Halwaxiids and the early evolution of the lophotrochozoans.
Halkieriids and wiwaxiids are cosmopolitan sclerite-bearing metazoans from the Lower and Middle Cambrian. Although they have similar scleritomes, their phylogenetic position is contested. A new scleritomous fossil from the Burgess Shale has the prominent anterior shell of the halkieriids but also bears wiwaxiid-like sclerites. This new fossil defines the monophyletic halwaxiids and indicates that they have a key place in early lophotrochozoan history.
Morris
Simon Conway
SC
Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK. sc113@esc.cam.ac.uk
Caron
Jean-Bernard
JB
D000818:Animals; D000845:Annelida / Q000033:anatomy & histology / Q000145:classification; D005075:Biological Evolution; D005580:Fossils; D007448:Invertebrates / Q000033:anatomy & histology / Q000145:classification*; D008974:Mollusca / Q000033:anatomy & histology / Q000145:classification; D010802:Phylogeny