
We know more of Marcus Tullius Cicero (106-43 BCE), lawyer, orator, politician and philosopher, than of any other Roman. Besides much else, his work conveys the turmoil of his time, and the part he played in a period that saw the rise and fall of Julius Caesar in a tottering republic.
Again, later Christian Greek texts (probably codices rather than scrolls) could have called "kephalaion" the thing Latin marked as "caput" (not in the article, but very common in Latin; Cicero uses it in _De Inventione_) or "capitulum," and in fact Greek texts did so in imitation of the Latin, but "kephalaia" is plural, and the author, despite writing about the history of terms, doesn't seem to know that.
It's also odd that he discusses Aulus Gellius' _Attic Nights_ without talking about Pliny the Elder's _Natural History,_ on which Gellius likely based his concept of an index and chapter headings. In Pliny, the chapter headings proceed logically through thematically related groups in a taxonomy, so you can drill down through the index to the chapter you want by looking for the larger genus to which it might be a species. If you're looking for a particular rock, for example, you start in the index under rocks and then look for a more specific type of rock, rather than looking under plants or geography. Gellius turns this on its head, quite possibly intentionally: none of his chapters fall into any sort of order that anyone has ever been able to discern, so you have to read the entire index of chapter headings (itself a book in length) in order to locate one you might be seeking. Besides being the first, to my knowledge, openly user-hostile interface, I think that makes it harder to believe what the author says about the Attic Nights being "only something to be consulted partially, and on occasion, rather than read and absorbed line-by-line." It's actually really hard to use the Attic Nights as a reference book in that way, not only because of how Gellius set up the index and disordered the chapters but also because it was originally published in linear-access scrolls rather than a random-access codex, making quick reference even more difficult. So, it's odd that the author skips from headings that organize a legal treatise straight to Gellius' chapter headings summarizing, but not organizing, his random miscellany without some mention in between of someone like Pliny, who organizes chapters into a taxonomy.
There's already a lot of scholarship about chapter markings and other paratextual devices in ancient literature: Butler (2009) "Cicero's Capita" in _The Roman Paratext_ shows that Cicero's speeches were capitulated in antiquity without written rubrics or headings, marking new units of text on the same argument instead by extending the first line into the left margin; surely this is a step that should have been considered on the road from legal text rubrics to chapters without headings as a temporal organizational device in novels.
Maybe the book did the topic more justice than the review.
Chirologia/Chironomia are more oriented to hand gestures rather than whole body, but they might have some clues. Roman orators had a set of stock poses (the memes of the day?), so maybe Cicero actually said something about shoulder shrugging in the "delivery" part of De Inventione? It's certainly a gesture that would have read well in the back rows, had they used it.
EDIT: maybe also somewhere in Quintilian? https://en.wikipedia.org/wiki/Institutio_Oratoria