With the exception of the three monotypic genera Sylviparus, Melanochlora, and Pseudopodoces, the tits are extremely similar in appearance, and have been described as "one of the most conservative avian families in terms of general morphology". The typical length of the family is between 10 and 16 cm (3.9 and 6.3 in) in length when the monotypic genera are added, this range is from 9 to 21 cm (3.5 to 8.3 in). In weight, the family ranges from 5 to 49 g (0.18 to 1.73 oz), this contracts to 7 to 29 g (0.25 to 1.02 oz) when the three atypical genera are removed. The majority of the variation within the family comes in plumage, and particularly colour. The bills of the tits are generally short, and vary between stout and fine dependent on diet. The more insectivorous species have finer bills, whereas those that consume more seeds have stouter bills. However, it is said that tits are evolving longer beaks to reach into bird feeders.The most aberrant bill of the family is possessed by Hume's ground tit, which is long and decurved.