During a hunt in the upper Widder Fm (Devonian) in the Thedford area, I encountered these curious bits among the usual clatter of trilobites, brachs, and nautiloids.
I have some ideas, but would like to see if they are on - or off - the mark. I've largely ruled out worm burrows as they appear in these shales as generally very thin and pyritized. They look like some form of plant matter, which would be a first for me in these shales.
I've collected the positive and impression. It measures about 3 cm. They appear to have very fine, fibrous striations (although detail is wanting when using the iPad camera ).
Could be something very underwhelming, but thought I'd canvass opinions! Thanks for having a look.