Re: esopotamian Seaway closure


alandarwinvanarsdale
 

A broken watch is correct twice per day. “The earliest known proboscidean is Eritherium, followed by Phosphatherium, a small animal about the size of a fox. Both date from late Paleocene deposits of Morocco . Proboscideans evolved in Africa, where they increased in size and diversity during the Eocene and early Oligocene.

 

Sent from Mail for Windows

 

From: fceska_gr via groups.io
Sent: Saturday, April 2, 2022 6:24 AM
To: AAT@groups.io
Subject: Re: [AAT] esopotamian Seaway closure

 

And this one:

 

https://www.nhm-wien.ac.at/jart/prj3/nhm/data/uploads/mitarbeiter_dokumente/roegl/1999_Roegl_Palgeo_GeolCarp.pdf

 

(see images)

 

F.

 

-----Original Message-----

From: AAT@groups.io <AAT@groups.io> On Behalf Of fceska_gr via groups.io

Sent: Saturday, April 2, 2022 1:53 PM

To: AAT@groups.io

Subject: Re: [AAT] esopotamian Seaway closure

 

IMO there weren't just two migration events between Africa and Eurasia, but several.

Across the Gomphotherium land bridge, c.19 Ma, when proboscideans migrated out of Africa (possibly ancestor of Hylobatidae migrated into Asia then too). 

14 Ma is probably closer to the separation date for Pongids but Griphopithecus (or similar) is found in Europe from 16.5 Ma, so Sivapithecus/Pongo could have diverged East, as Begun says, as apes travelled north from Africa/Arabia, or perhaps in a later wave, or perhaps south and east, branching away from the dryopiths that were colonising Europe at that time.

 

Biogeographic responses to geodynamics:

A key study all around the Oligo–Miocene Tethyan Seaway https://nhm-wien.ac.at/jart/prj3/nhm/data/uploads/mitarbeiter_dokumente/kroh/2007/Harzhauser_et_al_2007_ZoolAnz.pdf

 

F.

 

-----Original Message-----

From: AAT@groups.io <AAT@groups.io> On Behalf Of Marc Verhaegen

Sent: Friday, April 1, 2022 10:56 PM

To: AAT@groups.io

Subject: [AAT] esopotamian Seaway closure

 

Two-step closure of the Miocene Indian Ocean Gateway to the Mediterranean Or M Bialik cs 2019 Scient.Reports 9, 8842

 

The  Tethys Ocean was compartmentalized into the Med.Sea & Indian Ocean during the early-Miocene, yet the exact nature & timing  of this disconnection are not well understood.

Here we present 2 new Neodymium isotope records from isolated carbonate platforms on both  sides of the closing seaway, Malta (outcrop sampling) & the Maldives  (IODP Site U1468), to constrain the evolution of past water mass  exchange between the present day Med.Sea & Indian Ocean via the Mesopotamian Seaway.

Combining these data with box modeling results indicates:

water mass exchange was reduced by ~90 % in a first step  at c 20 Ma.

The terminal closure of the seaway then coincided with the sea-level drop caused by the onset of permanent glaciation of  Antarctica at c

13.8 Ma.

The termination of meridional water mass  exchange through the Tethyan Seaway resulted in a global reorganization  of currents, paved the way to the development of upwelling in the  Arabian Sea, and possibly led to a strengthening of S.Asian Monsoon.

 

_____

 

This seaway closure likely caused the pongid/hominid split, but was it

20 or 14 Ma?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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