Neural markers reveal a one-segmented head in tardigrades (water bears)Georg Mayer
Animal Evolution and Development, Institute of Biology, University of Leipzig, Leipzig, Germany
PLoS ONE 8:e59090. 2013
..To clarify this, we applied a variety of histochemical and immunocytochemical markers to specimens of the tardigrade Macrobiotus cf. harmsworthi and the onychophoran Euperipatoides rowelli...
- Growth patterns in Onychophora (velvet worms): lack of a localised posterior proliferation zone
Georg Mayer
Institute of Biology II, Animal Evolution and Development, University of Leipzig, Talstrasse 33, D 04103 Leipzig, Germany
BMC Evol Biol 10:339. 2010
..To determine whether such a localised posterior proliferation zone is an ancestral feature of Panarthropoda (Onychophora + Tardigrada + Arthropoda), we examined cell division patterns in embryos of Onychophora...
- A revision of brain composition in Onychophora (velvet worms) suggests that the tritocerebrum evolved in arthropods
Georg Mayer
Institute of Biology II, Animal Evolution and Development, University of Leipzig, Talstrasse 33, D 04103 Leipzig, Germany
BMC Evol Biol 10:255. 2010
..However, the segmental origins of their brain neuropils and the number of cephalic appendages innervated by the brain--key issues in clarifying brain composition in the last common ancestor of Onychophora and Arthropoda--remain unclear...
Neural development in Onychophora (velvet worms) suggests a step-wise evolution of segmentation in the nervous system of PanarthropodaGeorg Mayer
Department of Anatomy and Cell Biology, University of Melbourne, Victoria 3010, Australia
Dev Biol 335:263-75. 2009
..Our data best support the hypothesis that the ancestral panarthropod had only a partially segmented nervous system, which evolved progressively into the segmental chain of ganglia seen in extant tardigrades and arthropods...
- Velvet worm development links myriapods with chelicerates
Georg Mayer
Department of Anatomy and Cell Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
Proc Biol Sci 276:3571-9. 2009
..Our findings, thus provide, to our knowledge, first morphological/embryological support for the monophyly of the Paradoxopoda and suggest that the mandible might have evolved twice within the arthropods...
- Distribution of serotonin in the trunk of Metaperipatus blainvillei (Onychophora, Peripatopsidae): implications for the evolution of the nervous system in Arthropoda
Georg Mayer
Department of Anatomy and Cell Biology, University of Melbourne, Victoria 3010, Australia
J Comp Neurol 507:1196-208. 2008
..This finding implies that the "rope ladder-like" nervous system may have arisen independently in Panarthropoda and Annelida and does not represent a synapomorphy of these groups...
- Immunolocalization of serotonin in Onychophora argues against segmental ganglia being an ancestral feature of arthropods
Georg Mayer
Department of Anatomy and Cell Biology, University of Melbourne, Victoria, Australia
BMC Evol Biol 7:118. 2007
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- Extensive duplication events account for multiple control regions and pseudo-genes in the mitochondrial genome of the velvet worm Metaperipatus inae (Onychophora, Peripatopsidae)
Anke Braband
Institute of Biology, Comparative Zoology, Humboldt Universitat zu Berlin, Berlin, Germany
Mol Phylogenet Evol 57:293-300. 2010
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- When are cellular oscillators sufficient for sequential segmentation?
Rebecca H Chisholm
Department of Mathematics and Statistics, University of Melbourne, Victoria 3010, Australia
J Theor Biol 279:150-60. 2011
..Furthermore, the model predicts segment deletions when there is an interruption in cell division, just as seen in heat shock experiments, as well as the growth and final shrinkage of the presomitic mesoderm during somitogenesis...
- The mitochondrial genome of the onychophoran Opisthopatus cinctipes (Peripatopsidae) reflects the ancestral mitochondrial gene arrangement of Panarthropoda and Ecdysozoa
Anke Braband
Institute of Biology, Comparative Zoology, Humboldt Universitat zu Berlin, Berlin, Germany
Mol Phylogenet Evol 57:285-92. 2010
..biolleyi is less suitable for phylogenetic analyses of Ecdysozoa using mitochondrial genomic data than the peripatopsid O. cinctipes...
- Cryptic speciation in Brazilian Epiperipatus (Onychophora: Peripatidae) reveals an underestimated diversity among the peripatid velvet worms
Ivo S Oliveira
Institute of Biology Animal Evolution and Development, University of Leipzig, Leipzig, Germany
PLoS ONE 6:e19973. 2011
..We therefore used molecular approaches, in addition to morphological methods, to explore the diversity of Epiperipatus from the Minas Gerais State of Brazil...
- Opsins in onychophora (velvet worms) suggest a single origin and subsequent diversification of visual pigments in arthropods
Lars Hering
Animal Evolution and Development, Institute of Biology, University of Leipzig, Leipzig, Germany
Mol Biol Evol 29:3451-8. 2012
..We conclude that the diversification of visual pigments and color vision evolved in arthropods, along with the evolution of compound eyes-one of the most sophisticated visual systems known...
- Comparative anatomy of slime glands in onychophora (velvet worms)
Alexander Baer
Animal Evolution and Development, Institute of Biology, University of Leipzig, Talstrasse 33, D 04103 Leipzig, Germany
J Morphol 273:1079-88. 2012
..However, the direction of evolutionary changes in duct composition cannot be determined unambiguously due to current uncertainty regarding the phylogenetic relationships of Onychophora...
- The origins of the arthropod nervous system: insights from the Onychophora
Paul M Whitington
Department of Anatomy and Cell Biology, University of Melbourne, Victoria 3010, Australia
Arthropod Struct Dev 40:193-209. 2011
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The complete mitochondrial genome of the onychophoran Epiperipatus biolleyi reveals a unique transfer RNA set and provides further support for the ecdysozoa hypothesisLars Podsiadlowski
Institute of Biology, Freie Universitat Berlin, Berlin, Germany
Mol Biol Evol 25:42-51. 2008
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- Myoanatomy of Myzostoma cirriferum (Annelida, Myzostomida): implications for the evolution of the Myzostomid body plan
Conrad Helm
Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Talstraße 33, D 04103 Leipzig, Germany
J Morphol 274:456-66. 2013
..cirriferum arose secondarily in this species. Based on our data, we provide a scenario on the rearrangements of muscle fibers that might have taken place in the lineage leading to this species...
- Unexplored character diversity in onychophora (velvet worms): a comparative study of three peripatid species
Ivo de Sena Oliveira
Animal Evolution and Development, Institute of Biology, University of Leipzig, Leipzig, Germany
PLoS ONE 7:e51220. 2012
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- Ultrastructure of mesoderm in embryos of Opisthopatus roseus (Onychophora, Peripatopsidae): revision of the "long germ band" hypothesis for Opisthopatus
Georg Mayer
Animal Systematics and Evolution, Institute of Biology Zoology, Freie Universität of Berlin, D 14195 Berlin, Germany
J Morphol 263:60-70. 2005
..From this survey, no evidence in support of a "long germ band" hypothesis in Opisthopatus was found. Instead, the embryogenesis in representatives of Opisthopatus is more similar to that in other onychophorans than expected...
