Altogether they formed at least five thousand genera and sixty thousand species-though more turn up all the time.
它们总共至少有5000属，60000种——虽然新的品种不断出现。
英语百科
Form classification
（重定向自Form genera）
Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of science is to move "form taxa" to biological taxa whose affinity is known.