496
to Phase 1 and Phase 2, proportionately less so in subsequent phases. This early
evolutionary expansion of a major parasitoid group likely was involved in the ecological transformation of terrestrial food webs.
Although divergence-time estimation has played an important role in evolutionary biology (De Baets and Littlewood 2015; Warnock and Engelstädter 2021), it is
relevant also in evaluating historical ecological processes such as the MMPR. As a
prelude, a study based on total-evidence analysis concluded that the time-of-origin
for the order Hymenoptera was at 309 million years ago (Ronquist et al. 2012), or
the middle of the Pennsylvanian Period, with node dating providing a very similar
result of 311 Ma. Such an age date would be consistent with a major diversification
of basal Hymenoptera during the Permian. Nevertheless, the results of that study for
both the time of origin and time interval of early diversification of Hymenoptera are
considerably older than most previous estimates and the relevant fossil record. A
subsequent analysis of the same dataset using the joint and complementary dating
of clades (nodes) and terminal lineages (tips) (O’Reilly et al. 2015, O’Reilly and
Donoghue 2016) produced a time-calibrated phylogeny of Hymenoptera congruent
with the fossil record (Rasnitsyn 1969, 1975, 1988, 2002). These latter estimates
acknowledge the origin and early diversification of Hymenoptera as a Middle
Triassic to Early Jurassic event (Grimaldi and Engel 2005a), also consistent with the
fossil record. However, because of the sparseness of the relevant fossil record it is
difficult to evaluate a 74 million-year-long gap. This gap exists between the earliest
Late Triassic fossils of Hymenoptera at 235 Ma—Triassoxyela foveolata and
Leioxyela antiqua from the Madygen Biota (Rasnitsyn 1964)—and the presumptive
origin of Hymenoptera at 309 Ma (Rasnitsyn 1969; Rasnitsyn and Quicke 2002;
Ronquist et al. 2012). A similar pattern exists in Evanioidea (Ronquist et al. 2012),
which shows that the earliest divergence time of Evanioidea based on total-evidence
dating was the Late Triassic at about 221 Ma (Late Triassic, Norian Stage), 43 million years earlier than a node-dating result of 178 Ma (Early Jurassic, Toarcian
Stage) under an internal growth rate model. Currently the earliest record of
Evanioidea is several occurrences of Praeaulacidae dated as 165 Ma, of latest
Middle Jurassic age (Callovian Stage). These occurrences are Archaulacus (Li et al.
2014c), Aulacogastrinus (Rasnitsyn 1983), Eosaulacus (Zhang and Rasnitsyn
2008), Nevania (Zhang and Rasnitsyn 2007), Praeaulacus (Rasnitsyn 2008),
Praeaulacon (Zhang and Rasnitsyn 2008), Sinaulacogastrinus (Zhang and
Rasnitsyn 2008), the anomopterellid Anomopterella (Rasnitsyn 1975) and
Synaphopterella (Li et al. 2013a). This timing from fossil occurrence data indicates
that diversification within Evanioidea would have appeared no later and no earlier
than Middle Jurassic. Although combining the divergence time estimation (Ronquist
et al. 2012) with the origin age of Evanioidea may push this lineage to the Early
Jurassic, or conceivably Late Triassic, currently there is no fossil evidence for such
an early origination. A Middle Jurassic origination, indicated by the fossil record, is
consistent with the parasitoid habit as a fundamental feature of Evanioidea, and its
initial appearance during early Phase 1 of the MMPR, coincident with the Toarcian
to Callovian stages of the late Early to Middle Jurassic.
C. C. Labandeira and L. Li
to Phase 1 and Phase 2, proportionately less so in subsequent phases. This early
evolutionary expansion of a major parasitoid group likely was involved in the ecological transformation of terrestrial food webs.
Although divergence-time estimation has played an important role in evolutionary biology (De Baets and Littlewood 2015; Warnock and Engelstädter 2021), it is
relevant also in evaluating historical ecological processes such as the MMPR. As a
prelude, a study based on total-evidence analysis concluded that the time-of-origin
for the order Hymenoptera was at 309 million years ago (Ronquist et al. 2012), or
the middle of the Pennsylvanian Period, with node dating providing a very similar
result of 311 Ma. Such an age date would be consistent with a major diversification
of basal Hymenoptera during the Permian. Nevertheless, the results of that study for
both the time of origin and time interval of early diversification of Hymenoptera are
considerably older than most previous estimates and the relevant fossil record. A
subsequent analysis of the same dataset using the joint and complementary dating
of clades (nodes) and terminal lineages (tips) (O’Reilly et al. 2015, O’Reilly and
Donoghue 2016) produced a time-calibrated phylogeny of Hymenoptera congruent
with the fossil record (Rasnitsyn 1969, 1975, 1988, 2002). These latter estimates
acknowledge the origin and early diversification of Hymenoptera as a Middle
Triassic to Early Jurassic event (Grimaldi and Engel 2005a), also consistent with the
fossil record. However, because of the sparseness of the relevant fossil record it is
difficult to evaluate a 74 million-year-long gap. This gap exists between the earliest
Late Triassic fossils of Hymenoptera at 235 Ma—Triassoxyela foveolata and
Leioxyela antiqua from the Madygen Biota (Rasnitsyn 1964)—and the presumptive
origin of Hymenoptera at 309 Ma (Rasnitsyn 1969; Rasnitsyn and Quicke 2002;
Ronquist et al. 2012). A similar pattern exists in Evanioidea (Ronquist et al. 2012),
which shows that the earliest divergence time of Evanioidea based on total-evidence
dating was the Late Triassic at about 221 Ma (Late Triassic, Norian Stage), 43 million years earlier than a node-dating result of 178 Ma (Early Jurassic, Toarcian
Stage) under an internal growth rate model. Currently the earliest record of
Evanioidea is several occurrences of Praeaulacidae dated as 165 Ma, of latest
Middle Jurassic age (Callovian Stage). These occurrences are Archaulacus (Li et al.
2014c), Aulacogastrinus (Rasnitsyn 1983), Eosaulacus (Zhang and Rasnitsyn
2008), Nevania (Zhang and Rasnitsyn 2007), Praeaulacus (Rasnitsyn 2008),
Praeaulacon (Zhang and Rasnitsyn 2008), Sinaulacogastrinus (Zhang and
Rasnitsyn 2008), the anomopterellid Anomopterella (Rasnitsyn 1975) and
Synaphopterella (Li et al. 2013a). This timing from fossil occurrence data indicates
that diversification within Evanioidea would have appeared no later and no earlier
than Middle Jurassic. Although combining the divergence time estimation (Ronquist
et al. 2012) with the origin age of Evanioidea may push this lineage to the Early
Jurassic, or conceivably Late Triassic, currently there is no fossil evidence for such
an early origination. A Middle Jurassic origination, indicated by the fossil record, is
consistent with the parasitoid habit as a fundamental feature of Evanioidea, and its
initial appearance during early Phase 1 of the MMPR, coincident with the Toarcian
to Callovian stages of the late Early to Middle Jurassic.
C. C. Labandeira and L. Li