50 Fun Facts About Jurassic

The Jurassic Period is named after which mountain range on the France-Switzerland border?

Alexander von Humboldt named the limestone there Jura-Kalkstein in 1799; Alexandre Brongniart coined 'terrains jurassiques' in 1829.

Which period came immediately before the Jurassic?

The Jurassic began about 201.4 million years ago with the end-Triassic mass extinction.

Which period followed the Jurassic?

The Jurassic-Cretaceous boundary is the only boundary between geological periods still formally undefined.

Roughly how long did the Jurassic Period last?

It ran from around 201.4 to 143.1 million years ago.

The Jurassic is the middle period of which era?

It is also counted as the eighth period of the Phanerozoic Eon.

By the start of the Jurassic, the supercontinent Pangaea had begun splitting into which two landmasses?

The rift between North America and Africa opened first, linked to the Central Atlantic Magmatic Province eruptions.

What was notably absent from the Jurassic world because the climate was warmer than today?

Forests grew close to the poles while arid expanses covered the lower latitudes.

Atmospheric carbon dioxide during the Jurassic was likely how much higher than today?

Global temperatures ran roughly 5-10 °C warmer than at present.

Which fossils are the primary index fossils used to divide Jurassic rocks into stages and zones?

The first appearance of the ammonite Psiloceras spelae tirolicum marks the very start of the period.

Which volcanic event is associated with the mass extinction that opened the Jurassic?

A later Toarcian anoxic event around 183 million years ago is blamed on the Karoo-Ferrar eruptions.

Which naturalist named the Jura limestone 'Jura-Kalkstein' in 1799?

Von Buch later split the Jurassic into Black, Brown and White divisions in 1839.

Which French naturalist coined 'terrains jurassiques' in 1829, giving the period its name?

He was correlating the Jura limestone with oolitic limestones of similar age in Britain.

Into how many epochs is the Jurassic divided?

Early, Middle and Late, matching the Lower, Middle and Upper Jurassic rock series.

Which is the only Jurassic stage named from Greek mythology rather than a place?

Albert Oppel chose Tithonus, lover of the dawn goddess Eos, because the stage stands 'hand in hand with the dawn of the Cretaceous'.

Which English city gives its name to the Middle Jurassic Bathonian stage?

The Oxfordian, Kimmeridgian and Callovian are also named after English places.

Which Jurassic rock unit, named after a Dorset village, is the major source rock for North Sea oil?

Jurassic rocks of the Arabian basin also host Ghawar, the world's largest oil field.

During the Jurassic, which vertebrates dominated the skies?

The fish-eating Rhamphorhynchidae were a major Jurassic radiation; furry, insect-eating anurognathids appeared mid-period.

The first stem-group birds appeared in the Jurassic, evolving from which group of dinosaurs?

Archaeopteryx from Late Jurassic Germany is the classic example.

Archaeopteryx lived in the Late Jurassic in what is now which country?

Europe was then an archipelago of islands in a warm shallow tropical sea, much closer to the equator.

Archaeopteryx was first named in 1861 from what kind of fossil?

Hermann von Meyer described it; the London Specimen skeleton was unearthed the same year near Langenaltheim.

Archaeopteryx was roughly the size of which living bird?

The largest individuals may have reached raven size, about 50 cm long.

The Solnhofen Limestone that preserved Archaeopteryx lies in which German state?

It was originally quarried for lithographic limestone and even preserves jellyfish imprints.

Which Upper Jurassic rock unit of the western US is North America's most fertile source of dinosaur fossils?

Centred on Wyoming and Colorado, it covers 1.5 million square kilometres, though over 75% is still buried.

Which two rival palaeontologists fought the 'Bone Wars' over Jurassic fossil beds from 1877?

Arthur Lakes found the first fossils at Morrison, Colorado, that same year.

Besides fossils, those same Jurassic beds were a major source of which ore in the American Southwest?

Most fossils occur in its green siltstone beds, relics of Jurassic rivers and floodplains.

Which group of dinosaurs became the dominant large herbivores and the largest land animals ever in the Jurassic?

The earliest-Jurassic Ledumahadi of South Africa already weighed an estimated 12 tons.

What does the name Brachiosaurus mean, in reference to its unusually long forelimbs?

