Thread subject: Diptera.info :: Fossil nematoceran to ID
Posted by Rui Andrade on 02-10-2009 23:11
#1
Some years ago I bought an ambar with a fossil dipteran on a fossil fair at my university. I have no data on the fossil age or provenience. I'd love to know its family.
Posted by Peter Macdonald on 03-10-2009 21:11
#2
Rui,
I will let those who are more knowledgeable to try to put a family to your fly. But, we can think a little about the provenance of this.
The vast majority (99%+) of amber inclusions in commerce come from one of two sources. These are the Baltic and the Dominican Republic. The Baltic specimes are most probably Eocene, but that is not a universally accepted age. The problem is that the amber is not in its original deposits. Most is found washed up on beaches after storms. The bits that are found
in situ
are found in younger sediments, where they were washed from thier original deposits many millions of years ago.
The Dominican specimens are somewhat younger. They are Oligocene to Miocene in age.
A large percentage of the pieces of Baltic amber have small stellate plant hairs, from the male flowers of an oak (
Quercus
). These are usually a bit under one milimetre accross. So, if there is a stellate hair,it is from te Baltis. If there is not a stallate haor, it may be from either deposit.
Peter
Posted by Rui Andrade on 05-10-2009 21:23
#3
Hi Peter,
Thank you for your reply:). It doesn't seem that those hairs are present. So maybe it could be from the Dominican Republic. Would it be possible to know its age or provenience if the specimen can be studied? The fauna of the two epochs should be different.
Posted by John Carr on 18-03-2011 00:23
#4
Are the coxae enlarged? I can't count leg segments. I have the impression of a fungus gnat (Mycetophilidae s. lat). On the other hand, the extant fungus gnats that look like this tend to have very large tibial spurs.
Posted by phil withers on 18-03-2011 00:32
#5
This looks like a sciarid to me: the wing-fork is quite prominent.
Posted by John Carr on 18-03-2011 00:45
#6
I thought the fork of Cu didn't match Sciaridae, but on second look that's a crack or bubble or overlaid object rather than a fork. Are there known fossil Sciaridae with such large legs?
Posted by xylo on 18-03-2011 07:49
#7
Yes, CuA looks unusual: seems as if CuA branches do not merge and have no stem. However, m-fork is typical and the eye bridge seems to be entire(?) present: I would guess Sciaridae also. At least some recent Neotropical species I saw are "giants".