# Reappraisal of the extinct barbelthroat shark †Bavariscyllium and the nebulous origin of carcharhiniform galeomorphs

## TL;DR

This study re-examines an extinct shark species and finds it shows early diversity in shark body forms before modern types evolved.

## Contribution

The study challenges the classification of †Bavariscyllium and highlights early galeomorph morphological diversity.

## Key findings

- †Bavariscyllium's features do not conclusively place it in Carcharhiniformes or Orectolobiformes.
- Early galeomorphs showed diverse body forms before modern shark types diverged.
- Features of †Bavariscyllium resemble early carcharhiniforms but do not confirm their relationship.

## Abstract

We present a revised diagnosis of the extinct galeomorph shark †Bavariscyllium based on dental and skeletal material from the Upper Jurassic of Germany and test its purported carcharhiniform affinity through morphometric and phylogenetic analyses. Although †Bavariscyllium possesses a whisker-like throat barbel suggesting a closer relationship with orectolobiforms, our findings reveal insufficient evidence to confidently assign †Bavariscyllium to either Orectolobiformes or Carcharhiniformes. Additionally, we present quantitative evidence indicating that early galeomorphs, despite probably not being placed among extant orders, were exploring a variety of body forms, predating the divergence of most major body plans among modern representatives. †Bavariscyllium exhibits generalised clutching-type teeth with a hemiaulacorhize root characterised by strongly flared root lobes, closely resembling the supposed earliest carcharhiniforms from the Middle Jurassic. However, these features neither confirm nor refute a carcharhiniform affinity, questioning the reliability of these early galeomorphs as calibration fossils for dating the divergence of carcharhiniforms in phylogenomic analyses.

Reassessment of the Jurassic shark †Bavariscyllium challenges understanding of early galeomorph evolution, showing these sharks explored diverse body forms, predating the divergence of most major body plans among modern representatives.