Podcast 303 - When Is It The Crown

The gang discusses two papers that look into the timing of evolution of the “crown group”. The first paper looks at fossil glass sponges, and the second paper looks at the phylogeny of lampreys. Meanwhile, James gives some sound advice, Amanda has ambitious hobby plans, and Curt imagines the perfect media crossover.

Up-Goer Five: (Curt Edition)

The friends talk about two papers that look at groups of animals and try to see when the things that we see today in these groups may have first happened in the past and what we can tell us about why those things might have happened. The first paper looks at a group of animals that are made up of many single parts that can all act on their own and these animals get food out of water in a very simple way. This paper finds some very old animals that look a lot like some groups of these animals we see today. This would mean that this group may have been around a lot longer ago than we think.

The second paper looks at a group of animals that are long without much going on and a round mouth and live in the water. This group has animals that live in different places that have made people ask why. This paper looks at how all of these animals changed over time and uses that to see when the animals that we see today may have first been around. They find that these animals may have first appeared during a time that was really hot, and that might be why the animals are where they are today.

References:

Botting, Joseph P., et al. "Advanced crown‐group Rossellidae (Porifera: Hexactinellida) resembling extant taxa from the Hirnantian (Late Ordovician) Anji Biota." Papers in Palaeontology 11.1 (2025): e70000.

Hughes, Lily C., et al. "Phylogenomic resolution of lampreys reveals the recent evolution of an ancient vertebrate lineage." Proceedings B 292.2038 (2025): 20242101.