LATE JURASSIC

The 'Late Jurassic' (or 'Malm') Epoch of the Jurassic Period is the unit of geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago, which is preserved in 'Upper Jurassic' strata.^[1]

Contents

Subdivisions

Paleogeography

Life

References

Subdivisions

The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock:

Tithonian	(150.8 ± 4.0 – 145.5 ± 4.0 Ma)
Kimmeridgian	(155.7 ± 4.0 – 150.8 ± 4.0 Ma)
Oxfordian	(161.2 ± 4.0 – 155.7 ± 4.0 Ma)

Paleogeography

Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow.

Life

This period was well known for many famous types of dinosaurs:

★ Sauropods:

★
★ ''Camarasaurus''

★
★ Brachiosaurs

★
★ Diplodocids
Many smaller animals were flourishing on land:

★ Lizards

★ Early mammals

★ Very early birds (like ''Archaeopteryx'')
In the marine realm several different marine reptile groups flourished:

★ Metriorhynchid crocodiles

★ Ichthyosaurs

★ Plesiosaurs

★
★ Pliosaurs

References

★ Commentary: Usage of Stratigraphic Terminology in Papers, Illustrations, and Talks, , Donald E., Owen, Journal of Sedimentary Petrology, Reproduced here.

★ Late Jurassic — The Malm Epoch: The Acme of the Dinosaurs