New material of scalidophoran worms in Orsten-type preservation from the Cambrian Fortunian Stage of South China

Scalidophoran worms diversified in the Cambrian Fortunian, as indicated by recent reports from this stage, with two described species and two more unnamed forms exclusively from Orsten-type Lagerstatten yielding three-dimensionally phosphatized fossils. Here, we report new material of scalidophoran worms in Orsten-type preservation from the Cambrian Fortunian Xinli section in northern Sichuan Province, South China. At least five forms of scalidophoran worms were recovered from this location, including Eokinorhynchus rarus Zhang et al., 2015 and four unnamed taxa-Forms A, B, C, and D. Co-occurring disassociated spinose small shelly fossils might also be isolated cuticular elements of these early scalidophoran worms. The ontogeny of Eokinorhynchus rarus is revised. Forms A, C, and D are assigned to total-group Scalidophora to indicate their uncertain positions within Scalidophora, while Form B might be a close relative of Eokinorhynchus rarus. The current work highlights the significance of Orsten-type Lagerstatten in uncovering the morphology, ontogeny, and taxonomy of early Scalidophora and Cycloneuralia, made particularly available by the new finds in China.