Article: A revision of Holm's late Mid and Late Cambrian hyoliths of Sweden
Vivianne Berg-Madsen and John M. Malinky
Type specimens of Hyolithus tenuistriatus Linnarsson show this species to be the second definitive representative of the North American genus Nevadotheca in Scandinavia; H. subcostatus Wallerius is questionably assigned to that genus. Restudy of the types of the hyolithids Hyolithus pennatulus Holm confirms the earlier assignment of that species to Carinolithes Syssoiev and H. araneus Holm is assigned to Lovenedolithes gen. nov. Morphology of the orthothecids Hyolithus (Orthotheca) cor Holm, H. (O.) excavatus Holm and H. (O.) lineatulus Holm supports placement of the first in Contitheca Syssoiev and the others in Decoritheca Syssoiev. Hyolithus (Orthotheca) stylus Holm, type species of Circotheca Syssoiev, is of special significance as the basis for both a family and an order. The morphology of the species suggests that ordinal status is not warranted. Hyolithus obscurus Holm, on which Linevitus Syssoiev is founded, is known only from poorly preserved internal moulds and is unrecognizable.