A lichen-eroded pachycormid fossil from Antarctica

[Halichoeres]

This fossil is very incomplete, but based on its distinctive gill rakers, it's identifiably a pachycormid (like the much larger Leedsichthys). It was probably a toothless suspension (filter) feeder, and would have used these gill rakers to trap pieces of food. It's most similar to the pachycormid Asthenocormus but is probably not the same species. The specimen is also interesting because lichen had grown on it after fossilization, and had absorbed some of the minerals, leaving the bones pitted and eroded.

Here are the gill rakers:


(Acii are needle-shaped toothlike structures on the gill rakers)

Paper is paywalled but I may have a pdf for the curious: https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1524384