So-called Salterella from the Cambrian of Australia

Extract

THE Lower Cambrian genus Salterella, Billings, has lately received a good deal of attention in connection with the problem of the origin of the Cephalopoda. The genus, it may be remembered, was first described by its author as undoubtedly allied to Serpulites i.e. a worm-tube, but it was soon transferred by Billings himself to the pteropods. Barrande and Walcott also considered Salterella to be related to Tentaculites and Hyolithes. Clark (1925), who revised the genus, came to the conclusion that Salterella was a cephalopod, and not by any means a primitive type, but it did not seem to him to be ancestral to any subsequent form. Poulsen (1927) accepted this view, stating that the cephalopod characters were very conspicuous, but his later (1932) restoration of an East Greenland form, identified with S. rugosa from Labrador, is no more convincing than was Clark's restoration of S. conulata. Unfortunately, the genotype species of Salterella (S. rugosa Billings) is still incompletely known and I agree with Teichert (1935) that further investigation is needed before the real nature of Salterella can be held to be established. If the “septal necks” are still a doubtful feature and if the very existence of a “siphuncle” is open to question, as Teichert rightly says, it is clearly as premature to visualize Salterella as a possible forerunner of the holochoanites (Schuchert, in Schindewolf, 1929) as it is to connect the equally doubtful Volborthella with either holochoanites (Teichert and Kobayashi) or orthochoanites (Schindewolf, 1934).