title: Comment on "Fossilized nuclei and germination structures identify Ediacaran 'animal embryos' as encysting protists".
abstract: On the basis of putative nuclei and endospores, Huldtgren et al. (Reports, 23 December 2011, p. 1696) propose that embryo-like Doushantuo microfossils are nonmetazoan holozoans akin to mesomycetozoeans. However, both size and preservation preclude interpretation of internal structures as nuclei. Moreover, the authors may have conflated two different populations; some specimens display a pseudoparenchymatous organization incompatible with a mesomycetozoean comparison.
authors.affiliation: Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. xiao@vt.edu
authors.forename: Shuhai
authors.initials: S
authors.lastname: Xiao
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Knoll
authors.forename: James D
authors.initials: JD
authors.lastname: Schiffbauer
authors.forename: Chuanming
authors.initials: C
authors.lastname: Zhou
authors.forename: Xunlai
authors.initials: X
authors.lastname: Yuan
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure*; D056890:Eukaryota / Q000254:growth & development*; D005580:Fossils