Short answers, pulled from the story.
French geologist Alexandre Brongniart officially coined the term Jurassic for geological timekeeping in 1829. His book described terrains jurassiques while correlating Swiss rocks with similar oolitic limestones found in Britain.
The Hettangian Stage began around 201.4 million years ago when Psiloceras spelae tirolicum first appeared in Austria's Karwendel Mountains. This boundary was ratified in 2010 at Kuhjoch Pass.
Conifers formed the dominant component of Jurassic floras across the globe. Most modern conifer groups appeared in the fossil record by the end of the Jurassic having evolved from voltzialean ancestors.
Archaeopteryx from the Late Jurassic of Germany definitively represents the earliest avialans around 150 million years ago. This creature evolved from theropod dinosaurs within the clade Paraves alongside dromaeosaurs and troodontids.
By 1842, French palaeontologist Alcide d'Orbigny had subdivided the system further using ammonite fossils to establish ten stages. Seven of these stages remain in use today.