Other than the giant Dragonfly (which appears popular over the web) what other giant insects existed?

Is there a name for this classification of critter? I tried Giant Insects, Giant Bugs, Prehistoric Insects, Prehistoric Bug and all I seem to get is the same article over and over again about earth's early atmosphere being 30% oxygen.

What I want is a list of ancient insects, preferably one focusing on the larger insects. I do not know how to make a search for this. Please help.

Wikipedia has an article on Insect Evolution that say:

quote:

During this era, some giant dragonfly-like forms – e.g. Meganeura and Meganeuropsis (Order Protodonata) and Mazothairos (Order Palaeodictyoptera) – reached wingspans of 55 to 70 cm (22 to 28 in), making them far larger than any living insect. Also their nymphs must have had a very impressive size.

This gigantism may have been due to higher atmospheric oxygen levels (up to 80% above modern levels during the Carboniferous) that allowed increased respiratory efficiency relative to today. The lack of flying vertebrates could have been another factor.

The largest living insects today are found in the tropics, suggesting that warmer temperatures favor size. Insects breathe by gas diffusion through a passive system of tubules. Diffusion rate rises with temperature, so warmer insects can deliver oxygen to more cells fed by each tubule, i.e., larger bodies.

The "80% above modern levels" in the quote above refers to atmospheric oxygen levels in the Mesozoic of 35-40% compared to 21% today, allowing even more efficient oxygen delivery to the body.

So it was a combination of higher global temperatures with significantly higher oxygen levels that allowed those giant prehistoric insects to exist. But it sounds (from Wikipedia at least) like the famous giant dragonflies were standouts even then among the insects.

Yeah Read that, and from the other sites it is copied on to as well.

I think you may have misread what I wrote.

I am looking to learn about more than just the dragonfly, I want to know what other large insects once existed.

Thus my question above starts:

quote:

Other than the giant Dragonfly (which appears popular over the web) what other giant insects existed?

I didn't misunderstand -- just giving general principles -- you're right about the difficulty of finding details. From childhood I remember giant dragonflies in the Carboniferous diorama at the Field Museum of Natural History in Chicago, but I don't recall other insects, either.

Btw, to correct myself, oxygen levels may have reached 35% but not 40%.

From a blog article at The Littoral Zone: giant insects of the carboniferous

quote:

Many different species of gigantic dragonfly existed during this period, as well as gargantuan versions of our modern mayfly and, of course, cockroach. Scientists believe that high oxygen levels compensated for the inefficiency of the insects’ respiratory systems, which, unlike humans’, are not centralized and rely on the passive diffusion of air through their tissues. In the lower-oxygen-content atmosphere of today, insects’ respiration is too inefficient to allow their bodies to grow much thicker than (in the dragonfly’s case) a pencil, and indeed, giant insects began to disappear as the Permian period dawned and oxygen levels began to decline.

From Encyclopedia of Entomology:

quote:

At the close of the Paleozoic, the Permian period, the environment of earth was undergoing significant change, most notably a less tropical climate. Numerous insects from many deposits around the world document over a dozen orders of insects, including the occurrence of "giant" insects.

This 1916 survey of "Mesozoic and Tertiary insects of Queensland and New South Wales" notes "a fairly large moth"; "a large insect probably related to ...Protohemiptera" [ancestor of 'true bugs']; and a "rather large" member of Blattoidea [cockroaches]. Being an amateur insect collector (there's dg rolling her eyes again ) helps navigate some taxonomic terms.

"According to this article, "Mayflies grew to canary size."

Hope that helps. If you find a definitive source please post it -- I think it's a great question.

Dragonfly
Moth
Cockroach
And Mayflies the size of jets - I mean canaries

Hm. Not a large list.

"Not a large list." I don't know. In modern times gigantic tropical insects span a diverse range of orders -- butterflies, beetles*, true bugs, grasshoppers, lantern flies, etc. -- demonstrating success in multiple niches. So it's plausible that along with giant dragonflies, most insects in general several hundred million years ago might have been larger or even gigantic -- constrained only by their respiratory systems and with relatively fewer predators than today.

The articles point out that there are huge gaps in the insect fossil record. Maybe absence of evidence is not evidence of absence?