Elmer Riggs named it in 1903 from Colorado fossils; most pop-culture images are actually based on Giraffatitan from Tanzania.

Diplodocus takes its name from the 'double beam' shape of which bones?

Marsh coined the name in 1878; the Carnegie Museum's 'Dippy' was cast for museums from London to St Petersburg.

Which Late Jurassic dinosaur is known for kite-shaped plates along its back and spikes on its tail?

Its braincase was no larger than a dog's; the 'second brain in the hips' idea is a myth.

The plate-backed dinosaur became which US state's official fossil in 1982 after a fourth-graders' campaign?

Ruth Sawdo's class at McElwain Elementary in Thornton ran the two-year campaign.

What does the name Allosaurus mean, referring to its lightweight vertebrae?

For much of the 20th century it went by the name Antrodemus.

Which two groups of marine reptiles ruled Jurassic seas?

Ichthyosaurs peaked in diversity in the Early Jurassic with giants like Temnodontosaurus and the swordfish-like Eurhinosaurus.

Leedsichthys, the largest bony fish ever known, lived in the Jurassic and reached what estimated length?

It was a filter-feeder among the Pachycormiformes, a group that also included tuna-like predators.

Which group of animals made the transition from land to water during the Jurassic?

Meanwhile the first crown-group mammals and modern sharks and rays appeared.

Which of these groups first appeared during the Jurassic?

Eocarcinus praecursor from Early Jurassic England is the earliest, though it lacked the modern crab shape.

Prosalirus, from the Early Jurassic, is thought to be the first relative of which animals able to hop?

Modern lissamphibians, including salamanders, began to diversify in the period.

The Jurassic mammal relative Castorocauda was adapted to what kind of life?

Other Jurassic mammaliaforms, the Volaticotherini, did have gliding membranes like flying squirrels.

Juramaia, from the early Late Jurassic, is the earliest known member of which mammal group?

Most Jurassic mammals are known only from isolated teeth and jaw fragments.

Which class of jawless fish, key index fossils for 300 million years, went extinct in the earliest Jurassic?

Their hard tooth-like elements survive as microfossils; a few species lingered in Hungary and central Panthalassa.

Which squid-like cephalopods, known from bullet-shaped guards, first appear in the earliest Jurassic?

They lived in the upper 200 metres of shelf seas as both predator and prey.

Which reptile group, whose only living member is the tuatara, dominated small reptiles in the Jurassic?

They reached their peak diversity then, including snake-bodied aquatic pleurosaurs.

Which type of plant, making up 90% of living species, has no widely accepted Jurassic fossil record?

Ferns and gymnosperms dominated; the extinct Bennettitales looked so much like cycads that leaves are hard to tell apart.

Ginkgoales were diverse in the Jurassic, but which single species is their only living survivor?

The earliest members of the genus Ginkgo appear in the Middle Jurassic of the Northern Hemisphere.

Kulindadromeus, a Middle Jurassic ornithischian from Russia, showed that some plant-eating dinosaurs had what?

The earliest ankylosaurs and stegosaurs also appear in the Middle Jurassic.

The 70 km Morokweng impact structure lies buried beneath which desert?

Another Jurassic crater, Puchezh-Katunki, lies under Nizhny Novgorod Oblast in Russia.

The Jurassic-age Arabian Intrashelf Basin holds which field, the world's largest oil field?

The basin was laid down in the Middle and Late Jurassic and holds the world's largest oil reserves.

The Callovian stage takes its name from Kellaways, a village in which English county?

Alcide d'Orbigny named it in 1852; he also named the Sinemurian, Toarcian, Bajocian, Oxfordian and Kimmeridgian.

The Kimmeridgian's global boundary reference point, ratified in 2021, lies at Staffin Bay on which island?

The stage itself is named for the Dorset village of Kimmeridge and its oil-rich clay.

The Toarcian oceanic anoxia of about 183 million years ago is also named after which geochemist?

It is usually blamed on the Karoo-Ferrar eruptions and possible methane clathrate release, and left black shales worldwide.

Ledumahadi, a quadrupedal sauropodomorph from earliest Jurassic South Africa, weighed an estimated how much?

That was far heavier than any other land animal of its time, before true sauropods took over.