What's the plural form of palaeosalinity? Here's the word you're looking for.
Answer
The noun palaeosalinity can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be palaeosalinity.
However, in more specific contexts, the plural form can also be palaeosalinities e.g. in reference to various types of palaeosalinities
or a collection of palaeosalinities.