the.com/jurassic period

means The middle chunk of the Mesozoic Era, roughly 201 to 145 million years ago, when the supercontinent Pangaea kept splitting apart and dinosaurs grew large and dominant on land while new reptiles ruled the seas and skies.

from Named for the Jura Mountains on the France-Switzerland border, where in the early 1800s geologists identified thick limestone layers formed during this time. The name was proposed in the 1790s-1830s period by geologists studying the region (often credited to Alexandre Brongniart, building on earlier observations), and it stuck as the label for the whole span of Earth history when those rocks were laid down — long before anyone knew the age would become shorthand for 'big ancient lizards,' a reputation cemented much later by fossil discoveries and pop culture.