title: Fossil ginkgophyte seedlings from the Triassic of France resemble modern Ginkgo biloba.
abstract: BACKGROUND
  Fossil evidence of ginkgophyte ontogeny is exceedingly rare. Early development in the extant Ginkgo biloba is characterized by a series of distinct ontogenetic stages. Fossils providing insights into the early ontogeny of ancient ginkgophytes may be significant in assessing the degree of relatedness between fossil ginkgophytes and G. biloba.
  
  
  RESULTS
  An assemblage of seedlings from the early Middle Triassic of France is assigned to the ginkgophytes based on leaf morphology. The specimens represent an ontogenetic sequence consisting of four stages: (I) formation of the cotyledons in the seed and germination; (II) development of primary leaves and taproot; (III) thickening of the taproot and appearance of secondary roots; and (IV) development of the first differentiated leaves and absence of the seed remnants.
  
  
  CONCLUSIONS
  The fossil seedlings provide a rare opportunity to examine the early ontogeny of a Triassic ginkgophyte. Germination and seedling development in the fossil are nearly identical to that of the extant gymnosperm G. biloba. We hypothesize that the fossil may be closely related biologically to G. biloba, and that certain developmental processes in seedling development were in place by the Middle Triassic.
authors: Museum of Nature South Tyrol, Bindergasse 1, Bolzano/Bozen 39100, Italy. Kathleen.Bauer@naturmuseum.it.
authors: Kathleen
authors: K
authors: Bauer
authors: Lea
authors: L
authors: Grauvogel-Stamm
authors: Evelyn
authors: E
authors: Kustatscher
authors: Michael
authors: M
authors: Krings
mesh_terms: D005580:Fossils; D005602:France; D018525:Germination; D020441:Ginkgo biloba / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development; D018515:Plant Leaves / Q000033:anatomy & histology; D036226:Seedlings / Q000033:anatomy & histology*
references: Proc Biol Sci. 2003 Aug 7;270 Suppl 1:S29-32
references: 12952628
references: BMC Evol Biol. 2010 Nov 03;10:337
references: 21044353
references: Am J Bot. 2005 Aug;92(8):1294-310
references: 21646150