具有肿胀的第一跗跖节的侏罗纪蝎蛉（长翅目），表明存在两性异形。
Jurassic scorpionflies (Mecoptera) with swollen first metatarsal segments suggesting sexual dimorphism.
作者信息
Zhang Yan-Jie, Shih Peter J M, Wang Jun-You, McNamara Maria E, Shih Chungkun, Ren Dong, Gao Tai-Ping
机构信息
College of Life Sciences and Academy for Multidisciplinary Studies, Capital Normal University, 105 Xisanhuanbeilu, Haidian District, Beijing, 100048, China.
Academy for Allied Health Sciences, 1776 Raritan Road, Scotch Plains, NJ, 07076, USA.
出版信息
BMC Ecol Evol. 2021 Mar 20;21(1):47. doi: 10.1186/s12862-021-01771-3.
BACKGROUND
Sexual dimorphism is widespread in insects. The certain specialized structures may be used as weapons in male-male combats or as ornaments to enhance mating opportunities.
RESULTS
We report striking swollen first tarsal segments in two families, four genera and six species of scorpionflies from the Middle Jurassic Yanliao Biota of Northeastern China. Swollen tarsal segments are restricted to male specimens and to hind leg tarsi. The geometric morphometric analyses reveal that the degree of swelling within the orthophlebiid species possessing swollen first metatarsal segments is species-specific, which can be used as a diagnostic character for taxonomic and phylogenetic studies.
CONCLUSIONS
The new findings indicate that swollen first metatarsal segments are relatively common in the family Orthophlebiidae during the Middle Jurassic. The tarsal swellings are considered to be sexually dimorphic, potentially associated with sexually display by males and/or camouflage of a "nuptial gift" in the mating process.
背景
性二态性在昆虫中广泛存在。某些特化结构可在雄性间争斗中用作武器，或作为增强交配机会的装饰。
结果
我们报道了来自中国东北中侏罗世燕辽生物群的蝎蛉科两个亚科、四个属和六个物种的显著肿胀的第一跗节。肿胀的跗节仅限于雄性标本和后足跗节。几何形态测量分析表明，具有肿胀第一跖节的直脉蝎蛉科物种内部的肿胀程度具有物种特异性，可作为分类学和系统发育研究的诊断特征。
结论
新发现表明，在中侏罗世，肿胀的第一跖节在直脉蝎蛉科中相对常见。跗节肿胀被认为是性二态性的，可能与雄性的性展示和/或交配过程中“婚飞礼物”的伪装有关。
Zotero 插件