Palaeo After Dark (general)

The gang discusses two papers about archosaurs. The first paper looks at the trends in brain size relative to body size in birds over their entire evolutionary history. The second paper revisits the dinosaur Spinosaurus and adds more information to the debate over whether this animal had a semi-aquatic lifestyle. Meanwhile, James has some villagers he needs to “un-person”, Curt gives alternative definitions to slang, and Amanda just disappears (I’m sure she’ll be fine).

 

Up-Goer Five (Curt Edition):

Our friends talk about thinks they fly and something that moved through the water. The first paper looks at the brains of things that fly. As the body gets bigger, the brain usually gets bigger as well. But sometimes the way in which the brain gets bigger can change. Sometimes the brain gets bigger faster than the body and sometimes it gets bigger slower than the body. When looking at very old things that fly, what they find is that when the body gets smaller, the brain stays larger. This is something that big angry things which are brother and sister to the things that fly did as well. But later things that fly start changing how the brain gets bigger, with some things having their brains get way bigger faster than the body. This is often found in things that fly which are able to talk and use things which can make stuff work.

The second paper looks at an angry animal that some people think may move through the water and other people think those people are wrong. This paper finds more parts of the animal (the part at the end which can be moved up and down or side to side), which can help us better understand what this angry animal might have done. They find that the part at the end can shake to the side really well, which is something we see in animals that can move well through water. They use this to say that this adds more facts that say this thing may have moved through water.

 

References:

 Ibrahim, Nizar, et al. "Tail-propelled aquatic locomotion in a theropod dinosaur." Nature (2020): 1-4. 

 Ksepka, Daniel T., et al. "Tempo and Pattern of Avian Brain Size Evolution." Current Biology (2020). 

Direct download: Podcast_188_-_Bird_Brains_and_Propeller_Tails.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers about unique taphonomic conditions. One paper describes how these strange “train wrecks” of crinoid columnals might have formed, and the other paper models how bone jams in Dinosaur National Park could have formed. Meanwhile, James’s computer has a flux capacitor, Amanda mishears the best new BBC crime drama, and Curt enjoys the chance to talk about Nathan Fillion vehicles.

 

Up-Goer Five (Amanda Edition):

 Today our friends talk about animals with hard parts on their insides. Some of these animals have long arms with lots of parts and look like they sit on sticks. Others have many inside hard parts in place along their backs, and that is where they get their names. The animals with the long arms with lots of parts sometimes break into small pieces when they die. Usually they break into lots of little single round things, or they are very quickly covered up and are found all put together. But sometimes they break into big pieces that look like a train ran into another train. This paper talks about why they do that. They have long, strong bits of stuff like what is found on your knee. This stuff does not break down so easy and sometimes that is why you get these bigger pieces. The other paper looks at animals with hard parts inside their bodies put in a place along their backs, and what happens when these animals die and their hard parts come together in a moving water place. This paper does this by making tiny ones of the hard parts and putting them in a not-real moving water place. They find that these hard parts easily stick together and it explains why some of the these hard parts look the different ways they do once the animals are dead.  

 

References:

 Donovan, Stephen K. "Train crash crinoids revisited." Lethaia

 Carpenter, Kenneth. "Use of scaled dinosaur bones in taphonomic water flume experiments." Die Naturwissenschaften 107.3 (2020): 15-15. 

Direct download: Podcast_187_-_Taphonomy_Train_Wreck.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers that look at modifications of the vertebrate hand. The first looks at how the lobe fin evolved into the vertebrate hand, and the second paper looks at the early limb transformations of early whales as hands became fins. Meanwhile, James’s computer is a time traveler, Amanda is upset that everyone is upset about Bunny Day, and Curt wonders about numbers higher than 10.

 

Up-Goer Five (Curt Edition):

Our friends talk about how hands got started, and also how hands can become things that let animals move through the water. When this happens, we don't have a lot of remains because lots of the hard parts for these animals that are moving into or out of the water aren't there for us to look at. These two papers talk about new remains that have been found which give us more hard parts to look at so we can better understand how this happens. The first paper looks at new remains of old animals that let us know what the first animals which would have arms and legs and a back and lived on land looked like. This also lets us learn more about how hands first started. Big hard parts that used to be used to go through the water had some of those hard parts change to make fingers. While these first fingers started to form, the rest of the animal looked like it lived in the water.

