Palaeo After Dark

The gang discusses two papers that look at live birth in squamates. The first paper is fossil evidence of live birth in an ancient snake species, and the second paper looks at the evolutionary pressures that might drive some lizards towards live birth. Meanwhile, James has advice for reptiles, Curt celebrates a belated "spooky season", Amanda continues to have extreme face blindness, and we are all haunted by a corrupted PDF.

Up-Goer Five (Curt Edition):

Our friends talk about animals that have cold blood but also have babies inside of them. The first paper looks at some old animals that have cold blood and no legs that have babies inside of them. These parts of the old animal with babies inside of them might be one of the first times that this has been seen for this group at this time. It raises some interesting questions about how and why these animals that most do not have babies inside of them might change to having babies inside of them. One thought was that maybe this happens when these animals with cold blood have to live in cold places, but this paper is not able to say if that is the case.

The next paper looks at a different group of cold blooded animals that is close to the other one but has legs. In this group, there are some animals that have babies inside and some that do not. The people who worked on the paper looked at all of the things about these animals, from how cold they liked it, how warm they liked it, where they are found, how many babies they had and how big they got, and other things to try and see if having babies inside is something that happens when these animals move into cold. What they found was very cool. Animals with babies inside did like it colder than animals without babies inside. But they found that having babies inside did not match with where these animals lived, and that animals with babies inside could be in warm places, and animals without babies inside could be in colder places. It might make it easier to be in colder places, but it did not look like it was because they were in colder places. This means that having babies inside is part of a bigger thing, like do you want to live fast or do you want to live slow; because animals with babies inside would have less babies than animals without babies inside.

References:

Chuliver, Mariana, Agustín Scanferla, and Krister T. Smith. "Live birth in a 47-million-year-old snake." The Science of Nature 109.6 (2022): 1-5.

Domínguez-Guerrero, Saúl F., et al. "Exceptional parallelisms characterize the evolutionary transition to live birth in phrynosomatid lizards." Nature communications 13.1 (2022): 1-12.

After meeting the denizens of this vast contraption and escaping the tight and claustrophobic engine our heroes have nowhere to go but up. Will they meet the master of this grand device and bring its movements to an end or fall foul to some unfortunate fate on the way? Join Bepo the Bard (James), Bix the Druid (Aly), Gregg the Ranger (Curtis) and Kinross the Wizard (Amanda) for the conclusion to their adventure.

"Skye Cuillin", "Moonlight Hall", "The Pyre", "The Snow Queen", "Mystic Force", "Final Battle of the Dark Wizards", "Ascending the Vale", "Soaring", "Eternal Terminal", by Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License http://creativecommons.org/licenses/by/4.0/

After managing a precarious ascent up a magical clockwork limb we rejoin our heroes Bepo the Bard (James), Bix the Druid (Aly), Gregg the Ranger (Curtis) and Kinross the Wizard (Amanda) in the next stage of their journey to bring the roaming fortress to a halt.

"Skye Cuillin", "Mystic Force", "Malicious", "Scheming Weasel slower", "Holiday Weasel", "Krampus Workshop", "Sneaky Snitch", "Magic Escape Room", "Volatile Reaction", "Darkling" by Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License http://creativecommons.org/licenses/by/4.0/

Dispatched to pursue a giant roaming monolith laying waste wherever it walks join our heroes Bepo the Bard (James), Bix the Druid (Aly), Gregg the Ranger (Curtis) and Kinroth the Wizard (Amanda) as they set out to bring a halt to this lumbering gargantuan structure's meandering path of destruction in a story orchestrated and told by our visiting Dungeon Master (Antony).

"Skye Cuillin", "Lord of the Land", "Mountain Emperor", "Black Vortex", "Evening of Chaos" by Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License http://creativecommons.org/licenses/by/4.0/

"Snake Eater" midi from vgmusic.com http://www.vgmusic.com/new-files/MGS3_Snake_Eater.mid

The gang goes back to their favorite hypothetical deathtrap amusement park, Penguin Deathland. They discuss two papers that look at the taphonomy of penguin fossil deposits and what they can tell us about ancient environments and the processes that can break down bone. Meanwhile, James loves old movie cliches, Amanda upsets the natural order, and Curt enjoys totally real colors.

Up-Goer Five (Amanda):

Today our friends talk about animals with no hair that usually can fly but these can't fly. These are found on an small place surrounded by water that is very cold. These animals lived during the ice age so they are only sort of rock at this time. The first paper looks at numbers of these animals and other stuff all together in one place. The paper shows that there were places where there were baby animals long ago where there aren't any now. It also shows that there were some tiny animals with no rock parts that suck blood that are not on these small places today. But it is possible that some of these tiny animals were brought in later by people.

The second paper looks at how things that are green things and sometimes good to eat not-animals that are living together are hurting the rock parts of these animals with no hair that can usually fly but can't. It turns out that the things that are green things living together with sometimes good to eat not-animals might be very good at hurting the rock parts of these animals, and we can actually see exactly what that looks like and so can tell if we see this in rock parts that would be much much older.

References:

Acosta Hospitaleche, Carolina, et al. "Taphonomy of two Holocene penguin taphocoenoses in Potter Peninsula, South Shetland Islands, Antarctica." Historical Biology (2022): 1-18.

García, Renato, Carolina Acosta Hospitaleche, and Gonzalo Márquez. "Biodeterioration of Antarctic fossil penguin bones caused by lichens from the Eocene La Meseta Formation." Polar Biology 44.12 (2021): 2243-2254.

