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.
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.
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.
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.
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.
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.
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.
Come and join us for an extra length episode where we discuss the talks we saw during the 2018 Geological Society of America Meeting at Indianapolis.
Day 2 starts at 0:35:09, Day 3 starts at 2:04:36, and Day 4 starts at 3:28:07.
The gang discusses two papers that use the pelvis and spine material from pterosaur fossils to infer locomotion of these extinct flying archosaurs, Specifically, we talk about how muscle attachment structures as well as channels within the bones can be used to infer the mobility of ancient animals. Also, Amanda tries to resist talking about food, James makes boner jokes, and Curt ends up writing odd crossover fan-fiction.
Up-Goer Five (James “Oh God I Need an Adult” Edition):
The group look at two papers that are studying the dead animals that can fly but do not have anything covering their bodies. The first paper looks at how the part of the flying animal with nothing on their bodies that holds the legs and also where animals have to touch to make babies (here after: the fuck box) is different in different animals. The paper shows that the fuck box looks different in baby animals to grown animals, and that we need to recognize babies so that we don't make bad ideas about how these animals changed through time. They also show that the fuck boxes in the earliest of these animals look a little more like the fuck boxes of babies, but that they are very definitely actually over 18. They also show that there are at least two different types of fuck boxes in these animals, and this means that these animals would have walked in different ways to each other.
The other paper looks at the fuck box and back of a small animal that could fly that is not covered in stuff and looks at the spaces in it to see how the bits that make the animal go looked like. The spaces for the bits that make the animal go show that it had big legs, and probably was good at walking, even though it was small and would not have needed to be good at walking. It has family that got very big though, and it seems that these big family friends would have been good at walking too.
Hyder, Elaine S., Mark P. Witton, and David M. Martill. "Evolution of the pterosaur pelvis." Acta Palaeontologica Polonica 59.1 (2014): 109-124.
Martin‐Silverstone, Elizabeth, Daniel Sykes, and Darren Naish. "Does postcranial palaeoneurology provide insight into pterosaur behaviour and lifestyle? New data from the azhdarchoid Vectidraco and the ornithocheirids Coloborhynchus and Anhanguera." Palaeontology(2018).
The gang returns to one of their favorite pet topics, food! This week, we discuss two papers that investigate what different animals are eating. Specifically, we focus on a paper that uses fossil data to infer the feeding strategies of extinct giant otters, and another paper that seeks to answer the question of whether or not modern bonnethead sharks are omnivorous. Also, Amanda finds her spirit anime character, James workshops new ideas for the podcast at the worst possible time, Curt leads us on a strange aside about bears and wolves, and we all work together to invent the perfect animal.
Up-Goer Five (Curt Edition)
Our friends talk about what animals eat. First they talk about long four legged animals with hair who have high voices. Some of these long four legged animals from a long time ago were really really big. When we study the hard parts of these really big, long four legged animals, we find that they can break open other really hard things in order to eat them. When we look at the hard parts of living long, four legged animals with high voices, we find that these old big long four legged animals were probably able to break things in different ways than the living animals just because they were so very very big. This shows that long four legged animals in the past could fill different jobs in the world than the living, much smaller four legged animals.
Second, the friends look at animals that spend all their time in the water and have lots of inside parts that do not break. These water animals are often thought to eat other animals only. However, these water animals have been shown to eat green things that make food from the sun. People did not know if these water animals meant to eat the green things that make food from the sun, or if they did not mean to. Some people took some of these water animals and had these water animals eat a lot of green things that make food from the sun. The water animals got bigger, and seemed to do well when they were made to eat only these green things. The people decided that this meant the water animals meant to eat the green things and that meant that not all water animals with inside parts that do not break eat only other animals.
Tseng, Z. Jack, et al. "Feeding capability in the extinct giant Siamogale melilutra and comparative mandibular biomechanics of living Lutrinae." Scientific Reports 7.1 (2017): 15225.
Leigh, Samantha C., Yannis P. Papastamatiou, and Donovan P. German. "Seagrass digestion by a notorious ‘carnivore’." Proc. R. Soc. B 285.1886 (2018): 20181583.
The gang discusses two papers that look at our amazing fossil insect record. One of these studies looks at preserved fly pupae and shows some unexpected evidence of parasitism. The other study tries to understand the properties of tree sap that allows amber to preserve such amazingly detailed fossil insects. Meanwhile, Amanda has a weather catastrophe, Curt can do better, and James is a dream warrior.
