The phrase "and in the oldest" is not complete on its own, but it can be correct and usable in written English when placed in the right context.
You can use it when referring to something that is among the oldest in a particular category or group.
Example: "The artifacts were discovered in a site that dates back to ancient times, and in the oldest layers, we found tools that predate civilization."
Alternatives: "and among the oldest" or "and within the oldest".
In Norway and Sweden, the proportion of gynecologists routinely prescribing HRT for women without contraindications increased with age and in the oldest age group of gynecologists (>55 years) 49 and 56%, respectively, recommended HRT to all women.
The presence of closely related species in the Meliaceae family in reference forests and in the oldest restoration site, which was next to a forest remnant, points toward dispersal as the main factor driving phylogenetic patterns in the sites studied.
Rory Ross, a journalist living in London, has suits made by Kilgour (his measurements are kept on file there) and Richard Thompson, a London tailor who works independently through his company, Exclusive Tailoring, and in the oldest tradition of the trade, travels to his clients' homes and hotels, bringing along hundreds of samples of cloth for his customers to choose from.
The incidence of HL displays an unusual age distribution, with two peaks between the ages of 15 to 34 years and over the age of 60 years in most Western countries, but in children and in the oldest age groups in developing countries [2].
Our findings reveal that insomnia is more prevalent in women and in the oldest old.
There were more women in the youngest groups and in the oldest groups (5 14 and 65+).
Similarly, CHF ranked fourth and sixth in the "oldest-old" and the "old-old", respectively, but ranked tenth in the "young-old".
You hear sometimes when the Americans go to [Central America], and in the old days.
And in the old, established, now bygone tradition, a theater star tours.
Such adaptability spells resilience, and "good farming" is culturally embedded as a civic responsibility, both in the ethnographic present and in the older, elite agronomic writings.
Protests, so far quite small, have become more frequent in Mezze, to the west, and in the old city itself.
