Insect Id

[mdpaulhus]

I have two insects that I don't have any ID for. Perhaps someone knows insects better than me (not too tough).

The first one is from the midde Jurassic Rierdon Formation of Montana (about 165 Ma). It is about 3/4" from the head to the end of the legs. Interestingly long snout thing - I wouldn't want a swarm of these on me.

The second one is Eocene from Republic, Washington. It is about 1/2" across. It looks to me a like a modern crane fly but this would be smaller than crane flies I am aware of.

Any ideas?

[Shamalama]

Fossil Insect ID's are terribly hard to make unless you get superb preservation. It looks like you have a beetle of some sort on the left and maybe a water strider or wasp on the right?

[mdpaulhus]

Yes, I don't really expect a firm ID, but sometimes one comes along, and I certainly enjoy the speculation/educated guesses/general direction that usually does come along.

The more I look at the first "insect" the more I am confused. I am now questioning whether it is an insect at all and not just some assemblage of materials that makes it look this way. It certianly does look like it has a beetle type of body, but I don't know if any beetles have this long proboscis (mouth) like this appears to have. This could of course be an antenna perhaps or even one of the front legs that has been disarticulated. I could probable convince myself that some of the parts of the beetle are tucked under the body or missing and the fossil could be made up of the other pieces. You can kind of see the resemblance of many parts to the picture of a beetle that I have attached.

[ashcraft]

I would say the first one is from the order Hemiptera, the true bugs. Some of them are very beetle like, but the kicker is that they feed by sucking, usually with a straw like organ that tucks up under the body for resting. Examples would be assassin bugs (wheel bugs), giant water bugs, and stink bugs. Catch one of these and turn them over, and you'll see the "straw".

The second appears to be from the order diptera (flies), could be a crane fly. The way to tell is to count the number of wings. Diptera only have one pair, an individual wing on each side. Just about all other insects have two sets of wings. Look at the specimen under magnification and see.

Brent Ashcraft

[Nicholas]

Second looks to be a crane fly, the first looks to be a beetle of some sort but I'm not sure I'll run it by my bug books and see if I can come up with something.

Edit have you tried looking up Water scorpions as a possible id? It seems similar to me.

[ashcraft]

Water Scorpions are hemipterans. The more I look, the less I think coleoptera (beetle), the long thing coming off of the head looks to be a feeding tube. Some beetles do have tubes (but constructed differently), think weevil, which are very small. Attached is a hemipteran feeding structure, which folds up under the belly when not in use. They can be quite long a sturdy, giant water bugs catch and feed on fish with them.

[Guest Inyo]

I have two insects that I don't have any ID for. Perhaps someone knows insects better than me (not too tough).

The first one is from the midde Jurassic Rierdon Formation of Montana (about 165 Ma). It is about 3/4" from the head to the end of the legs. Interestingly long snout thing - I wouldn't want a swarm of these on me.

My understanding is that the Rierdon Formation is a marine deposit, full of invertebrate marine fossils. Here's a description of typical Rierdon exposures in central Montana:

RIERDON FORMATION -- Pale-yellow weathering, gray-brown, highly

calcareous shale and thin-bedded, light-gray weathering limestones; locally very

fossiliferous, dominated by oysters, Gryphea sp. brachiopods, and, locally,

belemnites; whole and fragmented fossils litter some exposures. Formation

mostly poorly exposed, forming soft soils. Rierdon apparently absent around east

flank of Little Snowy Mountains from south of Durfee Creek Dome northward

almost to South Mc Donald Creek and also on Button Butte; in these areas the

Swift Formation appears correspondingly thicker by the presence of the lower

shale interval. Two small exposures of a yellow weathering calcareous shale soil

on Spindletop Dome are thought to be Rierdon. Thickness of 0-80 feet reported.

I doubt your specimen is an insect. Think crustacean, something that lived in marine waters. I'd contact the Montana Bureau Of Mines And Geology. Probably somebody over there could identify it.

http://inyo.110mb.com/ammonoids/ammonoids7.html

A Parafrenchites meeki ammonoid from the Middle Triassic Prida Formation, Nevada.

[tracer]

wow. this is a good and very interesting thread. a lot of knowledge being mixed with a lot of reason and a couple of great fossils.

wish i could join in, but this one's way above my level. kinda bugs me. oops! thlip of the tongue.

