Questions for Further Thought

1. What clues from the rock record or the fossils themselves might tell you whether a fossil assemblage was autochthonous, transported only a little bit, or truly allochthonous?
2. Common co-occurrence in the fossil record is the weakest evidence for uniting disbursed organs into a single whole-plant species. What other processes (taphonomic, ecologic, or biologic) might generate such a pattern? How might you distinguish patterns produced by these processes from that produced by a single species shedding organs together?
3. Why is pollen dispersed by wind more likely to enter the fossil record than that dispersed by animals? List two different reasons.
4. If you have a plant community that includes both wind-pollinated and animal-pollinated members, how will the palynological record (pollen in the fossil record) reflect the living community? Will all species be present? Will the relative abundance of pollen in the fossil record match the relative abundance of individual plants in the community? If you are interested in reconstructing the relative abundance of plants in the ancient community, how might you transform your palynological data to account for the differences in relative abundance between wind- and animal-pollinated species?
5. We mentioned that most environments of deposition where plant fossils are preserved are wet. Describe a water-free environment where plant fossils could be preserved?
6. Most coal balls contain a mixture of plant parts from many taxa. What features suggest whether a coal ball formed soon or long after deposition of the peat? (Look at polished surfaces or thin sections of a few examples before trying to answer.) How can you demonstrate that permineralization does not involve replacement of cell-wall organic material?

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