The taxonomy of Cambrian lingulate (phosphatic shelled) brachiopods from England and Wales are reviewed in detail for the first time in nearly a century. 37 linguliformean brachiopod species, assigned to 23 genera, are described; 19 taxa are recorded in open taxonomy. Giving provisional names, three new genera, Svenjaella, Alexellus and Kayleigha are erected and nine new species are described (Chapter 4). Detailed cladistic analysis supports previous reports that Acrotretidae is a paraphyletic grouping of brachiopods which gave rise to other families within the Acrotretoidea (Chapter 6). Curticiidae is identified as lying outside the Acrotretoidea. The remaining families are supported as valid taxonomic units, albeit with some potential minor revisions. A new Scaphelasmatidae-Ceratretidae clade is consistently recovered. Support for the previously proposed subfamilies Neotretinae and Linnarssoniinae is partially recovered. The preservation of polygonal imprints of epithelial cells in lingulate brachiopods is reviewed and supplemented by new data (Chapter 7). The imprints are confirmed as representing moulds of epithelial cells as they are best preserved in areas where the shell has been thickened, and are similar in size to cells recorded in Lingula, the closest living relative to the extinct acrotretoids. Analysis of the morphology and sizes of cell-moulds demonstrates that there is no consistent relationship between cell width and valve size, and that they are not a useful taxonomic character within this group. The distribution of lingulate brachiopods across the Iapetus region is analysed using a number of statistical measures (Chapter 8). Although lingulate brachiopods have traditionally been considered to be of little utility in assessing palaeobiogeography, this analysis shows a clear palaeobiogeographic signal where lingulate faunas are sufficiently diverse, reflecting the history of the Iapetus ocean and the relative separation of Laurentia and Baltica through the Cambrian and Ordovician and provides confirmatory evidence that Palaeozoic lingulates had long-lived planktotrophic larvae.