The most obvious manifestations of geological materials in the urban environment are building and facing stones, and similar rocks used in street furniture, such as kerbstones. As a Londoner, SKD was impressed as a boy by the massive kerbstones that he saw in the City and locally where he lived. It was only as his knowledge of geology grew that he discovered such stones to be truly exotic, being largely crystalline rocks (mostly granites in the broad sense) and probably derived from the southwest or the north of the British Isles. A field guide to the kerbstones of London would have accelerated his education in geology at that time.
More satisfactorily to palaeontologists, such as the authors of this article, are building stones that are fossiliferous. We have particular interests in the palaeontology of Palaeozoic limestones. These are common building stones and street furniture in many cities in the Netherlands (and elsewhere). These rocks are all imported (Van Ruiten and Donovan, 2018; Dr Bernard Mottequin, email to DATH, 9 May 2018) and are mainly Mississippian, although there are some limestones of Devonian age here and there (Van Roekel, 2007; Reumer, 2016). However, the Mississippian limestones are the more widespread and contain abundant fossils, from the well-known, such as bryozoans (Donovan and Wyse Jackson, 2018), brachiopods, crinoids, and rugose and tabulate corals (Van Ruiten and Donovan, 2018) to the more exotic, such as rostroconch molluscs (Donovan and Madern, 2016).
This article presents our first exploration of the brachiopods in these building stones. For a pocket guide to brachiopods, we recommend Rudwick (1970), now a little long in the tooth, but packed with information. Clarkson (1998), together with Benton and Harper (2009), will also be useful. We have chosen one group amongst the Mississippian articulated brachiopods as being particularly distinct when viewed in section (Figs. 1 to 3), a group that were large, thick-shelled and, in consequence, obvious fossils, namely the productids. Productids are locally common fossils in the Mississippian of northern Europe (for example, Nolan et al., 2017) and have unusual shell geometry. In this article, we focus on Mississippian limestones in the Netherlands, imported from elsewhere, probably Belgium, but productids are identifiable in building stones in Britain as well (for example, Donovan, in press, fig. 3B, C).