492
11.7.2 Evanioidea (Ensign Wasps)
Evanioidea (ensign wasps) also illustrate the diversification of Hymenoptera during
phases 1 and 2 of the MMPR, reaching successive stepwise increases in species
richness during phases 1 and 2 of the Middle Jurassic to Early Cretaceous as the
major non-proctotrupomorph lineage (Table 11.1; Fig. 11.19, pink dot trajectory).
Evanioidea are a moderately diverse superfamily of parasitoid wasps that are characterized by two apomorphies (Li et al. 2018a). First, the metasoma is attached high
on the propodeum (Goulet and Huber 1993; Grimaldi and Engel 2005a), hence
designation of the group as ensign wasps. Second, all functional metasomal spiracles are lost except on the seventh segment (Goulet and Huber 1993; Grimaldi and
Engel 2005a). Historically, the superfamily Evanioidea included the three extant
families of Evaniidae, Gasteruptiidae and Aulacidae, and later five extinct families
from the Mesozoic were added, the Andreneliidae, Anomopterellidae, Baissidae,
Othniodellithidae and Praeaulacidae (Rasnitsyn 1972, 1975; Rasnitsyn and
Martínez-Delclòs 2000; Engel et al. 2016b). Subsequently, additional ensign wasps
were reported, including Exilaulacus loculatus (Li et al. 2018a) from midCretaceous Myanmar amber (Fig. 11.28), which was followed in the same report by
a preliminary phylogeny of Evanioidea. This phylogeny resulted from morphology
and DNA sequence data of selected fossil and extant genera that employed two
phylogenetic analytical methods: maximum parsimony and Bayesian inference (Li
et al. 2018a). Several distinctive relationships within Evanioidea resulted from the
phylogenetic analyses (Fig. 11.29). First, the extinct family Praeaulacidae is paraphyletic and occurs at the base of Evanioidea in-groups. Second, Anomopterellidae
is a monophyletic clade and is the sister clade to the remaining families. Third,
Aulacidae, Baissidae and Gasteruptiidae do not form a monophyletic clade. Fourth,
Othniodellithidae is a monophyletic clade in a position that is more basal to the
Andreneliidae + Evaniidae clade. Fifth, Andreneliidae is the sister clade of
Evaniidae, and both lineages are monophyletic clades. These results provided clarity to previous, mostly ambiguous, results regarding Evanioidea phylogeny. The
inclusion of all evanioid genera, especially fossil taxa, provided a straightforward perspective of Evanioidea phylogenetic events accompanying phases 1 and 2
of the MMPR.
Based on 59 genera and 171 described fossil species of Evanioidea (Zhang and
Rasnitsyn 2008; Li et al. 2013a, 2018a), histograms show the frequency of
Evanioidea species, genera and family richness during a 169 million-year-long
interval from Middle Jurassic to Miocene (Li et al. 2018a; Fig. 11.30a). From these
geochronologic, epoch-level data (Fig. 11.30a), a relatively flat level of genus-level
richness existed throughout the Mesozoic from 174 to 5 Ma, followed by a considerable decline in the transition to the Cenozoic, and ending in a flat, low level of
richness from the mid Eocene to the mid Miocene spanning approximately 40–14
million years ago. Although species-level richness during this time interval is considerably more variable and accentuated, the general pattern is similar to that of
generic richness, with both reaching a peak during the Early Cretaceous, followed
by a distinct downturn and low levels of occurrences thereafter during the Cenozoic.
C. C. Labandeira and L. Li
11.7.2 Evanioidea (Ensign Wasps)
Evanioidea (ensign wasps) also illustrate the diversification of Hymenoptera during
phases 1 and 2 of the MMPR, reaching successive stepwise increases in species
richness during phases 1 and 2 of the Middle Jurassic to Early Cretaceous as the
major non-proctotrupomorph lineage (Table 11.1; Fig. 11.19, pink dot trajectory).
Evanioidea are a moderately diverse superfamily of parasitoid wasps that are characterized by two apomorphies (Li et al. 2018a). First, the metasoma is attached high
on the propodeum (Goulet and Huber 1993; Grimaldi and Engel 2005a), hence
designation of the group as ensign wasps. Second, all functional metasomal spiracles are lost except on the seventh segment (Goulet and Huber 1993; Grimaldi and
Engel 2005a). Historically, the superfamily Evanioidea included the three extant
families of Evaniidae, Gasteruptiidae and Aulacidae, and later five extinct families
from the Mesozoic were added, the Andreneliidae, Anomopterellidae, Baissidae,
Othniodellithidae and Praeaulacidae (Rasnitsyn 1972, 1975; Rasnitsyn and
Martínez-Delclòs 2000; Engel et al. 2016b). Subsequently, additional ensign wasps
were reported, including Exilaulacus loculatus (Li et al. 2018a) from midCretaceous Myanmar amber (Fig. 11.28), which was followed in the same report by
a preliminary phylogeny of Evanioidea. This phylogeny resulted from morphology
and DNA sequence data of selected fossil and extant genera that employed two
phylogenetic analytical methods: maximum parsimony and Bayesian inference (Li
et al. 2018a). Several distinctive relationships within Evanioidea resulted from the
phylogenetic analyses (Fig. 11.29). First, the extinct family Praeaulacidae is paraphyletic and occurs at the base of Evanioidea in-groups. Second, Anomopterellidae
is a monophyletic clade and is the sister clade to the remaining families. Third,
Aulacidae, Baissidae and Gasteruptiidae do not form a monophyletic clade. Fourth,
Othniodellithidae is a monophyletic clade in a position that is more basal to the
Andreneliidae + Evaniidae clade. Fifth, Andreneliidae is the sister clade of
Evaniidae, and both lineages are monophyletic clades. These results provided clarity to previous, mostly ambiguous, results regarding Evanioidea phylogeny. The
inclusion of all evanioid genera, especially fossil taxa, provided a straightforward perspective of Evanioidea phylogenetic events accompanying phases 1 and 2
of the MMPR.
Based on 59 genera and 171 described fossil species of Evanioidea (Zhang and
Rasnitsyn 2008; Li et al. 2013a, 2018a), histograms show the frequency of
Evanioidea species, genera and family richness during a 169 million-year-long
interval from Middle Jurassic to Miocene (Li et al. 2018a; Fig. 11.30a). From these
geochronologic, epoch-level data (Fig. 11.30a), a relatively flat level of genus-level
richness existed throughout the Mesozoic from 174 to 5 Ma, followed by a considerable decline in the transition to the Cenozoic, and ending in a flat, low level of
richness from the mid Eocene to the mid Miocene spanning approximately 40–14
million years ago. Although species-level richness during this time interval is considerably more variable and accentuated, the general pattern is similar to that of
generic richness, with both reaching a peak during the Early Cretaceous, followed
by a distinct downturn and low levels of occurrences thereafter during the Cenozoic.
C. C. Labandeira and L. Li