Question about finding more fossils in an area

[TheEm]

I recently found a collection of marine fossils, such as shells, in a rural area of Spain called Pozo Alcon. I've done some research into the geology of the area but different geologic maps tell me different things in terms of era, age, epochs, etc of the land. So, I can't date them. Also, the land here has been underwater and not various times, but the last time it was sea was around 170 million years (Jurassic Period).

I want to go back to this area and look more, but I'm not exactly sure what I should be looking for.  

Is it possible that I could find different kinds of fossils here, for example, ones that are not marine life? Or is it too difficult to say for sure?

Sorry if this is a really basic or somewhat stupid question. I'm a beginner and these are only the 2nd set of fossils I've found so far, so bare with me.

 

Thanks for your knowledge.