-------------------
* I've got a tropical rhinoceros beetle hanging in a framed case on my wall -- it's the size of a mouse (purchased locally -- no big-bug safaris for me )

I thought I read somewhere years ago that gigantism in insects has physical limitations due to the fact that the bigger one gets the more likely it is to be crushed under its own weight, or something like that. I think what I read was referring to giant insects in movies and why they could never get that large. Can anyone elaborate further?

Yes, that refers to house-sized bugs -- you know, the ones that grew unnaturally large in the 1950s because of radiation in the aftermath of A-bomb tests, when mankind was tampering with forces it didn't understand and unwittingly unleashing nature's fury, and let that be a cautionary lesson for the rest of us...

An ant the size of cow could not support its own weight on those spindly legs. If you scale a bug up proportionally, its weight grows as the cube of its size while the strength of its parts grows only as the square (cross-sectional area). Strength to weight ratio always shrinks.

That's why elephants have short, stubby legs. King Kong's leg bones would have snapped under his great weight.

In the case of actual giant insects, they still don't / didn't weigh THAT much. Giant dragonflies had slender bodies and large, membranous wings and strong flight muscles -- a very efficient 'design' (produced by natural selection).

So there is lack of fossils?

Lately I have been reading up on other 'mega fauna' granted most of the reading has been on prehistoric 'ice age' varieties like Mammoth, Moa, Toxodon and 'odd' creatures like the Glyptodon (An armadillo nearly the size of a small car).

Of course there is a good deal of data out there on Dinosaurs, but there seems to be a lack of data on insect forms.

As for Oxygen and large life, I have often wondered if the Dino-period didn't have higher levels of oxygen that allowed such large beasties.

And I wonder about gravity. Granted the in fall of debris from space isn't that great, but I find it difficult to believe that T-Rex could run with that much mass, and the poor 'brontosaur' (who no longer exists as what I was taught as a kid) must of had difficulty in just standing, let alone walking. And then those pterodactyls seem a bit too heavy in design for flight in current atmospheric pressures and gravity.

I'm not expecting to 'discover' ants the size of houses, or roaches the size of a pick-up truck, but I was kind of hoping of finding specific sizes or ranges of sizes for 'mega-insects' of the prehistoric world so i can whip out the tape measure and get an idea how big of a bug we are talking.

Thanks

Here's nice article. I didn't read it all but sounded interesting.

"So there is lack of fossils?"
Fossils are rare and invertebrate fossils are rarer. Gaps in the record are inevitable & falsely exploited by creationists as a weakness in evidence for Darwinism -- the God of the Gaps argument.

Anyhow, this article includes a nice timeline -- if you can stand the British spelling of Cenozoic : Kendall Bioresearch.

quote:

The same coal deposits also contain the fossils of diverse archaic insects belonging to ancient lines that, unlike the cockroaches, gradually disappeared before the end of the Paleozoic era, leaving no modern descendants. Many of these archaic forms are huge dragonfly-like insects, with a wing-span of 20 cm or more, like the Palaeodictyoptera and Protodonata illustrated below - true 'dinosaurs' of the insect world.

It sounds like those critters, among paleolozoic insects over 300 million years ago, were in a size class by themselves.

Edit: paleolozoic paleozoic.

quote:

Originally posted by Professor:

if you can stand the British spelling of Cenozoic

Yet they spell Palaeozoic, 'Paleozoic' And, strictly, their Caenozoic should be Cainozoic [Greek: kainos 'new,recent' ] which is how it is, alternatively, written here.

quote:

Originally posted by FredPuli:
Yet they spell Palaeozoic, 'Paleozoic' And, strictly, their Caenozoic should be Cainozoic [Greek: kainos 'new,recent' ] which is how it is, alternatively, written here.

No offense meant -- just an aversion I have to ae ligatures. More jarring than usual because I hadn't seen geologic eras so labeled (I mean, labelled ).

The same Greek root appears as an ending -cene for periods after the Mesozoic, such as the Eocene ('dawn of recent time') etc. Never learned them all.

Speaking of giant insects, have you met my brother-in-law?

Budda-boom. Shoulda quit while I was ahead...

Sir, You're not funny. Ask around!
--Good Morning, Vietnam

Awwww, Professor, but you are funny.

You play the sax, don't you? Here, this'll make you smile:

Walrus

Thanks for brightening my day with a captive pinniped performing insipid tricks for human entertainment. The walrus has great articulation and intonation, but how on earth did it get a soprano sax to sound like an alto -- must be its embouchure. Of course in Alabama the Tuscaloosa.

ROLF - you guys are soo silly.