PIGG, KATHLEEN B.1*, MELANIE L. DEVORE2, and MARIA TCHEREPOVA1. 1Department of Plant Biology, Arizona State University, Box 871601, Tempe, AZ, 85287-1601 USA; 2Department of Biological & Environmental Sciences, Georgia College & State University, Milledgeville, GA, 31062-0001 USA. - Late Paleocene permineralized follicle from Almont, North Dakota with potential ranunculoid affinities.
Permineralized fruits from the Late Paleocene Almont flora of North
Dakota previously considered to be multiloculate fruits bearing single
seeds per locule with possible malvalean affinities are reinterpreted
as multiseeded follicles. Fruits are 1.3 cm long x 1.5 cm wide x 0.5
cm high, bilaterally symmetric, and contain tightly packed seeds that
give the internal organization of the fruit a honeycomb-like
appearance in section. Seeds have a prominent palisade outer
integumentary layer that typically splits from the inner integument.
This outer palisade layer was previously interpreted as septa
delimiting multiple locules. These fruits bear striking similarity in
structure, appearance and details of seed shape, attachment and
integumentary features to ranunculoid follicles such as those found in
Actaea, the baneberry (8 species, northern temperate Asia,
Europe and North America). As previously noted, the Almont fruits are
also similar to the single specimen known as Carpolithes
bowerbanki from the London Clay, underscoring shared floristic
elements across the Atlantic during the Paleocene-Eocene transition.
This is supported by both the distribution of Carpolithes
bowerbanki-like follicles and the present distribution
ofActaea.
Key words: Actaea, Almont, Carpolithes bowerbanki, fossil fruits, North Dakota, Paleocene