 Specimen AMNH NJ @-@ 90Z is a small wedge @-@ shaped fragment of pileus which was accidentally fractured during preparation for study , splitting it in half . Though the researchers had not intended to perform destructive analysis on the sample , this fracturing warranted the sacrifice of some parts of the specimen for structural and molecular study . Small pieces of the specimen were mounted directly on scanning electron microscopy ( SEM ) stubs and sputter coated with a gold / palladium alloy . The resulting images showed that little intact tissue remained , and only fragmented and crushed basidiospores were seen . Another sample of the specimen was mounted in spurr 's resin ( an embedding medium used in electron microscopy ) and sectioned with a diamond knife ; the resulting sections were examined with transmission electron microscopy ( TEM ) . The lack of discernible biological material from the mushroom seen in the SEM study was confirmed in the TEM analysis . A final section of the fossil was selected to attempt DNA sequencing . A small sample of the fossil was extracted at the AMNH and sent to the Peabody Museum of Archaeology and Ethnology for DNA amplification . None of the three selected extracts showed any results after the amplification was attempted . It is possible that the fractures and flowlines which split AMNH NJ @-@ 90Z during initial preparation had already penetrated into the fossil and destroyed the hermetic seal which would have been needed for preserving the organic matter of the mushroom . 
