The phrase "coeval with" is correct and can be used in written English.
It is an adjective which means "existing at the same time as another; contemporaneous". For example: "The pyramids of ancient Egypt are thought to be coeval with the oldest stone structures of Mesopotamia."
Modern scholarship's concern with animism is coeval with the problem of rational or scientific understanding of religion itself.
Kleiven, H. F. et al. Reduced North Atlantic Deep Water Coeval with the Glacial Lake Agassiz Freshwater Outburst.
These restricted conditions were coeval with intense evaporite deformation and brine recycling.
Poll-tax riots and uprisings at Broadwater Farm Estate are coeval with the burning of Newgate Prison: they are virtual-reality panoramas from the Museum of London.
The construction of the Altaid collage was coeval with the late Paleozoic assembly of the Pangea (or Pangaea) supercontinent (between about 320 and 250 million years ago).
They were related to the rifting of the West Siberian Plain and were coeval with basaltic eruptions in the Turgay Valley.
Gold precipitation was coeval with this second quartz episode and occurs as irregular masses (mostly <100 μm) and in fractures replacing the pyrite.
Another discovery has brought to light evidence of an early civilization at Ayabaca, in Piura in northwestern Peru, that was probably coeval with the Chavín.
Kinematic compatibility suggests that the synmetamorphic ductile shearing was coeval with the D1 event in the sedimentary cover.
Lama-bordo systems evolved as intensively and extensively managed landscapes coeval with climate shifting to more arid conditions.
Geological, archaeological and radiocarbon dating criteria all converge, indicating that the tsunami deposits are coeval with the Minoan Santorini eruption.
