The gang discusses two papers that investigate evidence of symbiosis in the fossil record. The first paper looks at wormy organisms living inside Cambrian vetulicolians, and the second paper shows potential evidence of hydroids growing in mollusc shells. Meanwhile, Amanda is haunted, James’s computer is totally cooperating, and Curt may or may not have had to stitch this podcast together from other sources.

Up-Goer Five (Curt Edition):

The friends look at two papers that look at animals that live inside of other animals. Sometimes these things live inside other things and both of the things do well because of it. Sometimes, these things live inside other things and they cause problems for the thing they live in. These two papers look at the ways we can see old bits of things that used to live in other things and how we can try and figure out why they might have lived inside other things. The first paper looks long animals living inside a weird animal from a long long time ago. These long animals are all in a small part of these animals that looks like where these weird animals would breathe. Many long animals live inside one of these weird animals. The second paper looks at how hard parts of animals grow over things trying to live on them and we can use use the way these things grow to get an idea of what could have been living on them.

References:

Li, Yujing, et al. "Symbiotic fouling of Vetulicola, an early Cambrian nektonic animal." Communications Biology 3.1 (2020): 517.

Wisshak, Max, et al. "Putative hydroid  symbionts recorded by bioclaustrations in fossil molluscan shells: a  revision and reinterpretation of the cecidogenus Rodocanalis." Papers in Palaeontology 9.2 (2023): e1484.

The gang discusses two papers that look at Mesozoic tracks that may or may not have been made by an avian archosaur. Meanwhile, Curt becomes activated, Amanda has to deal with harsh truths, James gets creative with taxon names, and everyone get distracted very quickly. (Editor’s Note: If you want to just “get to the science” skip to 11 minutes in. We hadn’t talked in 2 months and it shows. I just didn’t have the heart to cut all of it)

Up-Goer Five (Curt Edition):

The friends look at two papers that look at foot falls in the ground from a very very long time ago which may or may not be made by animals that can fly through the sky, or may have been made by big angry animals. The problem is that big angry animals and the animals that can fly are very close to each other, and their foot falls can look a lot like each other. The first paper looks at some very old foot falls and some of these foot falls do look like they were made by animals that can fly, but that would be very very strange because it would need a lot of other things to be true if that were true. They say that there was something moving like these animals today that can fly but were probably not those types of animals, but it shows how hard it can be to see if these foot falls were made by these animals that can fly.

The second paper uses numbers to try and see if we can really see if some of these foot falls were made by animals that fly. What they find is that we have used how big these foot falls are as a reason why we think some are from big angry animals and some are from animals that can fly. This is maybe a problem because we know there are small big angry animals, and that today there are some big animals that are from the group that can fly. If you use numbers to take how big they are out of the running, it seem like some of these foot falls could be from big animals part of the group that can fly.

References:

Abrahams, Miengah, and Emese M. Bordy. "The oldest fossil bird-like footprints from the upper Triassic of southern Africa." Plos one 18.11 (2023): e0293021.

Hong, Sung-Yoon, et al. "The discovery  of Wupus agilis in South Korea and a new quantitative analysis of  intermediate ichnospecies between non-avian theropods and birds." Cretaceous Research 155 (2024): 105785.