The second paper looks at another type of animal that later on moved off the land and back into the water. When that happened, the hands become more like things that are used to move through the water. This animal is just starting to move into the water, but its great great great great children would be large animals with warm blood who move through the water. This animal that is just starting to move into the water shows changes in the hand that we usually see with things in water, but also has some hard parts that we see on land.

 

References:

Cloutier, Richard, et al. "Elpistostege and the origin of the vertebrate hand." Nature 579.7800 (2020): 549-554. 

 Vautrin, Quentin, et al. "From limb to fin: an Eocene protocetid forelimb from Senegal sheds new light on the early locomotor evolution of cetaceans." Palaeontology 63.1 (2020): 51-66. 

Direct download: Podcast_186_-_Fish_Fingers_and_Mammal_Fins.mp3
Category:general -- posted at: 3:00am EDT

That gang discusses two papers about fossil soft-bodied Cambrian organisms; one of which is a unique lobopod and the other is a fossil worm. Meanwhile, Amanda could go for some fish, Curt can’t stop the puns, James is going to be a cowboy.

 

Up-Goer Five (James Edition):

This week the group looks at two papers that are looking at two very old animals that have long bodies with no legs. One of these is a true animal with a long body and no legs, but the other is actually an animal that would usually have a short body and lots of legs but has grown a long body with very few legs and live in a long hard home that they make. This animal is actually part of the group that is the parents of animals with many legs and hard outer skin. This animal seems to have grabbed small bits of food with the legs that it has left and live inside the hard home it made, a very different way of living to the rest of its family. The other animal is a true animal with long body and no legs. It has been known for a long time but we did not know what the head looked like and now we do. As well as the head, the paper looks at the very small hard parts on its long body to show that it is not the animal that people thought it was, but a new animal! In total, things with long bodies and no legs are very good.  

 

References:

 Howard, Richard J., et al. "A Tube-Dwelling Early Cambrian Lobopodian." Current Biology (2020). 

 Whitaker, Anna F., et al. "Re-description of the Spence Shale palaeoscolecids in light of new morphological features with comments on palaeoscolecid taxonomy and taphonomy." PalZ (2020): 1-14. 

Direct download: Podcast_185_-_As_the_Worm_Turns.mp3
Category:general -- posted at: 3:00am EDT

The gang talks about two papers which look at the ecology of the Ediacaran. One paper uses trace fossils to infer how ecological systems change as we move from the Ediacaran to the Cambrian, and the second paper identifies some interesting features previously undocumented in Ediacaran fossils. Meanwhile, Curt has ideas about sponges, the internet destroys James’s comedic timing, and Amanda is happy to finally put those years of teaching physiology to good use.

 

Up-Goer Five (Curt Edition):

Our friends talk about the time just before we have a lot of dead things that can appear in rocks. The first paper looks at the tracks left behind by animals and other things as they change through time. In the time before when we have a lot of dead things in rocks, there are still tracks. As we study these tracks, it turns out that there are lots of changes in these tracks that we didn't know about. It turns out that tracks show life was doing lots of things that we didn't see because the dead things themselves didn't get into rocks. This means the big changes we see as soon as dead things appear in the rocks might have been happening earlier.

The next paper looks at a group of weird things that were around a lot before we had a lot of dead things in the rocks. These weird things are like sticks with bits on either side. There used to be lots of these stick things, and it turns out that these stick things had small lines that goes to each of these sticks. These lines are very small, which is why it was so hard to find them. The paper thinks that these lines might mean that all of these sticks are a repeat of the same stick over and over again. This is something that some things that make their own food from the sun do today, meaning that making more of themselves by repeating over and over again might be something that first happened a long time ago.

 

References:

 Liu, Alexander G., and Frances S. Dunn. "Filamentous Connections between Ediacaran Fronds." Current Biology (2020). 

Laing, Brittany A., et al. "A protracted Ediacaran–Cambrian transition: an ichnologic ecospace analysis of the Fortunian in Newfoundland, Canada." Geological Magazine 156.9 (2019): 1623-1630.

Direct download: Podcast_184_-_Lockdown_Baby.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers that look at the human impact on the fossil record. The first paper runs multiple model studies to try and determine when hominines (the group that includes all of our ancestors) first began significantly impacting the biosphere. The second paper estimates what our future fossil record may look like by using the state of Michigan as a model system (much to Amanda’s delight). Meanwhile, Amanda attempts to train a cat, Curt and James invent the best machine, James has his mind blown, and everyone wonders what the “prepper layer” of the Anthropocene will look like in a few million years.

