#vertibrates

"It had all these features, and I said to myself, 'Is this really a brain that I'm looking at?'" says Friedman from University of Michigan.

"So, I zoomed in on that region of the skull to make a second, higher-resolution scan, and it was very clear that that's exactly what it had to be. And it was only because this was such an unambiguous example that we decided to take it further."

Usually, the only remaining traces of such ancient life are from more easily preserved hard parts of animals, like their bones, since soft tissues degrade quickly.

But in this case, a dense mineral, possibly pyrite, seeped in and replaced tissue that had likely been preserved for longer in a low-oxygen environment. This allowed scans to pick up what look like cranial nerve and soft tissue details of the small fish, Coccocephalus wildi.

The ancient specimen is the only one of its kind, so despite having been in the hands of researchers since it was first described in 1925, this feature remained hidden as scientists would not risk invasive methods of investigation.

But I'm one persistent son of a bitch

So

Scientists say a worm-like fossil with mysterious origins is actually the ancestor of living fish.The 300 million-year-old animal was found at an Illinois mine in 1958 by fossil collector Francis Tully.The "Tully monster" has been a puzzle to scientists ever since, and has been likened to worms and molluscs.US researchers say the fossil is a backboned animal rather than an invertebrate as once thought, based on an analysis of 1,000 museum specimens.Their findings, published in Nature, place it firmly on the tree of life of vertebrates and related to fish such as lamprey and hagfish.It has a rudimentary backbone, which has been misinterpreted in the past as a trace of gut, said Victoria McCoy of Yale University."The Tully Monster is very weird looking but we found it is related to modern lamprey," she told BBC News."It shows us how evolution can take something very familiar and make it very weird without changing what we know about the tree of life."

In this special edition of Wild Inaccuracies, Tammi offers up her scientific notes* and observations** about a series of extinct Cenozoic-era*** mammals that she just found out about.

*Stream-of-consciousness blather **Insubstantial opinions and thoughtless assumptions ***Probably Cenozoic, but it’s anyone’s guess really