They have been described as a transitional form between trilobites and true chelicerates.
The theory rejects transitional forms of plants and animals.
I am a transitional form, he told himself, and someday I will be obsolete.
It is considered a transitional form between Mecoptera and Diptera.
They want to meet you and talk about the work that you began a couple of years ago on transitional forms.
The text also uses a dotted form of the m-rune, which is considered to be a transitional form.
However, that in no way disqualifies it as a transitional form, or as evidence for evolution.
In a few areas, transitional forms with features of both cell types may be present.
There is little preservation of transitional forms between the two periods.
Rahne later learned to enter different transitional forms which vary slightly in appearance.