The gang discusses two papers about trilobite evolution and morphology. The first paper looks at disparity and taxonomic trends of trilobites across the Devonian, and the second paper looks at the unique tridents of Walliserops. Meanwhile, Amanda makes a choice, James does some unique functional morphology, and Curt critiques tilapia.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at small hard animals that live in the water and some of them can roll into a ball. The first paper looks at how these animals looked over time. They look at whether or not these animals looked more different when there were more different types of these animals around. This is not usually the case, for lot of animals how different the animals in the group look to each other is not just because to there being more types of animals. For this group that some can roll into a ball, it seems like they look a lot more different when there are also a lot of different types of them. So when something kills a lot of them, they also lose what makes them different. After a really bad time for these animals, only one group was left and we saw that they kind of looked the same for a long time until they all died.

The second paper looks at one of these types of animals that had a weird thing on its nose. They try and find out what it could have used this weird thing for because it is very big and it does not move on its own so it probably would not be good for a lot of things. They look at some other animals that have things on their nose they use to fight each other for space and girls. While these animals are very different, they show some ways that this thing on the nose look like these other animals. So maybe they used this thing on their nose to fight each other.

References:

Gishlick, Alan D., and Richard A. Fortey. "Trilobite tridents demonstrate sexual combat at 400 Mya." Proceedings of the National Academy of Sciences 120.4 (2023): e2119970120.

Bault, Valentin, Catherine Crônier, and Claude Monnet. "Coupling of taxonomic diversity and morphological disparity in Devonian trilobites?." Historical Biology (2023): 1-12.