Palaeo After Dark

The gang discuss two papers that discuss the methods we use to determine how different things are from each (i.e. disparity). In particular, do variations in parts of an animal give us a good sample of the morphological variability of the total animal? Meanwhile, Amanda wants a whale, James has strong opinions about vertebrae, and Curt tries to narrow in on what Amanda views as "cute".

 

Up-Goer Five (James Edition):

The group looks at two studies that want to see if we can say how different animals are. There are many ways that we can try to see how animals are different from each other. The first paper looks at two ways of seeing if animals are different, one by looking at how points on the animals change between them and another by looking at what parts the animals have. The paper shows that the both types of study give the same answer, which is good news.

The second paper wants to see if we get the same answer for how animals are different from each other when we look at only one part of the animal instead of looking at the whole animal. This study also shows that when you look at part of an animal, you get the same answer as when you look at the whole animal. This is also good news! There's lots of good news, let's have a party.

 

References:

Hetherington, Alexander J., et al. "Do cladistic and morphometric data capture common patterns of morphological disparity?." Palaeontology 58.3 (2015): 393-399. 

 Hopkins, Melanie J. "How well does a part represent the whole? A comparison of cranidial shape evolution with exoskeletal character evolution in the trilobite family Pterocephaliidae." Palaeontology 60.3 (2017): 309-318. 

Direct download: Podcast_115_-_Amanda_Now_Wants_Tiny_Whales_to_be_a_Thing.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that describe the life strategies of trilobites, a diverse and charismatic group of extinct arthropods. Specifically, they look at two papers that look at enrollment and movement of trilobites. Meanwhile, Amanda educates James on the nature of pain, James envisions Curt's inevitable end, and Curt invents a hockey/extinct arthropod family film.

 

Up-Goer Five (James Edition):

The group looks at two papers that look at old animals with many legs that live in the bad drink water place and are made out of rock. These animals are all over the place and are good to study much like small animals with hair and big ears are used today. One paper makes pictures of the old animal with many legs on the computer to see how they turn into a ball. This paper is very easy to understand and shows that these animals can turn into a ball in a number of different ways and that they started doing these different ways a number of different times. However, once they have made this change they seem to stick with it. The second paper is not very easy to understand. It looks at where these old animals with many legs form lines and tries to work out whether they are forming lines so it is easier for them to walk. A lot of numbers are used to work out how easy it is for them to walk, but it is not clear what the numbers say. They suggest the lines these animals with many legs make are the same as ones people that ride things with two round moving things instead of legs make, but this just makes things more confusing.

 

References: 

Trenchard, Hugh, Carlton E. Brett, and Matjaž Perc. "Trilobite ‘pelotons’: possible hydrodynamic drag effects between leading and following trilobites in trilobite queues." Palaeontology (2017). 

 Esteve, Jorge, et al. "Modelling enrolment in Cambrian trilobites." Palaeontology 60.3 (2017): 423-432. 

Direct download: Podcast_114_-_Trilobites_Mice_of_the_Paleozoic.mp3
Category:general -- posted at: 3:00am EST

The gang discuss the concept of the body plan, or "bauplan", and what it means for our understanding of evolution. When in the evolutionary history of a group do the morphological characteristics we associate with that group become fixed? Meanwhile, Amanda details the exploits of mischievous crows, Curt explains our free-to-play academic futures, and James educates America on British society. Also, we start talking about science about 9 minutes in.... it's one of those podcasts.

If you want to support the podcast, you can go to www.patreon.com/palaeoafterdark to find out more.

 

Up-Goer Five (Curt Edition):

Our friends talk about body plans. Yes, we can say body plan in this. Some animals and not animals are almost the same, and people wonder if it is because those animals and not animals are brothers and sisters but bigger. Also, people wonder when these animals and not animals first became the same, because they started out not the same and became more same over time. Does it matter that these animals and not animals are the same? Why are they the same? It turns out that some animals that are small with weird mouths were more different in the past than we thought, and they got their weird mouth before they became really same. Also big animals that were brother and sister but bigger to animals that would walk and maybe fly some day were very different in the past.

