FIGURE 2 Exceptional preservation of fossil terrestrial arthropods. (A) Centipede from Upper Devonian (New York). (Courtesy of William Shear, Hampton-Sydney College.) (B) Mycetobia woodgnat in Miocene amber (Dominican Republic), with parasitic nematodes bursting from abdomen. (C-E) Flight muscles of meliponine bee in Dominican amber, showing ultrastructural preservation of myofibrils (D) and even the fingerprint-like mitochondria (E). (F) Silicified replicas of early instar dytiscoid beetle, from Miocene of California (inset, photomicrograph; SEM is larger). (G) Cuticular remains of extant beetle species from the Wisconsin stage (ca. 10,000-80,000 years ago) of Alaska (left, weevil head; right, carabid elytron).
FIGURE 5 Representative Mesozoic (A-F) and Cenozoic (G, H) insects (not to the same scale). (A) Primitive, oldest known thysano-pteran (Triassic, Virginia). (B) fProtorhyphidae (Diptera) (Jurassic, Kazakhstan). (C) Sphecidae (Cretaceous, Brazil). (D) Oldest known zorapteran (Cretaceous amber, Burma). (E and F) Oldest definitive ants [Formicidae; Sphecomyrma (E), Kyromyrma (F)] (Cretaceous amber, New Jersey). (G) Large, extinct tsetse fly (Diptera: Glossinidae) (Upper Eocene/Late Oligocene, Colorado). (H) Spoon-winged lacew-ing (Neuroptera: Nemopteridae) (Colorado).
consisted entirely of primitive symphytans; the Diptera consisted of diverse nematocerans. fTitanoptera were restricted to the Triassic and the size of some species fit their name (e.g., Gigatitan, ca. 33-cm wing span). Others were no larger than typical orthopterans, to which they are probably most closely related. They may have been Early Mesozoic analogues of the predatory mantises because their forelegs, when preserved, were spiny and apparently raptorial.