Haug Joachim T, Müller Patrick, Haug Carolin
Ludwig-Maximilians-Universität München (LMU Munich), Biocenter, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany.
GeoBio-Center at LMU, Richard-Wagner-Str. 10, 80333 München, Germany.
iScience. 2021 Sep 24;24(10):103162. doi: 10.1016/j.isci.2021.103162. eCollection 2021 Oct 22.
Aquatic larvae are known in three early branches of Pterygota: Ephemeroptera (mayflies), Plecoptera (stoneflies), and Odonata (dragonflies, damselflies). A common origin of these larvae has been suggested, yet also counterarguments have been put forward, for example, the different position of larval gills: laterally on the abdomen in Ephemeroptera, terminally in Odonata, variably in Plecoptera. We discuss recent fossil findings and report a new dragonfly-type larva from Kachin amber (Myanmar), which possesses ancestral characters such as a terminal filum, maintained in ephemeropterans, but lost in modern odonatan larvae. The new larva possesses lateral protrusions on the abdominal segments where in other lineages gills occur. Together with other fossils, such as a plecopteran retaining lateral gills on the abdomen, this indicates that lateral protrusions on the abdomen might have well been an ancestral feature, removing one important argument against the idea of an aquatic larva in the ground pattern of Pterygota.
蜉蝣目（蜉蝣）、襀翅目（石蝇）和蜻蜓目（蜻蜓、豆娘）。有人提出这些幼虫有共同的起源，但也有人提出了反对观点，例如，幼虫鳃的位置不同：蜉蝣目的鳃在腹部侧面，蜻蜓目的鳃在末端，襀翅目的鳃位置多变。我们讨论了最近的化石发现，并报道了一种来自缅甸克钦琥珀的新型蜻蜓类幼虫，它具有一些祖先特征，如末端细丝，这种特征在蜉蝣目昆虫中保留了下来，但在现代蜻蜓目幼虫中已经消失。这种新幼虫在腹部节段上有侧向突出物，而在其他类群中这些位置是鳃所在之处。连同其他化石，比如一种在腹部保留侧向鳃的襀翅目昆虫化石，这表明腹部的侧向突出物很可能是一种祖先特征，消除了反对有翅亚纲基型中存在水生幼虫这一观点的一个重要论据。