The gang discusses two papers from a new locality of early fishes that give a lot of new insights into fish evolution. Meanwhile, Curt loves new Discord features, James shares some fun stories, and Amanda know how best/worst to keep everyone on track.

Up-Goer Five (Curt Edition):

Our friends look at two papers from a group of papers that just came out about a place where you can get really good parts from very very old things that live in the water and have hard parts on the inside and would be great great great great mom and dad to a lot of things that have hard parts inside and live on land. One paper looks at these animals that do not have a hard part in the place where they eat and looks at how they have really cool ways to move through water that gives us ideas about how these things that help move through water have changed over time. The other paper looks at a lot of different types of these animals that live in water and shows that they were doing a lot of different things very early on.

References:

Zhu, You-an, et al. "The oldest complete jawed vertebrates from the early Silurian of China." Nature 609.7929 (2022): 954-958.

Gai, Zhikun, et al. "Galeaspid anatomy and the origin of vertebrate paired appendages." Nature 609.7929 (2022): 959-963.

The gang discusses two papers that look at two papers that discuss the origin and evolution of a sessile filter feeding life habit. The first paper discusses how a new tommotiid fossil helps us better understand lophophorate evolution, and the second paper looks at the genetic pathways that barnacles and molluscs use to generate their shells. Meanwhile, James makes a sound, Amanda gets a surprise, and Curt shares totally real facts.

Up-Goer Five (Curt Edition):

Our friends look at how animals that make hard parts and do not do much moving around first started. The first looks at one type of animal that could be the start of one of these groups of animals that do not move much. These early animals are usually hard to find because they have parts that do not stick around for along time. However, this animal that was found had a lot of soft parts that showed what these animals would have looked like. It seems that these animals started out as being able to move a lot more, even though the animals that would come later would stop moving.

The second paper looks at two other groups of animals that make hard parts and do not move. It looks at how these animals make their hard parts. Even though these two groups are not close to each other, they both use a lot of the same ways of making their hard parts, with things that are not the same making sense because of how these animals need to stick to other things.

References:

Guo, Jin, et al. "A Cambrian tommotiid preserving soft tissues reveals the metameric ancestry of lophophorates." Current Biology (2022).

Yuan, Jianbo, et al. "Convergent evolution of barnacles and molluscs sheds lights in origin and diversification of calcareous shell and sessile lifestyle." Proceedings of the Royal Society B 289.1982 (2022): 20221535.

James, Curt, Carlie, and Brendan talk about the 2022 Geological Society of America Meeting in Denver.

The gang talks about two papers that look at evidence of parental care in the fossil record, in early synapsids and in insects. Meanwhile, Amanda is going to have an island, Curt is trying not to die, and James has some unique alternative interpretations to explain these fossils.

Up-Goer Five (Curt Edition):

Our friends talk about two papers that look at moms and dads from a long long time ago. Not all animals have moms and dads that stick around or do anything to keep the babies from not getting dead. The first paper looks at a group of animals that looks like some animals today and is part of a group that is close to the group that has hair. This paper looks at some hard parts from these animals that were in a thing made by pulling up the ground so you can live there under the ground. There is a big one and a small one. The big one looks like it was holding the small one when the place under the ground fell in and covered them. The other thing about this paper is that the small one looks like a lot of other animals we have found from this group, which could mean that most of our animals we have named from this group could be kids.

The second paper looks at a type of small animal with hard parts on the outside and many legs that lives in water and can go deep in the water but takes in air to live. This animal is old but looks a lot like the ones we still have around today. Some of these animals have a leg that looks different from the others, and this leg has a whole lot of small balls that hold babies in them on it. So some of these animals carry the babies with them until they are ready to leave the small balls. This is different from how the animals like these ones that we have today handle their babies.

References:

Fu, Yanzhe, et al. "The earliest known brood care in insects." Proceedings of the Royal Society B 289.1978 (2022): 20220447.

Maddin, Hillary C., Arjan Mann, and Brian Hebert. "Varanopid from the Carboniferous of Nova Scotia reveals evidence of parental care in amniotes." Nature Ecology & Evolution 4.1 (2020): 50-56.

The gang discusses two papers that look at the complicated path tetrapods took to getting on land. The first paper looks at a more derived stem tetrapod that went back into the water, and the second paper uses trace fossils to investigate the foodweb of a community dominated by some early tetrapods. Meanwhile, Amanda has a friend over, James knows how to be silent, and Curt teaches everyone that things continue to exist even when we don't see them.

Up-Goer Five (Curt Edition):

Our friends talk about two animals that are great great great great great great father and mother to all of the animals that are on the land. But these animals did not all make their way on to the land in a simple way. The first paper looks at an animal that looks like it went back into water. This animal has all of the parts that you need to live well in the water, even though it also has parts from animals that would be on the land, or at least spending some time on the land. This means that the way on to the land has a lot more steps forward and back than we like to think.

The second paper looks at the places these animals were living in and tries to use the parts that are around and how they were hurt to see what may have been eating what. People have thought that these animals went on to the land to get away from things that might have been eating them. This paper shows that those animals might have been the things that were eating other animals. It seems like being one of these animals that lives in the water was a pretty good way to live.

References:

Robin, Ninon, et al. "Vertebrate predation in the Late Devonian evidenced by bite traces and regurgitations: implications within an early tetrapod freshwater ecosystem." Papers in Palaeontology 8.4 (2022): e1460.

Stewart, Thomas A., et al. "A new elpistostegalian from the Late Devonian of the Canadian Arctic." Nature 608.7923 (2022): 563-568.