 

Up-Goer Five (Curt Edition):

Our friends talk about how people have changed the world. First, they talk about how big brains might have led to lost of animals dying. This first paper looks at how brains got larger in the great great great great parents of people over time. They run a lot of numbers in a computer in order to find out if the real big animals that died went away because of people or because of changes in the places where these animals live. They look at how big the brains of these people were, as well as how much rain fell and if there were trees. What they find is that, after running all the numbers, is that the best answer out of all the things they looked at was that these animals started to die when the brains of people got bigger. They think this could mean that the people with bigger brains started to take food from some of these big animals, and that made it harder for these big animals to stay living.

The second paper looks at what we will leave behind after people are gone in the rocks. It uses a state that looks like a hand (and which one of our friends really really likes) as a way to look into this. Turns out, people cover things in ground a lot more than would usually happen without people. But people only cover in ground a small number of animals, like people, dogs, cats, and animals that we use on places where we make food. This means that the rocks after we are gone will look very different from the rocks before us. These rocks will be filled with just a few things, and most of those things will probably be in the same position. Also, a lot of the animals will all be men and all will have died for the same reasons.

 

References:

Faurby, Søren, et al. "Brain expansion in early hominins predicts carnivore extinctions in East Africa." Ecology Letters.

Plotnick, Roy E., and Karen A. Koy. "The Anthropocene Fossil Record of Terrestrial Mammals." Anthropocene (2019): 100233.

Direct download: Podcast_183_-_Nobody_Wins_The_Human_Impact_on_Our_Future_Fossil_Record.mp3
Category:general -- posted at: 3:00am EDT

The gang celebrates their 7th anniversary by inflicting pain on themselves for your amusement by discussing a classic paper, Gould's "Paradox of the First Tier". They discuss the paper in its historical context, and also how our knowledge of mass extinctions has changed and evolved from this paper. Meanwhile, James comes up with unconventional ways to communicate, Amanda may need some more whiskey to get through this, and Curt is all smiles.

 

Up-Goer Five (Curt Edition):

Our friends have fun on the day that comes around every year which is when they first started doing this thing. They talk about a paper that is old but looking to the time ahead. This paper is interested in how things die, especially when a lot of things die. There are bad times in the past when lots of things have died all at once. This paper points out that these bad times might be really important. These bad times when lots of things die all at once might act to change the direction of how life is changing through time. Life might be changing in one way and doing just fine, but when one of these bad times happens the things that were doing well might do bad but the things that were doing bad might do really well. Our friends talk about how the ideas brought up in this old paper have changed over time.

 

References:

Gould, Stephen Jay. "The paradox of the first tier: an agenda for paleobiology." Paleobiology 11.1 (1985): 2-12.

Direct download: Podcast_182_-_The_Pain_Happy_Birthday.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers about unique fossil preservation. One paper looks at how fossil root systems can inform our understanding of early Devonian forests, and the other paper shows how slime molds can be preserved in the fossil record. Meanwhile, Amanda is excited for questionable reasons, James prepares for the pain, and Curt learns his role in the friendship.

 

Up-Goer Five (Amanda Edition):

Today our friends talk about weird cool things that have only one piece but can get very big, and the tall green things with many pieces above and under ground, that is trees. Because trees is a word we can use. We focus on the pieces under ground. The weird cool things that have only one piece are found in old tree blood. The part of the weird cool things that have only one piece look kind of like things that are good to eat but might also kill you that grow on the ground. They are where the weird cool things that have only one piece make more of themselves. They are very very old but look just like pieces around today. The paper says maybe this is a sign that things stay the same for a very long time because the world around things makes it so, but it is important to remember that sometimes two things that are not close brothers and sisters can look very very much like close brothers and sisters. The tree paper finds very very old tree parts under ground and says that groups of trees a very very long time ago were even more like groups of trees today than maybe we thought. This would make the ground safer for things to live on.   

 

References:

 Stein, William E., et al. "Mid-Devonian Archaeopteris Roots Signal Revolutionary Change in Earliest Fossil Forests." Current Biology (2019). 

 Rikkinen, Jouko, David A. Grimaldi, and Alexander R. Schmidt. "Morphological stasis in the first myxomycete from the Mesozoic, and the likely role of cryptobiosis." Scientific Reports 9.1 (2019): 1-8. 

