C-type asteroid
The largest unequivocally C-type asteroid is 10 Hygiea, although the SMASS classification places the largest asteroid, 1 Ceres, here as well, because that scheme lacks a G-type.
Chicxulub impactor
There are several competing models for the impactor's origin and its relationship to other asteroids that still exist in the Solar System. In September 2007, William F. Bottke, David Vokrouhlický, and David Nesvorný proposed an origin for the impactor in an article published in "Nature". This argued that a collision in the asteroid belt 160 million years ago resulted in the Baptistina family of asteroids, the largest surviving member of which is 298 Baptistina. They proposed that the Chicxulub impactor was an asteroid member of this group, referring to the large amount of carbonaceous material present in microscopic fragments at the site, suggesting that it was a member of a rare class of asteroids called carbonaceous chondrites, like Baptistina. According to Bottke, the Chicxulub impactor was a fragment of a much larger parent body about across, with the impacting body being around 60 km (40 mi) in diameter.