Fossil insect from China

[Quetzalcoatlus]

This piece was exposed an a mineral, fossil and gem fair.

I believe it's a dragonfly nymph (=inmature). It's very big in comparison with modern dragonfly nymphs: about 8 cm lenght.

Piece comes from Liaoning (China) and I think it's middle Jurassic.

Any help in ID?

Thanks!

[abyssunder]

Very interesting!
Possibly the find is related to the Jehol Biota.
Considering the large number of abdominal segments and the form of the terminal tracheal gill of the respiratory system, my guess would be damselfly nymph. Stonefly, mayfly and dragonfly nymphs have different termination of the abdomen, some kind of 'spines' (caudal lamellae) not 'flaps' (stoneflies have two, mayflies have three of that).

 

damselfly

 

Interesting is the large dimension of the specimen, also looks like there are lots of eggs around. If the eggs are from the specimen in question that means the specimen is an adult female which had deposited the eggs and died in the proximal moments. In this case where are the wings... ? So, I guess, it is not an adult and the eggs are from other individual. Maybe it's an emerging one.

dragonfly/damselfly

 

Also, my logical deduction could be wrong, I'm not a specialist in this domain.

[Quetzalcoatlus]

Thanks for your reply, Abyssunder. I'm familiarized with extant dragonfly, damselfly and stonefly nymphs and know the spines and flaps that you mention. (I never saw flaps in stoneflies, just thread-like cerci). However the flaps are always like lanceolated leaves in modern damselflies, the body is too robust and the size is much bigger than any modern damselfly. I believe that it can be an Odonata of an extinct suborder (not a dragonfly nor a damselfly), or even an extinct order similar to Odonata but not included in it (such as Protodonata, the order that included the Meganeura). I never tought in eggs for these small rounded things. I believed to be shells of something, maybe big ostracods. These things are also present in the grasshopper fossil.

[Fossildude19]

The ovate shells are the carapaces of some specie of conchostracan.  

(Clam Shrimp)

[abyssunder]

Tim is right about conchostracans. That's a good ID!

 

If you are familiar with extant dragonfly, damselfly, stonefly and probably mayfly nymphs, then why do you believe it's a dragonfly nymph ?

 

Maybe Dr. David Grimaldi could guide you in the right direction. Try contacting him.

 

 

 

[Quetzalcoatlus]

6 minutes ago, abyssunder said:

If you are familiar with extant dragonfly, damselfly, stonefly and probably mayfly nymphs, then why do you believe it's a dragonfly nymph ?

 

 

-Because of the shape. Too robust for damselfy, different to stonefly. Mayfly nymphs are extremely variable in shape depending on the families, but none like this.

-Because of the size. All extant damselfly, stonefly and mayfly nymphs are much smaller than this. Dragonfly nymphs are smaller than this but not so much.

-Because I don't noticed the flaps until reading your reply. Hence my correction in my own reply when I told "it can be an Odonata that is not a dragonfly (Anisoptera) nor a damselfly (Zygoptera) but a third order, or may be even a non-Odonata such as Protodonata".

-Because I told clearly "I believe that it's a dragongly nymph". That is not the same that say "I'm sure/almost sure that it's a dragonfly nymph".

-Because I tend to be inexact in the use of common names too, especially in my bad English (sorry!), and in the first message the term "dragonfly" was intended to mean "Odonata", including damselflies. But after your reply, looks like an specificaction and distinction between both suborder was necessary.

 

Thanks a lot for the contact info. I'll try to contact him, and if I receive any help from him I will transmit the info into this post.