Like Matt said, those are so-called winter tracks based upon widened standard tracks.
Spoiler
Late type "winterketten":

These were later replaced by more robust "eastern tracks", introduced in the summer of 1944. Ostketten were enlarged outwards and secured by bolts, making them easier to install. They helped to decrease the rolling resistance and ground pressure - for example, T-34-76 showed ground pressure of 0.71 kg/sq cm, Jagdpanzer IV with Ostketten had "only" 0.67 kg/sq cm - but they were twice as heavy as the standard tracks.
Comparison:


The 38th Guard Rifle Regiment of the 14th Guard Rifle Division climbing over Carro Armato L6/40 light tanks, destroyed/abandoned during early September 1942.