内蒙古自治区上侏罗统最原始的蠼螋昆虫化石(昆虫纲:革翅目:始螋亚目)(英文)

THE MOST PRIMITIVE EARWIGS (ARCHIDERMAPTERA, DERMAPTERA, INSECTA) FROM THE UPPER JURASSIC OF NEI MONGGOL AUTONOMOUS REGION, NORTHEASTERN CHINA

我国上侏罗统牛津阶—基末利阶 (163— 15 0 Ma)保存有完好的最原始的蠼螋昆虫化石。首次描述、分析和讨论了原始蠼螋后翅脉序特征 ,认为与现代生存的蠼螋后翅基本相同。因此 ,提出了与西方某些蠼螋昆虫分类学者不同的意见 ,认为始螋亚目 (Aechidermaptera)应归入于革翅目 (Dermaptera)之中 ,且视其为一个最原始的类群较为合理。内蒙古自治区这个原始类群的下列重要特征皆为首次发现 :胸骨具有特殊的形态结构 ;革翅锁具 (Tegminalocking device)和刺脊突 (spiny crest)发育 ;前、中、后足跗节皆为 5节 ;后足基节显著伸长 ;颈部被划分为前、后两个颈片 ;革翅后缘收缩变尖。上述 5项被视为最原始蠼螋特有的祖征。下列特征应为早期蠼螋共有的原始性状 :虫体扁平 ,通常具毛 ;腹部侧缘彼此近平行 ;触角显长 ,丝状 ,多节 (通常多于 11节 ) ;两只单眼发育 ;上颚具齿 ;中胸小盾片显大 ;革翅较长 ,通常具有明显的翅脉 ;股节具隆脊 ;爪和爪垫通常发育 ;腹部各节背板与腹板不重叠 (两者位置非简单的上、下关系 ) ;尾须柔软、多节 ;雌性产卵器鞘显著外伸。本文建立了始螋亚目 1新科 Sinopalaeo-dermatidae和 2新属 2新种 Sinopalaeodermata neimonggolensisgen.etsp.nov.,Jurassimedeola orientalis gen.etsp.nov.。

The most primitive earwigs were discovered from the Oxfordian-Kimmeridgian(corresponding to an age of 163 to 150 million years) of Upper Jurassic of China. They are identified as undoubted earwigs by the typical earwig-like venation of the hindwing, a character first illustrated in these fossils. This feature is wanting in all other fossils reported to be the most primitive earwigs. Three thoracic sterna show the special pattern and structures that are first described in this work and, are unknown in other sister-groups of Archidermaptera within Dermaptera. The tegmina locking device and spiny crests are strongly developed. Tarsi of all three pairs of legs are clearly five-segmented. Hindleg coxae are distinctly elongated. The posterior margins of the tegmina are produced into a tip. Neck is divided into anterior and posterior two proportions. These five diagnoses are considered as unique, plesiomorphic properties in these fossils and are the most primitive known earwigs. The following basic characters also are present in other early dermapterans: a compressed body; body vestiture of hairs; lateral margins of abdomen nearly parallel; antennae elongated, filiform and multi-segmented; two well developed ocelli and eyes; denticulate mandibles; mesoscutellum much enlarged; tegmina relatively long and armed with obvious veins;femora armed with keels; claws and arolia fully developed; abdominal tergites apparently not overlying the edges of sternites; soft and multi-segmented cerci; and prominent vaginulae. A new family, Sinopalaeodermatidae, and two new genera and two new species, Sinopalaeodermata neimonggolensis and Jurassimedeola orientalis, are described to accommodate these fossils. The origin and evolution of earwigs are reassessed.