Palaeo After Dark (general)

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 EDT

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 EDT

<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 EDT

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 EDT

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 EDT

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 EDT

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 EDT

The gang looks over two older review papers that are interested in communities and trophic disruption. What is important in keeping communities together and how can stable systems become destabilized? They use these two review papers as a general jumping off point to talk about the difference between a species that is just non-native vs invasive, trophic collapse or cascades, and the importance of systems interactions in keeping communities at a stable equilibrium. Meanwhile, Amanda is always meeting new people, James wants a reboot, and Curt messes up the simplest part of his job.

 

Up-Goer Five (Curt Edition):

Our friends talk about the groups that form when many different animals and the green things they eat all live in the same place and share matter. These groups are always changing over time, but they can  reach an even state for a short time. First, the friends talk about what happens when a new animal or green thing moves into the group. Most of the time, this is not a problem. However, sometimes one new type of animal or green thing can cause a lot of problems for the group. Usually, we see this happening when the group has gotten sick because people keep breaking the place where the group lives. We usually tell if a group is sick by the number of different animals and green things in it. The more different things in a group, the better off it usually is. However, sometimes a group that is not sick can still have one of these new types of animals or green things move in and cause problems. This is because the new thing moving in is helped by one of the animals or green things already living in the group. This means that people need to think bigger about which groups might end up having problems with new types of things, because groups that aren't sick may still have problems. People need to be better about not moving around animals and green things that don't usually live there.

Second, the friends talk about the ways in which these groups can become even over time. It turns out that just a few animals in these groups usually keep the entire group even. If these animals are taken away or hurt, then the whole group suddenly changes to a very different group with far less different animals and green things in it. In other words, if just these very important animals are hurt, the whole group can get very sick. Usually, the animals that are most important at keeping the group even are the ones that eat the most. These animals are also the things that people kill because of food or clothes or fear. People need to not kill these things or everything will break down.

 

References:

Estes, James A., et al. "Trophic downgrading of planet Earth." science 333.6040 (2011): 301-306. 

 Bulleri, Fabio, John F. Bruno, and Lisandro Benedetti-Cecchi. "Beyond competition: incorporating positive interactions between species to predict ecosystem invasibility." PLoS biology 6.6 (2008): e162. 

Direct download: Podcast_152_-_Community_Reboot.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers that use new findings to upend some of our previous interpretations of fossil taxa. First, they talk about the new biogeochemical studies that suggest the odd disc-shaped Ediacaran organism, Dickinsonia, might be the first animal in our fossil record. Second, they talk about some new fossil interpretations that challenge our understanding about the evolution of sauropods (the big, long necked dinosaurs). Also, James discusses posture, Curt buries the dinosaur lede, and Amanda finds out she has things to say… later.

 

Up-Goer Five (Curt Edition):

The friends get together to talk about new things that have been found out about some very old things. First, they talk about this round thing that was around a very very very long time ago. This round thing was very funny looking, and a lot of people had different ideas about what this round thing could have been. But some people just did a study to try and found out what the round thing was made of. It turns out, the round thing is made up of matter with 4 bits in rings. These types of matter rings are only found today in all of the animals. So, they then said that this funny looking round thing was probably an animal.

The friends next talk about these very large animals that had very long necks and lived a long time ago. These long necked animals were thought to have gotten really big after they started walking on all four of their feet and their legs became like trees. However, this study found that there were earlier long necked animals that were almost just as big, but were able to spend some time on two feet and their legs were still very much like legs. This means that these long necked animals got big and got small again over time without needing to get really thick tree legs that would make them have to only walk on four feet.

 

References:

Bobrovskiy, Ilya, et al. "Ancient steroids establish the Ediacaran fossil Dickinsonia as one of the earliest animals." Science 361.6408 (2018): 1246-1249. 

 McPhee, Blair W., et al. "A giant dinosaur from the earliest Jurassic of South Africa and the transition to quadrupedality in early sauropodomorphs." Current Biology 28.19 (2018): 3143-3151. 

Direct download: Podcast_151_-_New_Discoveries_Dickinsonia_and_Sauropodomorphs.mp3
Category:general -- posted at: 3:00am EDT

The gang gets together to discuss two papers that are sort of… kind of… very loosely held together by… size? First, they discuss a paper looking at size biases in our current biodiversity crisis and comparing it to our past extinction events. Is the present the same as the past? Second, they discuss a paper that looks at the evolution of whales and asks whether there were long term evolutionary trade-offs associated with growing massive in size. Meanwhile, James slowly freezes to death, Amanda becomes “Memento”, and Curt basically messes everything up. So, a typical podcast I suppose. HAPPY SESQUICENTENNIAL!!!

 

Up-Goer Five (Curt Edition):

Our friends look at two papers that try to see how being a big animal can maybe make it better or worse. The first paper asks whether or not being big is a bad thing for animals that live in the big blue wet thing. To do this, they looked at how many big animals who lived in the big blue wet thing died in the past during really really bad times, and then saw if that number was the same of different to the number of animals who live in the big blue wet thing today. It turns out that all the past really really bad times had about the same number of big things dying. However, today there are so many big animals dying in our big blue wet thing. This is probably because people like to eat these animals, and so they eat all the big things for food. So maybe what is happening today is maybe not quite the same as the really really bad times in the past.

The second paper looks at some really big animals with warm blood that breath through a spot near the tops of their heads, and live in the big blue wet thing. These really big animals didn't always start out so big. A long long long time ago, the older mothers and fathers of these really big animals were not always so big. This paper shows how the mothers and fathers and sisters and brothers of these animals changed over time. It turns out that these animals started getting really big very late in time, and that it might have been because of some changes in the big blue wet thing where they live. Also, when some of these animals got really really big, the rest of their sisters and brothers died out. The paper says that maybe these things that get really really big might also now be very slow at making new types of these animals.

 

References:

 Payne, Jonathan L., et al. "Ecological selectivity of the emerging mass extinction in the oceans." Science 353.6305 (2016): 1284-1286. 

 Marx, Felix G., and R. Ewan Fordyce. "Baleen boom and bust: a synthesis of mysticete phylogeny, diversity and disparity." Royal Society Open Science 2.4 (2015): 140434. 

 

Direct download: Podcast_150_-_Podcasting_About_the_Big_Boys.mp3
Category:general -- posted at: 3:00am EDT