The gang talks about two papers that look at potential examples of parasitism in the fossil record. One paper finds possible parasites attaching to ancient ostracods, and another paper details potential parasitic isopods on electric ray fossils. Meanwhile, James practices his spidey sense, Curt is suspicious that things are going too well, and Amanda's internet has amazing timing.

Up-Goer Five (Amanda and James Edition):

Today our friends talk about animals that eat other animals without killing them. First our friends talk about a paper that talks about an animal that has big teeth but no hard inside parts even though it is in a group that has hard inside parts and lives in the water. This animal has a number of smaller animals that have sort of hard outer parts, that may have been living on its skin by sticking its head inside its skin and living there. It is very hard to tell if this thing had its head in the animal with big teeth and no inside hard parts when it lived, or if it was just maybe eating the animal after it was dead. It is very hard to tell if things ate other things while they were still living or if they were there after it died.

Our friends also talk little animals that have five arms that today live in animals without legs that breath water. The animals with five arms first became animals with five arms that ate other animals without killing before the animals without legs that breath water came to be, so we did not know what the animals with five arms used to eat. Now we know that they would eat animals with lots of legs and a hard head, and that they would eat the animals with lots of legs and a hard head from lots of places, not just inside like they eat the animals with no legs that breath water.

References:

Siveter, David J., et al. "A 425-million-year-old Silurian pentastomid parasitic on ostracods." Current Biology 25.12 (2015): 1632-1637.

Robin, Ninon, et al. "Eocene isopods on electric rays: tracking ancient biological interactions from a complex fossil record." Palaeontology 62.2 (2019): 287-303.