  The unplaced Fragment D of the Antikythera Mechanism with an unknown
operation was a mystery ever since it was discovered. The gear r1, which was
detected in Fragment D radiographies by C. Karakalos is preserved in excellent
condition but this was not enough to directly relate it to the existing gear
trains of the Mechanism. The suggestion that Fragment D could be a part of the
hypothetical planet indication gearing is a hypothesis, in contradiction with
the AMRP tomographies, and leads to mechanical malfunctions. The analysis of
AMRP tomographies of Fragment D and its mechanical characteristics, revealed
that it could be part of the Draconic gearing. Currently, the three lunar
cycles Synodic, Sidereal and Anomalistic are represented on the Antikythera
Mechanism. Although the Draconic cycle was well known during the Mechanism era
as representing the critical fourth Lunar cycle, it seems that it is missing
from the Antikythera Mechanism. The study of Fragment D was supported by our
bronze reconstructions of the Fragment D, leading to the reconstruction of the
Draconic gearing. These results are very important, because with the use of
only one hypothetical,missing gear, the Draconic gearing is revealed on the
Antikythera Mechanism. Fragment D(raconic) can be perfectly correlated with the
Draconic cycle of the Antikythera Mechanism without mechanical problems and the
four lunar cycles appear on the Mechanism. Based on the Draconic pointer, the
eclipse events can be calculated and engraved on the Saros spiral cells.
