penecontemporary

That lived or existed at almost the same time (as another/others); nearly contemporary

The chalcolithic Corded Ware culture of North-Central and Eastern Europe has been found to display archaeological as well as genetic affinities to the penecontemporary Yamnaya horizon of the Pontic–Caspian Steppe.

That which is penecontemporary, living or existing at almost the same time (as another/others)

However, he found that features more prone to show environmental effects (whether phenotypically plastic or otherwise) separated the tropical Jebel Sahaba skeletons from their penecontemporaries at higher latitudes.