Walcott, Charles D. 1911. Cambrian geology and paleontology. Middle Cambrian annelids. Smithsonian Miscellaneous Collections, 57(5): 109-144.

52091

Walcott, C. D.

1911

57(5): 109-144

Publication

http://www.biodiversitylibrary.org/page/9263167

World Polychaeta Database (WPolyD). Most of Walcott's (1911) worm taxa have been reinterpreted as not annelids. However, his (then) Canadia seem mostly annelids. Canadia spinosa (with synonyms erected by Walcott) remains as a stem group polychaete, as do Canadia dubia, now Peronochaeta dubia, and Canadia setigera, now Burgessochaeta setigera, both genera of Conway-Morris (1979). A specimen included in Walcott's C. dubia later became Stephenoscolex argutus Conway Morris (1979). Of the others Canadia sparsa became Hallucigenia sparsa, as redescribed by Conway-Morris (1977), but later was interpreted the other way up, and head to tail reversed, and thought to be a lobopod, (a stem onychophoran), as is Aysheaia pedunculata . Wiwaxia corrugata is currently not placed as an annelid, lacks segmentation, and is probably a stem mollusc. Selkirkia are thought to be a priapulids as is Miskoia preciosa. Pollingeria grandis is a Problematica unknown. Worthenella cambria is a multi-legged arthropod. Ottoia (then in Gephyrea) are still Priapulida (or alternatively Enteropneusta), so Walcott correctly placed them, and Pikaia gracilens is a primitive chordate. Banffia constricta is thought to belong to an extinct phylum called Vetulicolia. Oesia disjuncta is still a Problematica, but has been placed as hemichordate.

Introduction extract: “As a rule the annelids have been known only by trails and borings in the muds and sands deposited in the various periods between the Pre-Cambrian Algonkian and the present, and only under very exceptional conditions have any traces of the actual animal been preserved. […] I have often searched the fine shales of the pre-Cambrian and Cambrian strata for remains of annelids but it was not until the summer of 1910 that anything more than trails and borings were found. The annelids of the Burgess shale, like the holothurians and medusae, are pressed flat so that the animal is represented by only a thin film. Fortunately this is darker than the shale and usually shiny, and the contents of the animal are often preserved as a glistening silvery surface, even to the fine details of structure. How clearly the specimens exhibit both external and internal characters is shown by the plate figures which are reproduced from photographs made by reflected light.”

Pacific, North East (Warm + cold temperate (boreal))

Paleontology, Fossils, Paleobiology

Annelida

RIS (EndNote, Reference Manager, ProCite, RefWorks)
BibTex (BibDesk, LaTeX)

[Back to search]