Amber is fossilized tree resin. Sap from trees falls on the ground, is covered and preserved. Tiny insects and other tiny animals can become fossils if they are trapped in the sticky resin. The movie and novel, Jurassic Park, popularized insect fossils in amber.
Fossil amber has been found that is well over 200 million years old. However, the oldest insect fossils in amber only date back to about 130 million years ago- until a recent discovery. Alexander Schmidt and colleagues report in the journal, PNAS* the presence of 2 mite fossils and a dipteran fossil in 230 million year old amber from Italy. This find pushes back the oldest amber arthropod fossils by 100 million years. The fly was disarticulated (separated into numerous pieces) but the scientists were able to determine that it is a fly. It shares some characteristics with midges.
The other arthropods were both gall-forming mites. This is interesting because the overwhelming majority of gall-forming mites are found on flowering plants. The oldest record of flowering plants is from 140 million years ago. This suggests that the gall forming mites, that are common on flowering plants today, originally were present on conifers and moved to the angiosperms once they evolved.
These fossil finds will likely intensify the search for more fossils in amber from this period.
Fossil fly from 230 million year old amber and artist’s rendition of the features.
Image: Museum of Geology and Paleon- tology, University of Padova, Italy/PNAS
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*Alexander R. Schmidt, Saskia Jancke, Evert E. Lindquist, Eugenio Ragazzi, Guido Roghi, Paul C. Nascimbene, Kerstin Schmidt, Torsten Wappler, and David A. Grimaldi
Arthropods in amber from the Triassic Period
PNAS 2012 ; published ahead of print August 27, 2012, doi:10.1073/pnas.1208464109
Living With Insects Blog 
Alternatively to gall-forming mites evolving from conifers, might this discovery suggest that fossils of flowering plants over 140 million years old also exist?
The fossils are associated with a conifer.
The appearance of angiosperm might be pushed back a few million years but certainly not 100 million years. Some extant Eriophyids feed on conifers. It is more parsimonious to postulate that feeding on conifers was the ancestral behavior. Later, they switched to angiosperms, radiated and were more successful.
Would it be possible to recreate the jurassic park idea or is that just science fiction?