478
and eastern United States. An examination of insect taxa from these deposits reveal
the presence of three insect orders—Hymenoptera, Diptera and Coleoptera—that
later in the fossil record would contribute the overwhelming bulk of parasitoid taxa
(Fig. 11.19). However, it is evident from the taxa in each of the four most diverse
deposits of this time interval that parasitoids are absent.
The first deposit is the Madygen Formation, of Ladinian to early Carnian in age,
consistent with a date of 237–220 Ma (Walker et al. 2013). Productive sites of the
Madygen Formation are located in the Fergana Valley where the frontiers of
Tajikistan, Kyrgyzstan and Uzbekistan complexly intersect (Shcherbakov 2008).
The principal localities are from the Dzhailyoucho area that consisted of an extensive Triassic lake deposit. No parasitoid insects are known. The relevant taxa are
Hymenoptera containing sawflies of the Xyeloidea (Xyelidae), and Diptera that are
represented only by the nematocerous taxa of Tipulomorpha (Limoniidae,
†
Vladipteridae), Psychodomorpha (
†
Nadipteridae,
†
Hennigmatidae) and
Bibionomorpha (
†
Protorhyphidae) (Shcherbakov 2008). The second deposit is the
Molteno Formation, which is slightly younger and is centered in the early Late
Triassic Carnian Stage, approximately 237–228 Ma (Walker et al. 2013), although
accurate age dates have not been determined from radioisotopic age dating. All 106
documented Molteno localities (Labandeira et al. 2018) originate from outcrops of
the Karoo Basin, mostly in South Africa that surround Lesotho. The major localities
are lake deposits such as Aasvoëlberg 411 and Birds River 111 (Anderson and
Anderson 2003). No parasitoid taxa are known (Riek 1974). The only Hymenoptera
known is a probable sawfly of Xyelidae (Schlüter 2000), and Diptera are absent
from the Molteno Formation (Anderson and Anderson 1993; Labandeira et al. 2018).
The second and third localities, from the Late Triassic localities to Triassic–
Jurassic boundary interval display no evidence for Hymenoptera, an increased
diversity of non-parasitoid Diptera, and the presence of non-parasitoid Coleoptera,
all of which indicate that the MMPR was in the future. The third deposit are the
related Beishan Formation and Shangtu Formation of Jilin and Hebei provinces,
respectively, which are of Late Triassic age (Rhaetian Stage), corresponding to an
age date of 209–201 Ma (Walker et al. 2013), although historically the position of
these deposits in the latest Triassic to earliest Jurassic continuum have been contentious (Lin 1982, 1986). There are several localities within each of these two formations have produced fossil insects from moderately diverse assemblages (Lin 1982,
1986; Grimaldi and Engel 2005a). Hymenoptera is absent; Diptera is represented by
the nematocerous groups of Tipulomorpha (
†
Eolimnobiidae, Limoniidae) and
Bibionomorpha (
†
Pleciofungivoridae), and Coleoptera consist of taxa that lack
known parasitoid members in the later Mesozoic and Cenozoic faunas (Lin 1982,
1986). Parasitoid taxa have not been discovered.
The fourth deposit is the Cow Branch Formation of the Martinsburg area along
the North Carolina–Virginia state border in the eastern United States. The Cow
Branch Formation is Late Triassic (Rhaetian Stage) to Early Jurassic (Hettangian
Stage) in age, equivalent to 209–199 Ma (Walker et al. 2013). The specific, major
locality yielding the fossils is the Solite Quarry, which is one segment of a series of
rift basins throughout the east coast of North America that are represented by very
C. C. Labandeira and L. Li
and eastern United States. An examination of insect taxa from these deposits reveal
the presence of three insect orders—Hymenoptera, Diptera and Coleoptera—that
later in the fossil record would contribute the overwhelming bulk of parasitoid taxa
(Fig. 11.19). However, it is evident from the taxa in each of the four most diverse
deposits of this time interval that parasitoids are absent.
The first deposit is the Madygen Formation, of Ladinian to early Carnian in age,
consistent with a date of 237–220 Ma (Walker et al. 2013). Productive sites of the
Madygen Formation are located in the Fergana Valley where the frontiers of
Tajikistan, Kyrgyzstan and Uzbekistan complexly intersect (Shcherbakov 2008).
The principal localities are from the Dzhailyoucho area that consisted of an extensive Triassic lake deposit. No parasitoid insects are known. The relevant taxa are
Hymenoptera containing sawflies of the Xyeloidea (Xyelidae), and Diptera that are
represented only by the nematocerous taxa of Tipulomorpha (Limoniidae,
†
Vladipteridae), Psychodomorpha (
†
Nadipteridae,
†
Hennigmatidae) and
Bibionomorpha (
†
Protorhyphidae) (Shcherbakov 2008). The second deposit is the
Molteno Formation, which is slightly younger and is centered in the early Late
Triassic Carnian Stage, approximately 237–228 Ma (Walker et al. 2013), although
accurate age dates have not been determined from radioisotopic age dating. All 106
documented Molteno localities (Labandeira et al. 2018) originate from outcrops of
the Karoo Basin, mostly in South Africa that surround Lesotho. The major localities
are lake deposits such as Aasvoëlberg 411 and Birds River 111 (Anderson and
Anderson 2003). No parasitoid taxa are known (Riek 1974). The only Hymenoptera
known is a probable sawfly of Xyelidae (Schlüter 2000), and Diptera are absent
from the Molteno Formation (Anderson and Anderson 1993; Labandeira et al. 2018).
The second and third localities, from the Late Triassic localities to Triassic–
Jurassic boundary interval display no evidence for Hymenoptera, an increased
diversity of non-parasitoid Diptera, and the presence of non-parasitoid Coleoptera,
all of which indicate that the MMPR was in the future. The third deposit are the
related Beishan Formation and Shangtu Formation of Jilin and Hebei provinces,
respectively, which are of Late Triassic age (Rhaetian Stage), corresponding to an
age date of 209–201 Ma (Walker et al. 2013), although historically the position of
these deposits in the latest Triassic to earliest Jurassic continuum have been contentious (Lin 1982, 1986). There are several localities within each of these two formations have produced fossil insects from moderately diverse assemblages (Lin 1982,
1986; Grimaldi and Engel 2005a). Hymenoptera is absent; Diptera is represented by
the nematocerous groups of Tipulomorpha (
†
Eolimnobiidae, Limoniidae) and
Bibionomorpha (
†
Pleciofungivoridae), and Coleoptera consist of taxa that lack
known parasitoid members in the later Mesozoic and Cenozoic faunas (Lin 1982,
1986). Parasitoid taxa have not been discovered.
The fourth deposit is the Cow Branch Formation of the Martinsburg area along
the North Carolina–Virginia state border in the eastern United States. The Cow
Branch Formation is Late Triassic (Rhaetian Stage) to Early Jurassic (Hettangian
Stage) in age, equivalent to 209–199 Ma (Walker et al. 2013). The specific, major
locality yielding the fossils is the Solite Quarry, which is one segment of a series of
rift basins throughout the east coast of North America that are represented by very
C. C. Labandeira and L. Li