The gang takes some time to discuss two papers about agnostids, a strange group of trilobite-like arthropods whose evolutionary history has been the subject of considerable debate. First, we discuss a short paper summarizing the history of the agnostid debate, and then we discuss a brand new paper using new material and Bayesian phylogenetics to offer a fresh new hypothesis. Also, James channels frustration into fun, Amanda nearly has her house destroyed by cats, and Curt asks the Star Wars questions no one wanted answered.

Up-Goer Five (Amanda Edition):

Today our friends talk about small animals that have no eyes that might be sisters of animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. The first paper talks about the small animals with no eyes and how hard it is to make one of these animals for people to look at. They talk about the past of the animal and where it lived, and who it might be close sisters to. They say that a very cool area where we find these animals lets us see the legs and that they are different, also that they have a different mouth, and that maybe they actually do have eyes but they are on the mouth? They are weird animals. The second paper also talks about these animals, but does not focus on making the animals for people to look at. It looks at these animals from a different very cool area and shows their legs are sort of like the legs of animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. The paper is different from others, though, because it says that these animals are really either part of or sister to animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball. But that is the only part of the tree that really is strong, so maybe who knows still? Our cat friend is writing this and did not really know what was going on that day, and does not know much about these cool animals with maybe no eyes that might really be animals that live in the water that have three parts and big eyes, many legs, and can make themselves into a ball.

References:

Eriksson, Mats E., and Esben Horn. "Agnostus pisiformis—a half a billion-year old pea-shaped enigma." Earth-Science Reviews 173 (2017): 65-76.

Moysiuk, J., and J-B. Caron. "Burgess Shale fossils shed light on the agnostid problem." Proceedings of the Royal Society B286.1894 (2019): 20182314.