Great post Keravne! Thank you for the information.
I had never thought that Thesprotoi an Thessaloi had common ancestors!
I also had the impression that the word Thessalia (ΘΕΣΣΑΛΙΑ) came from the words ΘΕΣΗ ΑΛΟΣ (Thessi alos), meaning "the position of the sea", which denotes that the Thessalian plains where sometime in the past under the sea, something which is confirmed by the findings in Meteora.