In this chapter we describe plant fossils, mainly from the Early Cretaceous, that for various reasons cannot be assigned reliably to any extant group of angiosperms. In a few cases the relationship to angiosperms themselves is also uncertain (sections 9.1, 9.7). Some of these fossils are well-preserved floral structures, and the available information is reasonably extensive, but assignment to an extant order or family is precluded because the fossil has characters, or suites of characters, that are difficult to relate to a particular extant angiosperm group. In some instances the lack of relevant comparative data for extant taxa is also a problem. Other fossils considered in this chapter are dispersed floral parts, such as pollen, fruits and seeds. These provide further documentation of diversity among early angiosperms, but are difficult to assign to an extant group because they lack sufficient diagnostic characters.

In addition to the material discussed in this chapter there are many other fossils, especially from the Portugal and Potomac Group mesofossil floras, that remain to be described and for which relationships are not yet evaluated. A comprehensive account of these fossils is beyond the scope of this book. However, many of them probably represent early-diverging lineages of angiosperms of uncertain relationship that would probably also be included here.