Nomenclature Of Fossil Plants

Historically, paleobotanists have utilized a somewhat artificial classification system, since in almost all instances

Figure 1.77 Sheila Hanes.

and discussed with other paleobotanists. The other reason is that some identical plant parts may be attached to different plants, for example the Carboniferous lycopsid rooting organ Stigmaria, a morphogenus, has been found attached to different genera of stems. In a case like this, the name of the part is maintained, even though the entire plant has subsequently been reconstructed. The name is also maintained because fossil Stigmaria is still found unattached, and a name is necessary to describe and study the part. In addition, some fossil plant parts, despite extraordinary preservation, cannot be distinguished as belonging to only one group of plants. For example, some species of the Carboniferous foliage type Sphenopteris were borne by marattialean ferns (Chapter 11), and other species of this morphotaxon were produced by lyginopteridalean seed ferns (Chapter 16).

Since most plants are constructed of many parts, referring to the entire plant once it has been reconstructed requires a complex system of nomenclature. In general, three procedures are followed when the entire plant is reconstructed: (1) the entire organism is provided with a new name, (2) the whole organism bears the generic name of the part that has priority, that is the first part given a formal name, or (3) the whole plant is referred to informally, for example the "Lepidodendron" plant. Non-paleobotanists may find the nomenclature used in paleobotany confusing and perhaps cumbersome, but the way that fossil plants are preserved necessitates its use, and it is currently the only system that provides for an orderly arrangement of names and, most importantly, for the retrieval of information on plant parts. Some have suggested that the Linnaean system of nomenclature be abandoned for certain types of fossils, especially the use of names that suggest affinities with extant taxa when the exact affinities are unknown (Spicer, 1986, for Cretaceous and Cenozoic angiosperm leaves). Hughes (1989) championed a system in which pollen and other plant parts were given artificial names, so-called paleotaxa (Chapman and Smellie, 1992 for fossil wood), but the system has never been in wide use among paleobotanists.

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