Inferring deep branchpoints in the largest animal phylum, Arthropoda, is a challenge for reconstructing the tree of life. A combined approach to arthropod phylogeny uses
Molecular work on arthropod phylogeny has featured collaboration with Gonzalo Giribet (Harvard University) and Ward Wheeler (American Museum of Natural History) since the 1990s. The position of myriapods (centipedes, millipedes, pauropods and symphylans) in arthropod evolution is a special focus of this work.
Collecting in the Emu Bay Shale, Buck Quarry, Kangaroo Island, 2011
Current research on soft-part preservation in the early Palaeozoic concentrates on
Nature article on the eyes of Anomalocaris (Paterson et al., 2011)
The Emu Bay Shale project was funded by a Linkage Grant from the Australian Research Council (2007-2009) and fieldwork has been supported by National Geographic. Arthropod descriptions are conducted with John Paterson (University of New England) and Diego Garcia-Bellido (University of Adelaide).
A combination of molecular and morphological data provides a toolkit for reconstructing the evolutionary history of Chilopoda (centipedes).
Centipede research explores
Taxonomic work has especially concentrated on Scutigeromorpha, Lithobiomorpha and Scolopendromorpha, with emphasis on the biota of Australia and other southern landmasses.
Head of Geophilus flavus imaged with confocal laser scanning (CLSM).
Scolopendropsis duplicata, described from Brazil in 2008, showing hitherto unknown variability in trunk segment numbers in Scolopendromorpha. Photo by Amazonas Chagas Jr.
Section through the cuticle and body wall muscles of the onychophoran Euperipatoides kanangrensis. Expressed Sequence Tags for this species support a close relationship between onychophorans and arthropods.
Collaboration on the interrelationships of animal phyla was initiated in the “Assembling the Protostome Tree of Life” project, funded by the U.S. National Science Foundation (2004-2008). The relationships of arthropods to other protostomes are one of its research foci.
Our approach has involved broad taxonomic sampling of Expressed Sequence Tags, which allow hundreds or thousands of genes to be used in phylogenetic inference. These have included the first transcriptomic data for several animal phyla. Molecular work has been led by Casey Dunn (Brown University), and Andreas Hejnol (University of Bergen).
Our morphology team developed complimentary morphological datasets for large parts of the Spiralia (especially annelids) and Ecdysozoa (especially scalidophorans), including key fossil taxa. Work on this project also includes Greg Rouse (Scripps Institute of Oceanography) and our collaborators at the University of Copenhagen (Reinhardt Kristensen, Martin Vinther Sørensen, Katrine Worsaae).
Limnognathia maerski (Micrognathozoa), a female photographed alive by Reinhardt Kristensen.
Recent expeditions have targeted phyla that still lack phylogenomic data, including Micrognathozoa and Loricifera. Collecting on Disko Island, Greenland, in the summer of 2010 built up a sample of the micrognathozoan Limnognathia maerski from its type locality. Work at the Station Biologique de Roscoff in May 2011, funded by the EU’s ASSEMBLE program, provided live material of the loriciferan Armorloricus. Phylogenomic data being generated in Casey Dunn’s lab will test the relationship of Limnognathia to other members of Gnathifera and explore the position of Loricifera in the Ecdysozoa.