Reply to L.E. Popov and L.E. Holmer (CG2003_A06_LEP-LEH): Obolid taxonomy

Since early in the 19th Century the taxonomy of fossil obolids has been the subject of numerous controversies (Table 1), so the development of new criteria for their proper differentiation is mandatory. Based on the extant species of the family Lingulidae (Emig, 1982, 1983) and later applied to fossil taxa (Biernat and Emig, 1993), new morpho-anatomical characters were established and their variability analysed. As a consequence, several shell structures commonly used to discriminate between genera and species of both extant and fossil taxa were determined to have no phylogenetic status.