Phylogeny and Classification

In contrast to that of the other paleopteran order, the Ephemeroptera, the fossil record of the Odonata is remarkably extensive. Carpenter (1992) suggested that the aquatic juvenile stage and the tendency of adults to remain near water would favor the fossilization of these generally robust insects. According to Carpenter (1992), the earliest odonates (from the Permian) belonged to the entirely fossil suborders Protanisoptera and Archizy-goptera. Other suborders include the Triadophlebiomorpha (Triassic), Anisozygoptera (Triassic—Cretaceous), Anisoptera (Jurassic—Recent) and Zygoptera (Jurassic—Recent). The Odonata underwent a rapid evolution during the Triassic period, and in the Jurassic Period, Anisozygoptera were especially abundant. Originally, two extant species of Epio-phlebia, described from Japan and the Himalayas, were placed in this suborder. However, with more information it has become clear that Epiophlebia is an early anisopteran offshoot, in the superfamily Epiophlebioidea. By the Late Jurassic, representatives of recent families of Zygoptera and Anisoptera were already in existence.

Some early authorities suggested that ancient zygopterans were the group from which the remaining Odonata evolved. In this proposal, an early dichotomy led, on the one hand, to the modern groups of Zygoptera, and, on the other, through the Anisozygoptera to the Anisoptera. However, the abundant fossil evidence for the Odonata shows that these three suborders arose contemporaneously; that is, no one suborder gave rise to the others. The higher-level relationships of Odonata remain controversial, with markedly different hypotheses being generated, depending on the type and quantity of information used in the analysis (compare Trueman [1996], Bechly etal. [1998], Misof [2002], and Rehn [2003]). Thus, at one extreme, the question of whether the Zygoptera are monophyletic continues to be debated, while at the other, the make-up of some families (i.e., whether they are monophyletic, paraphyletic, or polyphyletic) remains unresolved. A suggested proposal for the relationships of the extant groups of Odonata is shown in Figure 6.10. In this scheme the monophyletic Zygoptera fall into three superfamilies, Calopterygoidea being the sister group to the Lestinoidea (paraphyletic) + Coenagrionoidea. In the Anisoptera, the

Paleoptera

FIGURE 6.10. Proposed phylogeny of extant Odonata.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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