Yes and no, depending upon your definition of a transitional form.
It is not possible to have a transitional form between two species, since a genetic modification is binary. You have either have it, or you do not.
Within a family, each species will be closely related to each other. There, you will find many transitional species between the oldest and more recent along a time-line.
That is like stating that there are no transitional forms between male and female children in a family. Yes, that is very true and factual. However, they do share a common set of parents and are closely related.
As with the difference between male and female, you are one or the other. There are no transitional forms and it would be impossible to find any fossils of them.