Re: The taxonomy of Sahelanthropus tchadensis from a craniometric perspective

On 30.7.2024. 9:38, Mikko wrote:

On 2024-07-29 15:18:31 +0000, Pandora said:

Op 29-07-2024 om 07:19 schreef Primum Sapienti:

The paper's date is given at the very bottom as
Manuscript received on June 15, 2023;
accepted for publication on October 20, 2024
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https://www.scielo.br/j/aabc/a/GGPvzpzxZpPccBWzFncgRTG/?format=pdf&lang=en
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Abstract: Sahelanthropus tchadensis has raised
much debate since its initial discovery in Chad
in 2001, given its controversial classification
as the earliest representative of the hominin
lineage. This debate extends beyond the
phylogenetic position of the species, and
includes several aspects of its habitual
behavior, especially in what regards its
locomotion. The combination of ancestral and
derived traits observed in the fossils
associated with the species has been used to
defend different hypotheses related to its
relationship to hominins. Here, the cranial
morphology of Sahelanthropus tchadensis was
assessed through 16 linear craniometric
measurements, and compared to great apes
and hominins through Principal Component
Analysis based on size and shape and shape
information alone. The results show that
S. tchadensis share stronger morphological
affinities with hominins than with apes for
both the analysis that include size
information and the one that evaluates shape
alone. Since TM 266-01-060-1 shows a strong
morphological affinity with the remaining
hominins represented in the analysis, our
results support the initial interpretations
that S. tchadensis represents an early
specimen of our lineage or a stem basal
lineage more closely related to hominins
than to Panini.
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"Taken together, these two analyses show a
strong morphological affinity of
Sahelanthropus with hominins."
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"In conclusion, our analyses can safely
reject that the craniofacial morphology of
Sahelanthropus tchadensis is similar to that
of great apes, and in that sense they lend
support to those studies that place this
species within our lineage (Brunet et al.
2002, Guy et al. 2005, Zollikofer et al.
2005). However, from the perspective of
overall cranial morphology, Sahelanthropus
shows a bauplan that is significantly
departed from the one observed among apes
and early australopithecine, falling closer
to the morphospace occupied by early Homo
species. "

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It's a rather strange, counterintuitive, result that the cladistically most basal hominin, Sahelanthropus, is morphometrically closer to Homo than to Australopithecus and the great apes.

 Perhaps the climat at the time of Sahelanthropus was closer to climat at
the time of early Homo than the climat between those times.
 

My advice to you would be, if you want to understand the past, whenever you see the world "climate", or "climate change", just stop reading, and put this book/paper you are reading into garbage can. Because, those who don't know anything, when they are asked to explain something, they just use words "climate change". Climate changes every year. Maybe not in Finland, but in my country (Croatia), we have warm summers and cold winters. Look at that, "climate change".