Writing this history of paleontology has revived vivid fossil-related memories from my past. Ever since childhood I have been fascinated and inspired by the fragmentary vestiges of ancient creatures, the rubble of once great nations of animals.
Every birthday I would plead with my parents to be taken to the Natural History Museum in London, in a more naive era when a small boy could be set free to explore the terracotta halls of this Romanesque “cathedral of life.” I loved the grand dinosaur skeletons, of course, although I was already aware that some of them were made of plaster, but it was the unfrequented gallery of ancient fish that I remember most. Even more than their spectacular land-living descendants, this gallery’s inhabitants looked intriguingly, overwhelmingly old—crushed and mangled messengers from an alien era before feet trod the Earth. Many appeared timid and harmless, yet some were heavily armored, hinting that some awful threat was abroad in those days. <...>

Well-documented tectonic events in the central Appalachians of Pennsylvania are: (1) the early Paleozoic Taconian orogeny that occurred during convergence of Laurentian and the Chopawamsic-Wilmington complex magmatic arc over an east-dipping subduction zone, and resulted in intense metamorphism and deformation in the Piedmont, and (2) the late Paleozoic Alleghanian orogeny that resulted in the thrust and fold belt in the Valley and Ridge province and dextral shear zones in the Piedmont. Unlike the Paleozoic tectonic history for the northern and southern Appalachians, the north-central part of the orogen in Pennsylvania lacks evidence for Acadian deformation and metamorphism. The relative chronological order of deformation and metamorphic events in the eastern Piedmont of Pennsylvania, combined with published geochro-nology suggests the previously undocumented Acadian deformation possibly exists as a transcurrent conjugate shear zone pair.

The proceedings of the first International Conference on Trilobites and their Relatives held in Oslo in 1973 (Bruton 2019) were published in one of the earliest editions of Fossils and Strata (Martinsson 1975). It is highly fitting, therefore, that with the return of the conference to Baltoscandia (P€arnaste 2018), the Lethaia Foundation, under whose auspices Fossils and Strata is published, kindly offered to publish a volume of papers arising from the sixth meeting held in Tallinn, Estonia, in July 2017. The papers in the volume vary considerably in length. Although a notional page limit was given, it was made clear from the outset that there was some flexibility in this.