OK, I finally got through enough books to get to this series and I'm currently on book 4.
I'll start off with my biggest gripe about the entire series, which galls me to no end:
THERE ARE ONLY FOUR FRICKIN' BOOKS!
You, sir, are a SLACKER! It's taken me THREE FRICKIN' YEARS since your initial posting for to get through the backlog of other books in order to get started on this series and YOU ONLY HAVE FOUR BOOKS?!? You have exactly until I finish reading book 4 to come out with book 5...and that pretty much means after this weekend! But I'll be generous and give you until the week after Thanksgiving, because the kids and I are going to Universal Studios Orlando next week and I won't have time to do much reading until after we get back home. This "Spring 2024" date ain't gonna cut it!
😉
Seriously, I read a LOT, both from established authors and authors published through more traditional means as well as newer authors publishing through less traditional venues. Your Prehistoric books have come across as very well written with respect to character development, story line, plot complications, grammar, etc.
In fact, the only detractors I've found (and no, I haven't kept track of them for editing feedback) involved the occasional anachronistic use of "Ms." and the odd misspelling. The term "Ms." was nearly two decades away from its first linguistic use (1901) in the era your books take place in, and several more decades later (1970s) before it came into popular use in the English lexicon. And the occasional misspelling was very few and far between. None of which, by the way, actually detract from the stories, mind you. Just some things I noticed.
The firearms in use were historically accurate, too, so far as I understand them. Well done on this!
When I said well written character development, I mean the characters did not read as shallow. They had purpose (perhaps only as a snack), they had lives (however short some may have been), and the longer a character was present, the more their character took on depth.
I see that you've been laying groundwork for other potential story arcs, as well, with hints of potential shimmers located in other locations/eras. I'd be most interested to see story arcs from the differing perspectives of other cultures and peoples as well.
Then, of course, there's the question of the origin of the shimmers as well, which so far you've only treated as "they exist" with no hint towards how or why. Perhaps this is all that they'll ever be, but then who knows what evil lurks in the heart of the author?
As I said, I read a lot. Mostly SciFi and Fantasy, but a smattering of other genre's too. When you've read enough different material from enough different authors, you can kinda "taste" the style/flavor of the various writers and get a sense for how seasoned they are, how mature their writing is, etc. Your writing does not come across, in any way whatsoever, as that of a newbie or an amateur. It comes across like that of an established and skilled writer.
(About that publishing date...family comes first. I'll happily wait however long it takes for the next book(s) while you take care of your little girl.)
Keep up the good work. I'll be looking forward to your future contributions and will be happy to shovel some of my hard earned money into your pockets for books like these.