Data from: Palaeoscolecids from the Ludlow Series of Leintwardine, Herefordshire (UK) – the latest occurrence of palaeoscolecids in the fossil record

The documentation of cuticular micro-ornament is vital for the taxonomic
assignment of palaeoscolecids – vermiform lower Palaeozoic ecdysozoans
interpreted as stem-group priapulans or early diverging panarthropods.
This is due to the absence of the character-rich proboscis and tail hooks
in palaeoscolecid material not from Burgess Shale-type
Konservat-Lagerstätten. Here, the cuticular micro-ornamentation of
palaeoscolecids from the upper Silurian (Ludlow) fauna of Leintwardine
(Herefordshire, England), is described using scanning electron microscopy
(SEM) and Reflectance Transformation Imaging (RTI). This material is
taxonomically unstable as it was included in an effective wastebasket
genus (Protoscolex) long before these imaging techniques were developed.
This reveals the Leintwardine material is most closely comparable to a
palaeoscolecid from the Darriwilian (Middle Ordovician) of the
Builth-Llandrindod inlier, Powys, Wales, and is transferred accordingly to
Radnorscolex Botting et al. as Radnorscolex latus Bather. The Leintwardine
fauna represents the uppermost stratigraphic occurrence of
palaeoscolecids, constrained to the Saetograptus leintwardinensis Zone
(lower Ludfordian), and the comparatively sparse Silurian palaeoscolecid
record is subsequently discussed. It is hypothesised palaeoscolecids may
have become extinct during the mid-Ludfordian Lau Event, the onset of
which is recorded in the biozone immediately above the Leintwardine fauna
(Bohemograptus Zone). Finally, the British palaeoscolecid fauna is
summarised, including a new record from the Dapingian (Middle Ordovician)
of Carmarthenshire, South Wales.