488
non- Eremoneura–Diptera and Coleoptera (Fig. 11.19). Lineages such as Strepsiptera,
Eremoneura–Diptera and Aculeata–Hymenoptera were largely dominant during
Phase 3 and especially in Phase 4 that span the earliest Late Cretaceous (Albian
Stage) to the Holocene. It is for this reason that there is a focus on two of the most
important lineages of the MMPR, the non-proctotrupomorph Stephanoidea and
Evanioidea.
11.7.1 Stephanoidea (Stephanid Wasps)
Stephanidae (stephanid wasps) are a relatively nonspeciose family of parasitoid
wasps important during phases 1 and 2 of the MMPR in that recent studies have
considered Stephanidae as the sister group to all other extant Apocrita, the parasitoid wasps (Sharkey et al. 2012). This enigmatic lineage possesses peculiar characters that distinguish it from all other families of extant and extinct Hymenoptera.
Examples of the distinctiveness of Stephanidae include a distinct tuberculate crown
that occurs on the head capsule; and a hind femur usually swollen with two or three
large, ventral, tooth-like processes and several denticles of lesser size. Additional
features are a propodeum (first abdominal segment) with a dorsal profile that is
continuously rectilinear throughout, and a metasomal base (the abdomen excluding
the propodeum) of the thorax that nearly contacts the metacoxa (Hong et al. 2011;
Rasnitsyn and Zhang 2010). Although stephanid wasps are morphologically unusual
and rarely encountered in modern habitats, the clade is comprised of ten extant
genera with nearly 350 species (van Achterberg and Yang 2004; Aguiar 2004, 2006;
Aguiar and Jennings 2005; van Achterberg and Quicke 2006; Aguiar et al. 2010;
Hong et al. 2010; Hong and Xu 2011). The geographic distribution of Stephanidae
principally is among subtropical and tropical forests worldwide (van Achterberg
2002; Aguiar 2004; Hong et al. 2011). Consistent with their modern, species-poor
occurrence, stephanids have a poor fossil record consisting of six genera. Three of
these genera are of amber provenance, and are Archaeostephanus from the Late
Cretaceous of New Jersey, and Kronostephanus and Lagenostephanus from the Late
Cretaceous of Myanmar (Engel and Grimaldi 2004; Engel et al. 2013a, b; Li et al.
2017b). The three Eocene genera are Protostephanus from the Florissant Formation
of Colorado, USA, and Electrostephanus and Denaeostephanus from the Baltic
Region of northern Europe (Cockerell 1906; Brues 1933; Engel and Grimaldi 2004;
Engel 2005b; Engel and Ortega-Blanco 2008). The amber fossil species are widely
distributed geographically from Myanmar, the Baltic Region and to New Jersey,
USA, while the sole compression fossil comes from Colorado, USA. A second
stephanid wasp, Lagenostephanus lii, was described from mid-Cretaceous Myanmar
Amber (Li et al. 2017b). Lagenostephanus is an early apocritan lineage based on
overall habitus (Fig. 11.25), particularly head, leg and wing features (Fig. 11.26). It
likely resembled morphologically early members of Phase 1 of the MMPR.
A phylogeny of Stephanidae was provided based on character scoring of morphological features from all extinct and extant genera (Li et al. 2017b). Phylogenetic
C. C. Labandeira and L. Li
non- Eremoneura–Diptera and Coleoptera (Fig. 11.19). Lineages such as Strepsiptera,
Eremoneura–Diptera and Aculeata–Hymenoptera were largely dominant during
Phase 3 and especially in Phase 4 that span the earliest Late Cretaceous (Albian
Stage) to the Holocene. It is for this reason that there is a focus on two of the most
important lineages of the MMPR, the non-proctotrupomorph Stephanoidea and
Evanioidea.
11.7.1 Stephanoidea (Stephanid Wasps)
Stephanidae (stephanid wasps) are a relatively nonspeciose family of parasitoid
wasps important during phases 1 and 2 of the MMPR in that recent studies have
considered Stephanidae as the sister group to all other extant Apocrita, the parasitoid wasps (Sharkey et al. 2012). This enigmatic lineage possesses peculiar characters that distinguish it from all other families of extant and extinct Hymenoptera.
Examples of the distinctiveness of Stephanidae include a distinct tuberculate crown
that occurs on the head capsule; and a hind femur usually swollen with two or three
large, ventral, tooth-like processes and several denticles of lesser size. Additional
features are a propodeum (first abdominal segment) with a dorsal profile that is
continuously rectilinear throughout, and a metasomal base (the abdomen excluding
the propodeum) of the thorax that nearly contacts the metacoxa (Hong et al. 2011;
Rasnitsyn and Zhang 2010). Although stephanid wasps are morphologically unusual
and rarely encountered in modern habitats, the clade is comprised of ten extant
genera with nearly 350 species (van Achterberg and Yang 2004; Aguiar 2004, 2006;
Aguiar and Jennings 2005; van Achterberg and Quicke 2006; Aguiar et al. 2010;
Hong et al. 2010; Hong and Xu 2011). The geographic distribution of Stephanidae
principally is among subtropical and tropical forests worldwide (van Achterberg
2002; Aguiar 2004; Hong et al. 2011). Consistent with their modern, species-poor
occurrence, stephanids have a poor fossil record consisting of six genera. Three of
these genera are of amber provenance, and are Archaeostephanus from the Late
Cretaceous of New Jersey, and Kronostephanus and Lagenostephanus from the Late
Cretaceous of Myanmar (Engel and Grimaldi 2004; Engel et al. 2013a, b; Li et al.
2017b). The three Eocene genera are Protostephanus from the Florissant Formation
of Colorado, USA, and Electrostephanus and Denaeostephanus from the Baltic
Region of northern Europe (Cockerell 1906; Brues 1933; Engel and Grimaldi 2004;
Engel 2005b; Engel and Ortega-Blanco 2008). The amber fossil species are widely
distributed geographically from Myanmar, the Baltic Region and to New Jersey,
USA, while the sole compression fossil comes from Colorado, USA. A second
stephanid wasp, Lagenostephanus lii, was described from mid-Cretaceous Myanmar
Amber (Li et al. 2017b). Lagenostephanus is an early apocritan lineage based on
overall habitus (Fig. 11.25), particularly head, leg and wing features (Fig. 11.26). It
likely resembled morphologically early members of Phase 1 of the MMPR.
A phylogeny of Stephanidae was provided based on character scoring of morphological features from all extinct and extant genera (Li et al. 2017b). Phylogenetic
C. C. Labandeira and L. Li