 

References: 

Aria, Cédric, and Jean-Bernard Caron. "Burgess Shale fossils illustrate the origin of the mandibulate body plan." Nature 545.7652 (2017): 89-92. 

 Nesbitt, Sterling J., et al. "The earliest bird-line archosaurs and the assembly of the dinosaur body plan." Nature 544.7651 (2017): 484-487. 

 

"Brightly Friendly" Kevin MacLeod (incompetech.com)

Licensed by Creative Commons: By Attribution 3.0

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

Direct download: Podcast_113_-_Whats_In_a_Bauplan.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that use biogeochemical evidence to determine the diets of two specialist species. Just how restricted are the diets of these species? Meanwhile, Amanda finds a new pet she desperately needs, James copes with a changing environment, and Curt  gives James some advice on social situations.

If you want to support the podcast, you can go to www.patreon.com/palaeoafterdark to find out more.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about animals that can only do one thing or animals that can do many things. Most people think that animals that can only do one thing are not very good and will die fast. They also think that animals that can do many different things are good and will live a long time and have lots of babies. One paper our friends read actually says that sometimes animals look like they can do only one thing, but really they just really, really like to do that one thing, and if they have to they will do something else so that they can live. The other paper says that big stupid black and white animals that are not good are really not good and have been not good for a long time. A long time ago, there were even very small big stupid black and white animals that were not good, and even then they were not good. 

 

References: 

 Terry, Rebecca C., Megan E. Guerre, and David S. Taylor. "How specialized is a diet specialist? Niche flexibility and local persistence through time of the Chisel‐toothed Kangaroo Rat." Functional Ecology. 

 Stacklyn, Shannon, et al. "Carbon and oxygen isotopic evidence for diets, environments and niche differentiation of early Pleistocene pandas and associated mammals in South China." Palaeogeography, Palaeoclimatology, Palaeoecology 468 (2017): 351-361. 

 

"Scheming Weasel slower" Kevin MacLeod (incompetech.com)

Licensed by Creative Commons: By Attribution 3.0

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

Direct download: Podcast_112_-_How_Specialized_Are_Specialists_.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that use fossil evidence to determine how terror birds moved. Were they lumbering giants or fast sprinters? Also, James gets metaphysical, Curt unabashedly likes old Tim Burton films, Amanda doesn't appreciate science that ruins the fun, and everyone is very excited about birds that smash proto-horses.

If you want to support the podcast, you can go to www.patreon.com/palaeoafterdark to find out more.

 

Up-Goer Five (Amanda Edition):

 

Today our friends talk about very large animals with no teeth that could step on you. They did not fly but rather ran or walked slowly. Other animals, like big animals with little hair and long noses also walk slowly. The friends talk about how some of these very large animals with no teeth that could step on you looked like they ate other animals and ran very fast, and some looked like they ate other animals but did not and also walked very slow. But there are some very large animals with no teeth that we don't know if they ran very fast or walked very slow and there are other people trying to see if they walked fast or slow using how long legs are. Some parts of legs are longer than other parts of legs and that will mean if the very large animal with no teeth that could step on you could run or just walked slowly. One group looked at how long parts of legs are with other parts of the same legs. They found an easy way to see if these very large animals with no teeth that could step on you walked fast or slow. Another group looked at parts of legs in a different way with a harder numbers thing and found almost the same things as the first group!

 

References:

Angst, Delphine, et al. "A new method for estimating locomotion type in large ground birds." Palaeontology (2015). 

 Degrange, Federico J. "Hind limb morphometry of terror birds (Aves, Cariamiformes, Phorusrhacidae): functional implications for substrate preferences and locomotor lifestyle." Earth and Environmental Science Transactions of The Royal Society of Edinburgh 106.4 (2017): 257-276.

