This paper presents a phylogenetic analysis of the ‘‘Fallotaspidoidea,’’ a determination of the biogeographic origins of the eutrilobites, and an evaluation of the timing of the Cambrian radiation based on biogeographic evidence. Phylogenetic analysis incorporated 29 exoskeletal characters and 16 ingroup taxa. In the single most parsimonious tree the genus Fallotaspidella Repina, 1961, is the s...

ONE of John Shergold’s abiding research interests, and an area in which he made fundamental contributions to the fields of palaeontology and geology, was the study of Cambrian arthropods in general, and trilobites in particular (e.g., Shergold 1977, 1988, 1991; Shergold et al. 1990; Shergold & Laurie 1997). Here we focus on what Cambrian arthropods, including trilobites, can tell us about the n...

Clearly, the fossil record from the Cambrian period is an invaluable tool for deciphering animal evolution. Less clear, however, is how to integrate the paleontological information with molecular phylogeny and developmental biology data. Equally challenging is answering why the Cambrian period provided such a rich interval for the redeployment of genes that led to more complex body plans.

The early evolution of the Misty Creek embayment (MCE), a prominent, northwest-trending sub-basin economically important Selwyn basin, is poorly understood. abrupt contact between Cambrian Stage 4 (traditional lower Cambrian) carbonate ramp strata Sekwi Formation and overlying Miaolingian middle deep-water, calciturbiditic Hess River has been regarded as diachronous. This transition, which mark...

Abstract New occurrences of flask-shaped and envelope-bearing microfossils, including the predominantly Cambrian taxon Granomarginata , are reported from new localities, as well earlier in time (Ediacaran) than previously known. The stratigraphic range extends into System, where it had a cosmopolitan distribution. This newly Ediacaran record includes areas Norway (Baltica), Newfoundland (Avalon...

A rich body of empirically grounded theory has developed about food webs--the networks of feeding relationships among species within habitats. However, detailed food-web data and analyses are lacking for ancient ecosystems, largely because of the low resolution of taxa coupled with uncertain and incomplete information about feeding interactions. These impediments appear insurmountable for most ...