Up-Goer Five (Amanda Edition):
Today our friends talk about very small things with six legs that are often hard to find after they die. These very small things with six legs might get stuck in tree stuff and die. That is where we will usually find them. The first paper finds very small things with six legs inside the changing space of other even smaller very small things with six legs. These very small things with six legs would break into the changing space of the other even smaller very small things with six legs and eat them. We don't know if they ate them slowly or fast, but they ate them while they were not dead. This is not usual to find after things die so it is very good to find. The other paper talks about how very small things things with six legs get stuck in tree stuff and die. The idea is that if they dry out first maybe they are more probably not going away after getting stuck in tree stuff and dying. This paper says no, drying out will make these very small things with six legs go away more after they get stuck in tree stuff and die. They also look at the very very very small things inside the very small things with six legs and say that these very very very small things help make the very small things with six legs go away. If we make the very very very small things go away with doctor stuff then the very small things with six legs are going to stay when they get stuck in tree stuff and die.
van de Kamp, Thomas, et al. "Parasitoid biology preserved in mineralized fossils." Nature communications 9.1 (2018): 3325.
McCoy, Victoria E., et al. "Unlocking preservation bias in the amber insect fossil record through experimental decay." PloS one 13.4 (2018): e0195482.
The gang discusses two papers that deal with the origins of biomineralization (how living things make hard minerals to serve as skeletal structures). Specifically, we look at one paper focused on the origins of bone and a second paper focusing on some of the first instances of biomineralization in the fossil record. Also, Curt keeps a promise, James knows how to make a good impression on the neighborhood, and Amanda gets blamed for the actions of her cats.
Up-Goer Five (Amanda Edition):
Today our friends talk about things that have hard parts before there were supposed to be hard parts and how important hard parts that are inside of animals first was made. Very early animals that have hard parts before there were supposed to be hard parts are the same as things that do not hard parts. This paper says that it is because the place that they lived had too much of stuff that makes parts hard. These animals took the stuff out of water not because they wanted to, then they had to make it go away or they would die. So they made parts of their body hard. Later on making parts of the body hard was really important and they started doing it more and more even if there wasn't too much stuff in the water that makes parts hard. The second paper talks about how a weird type of hard part that is one of the important hard parts inside animals came to be. Some people think it is a new type of hard part inside of animals, but others say it is not. It turns out it is actually not really new like we thought but is actually a type of important hard part inside animals that is still around today. It is just a type that is not around today anymore.
Wood, Rachel, Andrey Yu Ivantsov, and Andrey Yu Zhuravlev. "First macrobiota biomineralization was environmentally triggered." Proc. R. Soc. B 284.1851 (2017): 20170059.
Keating, Joseph N., et al. "The nature of aspidin and the evolutionary origin of bone." Nature ecology & evolution(2018): 1.
The gang discusses two papers that investigate the ways that tetrapods return to the sea. It's another opportunity for Amanda talk at length about her favorite topic, CONVERGENCE. Meanwhile, James has ideas about "moral fortitude", Curt makes slightly off references to 80s films, Amanda exercises her desire to be deadly, and Mr. Jowls has some opinions that need to be heard.
Up-Goer Five (Amanda Edition):
Today our friends talk about animals with four feet that go back to the water. This is just a reason for our friends to talk about why some animals that are not very close like brothers look very much the same. The first paper says that since the start of the time of large animals with no hair and big teeth, there are more animals with four feet that go back to the water. Many of the animals with four feet that go back to the water look so very the same it is sometimes hard to tell that they are different if you do not look close. They talk about things that make these animals with four feet that go back to the water better for being in water, and how whole big groups of animals do not all change the same, but small groups change faster or more than others. They also talk about how and why these animals are changing. The second paper is about an animal with four feet and a long neck that goes back to the water. It has funny teeth and did not eat very small things like the largest animals living today that have no teeth, even though some things about this animal with four feet and a long neck that goes back to the water that might make you think that they ate very small things. It also has very heavy inside hard parts like big heavy water animals that get hit by people in wood things that go fast. This makes it heavy in water so it does not stay on top of the water but goes down to the bottom. This is how it ate food maybe.
de Miguel Chaves, Carlos, Francisco Ortega, and Adán Pérez-García. "New highly pachyostotic nothosauroid interpreted as a filter-feeding Triassic marine reptile." Biology Letters 14.8 (2018): 20180130.
Kelley, Neil P., and Nicholas D. Pyenson. "Evolutionary innovation and ecology in marine tetrapods from the Triassic to the Anthropocene." Science 348.6232 (2015): aaa3716.