This is unfortunate news... The specimens brought back by the field team were infected by X parasites. The X can mimic its prey; any specimen could have hosted it. Before the explosion, a security sensor scanned one...


The X Parasite shown on the security sensor.

A security sensor is a security detection system on the Biologic Space Laboratories research station. They appear in three Navigation Room briefings from the Adam computer in Metroid Fusion. Each time, it appears in the top right corner of the screen as a frame, surrounding the subject caught on camera. One security sensor detected an X Parasite before the explosion triggered by the SA-X in the Quarantine Bay (prior to Samus's arrival on the station). This is shown to Samus when she uplinks with Adam after exploring the Quarantine Bay and seeing another X Parasite. It later detects a Blue X as Samus is entering Sector 6; Adam shows the footage to Samus while warning her to steer clear of them. Finally, when Samus returns to her Gunship during the Reactor Silo shutdown, Adam informs her that the Dachoras and Etecoons have boarded, and shows her footage of them captured on a security sensor in the Habitation Deck (which is where she found and released them).