Anatomical and developmental study of petrified Quercus (Fagaceae) fruits from middle Miocene, Yakima Canyon, Washington, USA

Sandra J. Borgardt, Kathleen Pigg

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The first reported petrified acorns to show internal anatomical structure are here described from Middle Miocene (~15.6 million years old) chert of the Columbia River Basalt Group in Yakima Canyon, Washington. Quercus hiholensis Borgardt et Pigg sp. nov. is described from anatomical and morphological fruit features, as well as a little recognized anatomical feature, the umbilical complex. Acorns, each comprising a nut and its cupule, are up to 15.3 mm long and 18.8 mm wide with helically arranged, imbricate, tuberculate cupule scales. They show basal aborted ovules, short styles, broad stigmas, and lack grooves in their cotyledons. These characters and the developmental pattern seen in these fossil acorns demonstrate that Q. hiholensis conforms to genus Quercus (Fagaceae), subgenus Quercus, section Quercus (the white oaks). The correspondence of Q. hiholensis to the modern section Quercus reveals that the derived floral and fruit characters that distinguish section Ouercus within the genus had evolved by the Middle Miocene.

Original languageEnglish (US)
Pages (from-to)307-325
Number of pages19
JournalAmerican Journal of Botany
Volume86
Issue number3
DOIs
StatePublished - 1999

Keywords

  • Acorn
  • Cupule
  • Fagaceae
  • Fossil
  • Fruit
  • Middle Miocene
  • Paleobotany
  • Quercus

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Plant Science

Fingerprint Dive into the research topics of 'Anatomical and developmental study of petrified Quercus (Fagaceae) fruits from middle Miocene, Yakima Canyon, Washington, USA'. Together they form a unique fingerprint.

  • Cite this