Supplementary data for: Another worm bites the dust

Based on a dataset of most mid-Paleozoic scolecodonts photographed in the literature, the Carnegie Museum of Natural History, and newly presented data from the Appalachian Basin, we find that scolecodonts (polychaete jaw elements) decrease in size across the Late Devonian boundary, then increase again to baseline in the Carboniferous. The majority of the data representing small scolecodonts during the extinction event are newly presented data in this study. These individuals were sampled from black shales in a small geographic range at high stratigraphic resolution. Even when excluding these new data, scolecodonts after the Frasnian-Famennian boundary are smaller than scolecodonts before the boundary. Lithology or water depth has a relationship with scolecodont size, but those factors alone cannot explain the size reduction observed across the extinction (i.e., we also find big scolecodonts in black shales). This represents a novel, previously-unreported pattern in scolecodont size occu..., To increase our sample size of Appalachian Basin Lower Paleozoic scolecodonts, we also measured the scolecodonts from the extensive collections in the Carnegie Museum of Natural History (CMNH). These scolecodonts were collected, prepared, and described by former curator of the Museum E.R. Eller in the mid-1900s, and have also been described by M. Eriksson and C. Bergman. Some of these were photomicrographed under 40x magnification at Williams College, while most were photographed at the Museum using a ProScope EDU 300 Portable Standalone Digital Microscope. 

Literature review
We conducted an extensive literature review to collect data on as many published images of Devonian and Carboniferous age scolecodonts as possible, as well as a large sampling of Silurian scolecodonts. This search was conducted primarily using Google Scholar. We excluded from the dataset some images that were unusable because the scolecodonts were obscured or images were too low-quality; stratigraphic resolut..., , # Supplementary data for: Another worm bites the dust

Chilcoat, G., Cohen, P. Another worm bites the dust: The Lilliput Effect in scolecodonts from the Late Devonian Biodiversity Crisis. Paleobiology. [https://doi.org/10.5061/dryad.tqjq2bw72](https://doi.org/10.5061/dryad.tqjq2bw72)

Authors: 

Gwyneth Chilcoat

University of California Davis Department of Earth and Planetary Sciences

[[e-mail]](mailto:[e-mail])

Phoebe Cohen

Williams College Department of Geoscience

This dataset includes all measurable Devonian and Carboniferous scolecodont photomicrographs in the literature at the time of production, as well as many Silurian scolecodonts, newly-introduced Devonian Appalachian Basin data, and many of Eller's collections from the Carnegie Museum of Natural History. All measurements are in micrometers.

Code files here can be opened, viewed, and edited in R.

## Description of the data and file structure

* ***12172025WormCode.R***

Code for figures in the...,