 

"Aces High" Kevin MacLeod (incompetech.com)

Licensed by Creative Commons: By Attribution 3.0

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

Direct download: Podcast_111_-_Giant_Killer_Birds.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that show how diet can impact stress, strain, and wear patterns of the tooth and jaw, specifically on therizinosaur dinosaurs and lions. Also, James mistakes cats for people, Amanda makes the second worse joke of the podcast, and Curt tries to advertise at the worst possible times. Also cannibalism.

If you want to support the podcast, you can go to www.patreon.com/palaeoafterdark to find out more.

 

Up-Goer Five Summary (Amanda Edition):

Today our friends talk about big animals with no hair that had big long angry things on their hands that could hurt you. We do not know much about these big animals with no hair that had big long angry things on their hands that could hurt you. For a long time we did not know what they ate or how they lived or even what they looked like. Now we know that they are round and have very long arms. They are brothers of the big angry animals with no hair that have very large teeth and short arms. But these big animals with no hair and long angry things on their hands that can hurt you are not like their brothers that are big and angry with large teeth and short arms because they eat different things. The big animals with no hair that have very large teeth and short arms eat other big animals with no hair. And animals with hair. And any animals. The big animals with no hair that have long angry things on their hands that can hurt you do not eat other big animals with no hair. They eat leaves. When we used new ideas from brain-boxes to look at the heads of the big animals with no hair that have long angry things on their hands that can hurt you we see that they eat leaves and not other big animals with no hair.

 

Our friends also talk about big cats that ate people. 

 

References: 

Lautenschlager, Stephan. "Functional niche partitioning in Therizinosauria provides new insights into the evolution of theropod herbivory." Palaeontology 60.3 (2017): 375-387.

DeSantis, Larisa RG, and Bruce D. Patterson. "Dietary behaviour of man-eating lions as revealed by dental microwear textures." Scientific reports 7.1 (2017): 904.

 

"Honey Bee", "In Your Arms", "Monkeys Spinning Monkeys" Kevin MacLeod (incompetech.com)

Licensed by Creative Commons: By Attribution 3.0

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

Direct download: Podcast_110_-_Maneater.mp3
Category:general -- posted at: 3:00am EST

In this episode, the gang discusses two papers that use modern decay experiments to determine how decay can affect our understanding of the evolution of two groups, Coleoidea and Graptolithina. Are there certain structures or behaviors that make these animals more or less likely to be preserved in the fossil record? Also, the gang faces the existential void, James offers a gift, and Amanda learns something interesting about the greatest animals on the planet.

Up-Goer Five (James Edition): 

This time, the group talks about what happens to things after they die. They look at studies that took things that were not dead and made them dead (or found dead ones on ice at a shop) and then watched what happened to them as time went on. We can then use the brain facts that we get from seeing these things continue to be dead to figure out what we are seeing when we look at things that have been dead for a really long time and turned into rock. First, we look at things that live in the water and have many arms. One group is not found in rock although they should have been around a long time ago, and because of the brain facts we get from watching them be dead we can tell it is because they do not drop in the water once they are dead. The second study looks at things that building their own houses by being sick on themselves. There are lots of them in the past but now only one group is left. By killing some of the ones that are left to see how they die we can see why we only find the old houses in rock and not the animals themselves, and also if dark bits we see in the houses in the rock may in fact be those animals!

References: 

Clements, Thomas, et al. "Buoyancy mechanisms limit preservation of coleoid cephalopod soft tissues in Mesozoic Lagerstätten." Palaeontology 60.1 (2017): 1-14.

Beli, Elena, Stefano Piraino, and Christopher B. Cameron. "Fossilization processes of graptolites: insights from the experimental decay of Rhabdopleura sp.(Pterobranchia)." Palaeontology (2017).

 

Direct download: Podcast_109_-_Dead_Squids_and_Graptolites.mp3
Category:general -- posted at: 3:00am EST

In this episode, the gang decides to go back to some old papers they enjoy to discuss the concept of homology. What do we really mean when we say certain characteristics are shared due to evolutionary history? Also, for a brief minute in the second half, James was spontaneously possessed by demonic spirits that made him spout nonsense he doesn't actually believe. Unrelated to this, he also had a splitting migraine. 

