https://www.science.org/doi/10.1126/science.add9115

Abstract
In Africa, the scarcity of hominin remains found
in direct association with stone tools has
hindered attempts to link Homo habilis and Homo
erectus with particular lithic industries. The
infant mandible discovered in level E at Garba IV
(Melka Kunture) on the highlands of Ethiopia is
critical to this issue due to its direct
association with an Oldowan lithic industry. Here,
we use synchrotron imaging to examine the internal
morphology of the unerupted permanent dentition
and confirm its identification as Homo erectus.
Additionally, we utilize new palaeomagnetic ages
to show that (i) the mandible in level E is ca.
2 million-years-old, and represents one of the
earliest Homo erectus fossils, and (ii) that
overlying level D, ca. 1.95 million-years-old,
contains the earliest known Acheulean assemblage.


"The Melka Kunture complex consists of a cluster
of prehistoric sites that extends over tens of
km^2 in the Upper Awash, on the Ethiopian plateau
at =>2000 m above sea level (asl) (Fig. 1A). At
this high altitude, the Pleistocene climate would
have been cooler and wetter than at the lower
elevations of the Rift Valley where most fossil
evidence for early species of Homo derives. The
paleovegetation belonged to the Afromontane complex,
ranging from forest to grassland and bushland (1),
and the plant species were distinct from those of
the African savanna, which developed at lower
elevations in drier and warmer environments. The
degree of topographic relief of the region meant
that the highlands were relatively isolated,
leading to the appearance of endemic mammal
subspecies (2). In 1981, an infant mandible was
discovered in level E of the Garba IV site, though
which species of hominin it represents has been a
subject of debate (3). In this study we review the
geochronological context of the Garba deposits,
characterize the Oldowan and Acheulean lithic
assemblages, present the palaeoecological context
of the site based on analysis of the faunal
assemblage and palynology, and reassess the
taxonomic affinity of the mandible. Our aim is to
determine when, how, and which hominin species was
first able to adjust to the high-altitude
environment of the highlands ot Melka Kunture
during the Early Pleistocene and the associated
transition from the Oldowan to the Acheulean
technocomplex. Broadening our knowledge of the
environment at the time and not limiting it to
the savanna and to lower altitudes is relevant to
understand how Homo erectus was able to expand
outside Africa."

"The results show that hippos, bovids and equids
consumed C4 plants, suggesting C4 high-elevation
grasslands (11) (fig. S20)."

"A highland environment, such as that at Garba IV,
at an altitude of 2000 m asl and more, exposes
individuals to less oxygen, higher exposure to UV
rays, more rain and cooler temperatures."

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So they produced broken rocks. And broken rocks.




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https://uapro.tumblr.com/post/731302601269936128

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https://www.science.org/doi/10.1126/science.add9115 :

In Africa, the scarcity of hominin remains found in direct association with stone tools has hindered attempts to link H.habilis & H.erectus with particular lithic industries. The infant mandible discovered in level-E, Garba-IV (Melka Kunture, highlands
of Ethiopia) is critical to this issue, due to its direct association with an Oldowan lithic industry. Here, we use synchrotron imaging, to examine the internal morphology of the unerupted permanent dentition, we confirm its identification as H.erectus.
We utilize new palaeo-magnetic ages to show:
(i) the mandible in level-E is c 2 Ma, it represents one of the earliest H.erectus fossils,
(ii) overlying level-D c 1.95 Ma contains the earliest known Acheulean assemblage.
The Melka Kunture complex consists of a cluster of prehistoric sites that extends over 10s of km2 in the Upper Awash, on the Ethiopian plateau at =>2000 m ASL. At this high altitude, the Pleist.climate would have been cooler & wetter than at the lower
elevations of the Rift Valley, where most fossil evidence for early spp of Homo(?? habilis=Australopith, not erectus --mv) derives. The paleo-vegetation belonged to the Afro-montane complex (forest to grass- & bushland), the plant spp were distinct
from the Afr.savanna (which developed at lower elevations in drier & warmer environments). The degree of topographic relief of the region meant: the highlands were rel.isolated, leading to the appearance of endemic mammal subspp.
In 1981, an infant mandible was discovered in level-E of the Garba-IV site, but which hominin species it represents has been a subject of debate.
Here we review the geo-chronological context of the Garba deposits, characterize the Oldowan & Acheulean lithic assemblages, present the palaeo-ecol.context of the site (faunal assemblage & palynology), and re-assess the taxonomic affinity of the
mandible (when, how & which hominin species was first able to adjust to the high-altitude environment of the highlands ot Melka Kunture early-Pleist.?) & the associated transition Oldowan->Acheulean techno-complex. Broadening our knowledge of the
environment at the time, not limiting it to the savanna & lower altitudes is relevant to understand how H.erectus was able to expand outside Africa.
... The results show: hippos, bovids & equids consumed C4-plants, suggesting C4 high-elevation grasslands.
... A highland environment, such as that at Garba-IV, 2000 m ASL & more, exposes individuals to less O2, more UV, more rain, cooler Tps.


If the infant mandible is indeed erectus (?? many PAs will question this), they had followed the Indian Ocean shores & the rivers inland:
early-Pleist.H.erectus in Java regularly dived for shellfish:
• Archaic Homo's atypical tooth-wear was caused by "sand & oral processing of marine mollusks" https://onlinelibrary.wiley.com/doi/10.1002/ajpa.24500
• H.erectus s.s. typically fossilized in coastal sediments, e.g. Mojokerto: barnacles+corals, Trinil: Pseudodon+Elongaria edible shellfish, Sangiran-17 "brackish marsh near the coast".
• Stephen Munro discovered sea-shell engravings made by H.erectus, Joordens cs 2015 Nature 518:228 https://pubmed.ncbi.nlm.nih.gov/25470048/
• Ear-exostoses (H.erectus & H.neand.) develop after years of cold(er) water irrigation https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696936/
• Pachy-osteo-sclerosis is only seen in slow+shallow-diving tetrapods (de Buffrénil cs 2010 J.Mamm.Evol.17:101), e.g. erectus’ parietal bone is 2x as thick as in gorillas.
• Brain size in erectus (2x apes=australopiths) is facilitated by aquatic foods, e.g. DHA in shellfish… cf. Odontocetes, Pinnipedia.
• Late-Pleist. descendants or relatives colonized islands far oversea: Flores 100-50 ka, Luzon 67 ka https://www.academia.edu/36193382/Coastal_Dispersal_of_Pleistocene_Homo_2018
• Homo’s stone tool use & dexterity is typical for molluscivores, e.g. sea-otters.

In any case, the paper ("Afro-montane complex") confirms that only incrdible imbeciles still believe their ancestors ran after savanna antelopes. :-D

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