483
(154–139 Ma) and Jehol (125 Ma) biotas―also contain compression fossils,
although during this time the first appearance of major amber deposits such as
Lebanese amber (130–120 Ma) (Maksoud et al. 2017) and Spanish Álava Amber
(112–104 Ma) occur (Peñalver and Delclòs 2010; Azar et al. 2010). By contrast,
insect faunas deposited after the MMPR―Myanmar Amber (99 Ma), Canadian
Amber (79–78 Ma), Messel (48 Ma) and Dominican Amber (20.5 Ma) biotas―
incorporated more amber material. Consequently, this difference between deposits
before and after the MMPR imparted a distinctive preservational trend. Because of
this distribution of compression–impression versus amber deposits, there are different taphonomic qualities imparted to each of these 12 deposits. Advantages of compression deposits are: (1) a greater temporal completeness compared to amber
deposits that are absent from deposits older than about 135 million years; (2) fossils
occurring on rock slabs typically with expansive two-dimensional surfaces; and (3)
representation of a range of ecosystems, such as those from fluvial, lacustrine, deltaic and swamp environments (Labandeira 2014a). Advantages of amber deposits
are: (1) typically a significantly higher quality or preservation; (2) good availability
of trophic data to understand inter-organismic relationships and food webs; and (3)
elevated documentation of pathogens, parasites, parasitoids and evidence for disease that rarely are found in compression–impression deposits (Labandeira 2014a;
Poinar 2021). Although these two, major modes of preservation are different, they
are nevertheless complimentary; for example, amber deposits preserve small to
miniscule insects that would rarely be preserved in compression deposits.
Compression and amber deposits jointly provide a much more accurate of the fossil
record than would their individual representations.
The first major insect fauna of Phase 3 is Myanmar Amber originating in Kachin
State, in the Myitkyina and Upper Chindwin Districts along the Hukawng Valley of
northern Burma (Cruikshank and Ko 2003). The lithostratigraphic context of
Myanmar Amber is still poorly known, although the amber comes from lignite layers interbedded with thin strata of sandstones, siltstones, shale and micritic limestone (Zherikhin and Ross 2000). Source trees of most of Myanmar Amber are the
gymnospermous Araucariaceae (Agathis) and angiospermous Dipterocarpaceae,
which have yielded a lowermost Late Cretaceous radioisotopic date of approximately 99 Ma, equivalent to the early interval of the Cenomanian Stage (Shi et al.
2012) and approximately 23 million years more recent than the Jehol Biota.
Myanmar Amber contains a diverse insect biota (Rasnitsyn and Ross 2000; Ross
et al. 2010; Ross 2018 and updates). The single neuropteran parasitoid taxon of
Myanmar Amber is Hemerobioformia (Mantispidae). Coleopteran parasitoid taxa
were Caraboidea (Carabidae), Staphylinoidea (Staphylinidae), Cleroidea (Cleridae),
Cucujoidea (Passandridae), Tenebrionoidea (Meloidae, Ripiphoridae) and
Curculionoidea (Anthribidae). Strepsipteran parasitoids were Protostrepsiptera
(
†
Phthanoxenidae,
†
Cretostylopidae), Eleostrepsiptera (
†
?Mengeidae) and
Neostrepsiptera (
†
Kinzelbachillidae). The single, possible, trichopteran parasitoid
taxon is Hydroptilidae. Dipteran parasitoid taxa consisted of Nemestrinimorpha
(Acroceridae, Nemestrinidae), Archisargoidea (
†
Eremochaetidae), Asiloidea
(Asilidae, Bombyliidae), Empidoidea (Empididae) and Aschiza (Phoridae,
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution
(154–139 Ma) and Jehol (125 Ma) biotas―also contain compression fossils,
although during this time the first appearance of major amber deposits such as
Lebanese amber (130–120 Ma) (Maksoud et al. 2017) and Spanish Álava Amber
(112–104 Ma) occur (Peñalver and Delclòs 2010; Azar et al. 2010). By contrast,
insect faunas deposited after the MMPR―Myanmar Amber (99 Ma), Canadian
Amber (79–78 Ma), Messel (48 Ma) and Dominican Amber (20.5 Ma) biotas―
incorporated more amber material. Consequently, this difference between deposits
before and after the MMPR imparted a distinctive preservational trend. Because of
this distribution of compression–impression versus amber deposits, there are different taphonomic qualities imparted to each of these 12 deposits. Advantages of compression deposits are: (1) a greater temporal completeness compared to amber
deposits that are absent from deposits older than about 135 million years; (2) fossils
occurring on rock slabs typically with expansive two-dimensional surfaces; and (3)
representation of a range of ecosystems, such as those from fluvial, lacustrine, deltaic and swamp environments (Labandeira 2014a). Advantages of amber deposits
are: (1) typically a significantly higher quality or preservation; (2) good availability
of trophic data to understand inter-organismic relationships and food webs; and (3)
elevated documentation of pathogens, parasites, parasitoids and evidence for disease that rarely are found in compression–impression deposits (Labandeira 2014a;
Poinar 2021). Although these two, major modes of preservation are different, they
are nevertheless complimentary; for example, amber deposits preserve small to
miniscule insects that would rarely be preserved in compression deposits.
Compression and amber deposits jointly provide a much more accurate of the fossil
record than would their individual representations.
The first major insect fauna of Phase 3 is Myanmar Amber originating in Kachin
State, in the Myitkyina and Upper Chindwin Districts along the Hukawng Valley of
northern Burma (Cruikshank and Ko 2003). The lithostratigraphic context of
Myanmar Amber is still poorly known, although the amber comes from lignite layers interbedded with thin strata of sandstones, siltstones, shale and micritic limestone (Zherikhin and Ross 2000). Source trees of most of Myanmar Amber are the
gymnospermous Araucariaceae (Agathis) and angiospermous Dipterocarpaceae,
which have yielded a lowermost Late Cretaceous radioisotopic date of approximately 99 Ma, equivalent to the early interval of the Cenomanian Stage (Shi et al.
2012) and approximately 23 million years more recent than the Jehol Biota.
Myanmar Amber contains a diverse insect biota (Rasnitsyn and Ross 2000; Ross
et al. 2010; Ross 2018 and updates). The single neuropteran parasitoid taxon of
Myanmar Amber is Hemerobioformia (Mantispidae). Coleopteran parasitoid taxa
were Caraboidea (Carabidae), Staphylinoidea (Staphylinidae), Cleroidea (Cleridae),
Cucujoidea (Passandridae), Tenebrionoidea (Meloidae, Ripiphoridae) and
Curculionoidea (Anthribidae). Strepsipteran parasitoids were Protostrepsiptera
(
†
Phthanoxenidae,
†
Cretostylopidae), Eleostrepsiptera (
†
?Mengeidae) and
Neostrepsiptera (
†
Kinzelbachillidae). The single, possible, trichopteran parasitoid
taxon is Hydroptilidae. Dipteran parasitoid taxa consisted of Nemestrinimorpha
(Acroceridae, Nemestrinidae), Archisargoidea (
†
Eremochaetidae), Asiloidea
(Asilidae, Bombyliidae), Empidoidea (Empididae) and Aschiza (Phoridae,
11 The History of Insect Parasitism and the Mid-Mesozoic Parasitoid Revolution