Best part (besides the fossils)? Horses and ranch hands pitching in to move the fossil-rich rock matrix!
Fieldwork was led by co-author Michael Newbrey (Columbus State University, pictured in the second image pointing to the matrix). Images credit: Michael Newbrey
www.science.org/doi/10.1126/...

Those shifts stacked up distinct layers: tough sandstone from the swift flows, and softer mudstone from calm water. Think of it like pages in a rock history book. Here’s the cool part: the best, fully connected fish fossils often appear exactly where a sandy layer meets a muddy one.

Here you go!

artwork by Ken Naganawa

Juan Liu et al. ,Marine origins and freshwater radiations of the otophysan fishes.Science390,65-69(2025).DOI:10.1126/science.adr4494

This tiny fossil helped rewrite the evolutionary timeline of 2/3 extant freshwater fish thanks to my collaborative US-Canada team @ucberkeleyofficial.bsky.social @ucmpberkeley.bsky.social @ualberta.bsky.social @michiganstateu.bsky.social @westernu.ca, Royal Tyrrell Museum, Columbus State University

Otophysans dispersed into fresh water at least twice. During the incursions, two parts of a Weberian ossicle fused into one, just like in modern otophysans. Computational models show this system was already functional back then, boosting hearing and paving the way for otophysans’ global success.

Until now, the story was: otophysans originated once, in freshwater, a long time ago — before Pangea even split apart.
But our study tells a different story. Our new data suggest otophysans actually originated ~150 million years ago — and in the ocean 🌊.
More data on @datadryad.bsky.social

Using synchrotron & microCT scans at the FAVE lab @tsengzj.bsky.social, @mcgilluniversity.bsky.social, and @CanadianLightSource, we saw something extraordinary: a set of tiny bones called the Weberian ossicles, part of the modified vertebral column to enhance hearing capbility.

The name:
🔹 Acro- = sharp, for its sharp hearing ability
🔹 ichthys = fish
🔹 maccagnoi honors volunteer John Maccagno, who spent countless hours sorting fossils at Royal Tyrrell Museum where the fossil specimens are housed.

what an extraordinary way to remember Mark!

@ucmpberkeley.bsky.social @IB @ucberkeleyofficial.bsky.social @MVZ, @anatrecord.bsky.social
doi.org/10.1002/ar.2...