†Kryptovelona carstengroehni gen. et sp. nov. and †Orussus juttagroehnae sp. nov. are the first female members of the parasitoid wasp family Orussidae recorded from Baltic amber. We describe them, including relevant parts of the internal anatomy examined with synchrotron scanning. The fossils display a number of modifications in the antennae and foreleg correlated with the specialized host-detection mechanism, and in the ovipositor apparatus, as well as in the thorax and abdomen for accommodating the internalized ovipositor. The presence of these and other features places them as crown-group members of the Orussidae, as demonstrated by Bayesian phylogenetic analyses. The recently described stem-group orussoid fossils from Burmese amber, the probable female †Cretorussus vilhelmseni, and probable male †Burmorussus mirabilis (both placed in Burmorussidae), were also included in the dataset. By comparing the new Baltic amber taxa with †Cretorussus, it is possible to trace the progressive refinement of the echolocation mechanism through reductions in the number of antennomeres and foreleg tarsomeres. Unfortunately, †Cretorussus does not have the posterior part of the abdomen with the ovipositor preserved. Nevertheless, it is possible to infer that the putative echolocation mechanism for host detection evolved at least 100 Mya, whereas the concealed ovipositor apparatus has not been documented in fossils older than approx. 35 Mya.

中文翻译：

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白垩纪的回声：新化石揭示了寄生蜂超科 Orussoidea（膜翅目）宿主检测和隐藏产卵器的进化

†Kryptovelona carstengroehni gen。等 十一月 和 †Orussus juttagroehnae sp。十一月 是从波罗的海琥珀中记录到的寄生蜂科 Orussidae 的第一批雌性成员。我们描述了它们，包括通过同步加速器扫描检查的内部解剖结构的相关部分。这些化石显示出与专门的宿主检测机制相关的触角和前腿、产卵器以及用于容纳内化产卵器的胸部和腹部的许多修改。正如贝叶斯系统发育分析所证明的那样，这些特征和其他特征的存在使它们成为 Orussidae 的冠群成员。最近描述的来自缅甸琥珀的干群 Orussoid 化石，可能的雌性 †Cretorussus vilhelmseni 和可能的雄性 †Burmorussus mirabilis（均属于 Burmorussidae），也包含在数据集中。通过将新的波罗的海琥珀类群与†Cretorussus进行比较，可以通过触角和前肢跗节数量的减少来追踪回声定位机制的逐步完善。不幸的是，†Cretorussus 的腹部后部没有保留产卵器。然而，可以推断，用于宿主检测的推定回声定位机制至少在 100 Mya 进化而来，而隐藏的产卵器尚未在大约 100 Mya 之前的化石中记录下来。35 米娅。