Professor Nielsen was born on 28th March 1938 in Copenhagen, Denmark. Working at the Natural History Museum of Denmark (University of Copenhagen) his main interest were the origin and evolution of the animal kingdom. More specific interests included larval development of marine invertebrates, structure and function of ciliary bands (especially in larvae but also in adult polychaetes), entoprocts. Classification and phylogeny, i.e. the knowledge of the evolutionary relationships of the organisms, have been changed with increasing knowledge to which he contributed. He passed away in January 2024.

Some of his publications on brachiopods...

Bourlat S.J., Nielsen C., Economou A.D. & Telford M.J., 2008. Testing the new animal phylogeny: a phylum level molecular analysis of the animal kingdom. Molecular phylogenetics and evolution, 49 (1), 23-31.

Nielsen C., 1979. Larval ciliary bands and Metazoan phylogeny. Fortschr. Zool. Syst. Evolut.-forsch., 1, 178-184.

Nielsen C., 1985. Animal phylogeny in the light of the Trochaea theory. Biol. J. Linn. Soc., 25, 243-299.

Nielsen C., 1987. Structure ans function of Metazoan ciliary bands and their phylogenetic significance. Act. Zool. (Stockh.), 68 (4), 205-262.

Nielsen C., 1988. 50. Brachiopoda. p. 445-456. In: Introduction of the study of meiofauna, Higgins R. P. & H. Thiel Eds, Smiths. Inst. Press, Washington, 488 pp.

Nielsen C., 1991. The development of the brachiopod Crania (Neocrania) anomala (O. F. Müller) and its phylogenetic significance. Acta zool. (Stockholm), 72 (1), 7-28.

Nielsen C., 1994. Larval and adult characters in animal phylogeny. Amer. Zool., 34, 492-501.

Nielsen C., 1995. The phylogenetic position of the Bryozoa Ectoprocta. 10th Intern. Bryozoology Ass. Conf., Wellington N.Z., 1 p.

Nielsen C., 1995. Animal evolution. Oxford University Press, 467 pp.

Nielsen C., 1998. Morphological approaches to phylogeny. Amer. Zool., 38, 942-952.

Nielsen C., 2002. The phylogenetic position of Entoprocta, Ectoprocta, Phoronida, and Brachiopoda. Integrative and Comparative Biology, 42 (3) 685-691.

Nielsen C., 2003. Proposing a solution to the Articulata-Ecdysozoa controversy. Zoologica Scripta, 32, 475-482.

Nielsen C., 2003. Defining phyla: morphological and molecular clues to metazoan evolution. Evolution & Development, 5 (4), 386-393.

Nielsen C., 2010. Some aspects of spiralian development. Acta Zoologica (Stockholm), 91, (1), 20-28.

Nielsen C., 2012. Brachiopoda. In: Animal evolution: Interrelationships of the living phyla. 3rd ed., Oxford University Press, p. 229- xxx (402 p.).

Nielsen C., 2012. How to make a protostome. Invertebrate Systematics, 26, 25-40.

Nielsen C., Scharf N. & D. Eibye-Jacobsen, 1996. Cladistic analyses of the animal kingdom. Biol. J. Linn. Soc., 57, 385-410.

Collated by Christian C. Emig, BrachNet