Direct download: Podcast_181_-_Before_the_Pain_The_Root_of_the_Problem.mp3
Category:general -- posted at: 3:00am EDT

The gang returns back from their winter break to discuss two papers that look at the important information we can glean from soft-bodied organisms in the fossil record. First, we take a look at a paper that shows some incredible preservation of Cretaceous snails in amber and how we can use that exceptionally preserved material to infer important information about the evolutionary history of these groups. Second, we talk about a cool example where hypotheses pulled from trace fossils can inform the distribution of modern worm species. Meanwhile, Amanda was not content with being driven mad by just TWO cats, James somehow manages to complain about being good at things, Curt spills the secrets on his friends, the internet TOTALLY doesn’t mess up our recording, SpaceX should probably paint their satellites, and we completely stay on topic this entire time….. believe me…..

 

Up-Goer Five (Curt Edition)

The friends talk about two papers about things that have soft bodies. First, the friends talk about a paper where a soft animal who makes a hard home out of rock that it carries around with it was stuck in some stuff that comes off of trees. This stuff that comes off of trees made it so that things we usually do not see got saved in the rocks. This allows us to see all of these different soft things that don't show up in rocks. People used these bits of tree stuff with soft things in them to find out that some of the soft things we see today in these animals that make a home for themselves out of rock may have first showed up very very long ago. They use this to try to find out when these groups of animals may have first showed up.

Next, our friends look at the changes in broken up bits of rock that form from soft and long animals live in the ground. As these animals move through the ground, they leave behind remains of where they were that can be seen in the broken up bits of rock they live in. These remains are usually very much the same when they are made by soft and long animals which live in very much the same way. One type of remain is usually found in places that are cold, but some people think they have found some of these remains in places that are usually pretty hot. This might be because there are ways that water moves which can cause areas that are usually very hot to have very cold water in them. That might make it just right for these soft and long animals which form these remains to live and be happy. To figure out if this is true, people went to a very warm place where in one side of the land the water was very cold and on the other side it was very warm. What they found was that the cold side had these remains, but the warm side did not. This means that these animals can live in warm places if the changes in the water allow for places with cold water.

 

References:

Hirano, Takahiro, et al. "Cretaceous amber fossils highlight the evolutionary history and morphological conservatism of land snails." Scientific reports 9.1 (2019): 1-16. 

 Quiroz, Luis I., et al. "the search for an elusive worm in the tropics, the past as a key to the present, and reverse uniformitarianism." Scientific Reports 9.1 (2019): 1-8. 

Direct download: Podcast_180_-_Worms_and_Snails.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers on insect behavior, one fossil study and one modern study. The fossil study illustrates a cool example of how amber can help us to understand the evolution of pollination throughout Earth history. The modern paper investigates how bury beetles care for and communicate with their young. Meanwhile, James’s computer lives in the past, Amanda has to deal with cat-nap related choices, Curt has his honor besmirched, and everyone is a little overwhelmed by how little people care about invertebrates.

 

Up-Goer Five (Amanda Edition):

 Today our friends talk about small things with six legs. Some of these small things with six legs go to green things with pretty colored bits and take their tiny baby parts, and take them to other green things with pretty colored bits. It might be that a long time ago, when green things with pretty colored bits were new, that small things with six legs and sort of hard parts over their flying parts were the ones that took the tiny baby parts of green things with pretty colored bits to other green things with pretty colored bits. The paper shows a small thing with six legs and sort of hard parts over their flying parts carrying tiny baby parts of green things on its body. That means that these small things with six legs and sort of hard parts over their flying parts helped these green things with pretty colored bits make more green things with pretty colored bits, but also that they ate the tiny baby parts. The other paper has different small things with six legs, and their babies. Their babies will ask the old small things with six legs for food. If they do not, they die. But if they ask too much, they also die, This paper takes away the old small things with six legs and shows babies will do nothing but ask for food and die.  

 

References:

Bao, Tong, et al. "Pollination of Cretaceous flowers." Proceedings of the National Academy of Sciences 116.49 (2019): 24707-24711. 

 Takata, Mamoru, et al. "A Parental Volatile Pheromone Triggers Offspring Begging in a Burying Beetle." iScience 19 (2019): 1260-1278. 

Direct download: Podcast_179_-_Pollinators_and_Begging_Grubs_Studies_of_Insect_Behavior.mp3
Category:general -- posted at: 3:00am EDT