This was a while ago, so the details are a bit fuzzy for me.
About three years ago I doodled up this sketch in my linguistics class instead of paying attention to the intro to historical linguistics lecture. It sat on my computer for most of that time, but tonight I rediscovered it and decided to typeset it. I remember very little about the language family I was sketching out, I don't think I ever really got as far as an actual phonology on any of them
Anyway, here's the sketch. I gave a rendering of the same sentence in nine languages. The first language was the already-archaic normative standard, and the next six are its main daughters. Language 8 was a neighboring language, and 9 was a creole formed from 1 and 8's interaction, using 1 as the lexifier.
The universe was sort of a loosely-conceived largely parody science fiction universe I was putting together. It involved re-scaled physics, where planets were so small they had only a couple dozen square miles of surface area (which has never been, and continues to not be, the way physics works). Anyway that was how I rationalized having the entire planet speak one language (there could only ever be < 100 people or so on even the most densely populated planets).
If I recall correctly, the action was mostly set in the remnants of a large interstellar empire, which had spread out from a planet called Irth. There was faster-than-light travel but transportation was limited to the speed of the fastest ship. The empire spread out significantly, encountering a number of other intelligent races. Then there was some kind of catastrophe (it involved a couple things: a demonic invasion, a plague, and the machines started to come to life) which caused the central power structure to break down. The sketch I gave was for languages of the empire around the time of that breakdown, and it advocates for the people who live in "sprawlworlds" (planets whose landmass is mostly city) to abandon those planets for more scarcely populated homes.
Normative Imperial Irth
Normative Imperial Irth s a very lightly fusional VSO language. Verbs are marked for person, tense and mood. Case for nouns is marked by prepositions. Nouns are mostly unmarked, and was no paradigm of agreement.
Phonologically, I think it had a phoneme inventory that looked something like this:
a i e o u b p d t g k q f s š x w r l j N
If I recall correctly, ⟨q⟩ is a glottal stop. The only noteworthy feature of the phonology is the lack of phonemic voiced fricatives. Phonetically, there was some allophony with the fricatives:
C[-voice, +continuant] > C[+voice, +continuant] / #_V C[-voice, +continuant] > C[+voice, +continuant] / V_V
The one nasal phoneme, ⟨N⟩ also had some allophony, with the homorganic nasal rule.
N > C[∂place +nasal] / _C[∂place]
There was unpredictable phonemic stress. All in all, nothing to write home about, but the sort of thing that's not too bad for an intro linguistics student.
Sound changes in the descendent languages.
I haven't made up full lists of sound changes into the daughter languages, but here are the chain shifts that happened to *q in the daughter languages:
*q (vulgar proto-Imperial) > *k (proto-central) > k (central imperial #2); t (guilder high imperial #3, south tributary imperial #4) *q (vulgar proto-Imperial) > *h (proto-spinward) > j (spinward imperial #5); h (special administrative zone imperial #7)