I will allow you a tiny victory … clearly the quote above, where the term “intermediate” introduces the phrase “between an ancestral form and that of its descendants” was certainly a premature expectation of the early writers!
However, in those cases where the situation can be actually proven true (!!), as determined by dating layers and/or finding a tight correspondence between features in the fossil of a proven ancestor and features in a proven descendant sample, then certainly the term “Transitional” should be allowed.
But given the general inclination of writer or reader to miss the nuances, or psychologically introduce nuances where one shouldn’t, when the ancestors and/or the descendants aren’t proven, we have no other word to use but “Intermediate”.
Marty, you will allow a writer some word, yes? Do you have one that you think is more fair and appropriate than “intermediate”?
Re-read the paragraph on the Tiktaalik. The features of the fossil being described are not frivolous comparisons. They illustrate - - by means of another living creature now fossilized - - that new traits (expected of land-roving tetrapods) can appear on a creature that otherwise satisfies many of the anatomical definitions of the earlier forms (more fish-like) - - and they exist on a single creature.
This is not philosophy. This is immutable truth.
You and I are ones doing the philosophy - - the philosophy of semantics, meaning and intention.
As I imply above, you can’t expect us to go silent over someone else abusing terminology. There is something to be said - - and I will be happy to say whatever word you think is best (if you are persuasive) !
I just now realized I missed your objection to Intermediate:
Between any two points, there is always a middle point. It’s the inevitable nature of geometry.
If either of us could manage to get everyone to use Intermediate instead of Transitional, I would consider it a great victory. How exactly do you expect to convince someone to write about “Similar Forms” instead of “Intermediate Forms”?
The intended point of the comparison is to show a form that is not just “similar”… but that it represents a “way point” Between anatomical comparisons. I would certainly never use the phrase “related structures”… because then I would be accused of saying the fossil is closely “related” - - instead of distantly “related”.
In Latin, “Intermediate” is what it’s about… “the middle between” … and so it should be used, until the better substitute is found.
An Anecdote: Recently the Washington Post featured an article about amoeba - - true one celled animals - - that build homes out of tiny bits of shell! They exist today.
But they also existed millions of years ago, during the Eocene! And one form was a giant!!! Now extinct, by carefully enlarging its home as a flat and very perforated disk, it could grow to the size of four centimeters! Can you imagine a one-celled creature the size of four centimeters!
The writer of the science article became very enthusiastic at this point, and mentioned that the ancient Egyptians used them as money. The writer said they were called “Nummulites”, which was a Greek word derived from the word for money! But the author got the story garbled! Herodotus called the fossils Nummulites, because they Looked like money - - not because they were used as money. The pyramids were built with stones that had great numbers of fossilized, giant foraminifera. The story made me wince. And every time you (or I) read an article that incorrectly suggests or implies an intermediate form is “transitional”, we should wince too… and maybe even burn the article !!! Or maybe burn the smart phone we read the article on ?? (make sure it’s someone else’s smart phone!).
[[ Giant homes for Giant one-celled Amoebas!! ]]