Sun, 30 August 2020
The gang discusses two papers that use the trace fossil record to give us a more detailed understanding of the impacts of mass extinctions. Meanwhile, Curt has a new CSI, Amanda has too many synapsids, and James “understands comedy”.
Up-Goer Five (Curt Edition):
Our friends talk about the marks that feet make on the ground and how these marks can tell us about things that died when really bad things happened. They look at two times in the past that a lot of stuff died all of a sudden. The first paper looks at when some big angry animals that are aunts and uncles to things with hair lived. This is from a place where there is a lot of dead things and also foot marks. The paper shows that the death of these big angry animals can be seen if you look for the dead parts or if you look at the feet marks.
The second paper looks at a time when a huge rock hit the ground and nearly killed everything. This paper looks at how foot marks and other marks in the ground changed before and after the rock hit at the place where the rock hit. What they find is that, the rock hitting caused there to not be a lot of marks because things were probably dead. But after a pretty short time, there were a lot or marks again and those marks were not just at the top but also showed that animals were moving up and down as well in the ground.
Marchetti, Lorenzo, et al. "Permian-Triassic vertebrate footprints from South Africa: Ichnotaxonomy, producers and biostratigraphy through two major faunal crises." Gondwana Research 72 (2019): 139-168.
Rodríguez-Tovar, Francisco J., et al. "Rapid macrobenthic diversification and stabilization after the end-Cretaceous mass extinction event." Geology (2020).
Sun, 16 August 2020
The gang discusses two papers about the ecological data that we can learn from looking at trace fossils. The first paper looks at a unique ancient crocodilian behavior, and the second paper shows similar shore bird behaviors over the course of tens of millions of years. Meanwhile, James is full of bones, Amanda is honored, and Curt loves Hanna Barbera.
Up-Goer Five (Amanda Edition):
Today our friends talk about foot marks. They talk about the foot marks of two-legged animals with no hair and no teeth that can usually fly, and also the foot marks of two-legged animals that are usually four-legged, with big teeth and long faces and hard skin. The foot marks of two-legged animals with no hair or teeth that can fly are fun because they look at ones that have been known about for a very long time, but no one has ever done anything with them. They are not so old, and they look at them and some ones that are very very old, and find that they have the same sort of groups of foot marks, even though one is very old and very far away from the other one, which is much less old. They also say that you can see the same sort of groups of foot marks today, too. The other foot marks are from animals that are usually four-legged, but this one is two-legged. That is not so weird, because they were two-legged a long, long time ago. But this one is two-legged after we thought they all were four-legged. That's weird because at the same time there were very large angry animals with big teeth and no hair, which people thought maybe made it so these other usually four-legged animals with big teeth and long faces and hard skin couldn't be two-legged anymore. Maybe that isn't really the case, because it doesn't look like these foot marks were made by something that is only going two-legged for a short time.
Lockley, Martin, et al. "Bird tracks from the Green River Formation (Eocene) of Utah: ichnotaxonomy, diversity, community structure and convergence." Historical Biology (2020): 1-18.
Kim, Kyung Soo, et al. "Trackway evidence for large bipedal crocodylomorphs from the Cretaceous of Korea." Scientific Reports 10.1 (2020): 1-13.
Sun, 2 August 2020
The gang discuss two papers that describe unique animal fossils which have been known but haven’t (until now) been formally described. The first is “Collins Monster”, a lobopod from the Cambrian, and the second is a fossil dolphin which is similar to an orca. Meanwhile, James rehabilitates some dolphins, Amanda saw a thing, and Curt witnesses true beauty.
Up-Goer Five (Amanda Version):
Today our friends talk about a strange animal with cute legs and big parts that go to a point, and a really big animal that used to have hair that looks like an animal with no legs but actually does have legs. Both of these things have been known about for a long time, but no one gave them a name. They were used to figure out the family tree of animals, but never had a name. These papers give them a name, which is a very important thing. The strange animal with cute legs and big parts that go to a point is very close to other strange animals with cute legs that we have talked about before. The paper does put them in a different box than we are used to seeing, which we talk about a little and find maybe a little strange. The big animal that used to have hair and looks like an animal that has no legs but it actually has legs looks like it is close to one animal that had hair and looks like it has no legs, which shows that these things show up many times as time goes on. They also show some family trees, but only one is in the paper, the rest are in the other stuff on the space where people store all their stuff today.
Caron, Jean‐Bernard, and Cédric Aria. "The Collins’ monster, a spinous suspension‐feeding lobopodian from the Cambrian Burgess Shale of British Columbia." Palaeontology (2020).
Boessenecker, Robert W., et al. "Convergent Evolution of Swimming Adaptations in Modern Whales Revealed by a Large Macrophagous Dolphin from the Oligocene of South Carolina." Current Biology (2020).