Abstract
SynopsisFour new petrified specimens of cupules assigned toHydraspermacf.tenuisLong are described from the Cementstone Group of Oxroad Bay, East Lothian. In one of these specimens four ovules are present. Three of the specimens are interpreted as representing a pair of cupules derived from a single megasporophyll showing dichotomy so that each cupule is termed a hemi-cupule and has two lobed halves which represent quarters of the entire megasporophyll. In the fourth specimen five cupules are present, each possessing two lobed halves not sub-divided into quarters.Hydraspermais thus interpreted as showing two kinds of cupules designated mega-cupules and paired hemi-cupules. The theory is developed that angiosperm carpels have evolved from the two kinds of pteridosperm cupules.
Publisher
Cambridge University Press (CUP)
Subject
General Earth and Planetary Sciences,General Environmental Science
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