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Abstract Detail

A synthesis of new paleontological and phylogenomic perspectives on gymnosperm evolution

Looy, Cindy [1].

The evolution of Paleozoic voltzian conifers: the Majonicaceae revisited.

The voltzian conifer family Majonicaceae (voltzian Voltziales) was originally described based on fertile and vegetative materal from the late Permian of Europe. More recent finds in north-central Texas and northern Italy from deposits of the latest early Permian and the earliest middle Permian considerably extended the temporal and spatial range of this group. Members of this family are characterized by their irregular branching patterns, bifacial ovate to linear medium-sized leaves, and the morphology of the ovuliferous dwarf shoots. The dwarf shoots were organized in cones or fertile zones, had a flattened bilateral organization, lateral to adaxial ovule attachment areas, and a degree of fusion between sporophylls and sterile scales. Before the discovery of the older floras, several authors speculated about the ancestry of the Majonicaceae and it was generally inferred that they evolved from the so-called walchian conifers during the early to middle Permian. An ancestral dwarf shoot form was hypothesized having many sterile scales, a long stalk and lateral ovule attachments. Through time, transformation to more derived conditions would have included initially free dwarf shoots to become partially fused with the bract, shifts in ovule attachment positions, and a reduction of the number of sterile scales. Here I will present an overview of the known Paleozoic voltzian conifers to date, and re-evalute the evolutionairy trends in ovuliferous structures.

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1 - University of California, Berkeley, Integrative Biology, 3040 Valley Life Sciences Bldg #3140, Berkeley, CA, 94708, US

dwarf shoots

Presentation Type: Colloquium Presentations
Session: C04, A synthesis of new paleontological and phylogenomic perspectives on gymnosperm evolution
Location: 102/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 3:00 PM
Number: C04007
Abstract ID:961
Candidate for Awards:None

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