Convergent evolution of the ladder-like ventral nerve cord in Annelida
- C. Helm, P. Beckers, C. Bleidorn
- BiologyFrontiers in Zoology
- 27 September 2018
A ladder-like appearance of the ventral nerve cord evolved repeatedly, and independently of the transition from an intraepidermal to a subepidersmal cord during annelid evolution, to propose an alternative set of neuroanatomical characteristics for the last common ancestor of Annelida or perhaps even Spiralia.
The Nervous Systems of Basally Branching Nemertea (Palaeonemertea)
- P. Beckers, R. Loesel, T. Bartolomaeus
- BiologyPLoS ONE
- 13 June 2013
This study provides evidence that the nemertean brain primarily consists of two lobes connected by a strong ventral commissure and one to several dorsal commissures, and provides a first attempt to reconstruct the primary organization of the nEmertean nervous system.
The central nervous system of Oweniidae (Annelida) and its implications for the structure of the ancestral annelid brain
- P. Beckers, C. Helm, G. Purschke, K. Worsaae, P. Hutchings, T. Bartolomaeus
- BiologyFrontiers in Zoology
- 12 March 2019
The central nervous system of Oweniidae is the simplest in terms of enlargement of the dorsal part of the brain and neuron distribution found among Annelida, and shows the medullary nervous system to be a common feature and thus possibly representing the ancestral state of the spiralian nervous system.
The nervous systems of Pilidiophora (Nemertea)
- P. Beckers
- BiologyZoomorphology
- 1 March 2015
Although in H. dubia some characters of the nervous system show the plesiomorphic state, the morphology of the cerebral organ provides an apomorphic character for a taxon Pilidiophora, which is now supported as the sister group to heteronemerteans.
Early evolution of radial glial cells in Bilateria
- C. Helm, A. Karl, C. Bleidorn
- BiologyProceedings of the Royal Society B: Biological…
- 19 July 2017
It is shown that protostomes also possess radial glia-like cells, which are very likely to be homologous to those of deuterostomes, and antibody staining indicates that the secretory character of radial glial cells is maintained throughout their various evolutionary adaptations.
The anatomy and development of the nervous system in Magelonidae (Annelida) – insights into the evolution of the annelid brain
- P. Beckers, C. Helm, T. Bartolomaeus
- BiologyBMC Evolutionary Biology
- 28 August 2019
The data reveal that early in annelid evolution complexity of brains and anterior sensory structures rises, andPolymorphic neurons in clusters and distinct brain parts, as well as lateral organs - all of which are not present in outgroup taxa and in the putative magelonid sister group Oweniidae - already evolved in Magelonidae.
Nemertean taxonomy—Implementing changes in the higher ranks, dismissing Anopla and Enopla
- M. Strand, J. Norenburg, Cong-mei Xu
- BiologyZoologica Scripta
- 29 October 2018
The ranks Anopla and Enopla are eliminated and the following system of the Nemertea phylum is implemented and genus Hubrechtella is transferred from class Palaeonemertea to the class Pilidiophora.
Lophotrochozoan neuroanatomy: An analysis of the brain and nervous system of Lineus viridis(Nemertea) using different staining techniques
- P. Beckers, Simone Faller, R. Loesel
- BiologyFrontiers in Zoology
- 19 July 2011
This study used different staining techniques and confocal laser scanning microscopy to reveal the architecture of the nervous system of Lineus viridis with high anatomical resolution and did not support any hypothesis on the phylogenetic position of Nemertea within Lophotrochozoa.
Unravelling the Lineus ruber/viridis species complex (Nemertea, Heteronemertea)
- Daria Krämer, C. Schmidt, L. Podsiadlowski, P. Beckers, Lisa Horn, J. Döhren
- Biology
- 1 January 2017
A comprehensive data set combining external morphology and three genetic markers (mitochondrial cytochrome c oxidase subunit I, 16S rRNA and nuclear internal transcribed spacer region) from 160 specimens of L. ruber and L. viridis provides a framework to unequivocally identify specimens as members of any of the three species.
Fine structure of the brain in Amphinomida (Annelida)
- P. Beckers, Ekin Tilic
- BiologyActa Zoologica
- 3 May 2021
The study of the annelid nervous system provides a complex range of morphological characters to assess potential homologies and to find synapomorphies for clades within Annelida.
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