Abstract Detail

Mesozoic and Cenozoic plant evolution and biotic change: A symposium in honor of Ruth Stockey

Stockey, Ruth A. [1], Atkinson, Brian A. [2], Rothwell, Gar W. [3], Buczkowski, Emma [1], Beard, Graham [4].

A cunninghamioid pollen cone cluster from the Appian Way (Eocene) of Vancouver Island.

A large pollen cone cluster attached to a cunninghamioid twig and surrounded by leaves has been identified from Eocene calcium carbonate marine concretions from the Appian Way locality on Vancouver Island, British Columbia, Canada. The cluster preserves 19-22 cones, but probably bore at least 24 pollen cones based on cone placement in the cluster. Cones are helically arranged around the tip of an ultimate leafy branch that terminates in scale leaves, each showing a central resin canal and sometimes two smaller lateral canals. The twig on which the cones are borne has a parenchymatous pith surrounded by a ring of secondary xylem five-to-seven cells thick, a parenchymatous cortex with numerous resin canals, and a hypodermis of thick-walled cells. Vegetative leaves on the twig are amphistomatic, showing typical cunninghamioid anatomy with a large central resin canal that is abaxial to the vascular bundle, an elongate zone of transfusion tissue, a non-plicate mesophyll, and a hypodermis 3-4 cells thick. Each pollen cone is produced in the axil of a bract and has three scale leaves surrounding the base of the cone axis. Individual pollen cones consist of a cone axis with helically arranged microsporophylls, each with a central resin canal. While the cones are immature, pollen sacs with pollen are present in several cones. There are 3 elongate, abaxial pollen sacs per microsporophyll. The exine shows granular orbicules and no papilla is evident. This cluster provides the first anatomically preserved fossil evidence for the pollen cones of Cunninghamia. It shows a large number of similarities to the pollen cone clusters of extant C. lanceolata and the Late Cretaceous C. taylorii, further strengthening hypotheses for a basal position of cunninghamioids within the Cupressaceae, and that some Cunninghamia species have remained relatively unchanged since at least the mid-Cretaceous.

1 - Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331, USA
2 - Oregon State University, Botany And Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331, USA
3 - Oregon State University and Ohio University, Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, OR, 97331, US
4 - Qualicum Beach Paleontology Museum, Qualicum Beach, BC, V9K 1S7, Canada

Keywords:
Pollen cone
Cunninghamioid
fossil
Eocene
Cupressaceae.

Presentation Type: Colloquium Presentations
Session: C6
Location: Salon 5/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 5:00 PM
Number: C6014
Abstract ID:423
Candidate for Awards:None