We present WSRT observations of the neutral hydrogen in the nearby radio galaxy B2 0648+27 .
In emission , we detect a very large amount of H I ( M _ { HI } = 1.1 \cdot 10 ^ { 10 } M _ { \odot } ) that is distributed in a very extended disk , or ring-like structure , of about 160 kpc in size .
We also detect H I absorption against the central radio continuum component .
The detection of the H I , its structure and kinematics , give us key information for building a possible evolutionary scenario .
The characteristics of the detected H I are explained as the result of a major merger event that is likely to have occurred \lower 2.15 pt \hbox { $ \buildrel < \over { \sim } $ } 10 ^ { 9 } yr ago .
Interestinly , we find that , when observed in radio continuum at higher resolution , this galaxy has a double lobed , steep spectrum structure of about 1 kpc in size .
Thus , despite its low radio power , B2 0648+27 bears striking similarities with Compact Symmetric Objects , i.e .
objects believed to represent the early phase of radio galaxies ( \buildrel < \over { \sim } few thousand yrs old ) .
B2 0648+27 is one of the few nearby radio galaxies where extended neutral hydrogen has been detected so far .
This , and other recent results , appear however to indicate that nearby radio galaxies are more often gas rich than commonly assumed .
The phenomena described are likely to be much more common at high redshift and galaxies like B2 0648+27 may provide valuable information on the evolution of high redshift radio sources .