The gang discusses two papers that look at some Cambrian problematic fossils and find new clues that allow us to determine what groups they might belong to. One paper finds new evidence that some of these tube fossils in the Cambrian may be cnidarians and the other paper identifies potential gastropod radula in Cambrian rocks with adaptations for grazing. Meanwhile, James is not at all tired, Amanda will totally clean out her garage, and Curt is in the loop about what is going on.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at some things from a long time ago that are very hard to see what is going on with them but these new finds give us a better idea of what they might be. The first paper looks at these long and soft things. We used to think they were long and soft things that live in the ground today. However, this paper finds that there are little arms on one side and that they have these parts that we see in a very different group of animals that instead has one way in that it uses to eat and shit and has lots of these small arms. They show this for one of these types of animals but it could be that a lot of the long soft animals we find that we are not sure about could all be parts of this group.

The second paper looks at these small bits that people find when they take rocks and break them down into bits. These small things look like the mouth parts of animals that are soft and some of them carry their home with them. Not just mouth parts, but mouth parts that can eat green things that make their own food. This could be the first time we see animals that just eat these kinds of green things in the past.

References:

Zhang, Guangxu, et al. "Exceptional  soft tissue preservation reveals a cnidarian affinity for a Cambrian  phosphatic tubicolous enigma." Proceedings of the Royal Society B 289.1986 (2022): 20221623.

Slater, Ben J. "Cambrian ‘sap-sucking’molluscan radulae among small carbonaceous fossils (SCFs)." Proceedings of the Royal Society B 290.1995 (2023): 20230257.

The gang discusses two papers that use morphometric studies to investigate patterns of ecomorphy in the fossil record. Specifically, they look at two papers that investigate how morphology in sloths and pterosaurs changes over time, and how well these changes map onto changes in body size and ecological shifts. Meanwhile, Amanda could be dean, Curt has opinions on figures, and James provides butchery advice.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at how things look and how that changes over time, and looks to see if these things are changing because of what they do. The first paper looks at animals with hair and long arms that move very slow. There are not a lot of these animals today, but in the past there was a lot of these animals and they did a lot of other things that we do not see them do today. These animals were also looking different as well. But it seems that the things that look different are closer to each other by being close sisters to each other. They also do find that these animals are also doing different things when they look different.

The second paper looks at angry animals who can fly but are not the animals that can fly today. These animals start small and get big over time. They actually get big a few times. This paper looks at the parts of these animals and shows the many different ways that parts can change to make these animals big or small. It also shows that, when these things get really big is when the group seems to be doing really bad.

References:

Yu, Yilun, Chi Zhang, and Xing Xu. "Complex macroevolution of pterosaurs." Current Biology 33.4 (2023): 770-779.

Casali, Daniel M., et al.  "Morphological disparity and evolutionary rates of cranial and  postcranial characters in sloths (Mammalia, Pilosa, Folivora)." Palaeontology 66.1 (2023): e12639.