The number and location of bones of many fossil vertebrates are similar to those in living vertebrates. this is evidence in support of which of the following concepts?
a. lamarck's tendency towards perfection
b. common descent
c. analogous structures
d. the inheritance of acquired traits

Vertebrates are defined as they consist  of a backbone or spinal column including mammals, birds, reptiles, amphibians, and fishes.
therfore
The number and location of bones of many fossil vertebrates are similar to those in living vertebrates.So evidence in support of common descent .
hence the right answer is b. common descent