Corrections of so-called “savanna” habitats, e.g.

Revised stratigraphy of Area 123, Koobi Fora, Kenya,
and new age estimates of its fossil mammals, including hominins
PN Gathogo & FH Brown 2006 J.hum.Evol.51:471-9  

… all hominins … from Paleontol.Coll.Area 123 derive from levels between the KBS Tuff (1.87 Ma) & the Lower Ileret Tuff (1.53 Ma) :
53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, esp. those units containing molluscs & algal stromatolites. 

On Sun, 31 Oct 2021 06:10:20 -0700 (PDT), "littor...@gmail.com"
<littoral.homo@gmail.com> wrote:

>Corrections of so-called “savanna” habitats, e.g.
>
>Revised stratigraphy of Area 123, Koobi Fora, Kenya,
>and new age estimates of its fossil mammals, including hominins
>PN Gathogo & FH Brown 2006 J.hum.Evol.51:471-9  
>
>… all hominins … from Paleontol.Coll.Area 123 derive from levels between the KBS Tuff (1.87 Ma) & the Lower Ileret Tuff (1.53 Ma) :
>53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, esp. those units containing molluscs & algal stromatolites. 

Today there are at least 14 species of freshwater molluscs in the Mara
River Basin of Kenya and Tanzania (including iconic savanna of Masai
Mara Game Reserve and Serengeti National Park):
https://wwfint.awsassets.panda.org/downloads/wwf_2020_marafreshwaterbiodiversityreview.pdf

littor...@gmail.com wrote:
> Corrections of so-called “savanna” habitats, e.g.
>
> Revised stratigraphy of Area 123, Koobi Fora, Kenya,
> and new age estimates of its fossil mammals, including hominins
> PN Gathogo & FH Brown 2006 J.hum.Evol.51:471-9
>
> … all hominins … from Paleontol.Coll.Area 123 derive from levels between the KBS Tuff (1.87 Ma) & the Lower Ileret Tuff (1.53 Ma) :
> 53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, esp. those units containing molluscs & algal stromatolites.
>

https://pubmed.ncbi.nlm.nih.gov/16815529/

Abstract
Recent geologic study shows that all hominins and nearly all other published
mammalian fossils from Paleontological Collection Area 123, Koobi Fora,
Kenya,
derive from levels between the KBS Tuff (1.87+/-0.02 Ma) and the Lower Ileret
Tuff (1.53+/-0.01 Ma). More specifically, the fossils derive from 53 m of
section
below the Lower Ileret Tuff, an interval in which beds vary markedly
laterally,
especially those units containing molluscs and algal stromatolites. The upper
Burgi Member (approximately 2.00-1.87 Ma) crops out only in the southwestern
part of Area 123. Adjacent Area 110 contains larger exposures of the member,
and there the KBS Tuff is preserved as an airfall ash in lacustrine
deposits and
also as a fluvially redeposited ash. We observed no mammalian fossils in
situ in
this member in Area 123, but surface specimens have been documented in
some monographic treatments. Fossil hominins from Area 123 were attributed
to strata above the KBS Tuff in the 1970s, but later they were assigned to
strata
below the KBS Tuff (now called the upper Burgi Member). This study
definitively
places the Area 123 hominins in the KBS Member. Most of these hominins are
between 1.60 and 1.65 myr in age, but the youngest may date to only 1.53 Ma,
and the oldest, to 1.75 Ma. All are 0.15-0.30 myr younger than previously
estimated. The new age estimates, in conjunction with published taxonomic
attributions of fossils, suggest that at least two species of Homo
coexisted in the
region along with A. boisei until at least 1.65 Ma. Comparison of crania
KNM-ER 1813 and KNM-ER 1470, which were believed to be of comparable age,
is at the focus of the debate over whether Homo habilis sensu lato is in fact
composed of two species: Homo habilis and Homo rudolfensis. These two crania
are separated in time by approximately 0.25 myr, and therefore, arguments for
their conspecificity no longer need to confront the issue of unusually high
contemporaneous variation within a single species.

Some day you'll learn to be honest...

On Monday, November 1, 2021 at 1:22:32 AM UTC-4, Primum Sapienti wrote:
> littor...@gmail.com wrote:
> > Corrections of so-called “savanna” habitats, e.g.
> >
> > Revised stratigraphy of Area 123, Koobi Fora, Kenya,
> > and new age estimates of its fossil mammals, including hominins
> > PN Gathogo & FH Brown 2006 J.hum.Evol.51:471-9
> >
> > … all hominins … from Paleontol.Coll.Area 123 derive from levels between the KBS Tuff (1.87 Ma) & the Lower Ileret Tuff (1.53 Ma) :
> > 53 m of section below the Lower Ileret Tuff, an interval in which beds vary markedly laterally, esp. those units containing molluscs & algal stromatolites.
> >
> https://pubmed.ncbi.nlm.nih.gov/16815529/
>
> Abstract
> Recent geologic study shows that all hominins and nearly all other published
> mammalian fossils from Paleontological Collection Area 123, Koobi Fora,
> Kenya,
> derive from levels between the KBS Tuff (1.87+/-0.02 Ma) and the Lower Ileret
> Tuff (1.53+/-0.01 Ma). More specifically, the fossils derive from 53 m of
> section
> below the Lower Ileret Tuff, an interval in which beds vary markedly
> laterally,
> especially those units containing molluscs and algal stromatolites. The upper
> Burgi Member (approximately 2.00-1.87 Ma) crops out only in the southwestern
> part of Area 123. Adjacent Area 110 contains larger exposures of the member,
> and there the KBS Tuff is preserved as an airfall ash in lacustrine
> deposits and
> also as a fluvially redeposited ash. We observed no mammalian fossils in
> situ in
> this member in Area 123, but surface specimens have been documented in
> some monographic treatments. Fossil hominins from Area 123 were attributed
> to strata above the KBS Tuff in the 1970s, but later they were assigned to
> strata
> below the KBS Tuff (now called the upper Burgi Member). This study
> definitively
> places the Area 123 hominins in the KBS Member. Most of these hominins are
> between 1.60 and 1.65 myr in age, but the youngest may date to only 1.53 Ma,
> and the oldest, to 1.75 Ma. All are 0.15-0.30 myr younger than previously
> estimated. The new age estimates, in conjunction with published taxonomic
> attributions of fossils, suggest that at least two species of Homo
> coexisted in the
> region along with A. boisei until at least 1.65 Ma. Comparison of crania
> KNM-ER 1813 and KNM-ER 1470, which were believed to be of comparable age,
> is at the focus of the debate over whether Homo habilis sensu lato is in fact
> composed of two species: Homo habilis and Homo rudolfensis. These two crania
> are separated in time by approximately 0.25 myr, and therefore, arguments for
> their conspecificity no longer need to confront the issue of unusually high
> contemporaneous variation within a single species.
>
> Some day you'll learn to be honest...

:DD