  Images taken with the IRAC instrument on the Spitzer Space Telescope show
that the spatial distribution of warm dust emission in lenticular galaxies is
often organized into dynamically-stable structures strongly resembling spiral
arms. These galaxies have bulge-to-disk-ratios and colors for their stellar
content appropriate for their morphological classification. Two of the three
galaxies with warm dust detected at 8.0 um also show far-IR emission expected
from that dust. More importantly, the [5.8]-[8.0] color of the dust emission
matches the colors found for late-type, star-forming galaxies, as well as
theoretical predictions for PAH emission from dust grains. The spatially
resolved dust structures may be powerful indicators of the evolutionary history
of the lenticular class of galaxies, either as a tracer of on-going quiescent
star formation or as a fossil record of a previous episode of more active star
formation.
