Abstract Detail

Paleobotanical Section

Ryberg, Patricia E. [1], Stockey, Ruth A. [2], Hilton, Jason [3], Riding, James B. [4], Rothwell, Gar W. [5].

Early evolution of Pinaceae: an anatomically preserved Pinus seed cone from the Early Cretaceous of Yorkshire.

An ovulate cone from the Geology collection of the University of Birmingham has morphological and anatomical features similar to the extant genus Pinus. The palynological assemblage from attached sediment dates the cone as part of the Speeton Clay Formation of the Purbeck Group from the coast of North Yorkshire, England, dated as Verriasian to Albian (Early Cretaceous). The cone measures approximately 2.5 cm in width and 10 cm in length with bract/scale complexes arranged helically around the cone axis. Pith tissue is incompletely preserved and the presence of sclerenchyma or resin canals is unknown. Vascular tissue is preserved in some portions and consists of a continuous cylinder of secondary xylem with uniseriate rays. Resin canals are not observed in the vascular cylinder. The cortex contains a ring of large resin canals that extend into the bracts and scales. The bract subtending the ovuliferous scale is free its entire length. Scales diverge from the cone axis at a 90 degree angle for approximately 1.5 mm then curve upward. The scale contains thin-walled parenchyma adaxial to the vasculature, abaxially the scale contains thick walled cells that run the length of the scale and fill the abaxial and marginal regions of the apophysis. Two resin canals, lateral to the scale trace, enter each scale and divide forming a row of 10-12 resin canals abaxial to the vasculature in the distal portion of the scale. Each scale contains two anatropous winged seeds on the adaxial surface. The wings are fused to the base of the scale and free for two-thirds the length of the wing. Megagametophyte tissue and embryos are preserved within some seeds. This cone represents a new fossil species of Pinus. It is the second fossil pine cone from the European Cretaceous, and possibly the oldest seed cone of the genus.

Broader Impacts:

1 - Ohio University, Environmental and Plant Biology, Porter Hall, Athens, Ohio, 45701, USA
2 - University of Alberta, Department of Biological Sciences, Biological Sciences Centre, Cw 405, Edmonton, Alberta, T6G 2E9, Canada
3 - University of Birmingham, Earth Sciences, School of Geography, Earth and Environmental Science, Edgbaston, Birmingham, B15 2TT, U.K.
4 - British Geological Survey, Nottingham, NG12 5GG, UK
5 - Ohio University, Department of Environmental and Plant Biology, Athens, OH, 45701, USA

Keywords:
Conifer
Fossil
Lower Cretaceous
Pinus
Seed Cone
Yorkshire.

Presentation Type: Oral Paper:Papers for Sections
Session: 32
Location: 555A/Convention Center
Date: Tuesday, August 3rd, 2010
Time: 10:15 AM
Number: 32001
Abstract ID:98