The gang discusses two papers that look at the morphology and ecology of early fishes. The first paper investigates a hypothesis for how the pectoral girdle could have evolved, and the second paper looks at the functional morphology of a Paleozoic jawless fish. Meanwhile, Amanda missed some context, James throws some shade, and Curt is annoyed by AI.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at animals from a long time ago that live in water. The first paper looks at how part of the shoulder in people may have first started as a part of another part of the animal in these animals that lived in water a long long time ago. They find these parts of this animals from a long long time ago that they can use to see how the parts around the head grew. They use this to say that the shoulder parts may have started as a part of the thing these animals use to breath.

The second paper looks at the mouth of a type of animal that lived in water a long long time ago that did not have a hard part in the mouth to move up and down and eat food. They use an animal they found with a lot of parts to see how these animals may have lived and what they could have eaten. They find that this animal could have been picking up food from ground at the bottom of the water or they could have been of taking food out of the water. This shows that even animals without a hard part to move up and down to eat food were finding ways to eat a lot of different things.

References:

Brazeau, Martin D., et al. "Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle." Nature 623.7987 (2023): 550-554.

Dearden, Richard P., et al. "The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes." Proceedings of the Royal Society B 291.2019 (2024): 20232258.