Abstract Detail

Paleobotanical Section

Benca, Jeffrey [1], Stromberg, Caroline [1], Carlisle, Maureen  [2].

Morphological variation in the panglobal Devonian lycopsid genus Leclercqia: A new species from Washington state.

The basal lycopsid genus Leclercqia had a vast biogeographic range, inhabiting both Gondwana and Euramerica during the Early-Middle Devonian (~400-385 Ma). Despite its broad distribution, only two species have been described to date (L.complexa and L. andrewsii). A new Middle Devonian flora in northern Washington State has yielded a new morphotype for the genus. To determine whether this morphotype represents a new species, we developed a series of measurements capturing vegetative and reproductive morphology to assess the morphological and taxonomic diversity within the genus. Analysis of Variance (ANOVA) of measurements shows that the new morphotype from the Chilliwack Group is statistically significantly different from both L. complexa and L. andrewsii in four out of twelve characters, L. complexa in ten out of twelve characters, and L. andrewsii in nine out of twelve characters. In addition, L. complexa shows statistically significant differences from L.andrewsii in nine of the twelve characters measured. Multivariate techniques using vegetative characters similarly separate the new morphotype from L. complexa and L. andrewsii. To test whether intraspecific and interspecific variation are distinguishable in modern lycopsids, these same analyses were used to compare extant variants and species of Lycopodium. The analyses showed that biological species are distinguishable from one another while intraspecific variants are not. Based on these results, we suggest the addition of a new species to the genus: Leclercqia scolopendra. Additionally, intraspecific comparison of L. complexa from localities spanning six continents showed that some regional morphological variation exists within this species, providing another possible line of evidence for continental proximities during the Early-Middle Devonian. This study represents the first global morphometric analysis of a Devonian lycopsid genus and demonstrates that this method can be used to quantify degrees of taxonomic and morphological diversity between and within long-extinct plant groups using relatively few diagnostic features.

Broader Impacts:

1 - University of Washington, Biology, 24 Kincaid Hall, Box 351800, Seattle, WA, 98195-1800, USA
2 - Burke Museum, University of Washington, Box 353010, Seattle, WA, 98195-301, USA

Keywords:
Leclercqia
Lycopsids
interspecific
intraspecific
morphometrics.

Presentation Type: Oral Paper:Papers for Sections
Session: 06
Location: Lindell C/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 8:45 AM
Number: 06001
Abstract ID:181