Up-goer Five (Amanda in a fever-based fugue state edition): 

Today our friends talk about how things are the same because animals are brother and sister. This means that the brother and sister animals have parts that are the same because they have the same mother and father animals. But the way that brother and sister animals have the same parts can be because of different ways. People do not understand really what it means when we say that these brother and sister animals have the same parts. So our friends try to explain how these parts came to be and why.

References:

Van Valen, Leigh M. "Homology and causes." Journal of Morphology 173.3 (1982): 305-312.

Wiley, E. O. "Homology, identity and transformation." Mesozoic fishes 4 (2008): 9-21.

Direct download: Podcast_108_-_Homology_Party.mp3
Category:general -- posted at: 3:00am EST

The gang talks about two papers that detail the ecology and evolution of some early fishy vertebrates. Can we tell what early coelacanth fish might have eaten? What evolutionary changes occurred when early tetrapods started making their way onto land? Is there an evolutionary trend towards kawaii? All this and less will be discussed.

 

Oh, and James has made some interesting discoveries about The Legend of Zelda.

Up-Goer Five (James Edition): 

The group looks at two papers that are to do with animals with no legs that live in water although in one of the papers one of the animals is trying to have legs. In the first paper we see a very old animal with no legs that lives in water that has family around today that are thought to be pretty much the same but actually may be doing different things. We see that this old thing with no legs was eating a type of animal that we do not get any more, which is interesting as we have no way of telling that anything else ate this animal. In the second paper we look at things with no legs that are starting to having legs. We see that their eyes are moving on top of their heads like big angry things with hard skin and big teeth in long faces that live in the water. At the same time the eyes are moving onto the top of the head they are also getting bigger, and it is shown that the animals would have been able to see better out of the water. This seems to be happening at the same time as them starting to change their not legs into legs. The most interesting thing is that when some of the animals that then have legs go back into the water their eyes get smaller but do not move back down the side of the head; they are stuck there even though they are no good there any more!

 

References:

MacIver, Malcolm A., et al. "Massive increase in visual range preceded the origin of terrestrial vertebrates." Proceedings of the National Academy of Sciences 114.12 (2017): E2375-E2384.

Zatoń, Michał, et al. "The first direct evidence of a Late Devonian coelacanth fish feeding on conodont animals." The Science of Nature 104.3-4 (2017): 26.

Direct download: Podcast_107_-_A_Very_Fishy_Podcast.mp3
Category:general -- posted at: 3:00am EST

The gang celebrates four years of podcasting with a lengthy discussion about living fossils. What do we mean when we use the term living fossil, and can we come up with an operational definition? Also, Amanda risks invoking the destructive powers of John Wick, James invents the best Mass Effect slash fiction, and Curt plans for Amanda's replacement.

Musical track, "Sail the Canals" from Mario Party 7 is owned by Nintendo and Hudson. Used under fair use.

Up-goer Five (Amanda Edition): 

Today our friends talk about animals that lived a long time ago but still kind of are here today. People say that these animals that lived a long time ago are still here today and have not become any different than they were a long time ago. But our friends have a talk about how the animals that lived a long time ago and do not look different today are actually very different today than they were a very long time ago. Some of them might not look different but their stuff that makes them them is actually very different. Some of them have family that used to look very different even though they look like old, old animals that lived a long time ago. In the end, our friends decided that animals that look like animals that lived a long time ago are actually not the ones that lived a long time ago.

References:

Herrera‐Flores, Jorge A., Thomas L. Stubbs, and Michael J. Benton. "Macroevolutionary patterns in Rhynchocephalia: is the tuatara (Sphenodon punctatus) a living fossil?." Palaeontology (2017).

Kin, Adrian, and Błażej Błażejowski. "The horseshoe crab of the genus Limulus: living fossil or stabilomorph?." PLoS One 9.10 (2014): e108036.

Direct download: Podcast_106_-_A_Bunch_of_Living_Fossils_Four_Years_of_Podcasting.mp3
Category:general -- posted at: 3:00am EST