112 Paleontology: Reconstructing Ecosystems

Monday, 5 November 2012
1:30 PM - 5:30 PM
217A

EXTENSIVE AND VARIED HERBIVORY FOR THE LOWER PERMIAN COLWELL CREEK POND SITE OF NORTH-CENTRAL TEXAS, USA

Paper number: 112-6
Program: Technical Sessions
Time: 2:45 PM – 3:00 PM

Authors

Abstract

The youngest Permian deposit assessed for herbivory in western equatorial Pangaea shows a far greater variety of damage types than other previously analyzed, published Early Permian deposits (Taint, Coprolite Bone Bed). Over 1,500 foliar elements from the Lower Permian (Kungurian) Colwell Creek Pond (CCP) site in Texas reveal low external foliage feeding levels but high incidences of piercing-and-sucking, oviposition, and galling. A diversity of galls were overwhelmingly represented on the peltasperm Auritifolia waggoneri. Leaves belonging to the form genus Taeniopteris suffered a high incidence and wide range of insect damage. The Gigantopteridaceae, an enigmatic seed-plant group, were represented by only one species, Evolsonia texana, which was not heavily herbivorized, in contrast to gigantopterid foliage in the two older, published floras from the same region. Incidences of new gall types add significantly to the late Paleozoic gall record and may shed light on the early transition from the Paleozoic to Modern insect fauna. In addition, there was significant presence of new scale-insect damage types on a variety of plant hosts.

This unusually robust data set gains significance as part of the iconic Pennsylvanian-Permian terrestrial section of North-Central Texas, which preserves an exceptional plant and animal record of this time period. Comparisons of the functional feeding groups represented at CCP with other sites within this section indicate that herbivory type and intensity were highly variable across habitat space during the late Paleozoic. Significantly higher incidences of insect damage occur at CCP than on Upper Permian foliage from Gondwanan South Africa, which is much better sampled than equatorial Pangaea. These qualitative and quantitative data shed light on changing plant-insect dynamics as lineages from the older late Paleozoic and the emerging Modern insect faunas coexisted until the end-Permian Extinction.