<snoopy dancing out of the thread like he's got ants in his pants>

[Fossilcollector]

Hi,

Just to check, did you collect the Rierdon formation insect yourself?

I'm leaning towards Cockroach or something in the roach family for the first specimen. It's viewed from the ventral side. Insect fossils can turn up in random places including marine deposits, for example; look at all the insect fossils that turn up in solnhofen.

The second fossils is in the diptera family; flies, midges, etc. Way too difficult to ID it beyond order unless you have detailed wing venation.

-YvW

[paleozoicfish]

Hi,

Just to check, did you collect the Rierdon formation insect yourself?

I'm leaning towards Cockroach or something in the roach family for the first specimen. It's viewed from the ventral side. Insect fossils can turn up in random places including marine deposits, for example; look at all the insect fossils that turn up in solnhofen.

The second fossils is in the diptera family; flies, midges, etc. Way too difficult to ID it beyond order unless you have detailed wing venation.

-YvW

Im going to have to agree with Veo, while I mainly study fish and amphibians...I know an insect when I see one, those are not crustaceans.

-PzF

[mdpaulhus]

Hi,

Just to check, did you collect the Rierdon formation insect yourself?

I'm leaning towards Cockroach or something in the roach family for the first specimen. It's viewed from the ventral side. Insect fossils can turn up in random places including marine deposits, for example; look at all the insect fossils that turn up in solnhofen.

The second fossils is in the diptera family; flies, midges, etc. Way too difficult to ID it beyond order unless you have detailed wing venation.

-YvW

Yes, I collected both of these myself. The Rierdon formation, at least in thsi area, is definitely a marine exposure, This "insect: was found in the same strata that I found the fish psoted in the folowing post.

http://www.thefossilforum.com/index.php?sh...ic=5403&hl=

These fossils are from the middle section fo the Rierdon formation in a laminated sandstone strata that was exposed in the area I was digging to a dpeth of about 15 feet or so. The strata with the belemenites and gryphae immediately overlays this strata and is incredibly abundant. I would estimate perhaps 30 beleminites or beleminite fragments per square foot, and plenty of gryphae and coral fragments to go with them.

I have actually read about the Rierdon formation in this area having insects. I would guess that this was a shallow water marine environment based on the size of the fish here (all less than 6 incehs in length) and the number of hatchling fish that were present.

Great discussion, this really gives me a lot more to research. I will probably get in touch with the Montany Beureau of Mines and Geology or the Museum oin Bozeman on this also as I would really like to know the ID of the fish also.

[a.brix]

Hello,

the first bug looks realy good and seems to be very well preserved.

Is it the same age like Solnhofen Limestone ?? ( Jurassic - Malm - Tithon - Zeta 2 )

If it is the same age it could be possible that there are fossil bugs which could be the same like yours.

( Excuse my English - I'm not writing alot in English )

[jkfoam]

Yes, I don't really expect a firm ID, but sometimes one comes along, and I certainly enjoy the speculation/educated guesses/general direction that usually does come along.

The more I look at the first "insect" the more I am confused. I am now questioning whether it is an insect at all and not just some assemblage of materials that makes it look this way. It certianly does look like it has a beetle type of body, but I don't know if any beetles have this long proboscis (mouth) like this appears to have. This could of course be an antenna perhaps or even one of the front legs that has been disarticulated. I could probable convince myself that some of the parts of the beetle are tucked under the body or missing and the fossil could be made up of the other pieces. You can kind of see the resemblance of many parts to the picture of a beetle that I have attached.

For a bettle with a long proboscis Google the Assassin bug or Assassin bettle. This is a modern day "beneficial" but it is one mean looking critter. They are a pretty common summertime bug out here in the county in central Texas.

JKFoam

[ashcraft]

Assassin bugs are from the order hemiptera, while beetles are from the order coleoptera. The main way to tell them apart is by their mouth parts. Hemipterans also tend to have a pentagram shape of their backs. Both orders are very common, although beetles more so. Hemipterans include species that are plant eaters, such as stink bugs, or can be highly predacious, such as assassin bugs or giant water bugs, which prey on fish. As far as being beneficial, assassin bugs in most of US are, feeding on other insects. If you want a really good show, put an assassin bug and a large preying mantis into the same container. The assassin bug will prevail. Assassin bugs are closely related to bed bugs, and other blood feeders that cause Chaga's disease.

Brent Ashcraft