For example, the planktonic larvae of many marine invertebrates are commonly described as separate species when they are first discovered in the ocean. Only later when they can be reared in the laboratory can the link to their adult form be recognized. Similarly, the different life stages of many fungi are given different names because they have different physical forms and hosts. Only through detailed inoculation studies can mycologists work out which forms are members of the same life cycle. Since some fungi may have more than five discrete life cycle stages, this can be a long process.
Similar problems exist for some marine algae and multiple-host parasitic organisms of many kinds.
Even among well-studied vertebrates, some tropical birds have been described as separate species until they are observed to mate and rear young together. Not all plants in a given community are equally likely to find their way into the fossil record. Processes of fossilization often favor large or woody plants with resistant tissues over small herbs. Likewise, wind dispersed pollen is much more common in the fossil record than pollen dispersed by animals. Environmental Level Plant preservation depends on removing the organic material from the zone of aerobic decomposition.