RE: Fossil Insects

Donald Frack (
Sun, 7 Mar 1999 04:46:20 -0800


You wrote to Steve Schimmrich:

> -----Original Message-----
> From:
> []On Behalf Of Karen G. Jensen
> Sent: Friday, March 05, 1999 9:11 AM
> To: Steven H. Schimmrich
> Cc:
> Subject: Re: Fossil Insects

> and you [Steve Schimmrich] asked:
> > On what basis are you saying that there are few Mesozoic
> insects? Few in
> >terms of diversity? Few in terms of fossil localities? What
> exactly is the
> >"puzzle" you're referring to?
> Relatively few in diversity and locality, and especially in numbers of
> specimens (abundance).
> There are many fossil insects in Carboniferous deposits (giant
> cockroaches,
> etc.), and many more (flies, beetles, ants, crickets, even butterfiles) in
> Tertiary deposits. There are some (e.g. large dragonflies in the
> Solenhofen limestone) in Mesozoic deposits, but not anything like what
> would be expected if the flowering plants were co-evolving with insects.

Apparently, you know something about fossil insects I don't. Moreover, you
seem to be more up-to-date than the references in my library on fossil

J. Kukalova-Peck is a well-known author on fossil insects. The book cited
below is one of the most respected texts on insects in the world:

"The ***Triassic record*** of Europe and America is poor or unworked, but
***that of the U.S.S.R. (Tien Shan, Central Asia), Australia and South
Africa is extensive and well documented***. ***A rich Jurassic record is
available***, especially from England, West Germany, U.S.S.R. (Kazakhstan
and Siberia), China and Mongolia. ***Cretaceous insects are numerous*** and
are found especially in Australia, Lebanon, Mongolia, Siberia, China,
England and Brazil. U. Cretaceous amber fossils are plentiful in Canada."
(J. KUKALOVA-PECK "Fossil History and the Evolution of Hexapod Structures",
in CSIRO. 1991. _The Insects of Australia_, Vol. 1) [***emphasis*** mine]]

Carpenter's reputation is shown by the fact he wrote the insect volumes for
the huge Treatise series named below:

Carpenter, F. M. (1992) _Treatise on Invertebrate Paleontology_: Arthropoda
(4), Vol. 3/4 Superclass Hexapoda [insects and hexapod relatives]

The numbers listed below are the oldest records for **families** of fossil
insects according to Carpenter (1992). I include here only the "big four"
Coleoptera (beetles), Diptera (flies), Hymenoptera (bees, wasps, ants,
etc.), and Lepidoptera (butterflies and moths), which account for about 85%
of living species. Although living insects account for 3/4 of the described
species of animals, their fossil record is poor relative to other groups.
This is understandable since relatively few are aquatic, none are marine,
and many live in habitats that do not favor fossilization.

Coleoptera (Adaphaga, etc. [primitive beetles])
Triassic-Jurassic: 13 (to Cretaceous 4, to Present 4)
Cretaceous: 1 (to Present 0)
Post-Cretaceous only: 1

Coleoptera (Polyphaga)
Triassic: 4 (all to Present )
Jurassic: 13 (all to Present )
Cretaceous: 7 (all Present)
Post-Cretaceous only: 31

Diptera (Nematocera, etc. [primitive flies])
Triassic-Jurassic: 35 (to Present 1)
Cretaceous: 6 (all to Present)
Post-Cretaceous only: 8

Diptera (Brachycera [advanced flies])
Triassic-Jurassic: 12 (to Present 3)
Cretaceous: 6 (all to Present)
Post-Cretaceous only: 56

Hymenoptera (Symphyta [primitive hymenopterans: sawflies, etc.])
Triassic to Present: 1
Jurassic: 13 (to Present 4)
Post-Cretaceous only: 6

Hymenoptera (Apocrita [advanced hymenopterans: bees, wasps, ants, etc.])
Triassic: 0
Jurassic: 9 (to Present 2)
Cretaceous: 26 (all to Present)
Post-Cretaceous only: 23 (all social bees and wasps)

Cretaceous: 1 (to Present [Micropterygidae, the most primitive moths])
Post-Cretaceous only: 20 (all fossil families except Micropterygidae)

Total Mesozoic **families** ("big four" only): 147

Unless you have information more recent or contradictory to these
references, you appear to be mistaken. If you do have such information, I
would appreciate it if you could cite it so I can add it to my library.

You further state that these insects are "not anything like what would be
expected if the flowering plants were co-evolving with insects" I have no
idea what this is supposed to mean. The numbers of insects in the fossil
record is affected by their diversity, abundance, and the chances that they
will be fossilized. How many should we "expect"? Most of the co-evolution
discussed is a Cenozoic phenomenon, not Mesozoic. Why would you expect
great numbers of insects within the context of co-evolution if the plants
weren't diverse enough to encourage the insects? The Cretaceous is the
first time that angiosperms appear at all commonly. Their adaptive
radiation in the early Cenozoic is matched by an increase in those insect
groups most commonly associated with pollination, Lepidoptera and
Hymenoptera: Apocrita. If there is not a cause-effect relationship here, do
you have a better explanation for the coincidence?

> This has been noted as a "problem" among angiosperm paleobotanists. I
> remember talking to the entomologist that worked with N.F.Hughes at
> Cambridge, who was eager to find any Cretaceous insects. That was 1980.
> Some have been found, showing that the depositional environments were
> capable of preserving insects. The paucity is a puzzle for those who
> expect to trace the origins of entomopyllous (insect pollinated) plants in
> the fossil record.

I'm still with Steve in wondering what you mean to imply by "problem" and
"puzzle". In the trivial sense, every researcher deals with "problems" and
"puzzles". You clearly seem to imply that these have some important
significance. I doubt that all of the fossils I referred to above have been
found since 1980, so either the person you refer to above wants specimens,
wants a better fossil record than we have, or doesn't know the literature.
What point are you trying to make here?

Don Frack