"remained unstudied" is grammatically correct and can be used in written English.
For example, you could use it in a sentence such as: "The mysterious creature's habits remained unstudied until a team of researchers conducted a detailed study."
"Seagrass has largely remained unstudied in Palau compared to coral reefs, yet it may comprise a highly influential ecosystem with the potential to locally counteract ocean acidification," Francis said.
However, the connectedness of approximate solutions set for VEPs remained unstudied.
However, the connectedness and the compactness of the set of solutions to the set-valued vector equilibrium problem remained unstudied.
Suhrawardi's Intimations, Paths and Conversations, and Oppositions contain substantial sections on physics, although all have remained unstudied.
Of interest is the history of its discovery: "The first specimen was discovered by a team of Soviet paleontologists in 1979 but remained unstudied for more than thirty years.
The species remained unstudied and its affinities unclear until 2011, when it was recognized as a member of the genus Juliomys, which includes three other species from southern Brazil and nearby Argentina and Paraguay.
The extent of human settlement in the Amazon remains hotly debated, partly because huge swaths of the 6-million-square-kilometer rainforest remain unstudied by archaeologists.
The evolutionary origin of the MORC family also remains unclear, as their specific relationship to other conserved eukaryotic members of the GHKL superfamily remain unstudied.
Parts of the material collected during his famous Sunda Expedition still remain unstudied.
However, their contemporary use and influence on cleft patients remain unstudied.
But about 3,000 nuclei that exist between the stable region and the upper limit for neutron-richness — known as the neutron-drip line — remain unstudied.
