt Edition):

Our friends talk about animals with small heads and how these animals lived and ate. First, they talk about a thing that lived in the big blue wet place a long long time ago which had a very very large body. Before hand, we didn't know what the head of this thing looked like. But now we found out that it had a really really small head for its really big body. Also, the head is weird, and has these cuts in it that seem to be where a round long mouth thing used to be. Also, it has a strange hard part in the middle of the head which is not stuck to anything. All of these weird head bits are very much like what we see in one weird animal today which looks like it was made from parts of other animals. This has lead people to think that this old animal who lived in the big blue wet place might have eaten in a way that is a lot like this animal we have today that looks like it was made from parts of other animals.

Next, our friends talk about these animals with no legs who eat rock hard animals with cutting hands who sometimes lose their skin. There are lots of types of these animals with no legs, but only a few of these animals with no legs try to eat these rock hard animals with cutting hands who sometimes lose their skin. This paper wanted to know how these animals with no legs go about eating these rock hard animals. It turns out there are many different ways to do it, with some of them pulling off legs, some of them eating the rock hard animals whole, and some of them waiting until these rock hard animals lose their skin. But the really cool thing is that animals with no legs who had very small mouths could actually eat rock hard animals much larger than themselves. By waiting until these rock hard animals lost their skin, these very small animals with no legs could tear their food to small pieces while it was still able to move and breathe. So the way that the animal with no legs lived was very important for deciding which of the rock hard animals it could eat.

 

References:

Cheng, Long, et al. "Early Triassic marine reptile representing the oldest record of unusually small eyes in reptiles indicating non-visual prey detection." Scientific reports 9.1 (2019): 152. 

 Jayne, Bruce C., Harold K. Voris, and Peter KL Ng. "How big is too big? Using crustacean-eating snakes (Homalopsidae) to test how anatomy and behaviour affect prey size and feeding performance." Biological Journal of the Linnean Society 123.3 (2018): 636-650. 

Direct download: Podcast_156_-_Never_Underestimate_the_Little_Snake.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that use fossil evidence to interpret physiology and functional morphology of extinct animals. First, we discuss a new study that suggests ichthyosaurs may have evolved blubber to help them regulate their temperatures. Second, we talk about a new study that uses robotic models to test how early tetrapods may have moved. Meanwhile, Amanda mixes caffeine and alcohol, Curt forgets Shane Black movies, and James tries to pull the ultimate mid episode twist. <Editor’s note: James finally gets to starting the podcast roughly 10 minutes in after forcing connections for every minor digression>

 

Up-Goer Five (Amanda Edition):

Today our friends talk about animals that are very big but not large, and how early animals with four feet walked. The first paper is very good and talks about an animal that looked like an animal that breathes water but actually is an animal that has just skin and breathes air. These animals had thick skin with lots of stuff under the skin like cute animals with hair that live where it's cold. This stuff is very very very easy to see in this old animal. It also has color. But real color not color that might not be real like in other old animals. One friend thinks that this animal might be very good to eat. Our friends also talk about a very good paper that looks at how early animals with four feet walked. This paper has a lot of people all working together and they do a lot of different things that they are all very good at, so this paper does some different things than other papers. They make a not-real animal, both in a computer and in real life. The computer not-real animal is used to make sure the real-life not-real animal can do things right. It looks like a lot of work. Then they make the real-life not-real animal walk and show that it looks like foot marks left a long time ago by early animals with four feet. They make the real-life not-real animal walk a number of different ways to make sure that they are doing the right thing. The real-life not-real animal leaves foot marks that match up just right with the foot marks left a long time ago.  

 

References:

 Nyakatura, John A., et al. "Reverse-engineering the locomotion of a stem amniote." Nature 565.7739 (2019): 351. 

 Lindgren, Johan, et al. "Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur." Nature 564.7736 (2018): 359. 

Direct download: Podcast_155_-_But_What_Would_It_Taste_Like.mp3
Category:general -- posted at: 3:00am EST

The gang gets together to record their first episode back from the holidays. And what better topic to discuss than hyoliths, those strange shelly Cambrian fossils. Specifically, the gang discusses two papers that look at new discoveries of the soft tissue and the hard shells of these hylothis to try and determine the evolutionary placement of hyoliths. Are hyoliths molluscs? Are hyoliths brachiopods? Are they somewhere in between? Meanwhile, Amanda hears some good news, Curt does his best hyolith impression, and James hits some unexpected snags when he discusses the ramifications of his ideal super powers.

 

Up-Goer Five (Amanda Edition):

 Today our friends talk about animals that are big at one end and small at another end. They might be close to things with two parts that are good to eat, or they might be close to things with two parts that are not good to eat. Some people have said not long ago that they are more close to the things with two parts that are not good to eat. Our friends look at two papers that talk about these strange animals that are big at one end and small at the other. One paper says that yes, these animals are more close to the things with two parts that are not good to eat, and says that this is shown by the fact that they have a long thing that makes them stick to the ground. Animals with two parts that are good to eat don't have this long thing that makes them stick to the ground, but animals that have two parts that don't aren't good to eat do. Our friends don't really know if this thing is actually a part that makes the strange animals that are big at one end and small at the other stick to the ground, and would like to see some cool pictures taken to help show more things. The second paper tells us that actually these strange things that are bigger at one end and smaller at another are sort of between the things with two parts that are good to eat and the things with two parts that are not good to eat. They do this by looking at the hard parts that make up the strange things that are big at one end and small at the other, and then looking at the hard parts of the animals with two parts (both good and not good to eat). They look at these hard parts very, very close up. It is very cool.  

 

References:

 Sun, Haijing, et al. "Hyoliths with pedicles illuminate the origin of the brachiopod body plan." Proceedings of the Royal Society B: Biological Sciences 285.1887 (2018): 20181780. 

 Li, Luoyang, et al. "Homologous shell microstructures in Cambrian hyoliths and molluscs." Palaeontology (2018).

Direct download: Podcast_154_-_Heyo_Hyoliths.mp3
Category:general -- posted at: 3:00am EST

At the end of a long year, the gang takes a moment to reflect on the various strategies they use to try and keep themselves sane when things get stressful. So please join us as we discuss the joys of knitting, painting, and unconventional youtube video series in this special self care episode of Palaeo After Dark. Honestly though, it's a lot of knitting. Here’s to a safe and happy new year.

Direct download: Podcast_153_-_Holiday_Self_Care_Spectacular.mp3
Category:general -- posted at: 6:35pm EST

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