Demecology in the Cambrian: synchronized molting in arthropods from the Burgess Shale
1 Zoological Institute and Museum, Department of Cytology and Evolutionary Biology, Soldmannstrasse 23, 17487 Greifswald, Germany
2 Department of Natural History - Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, M5S 2C6, Canada
3 University of Toronto, Department of Ecology and Evolutionary Biology, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
BMC Biology 2013, 11:64 doi:10.1186/1741-7007-11-64Published: 30 May 2013
The Burgess Shale is well known for its preservation of a diverse soft-bodied biota dating from the Cambrian period (Series 3, Stage 5). While previous paleoecological studies have focused on particular species (autecology) or entire paleocommunities (synecology), studies on the ecology of populations (demecology) of Burgess Shale organisms have remained mainly anecdotal.
Here, we present evidence for mass molting events in two unrelated arthropods from the Burgess Shale Walcott Quarry, Canadaspis perfecta and a megacheiran referred to as Alalcomenaeus sp.
These findings suggest that the triggers for such supposed synchronized molting appeared early on during the Cambrian radiation, and synchronized molting in the Cambrian may have had similar functions in the past as it does today. In addition, the finding of numerous juvenile Alalcomenaeus sp. molts associated with the putative alga Dictyophycus suggests a possible nursery habitat. In this nursery habitat a population of this animal might have found a more protected environment in which to spend critical developmental phases, as do many modern species today.