title: A species' Odyssey: evolution of obstetrical mechanics from Australopithecus Lucy to nowadays.
abstract: OBJECTIVE
  Study of obstetrical mechanics of Australopithecus Lucy, Homo neanderthalensis and Homo erectus relative to modern Homo sapiens and the Catarrhines.
  
  
  METHODS
  The material comprised a total of 360 pelves: 3 fossil pelves reconstructed using casts (Australopithecus afarensis Lucy or AL 288-1, Homo erectus KNM-WT 15000, H. neanderthalensis or Kebara 2), 305 female modern adult pelves and 52 female Catarrhine pelves (29 gorillas, 18 chimpanzees, 5 orang-utans). All these pelves were reconstructed in order to carry out 11 pelvimetric measurements. Each measurement was carried out twice and by two different operators.
  
  
  RESULTS
  The pelvis of Lucy was platypelloid at each pelvic plane. The pelvic inlet of H. neanderthalensis was anteroposteriorly oval whereas the midplane and the outlet were transversely oval. The pelvis of H. erectus was globally round. In modern women, the inlet was transversely oval. The pelvic midplane and outlet were anteroposteriorly oval. In the great apes, the shape of all three pelvic planes was anteroposteriorly oval. The discriminating value of the various pelvimetry measurements place Australopithecus Lucy, H. neanderthalensis Kebara 2, and H. erectus KNM-WT 15000 close to modern humans and less similar to the great apes.
  
  
  CONCLUSIONS
  Obstetrical mechanics evolved from dystocic delivery with a transverse orientation in Australopithecus to delivery with a modern human-like rotational birth and an increase in the anteroposterior diameters in H. erectus, H. neanderthalensis and modern H. sapiens.
authors.affiliation: Department of Gynecology and Obstetrics, CHU of Saint-Etienne, 42023 Saint-Etienne, France; Department of Gynecology, HFME, CHU of Lyon, 69000 Lyon, France. Electronic address: chenegautier@yahoo.fr.
authors.forename: G
authors.initials: G
authors.lastname: Chene
authors.affiliation: Department of Gynecology and Obstetrics, Hospital of Firminy, Firminy, France.
authors.forename: A-S
authors.initials: AS
authors.lastname: Tardieu
authors.affiliation: Department of Medical Information, CHU of Saint-Etienne, Saint-Etienne, France.
authors.forename: B
authors.initials: B
authors.lastname: Trombert
authors.affiliation: Department of Rheumatology, CHU of Saint-Etienne, Saint-Etienne, France.
authors.forename: A
authors.initials: A
authors.lastname: Amouzougan
authors.affiliation: Department of Gynecology, HFME, CHU of Lyon, 69000 Lyon, France.
authors.forename: G
authors.initials: G
authors.lastname: Lamblin
authors.affiliation: Department of Gynecology, HFME, CHU of Lyon, 69000 Lyon, France.
authors.forename: G
authors.initials: G
authors.lastname: Mellier
authors.affiliation: Department of Paleoanthropology, Collège de France, Paris.
authors.forename: Y
authors.initials: Y
authors.lastname: Coppens
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D005260:Female; D006071:Gorilla gorilla / Q000033:anatomy & histology; D015186:Hominidae / Q000033:anatomy & histology*; D006801:Humans / Q000033:anatomy & histology; D007743:Labor, Obstetric; D059125:Neanderthals / Q000033:anatomy & histology; D002679:Pan troglodytes / Q000033:anatomy & histology; D010384:Pelvic Bones; D010387:Pelvimetry; D057079:Pongo / Q000033:anatomy & histology; D011247:Pregnancy
keywords: Australopithecus afarensis; Homo erectus; Homo neanderthalensis; Lucy; Obstetrics; Pelvis