A thesis that some of this data (yes, data is a singular mass noun in actual English) seems to support: style features that are traditional in some fields/journals can be traced to what style manuals happened to be saying at the time those fields'/journals' styles were fixed. This appears to be the case, for example, for the journal Language's use of small caps for author names, which seems to have everything to do with the year 1966, when the journal switched from notes style to reference-list style and when the current edition of CMS was the eleventh.
Some features of Language author–date style are still, however, of mysterious provenance.
Sources: CMS 11 = A manual of style, University of Chicago Press, eleventh edition (1939). CSE 1 = Style manual for biological journals, Conference of Biological Editors, first edition (1960). CSE 2 = Style manual for biological journals, Conference of Biological Editors, second edition (1964). CMS 14 = The Chicago manual of style, University of Chicago Press, fourteenth edition (1993). Paragraph locators are used instead of page numbers in CMS.
In its "Notes and footnotes" chapter on references in journal articles, CMS 11 explains the exceptional reference-list format used in the sciences. Note the use of caps and small caps for author names, a general feature of Chicago style at the time—and a recurring tendency: giving author names a distinctive, marked style. Note also the uniform inversion of author names (not first author only).
In its chapter "Bibliographies"—apparently invoking a traditional restriction of the term bibliography to the reference list/bibliography of a book, as opposed to an article—CMS 11 contrasts the style for "books of a purely scientific nature" with that for other books. The style shown is essentially the same as the one for journal articles. The distinguishing features of this style, within CMS's norms, are the author–date format (year in second position), abbreviation of first names, sentence case for titles, and no quotation marks around nonitalicized titles. Compare some "normal" entries:
Note the position of the page locator, between the identifiers and the containing publication. Note also CSE's failure to adopt the city: publisher format, as well as its failure to italicize book titles.
No change:
Language 42.3, September 1966, with William Bright as new editor, introduces the now linguistics-typical variant of author-year format, including the distinctive way of adding page numbers to an in-text citation with a colon (e.g., Bright 1966:23). Distinction between author and work is consistent. Reference list shows full names instead of initials, sentence case for work titles, period between volume and page numbers.
Same year, in the LSA Bulletin 39 (September 1966), the LSA style sheet is updated with these “new style rules” for bibliographical references. No source is given. Previous system involved footnotes, no alphabetical references list at the end.
Looks kind of like a combination of CMS and CSE. Note the CMS-like small caps on authors' names and title–editors–page numbers order for book chapters. A couple features are drawn from CMS's humanities style: the full authors' names and the abbreviated page ranges. The lack of italics, meanwhile, is reminiscent of CSE. Anomalous and interesting are the lack of in (already this calling card is present! check Esper 1935), the use of a period instead of a colon between volume and page numbers, and the absence of publishers' names.
Where does the colon come from? Neither CMS nor CSE. Evidently not an extension of the volume–page number divider in the reference list, because Language is using a period there. (Could still have been the source of it, though—reuse.)
Linguistic Inquiry launched 1970. Author-year format for in-text citations, but basic form (name of work) includes parentheses around the year: Quirk (1965, 217). References list: in J. Fodor’s “Three reasons for not deriving ‘kill’ from ‘cause to die’” (LI 1:4), at least, we have: first initials instead of full names; APA-style parentheses on year; Chicago-style capitalized titles; Chicago-style quotation marks on nonitalicized titles; comma instead of period as basic block divider; comma between volume and page numbers. This style persisted into the 1990s.
In 1993 (24:1), LI style is updated [style sheet published in back matter, apparently not previously—get it!]. In-text citation: Postal 1972:247. References: Full names, no parentheses on year, sentence capitalization for titles, ed. for edited by, colon with no space between volume and page numbers.
This edition came out in 1993.
After the change:
Note particularly the order title–editors and the use of ed. as an abbreviation of edited by.
Before (23.XXX):