title: Animal evolution: stiff or squishy notochord origins?
abstract: The notochord is considered an evolutionary novelty and one of the defining characters of chordates. A new study of an annelid challenges this view and proposes an earlier evolutionary origin in the most recent common ancestor of chordates and annelids.
authors.affiliation: Sars International Centre of Marine Molecular Biology, University of Bergen, Norway; Hopkins Marine Station, Department of Biology, Stanford University, USA. Electronic address: andreas.hejnol@sars.uib.no.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hejnol
authors.affiliation: Sars International Centre of Marine Molecular Biology, University of Bergen, Norway; Hopkins Marine Station, Department of Biology, Stanford University, USA. Electronic address: clowe@stanford.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lowe
mesh_terms: D000818:Animals; D005075:Biological Evolution; D008648:Mesoderm / Q000196:embryology*; D009672:Notochord / Q000196:embryology*; D011077:Polychaeta / Q000145:classification* / Q000196:embryology*