Late Jurassic


The Late Jurassic is the third epoch of the Jurassic period, and it spans the geologic time from 161.5 ± 1.0 to 143.1 ± 0.6 million years ago, which is preserved in Upper Jurassic strata.
In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, Malm was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units.

Subdivisions

The Late Jurassic is divided into three ages, which correspond with the three faunal stages of Upper Jurassic rock:
NameLower boundary
Tithonian149.2 ± 0.7
Kimmeridgian154.8 ± 0.8
Oxfordian161.5 ± 1.0

Paleogeography

By the Late Jurassic, Pangaea had broken apart into Laurasia to the north and Gondwana to the south, divided by the wide Tethys Ocean. During the Late Jurassic, narrow ocean basins formed separating Eastern Gondwana, Western Gondwana and Laurasia. These nascent oceans – including the young Atlantic Ocean – brought increased moisture to the formerly highly arid subtropical interior of Pangaea.

Climate

Deep ocean basins covered the poles, inhibiting the formation of polar ice caps. Polar summers were ice-free. The circulation of ocean currents between the high and low latitudes contributed to a generally warmer climate than today. Europe became progressively more arid over the Late Jurassic.

Life forms

This epoch is well known for many famous types of dinosaurs, such as the sauropods, the theropods, the thyreophorans, and the ornithopods. Other animals, such as some crocodylomorphs and the first birds, appeared in the Jurassic. Listed here are only a few of the many Jurassic animals:
NameDescriptionWhere found
AllosaurusThe most common Late Jurassic theropodNorth America, also present in Europe
AnurognathusOne of the smallest pterosaursEurope
ApatosaurusA large herbivorous sauropod dinosaurNorth America
ArchaeopteryxA bird-like maniraptoranEurope
BarosaurusAn exceptionally long herbivorous sauropod dinosaurNorth America
BrachiosaurusA massive herbivorous sauropod dinosaurNorth America
BrachytrachelopanA small herbivorous sauropod dinosaurSouth America
BrontosaurusA large herbivorous sauropod dinosaurNorth America
CamarasaurusA large herbivorous sauropod dinosaurNorth America
CamptosaurusAn ornithopodNorth America and possibly Europe
CeratosaurusA medium-sized Jurassic carnivoreNorth America, Europe, and possibly Africa
ChaoyangsaurusAn early marginocephalian dinosaurAsia
CompsognathusA small theropodEurope
DakosaurusA medium-sized sea-going crocodylomorphEurope
DicraeosaurusA large herbivorous sauropod dinosaurAfrica
DiplodocusAn exceptionally long herbivorous sauropod dinosaurNorth America
DryosaurusAn ornithopodNorth America
ElaphrosaurusA medium-sized Jurassic carnivoreAfrica
EpanteriasA massive carnivore North America
EuropasaurusA small herbivorous sauropod dinosaurEurope
GargoyleosaurusA thyreophoranNorth America
GiraffatitanA large sauropod Africa
JuramaiaA basal mammalAsia
KentrosaurusA thyreophoranAfrica
LiopleurodonA medium-sized sea-going pliosaurEurope
MaraapunisaurusPossibly among the largest sauropod dinosaurs ever known
OphthalmosaurusA very common sea-going ichthyosaurEurope and North America
OrnitholestesA small theropodNorth America
PerisphinctesAn ammonite
PterodactylusA short-tailed pterosaurEurope
RhamphorhynchusA long-tailed pterosaurEurope
SaurophaganaxA giant carnivore; possibly the largest land predator
of the Jurassic 		North America
StegosaurusA thyreophoranNorth America and Europe
SupersaurusPossibly the longest sauropod dinosaur of them all
TorvosaurusA large Jurassic carnivoreNorth America and Europe
TuojiangosaurusA thyreophoranAsia
YangchuanosaurusA large theropodAsia
YinlongAn early marginocephalian dinosaurAsia