Abstract Detail

Lightning Talks – Germinating Ideas

Fossilized Miocene midge galls from Washington and Idaho.

Herbivory damage on fossilized leaves often can be correlated with a similar patterns on modern analogs to infer the existence of certain insect taxa. Galls from the gall midge Taxodiomyia cupressiananassa (Cecidomyiidae) occur in extant taxa of Taxodium in the southeastern US, and galls with the same distinct morphology are found on fossil Taxodium species from Miocene deposits in Yakima Canyon in central Washington and Emerald Creek in central Idaho. Remains of the actual insect are rare due to the conditions that make the fossil and the size of the midge, and until now, the gall proper has been a proxy for the insect. The Emerald Creek specimens consist of leaf compressions of Taxodium foliage with galls attached. The Yakima Canyon fossils are anatomically preserved small twigs and found in the round that show both the external morphology and internal structure of the gall. My research investigates the correlation between the fossil galls and extant galls on Taxodium. In this study I hope to find evidence of the insect with serial sections of the Yakima fossils and CT scans of fossils from both localities to answer the following questions: 1) Can the fossil galls be interpreted to represent related species of extant Taxodiomyia? 2) Can we use CT scans to discover body remains of insects in these galls? 3) Can we identify corresponding gall layers in both fossil and extant galls using CT scans? 4) Are the fossil insects closely related to the modern taxa? 5) What do these findings say about Miocene environment in the fossil sites? Addressing these questions will further our knowledge of the biogeography and community development of Southeastern wetlands since, today, Taxodium is a keystone species in these wetlands.

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Keywords:
paleobotany
Paleoentomology
plant-insect ecology.

Presentation Type: Germinating Ideas Lightning Talk
Number: LT2016
Abstract ID:741
Candidate for Awards:None