Re: Zinjanthropus afarensis->boisei
Always hard to tell how much is guesswork with these bold statements, especially when they are made in support of a theory about the "chronicle of dispersal" of tiny insects many millions of years ago. Is the sea level evidence presented to support the dispersal theory, or is the apparent distribution of the insects presented as evidence for higher sea levels?
If sea levels were high enough to cover Syria and most of Italy ( current altitude ca 500metres) in the middle and late Miocene, why was most of the Sahara (alt. ca. 200 m.)not also flooded?
I reckon you can make any guesses you want to fit any theory and no one can contradict you.
From: AAT@groups.io <AAT@groups.io> on behalf of fceska_gr via groups.io <f-ceska@...>
Sent: Monday, April 25, 2022 6:02 PM
To: AAT@groups.io <AAT@groups.io>
Subject: Re: [AAT] Zinjanthropus afarensis->boisei
These maps clearly shows Crete was part of the mainland at least till 12 Ma but completely separate by 8 Ma. It clearly rejoined during the MSC, between 5.9 – 5.3 Ma.
(Sorry, I’ve shared these before to the group).
The Scolopendra species (Chilopoda: Scolopendromorpha: Scolopendridae) of Greece (E-Mediterranean): a theoretical approach on the effect of geography and palaeogeography on their distribution
Neogene supradetachment basin development on Crete (Greece) during exhumation of the South Aegean core complex
Hence, three main tectonic phases are recognised: (1) Early to Middle Miocene N–S extension formed during the Cretan detachment, exhumed in the South Aegean core complex. The Cretan detachment remained active until 11–10 Ma, based on the oldest sediments that unconformably overlie the metamorphic rocks. Successions older than 11–10 Ma unconformably overlie only the hanging wall of the Cretan detachment, and do not contain fragments of the footwall rocks; they therefore predate the oldest exposure of the metamorphic rocks of the footwall. The hanging wall rocks and Middle Miocene sediments form isolated blocks on top of the exhumed metamorphic rocks, which are interpreted as extensional klippen. (2) From approximately 10 Ma onward, southward migration of the area that presently covers Crete was accompanied by E–W extension, and the opening of the Sea of Crete to the north. Contemporaneously, large folds with WNW–ESE striking, NNE dipping axial planes developed, possibly in response to sinistral transpression. (3) During the Pliocene, Crete emerged and tilted to the NNW, probably as a result of left-lateral transpression in the Hellenic fore-arc, induced by the collision with the African promontory.
Mammal faunas reported by De Bruijn et al. (1971) and De Bruijn & Meulenkamp (1972) led Drooger & Meulen-kamp (1973) to suggest that the connection of Crete to the European mainland was lost in the course of the early Tortonian, as a result of the onset of foundering of the Cretan Basin underlying the Sea of Crete (Fig. 8).We follow this conclusion, as it is in line with the fact that the youngest sediments that provide evidence for a northern sediment source are the deep-marine early Tortonian sediments in the Ierapetra area (Kalamavka, Section 64; Fortuin, 1978; Fortuin & Peters, 1984).
From: AAT@groups.io <AAT@groups.io>
On Behalf Of Gareth Morgan
Crete was an island at that time?
I've wondered about this. The water between Crete and mainland Greece is about 100 m deep today in the shallowest places.
Water levels would have been lower during the Messinian and probably other times, but there is also evidence that the whole area has been sliding downwards and to the west.
These earthquakes (brown pixels)...https://sp.lyellcollection.org/content/291/1/1
are related to this movement, south westward.
From the top picture, we can see that the whole Aegean basin would be sliding down into deeper water with every tremor.
So I can happily accept that Crete and the sea bed around it would have been higher in the past, which would provide land bridges to the mainland, if not continuous dry land. There have, I believe, been a number of cities discovered on the sea floor in the area that must once have been on dry land.
The sea to the south of Crete is 2,000 m deep, so I don't think a land bridge to Africa is feasible.
AAT@groups.io <AAT@groups.io> on behalf of fceska_gr via groups.io <f-ceska@...>
Yes, Madelaine Bohme's book "Ancient Bones" is really good. I read it last year (well, I listened to it on Audible). She is also proposing a possible connection between Graecopithecus as LCA / oldest hominin
and Trachilos (original hominins).