A new species of Baeomorpha (Hymenoptera, Rotoitidae) from mid-Cretaceous Burmese amber

Abstract

A fossil species from mid-Cretaceous Burmese amber, Baeomorpha liorum Huber, Shih & Ren, sp. nov. (Rotoitidae: Hymenoptera), is described and illustrated. Its relationship to other extinct and extant taxa of Rotoitidae is discussed. The location of the amber deposits in which this species was found is well south of the “Baeomorpha Realm” proposed by previous authors who suggested that the origin and diversification of Rotoitidae occurred in North Laurasia. Based on the Burmese specimens, we suggest instead that the most parsimonious explanation for the past and present distribution of the family is to assume that Rotoitidae is an ancient lineage of Chalcidoidea that was originally widespread in suitable habitats across both Laurasia and Gondwana and later became extinct everywhere except Chile and New Zealand where the two extant genera occur.

The Chalcidoidea bush of life – a massive radiation blurred by mutational saturation

“…The fossil record shows that Baeomorphidae were largely distributed in Laurasia, but also on the Myanmar terrane, between the lower Cenomanian and the Campanian (98.2-72.1 Ma) (Gumovsky et al 2018;Huber et al 2019), which suggests, in the framework of our scenario, a long northward dispersal. Our results contradict the hypothesis of a Laurasian origin for Baeomorphidae (Gumovsky et al 2018) that has been made outside of a formal phylogenetic framework.…”

The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps

“…In addition, the split between peloridiids from Chile and New Zealand [98 Ma (46–155 Ma); Ye et al., 2019) is close to our estimate for Baeomorphidae and corroborates our time‐scale for Chalcidoidea. The fossil record shows that Baeomorphidae were largely distributed not only in Laurasia, but also on the Myanmar terrane, between the lower Cenomanian and the Campanian (98.2–72.1 Ma; Gumovsky et al., 2018; Huber et al., 2019), which suggests, in the framework of our scenario, a long northward dispersal. Our results contradict the hypothesis of a Laurasian origin for Baeomorphidae (Gumovsky et al., 2018) that has been made outside of a formal phylogenetic framework.…”

“…But the uncertain affinities of this fossil precluded its use in our analyses. The oldest unambiguous chalcid fossils are a Mymaridae [ Myanmymar aresconoi des; Poinar Jr. and Huber, 2011] and a Baeomorphidae ( Baeomorpha liorum ; Huber et al., 2019) from Myanmar (Burmese) amber (minimum age 98.2 Ma; see rationale for calibration priors in the Supporting information Materials and Methods). Species of Baeomorphidae are also frequent in Cretaceous ambers of the Northern Hemisphere [in the retinites of Baikura (minimum age 94.3 Ma) and of Yantardakh (minimum age 83.6 Ma; Gumovsky et al., 2018), and Canadian ambers of Cedar Lake and Grassy Lake, which are Campanian in age (83.6–72.1 Ma; McKellar et al., 2008)].…”

A golden age for ectoparasitoids of Embiodea: Cretaceous Sclerogibbidae (Hymenoptera, Chrysidoidea) from Kachin (Myanmar), Charentes (France) and Choshi (Japan) ambers

“…Following analysis of Cretaceous faunas, two zoogeographic realms of the Northern Hemisphere ("Baeomorpha" and "Isoptera") were recognized (Gumovsky et al, 2018): the Baeomorpha Realm, with a temperate or warm temperate climate, characterized by the presence of very numerous and diverse parasitic wasps of the genus Baeomorpha (Rotoitidae), very abundant aphids (eight families of four superfamilies endemic to this realm), few termites, and no webspinners; and the Isoptera Realm (Fig. 15), which had a warmer climate, contained almost no Rotoitidae (Huber et al, 2019), no or few aphids (often with strongly reduced hind wings), but with abundant and diverse termites and webspinners (Perkovsky and Vasilenko, 2019). Here, we demonstrate the abundance and diversity of webspinners in the Isoptera realm (inferred by sclerogibbids as a proxy for the presence of webspinners in the Cretaceous Old World that belonged to this Realm).…”