Sedimentology and Paleontology Lecture 8: PalaeoBiogeography

Question 1

Who is the father of Paleobiogeography?

Answer 1

Father of Biogeography is Alfred Russel Wallace (1823 - 1913).

Question 2

Define Correlating fossil bearing formations

Answer 2

Correlating fossilbearing formations =
glimpse distribution of
ancient provinces

Question 3

What and where is Beringia

Answer 3

Beringia is a currently submerged landmass located between Eastern Siberia and Alaska beneath the Bering sea.

Question 4

Describe history of Beringia

Answer 4

For 11,000 years, the Bering Strait has divided North America and Asia, limiting interchange of animals.

Region was repeatedly flooded during Pleistocene, in response to contracting and expanding glaciers.

Around 15,000 - 20,000 there was a land bridge between Alaska and Siberia. Early humans and other asian faunas traversed this land bridge/Beringia to enter the Americas.

These early humans and fauna first populated the West coast first due to mountain and ice sheet barriers blocking the east coast.

or much of the Pliocene and Pleistocene, Beringia was a
complex habitat of arctic scrub with a differentiated climate. It was also ice-free, and partially covered in forests and
woodlands.

Palaeomagnetic data indicates that Alaska and Russia were in
contact by the mid-Cretaceous (c. 100 Million years)

link between North America and Asia was not severed by rising waters until the Miocene/Pliocene

Land bridge potentially open as as early as 105 million years ago.

Question 5

Describe evidence of Beringia’s opening and closing

Answer 5

The occurrence of the Atlantic/Arctic bivalve Astarte and
associated diatoms in the north Pacific is good evidence of
this link.

The Bering straits had to exist for them to extend their range
in this fashion

Question 6

What is the Early [K] Cretaceous Laurasian Interchange event

Answer 6

Early [K]Cretaceous Laurasian Interchange Event: dinosaur
faunas of North America are replaced with exotic Laurasian
forms

Early Cretaceous faunas of North America are similar to those
of Europe (FAUNAL ASSEMBLAGE 1): - Dromaeosaurs (‘raptors’), carnosaurs, iguanodontids,
nodosaurs and brachiosaurs

The EKLInE, therefore, started at least 108 million years ago

Extremely close relationships
are found between
Asiamerican dinosaurs
throughout the Late
Cretaceous. For example the North American Tyrannosaurus and the European Tarbosaurus

Question 7

Define fosters island rule

Answer 7

Strange evolutionary trends have been found in isolated/ geographically restricted animal populations.

Fosters island rule = Generally big animals (when found in other parts of the world) are much smaller when found on islands.

And smaller animals (when found in other parts of the world) are much larger on islands.

Question 8

What is the Hateg basin/faunas and who was the Paleontologist who worked on it?

Answer 8

Baron Franz Nopcsa (1877 – 1933) identified ancient island
ecosystems in the late Mesozoic of Transylvania early as 1914

Nopcsa deduced this entirely from the Maastrichtian fauna of the Haţeg Basin

Sauropods and ornithischians dinosaurs of Haţeg are tiny
compared to mainland relatives

E.g. Adult Magyarosaurus grow no longer than 6 m, compared to
a typical 20 m for other sauropods.

comprised of Lower Cretaceous
clades Haţeg Basin must have been isolated from rest of world

Haţeg is comprised of 10 – 13 dinosaur species

compared to 30 - 40 in contemporaneous parts of
the world