  The sharp change in slope of the ultrahigh energy cosmic ray (UHECR) spectrum
around 10^18.6 eV (the ankle), combined with evidence of a light but
extragalactic component near and below the ankle and intermediate composition
above, has proved exceedingly challenging to understand theoretically, without
fine-tuning. We propose a mechanism whereby photo-disintegration of ultrahigh
energy nuclei in the region surrounding a UHECR accelerator accounts for the
observed spectrum and inferred composition at Earth. For suitable source
conditions, the model reproduces the spectrum and the composition over the
entire extragalactic cosmic ray energy range, i.e. above 10^17.5 eV.
Predictions for the spectrum and flavors of neutrinos resulting from this
process are also presented.
