On Sunday, October 3, 2021 at 5:50:27 AM UTC-4,
littor...@gmail.com wrote:
Op zondag 3 oktober 2021 om 02:07:50 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:
(from a discussion at a...@groups.io)
Where the hominoids originally (>25 Ma) came from, or where cercopithecoids & hominoids split, I don't know, but there must have been very drastic changes in the hominoid LCA >25 Ma (vs cercopithecoids):
- very broad sternum (Latisternalia), thorax & pelvis = lateral movements of arms & legs?
- weight perhaps x 10 (?secondarily reduced in hylobatids, but still disproporitonally long gestation)
- centrally-placed spine (vs dorsally in monkeys & most mammals) = vertical??
Was the hominoid LCA (late-Oligocene? >25 Ma) already (semi)aquatic?? or *only* aquarboreal?
In both cases, early hominoids very likely spread along the Tethys Ocean coasts.
I don't think we can be more specific at this moment:
it could have been SE.Asia, but not impossibly +-everywhere along the Tethys Ocean coasts.
Probably, the Mesopotamian Seaway closure c 15 Ma caused the hominid/pongid split (W/E):
-In the E, I'd think aquarboreal pongids along the Ind.Ocean forced hylobatids higher into the trees.
-In the W, hominids lived all around the Tethys Sea (later Med.Sea) coasts.
1 hominid branch colonized the Red Sea coasts (c 10 Ma??).
Anatomical comparisons (my 1994 & 1996 Hum.Evol.papers) suggest:
- when G & HP split (10-7 Ma?), G followed the Rift ->afarensis, aethiopicus, boisei, gorilla, beringei...
- c 7-4 Ma, H & P split: P followed the E.Afr.coasts? ->africanus, naledi, robustus, paniscus, troglodytes...
- Homo (already Pliocene? or only early-Pleist.??) followed the Ind.Ocean coasts as far as Flores & Luzon, but also E.Africa etc.
https://www.karger.com/Article/FullText/501557
Author completely ignores fossil observation bias, claims lca hominoid lived in deciduous woodlands partly terrestrially yet says they broadened their chests and had curved fingers etc. Idiot. They were arboreal slow climbers, slow brachiators and
upright arboreal bipeds.
Wading is irrelevant, sifakas & gibbons are obligate orthograde bipeds who avoid water, gorillas & chimps wade then walk quadrupedally.
Think a little bit, DD: sifakas etc are arboreal hoppers,
Bipedal hoppers!
the opposite of hominid BPism,
Bipedal striders!
google "gorilla bai" or "bonobo wading".
Quadrupedal terrestrial / bipedal arboreal striders!
Of course, gibbons avoid water, haven't you read my post??
Every week you flipflop about gibbons, I never know why!
Broadened chests (not yet in the earliest hominoids?) + sternum (Latisternalia) + pelvis (flaring ilia) + complete tail loss + centrally-placed spine (not dorsally).
25ma tail lost! 11.6ma flat torsos!
New Ancient Ape Species Rewrites the Story of Bipedalism
Danuvius guggenmosi, a “totally new and different” species of ape, would have moved through the trees using its forelimbs and hindlimbs equally
Andrea Michelson: Reporter, Smithsonian
November 6, 2019
Ape Bones
The 21 bones of the most complete partial skeleton of a male Danuvius guggenmosi. Christoph Jäckle
The picture is on T-shirts, coffee mugs and bumper stickers: the ubiquitous but misinformed image of the evolution of humankind. A knuckle-walking ape rouses himself to stand on two feet, and over a 25-million-year “March of Progress,” he becomes a
modern man.
Most paleoanthropologists will tell you that this version of evolution is oversimplified, misleading or just plain wrong. The theory that the last common ancestor of humans and apes walked on its knuckles like a chimpanzee is not supported by the fossil
record, although it has seen popularity in scientific discourse. David Begun, a paleoanthropologist at the University of Toronto, used to be an outspoken proponent of the knuckle-walking hypothesis, until he was asked to consult on a newly discovered
fossil that would challenge his assumptions about early hominid locomotion.
When Madelaine Böhme, a researcher at the University of Tübingen in Germany, unearthed the partial skeleton of an ancient ape at the Hammerschmiede clay pit in Bavaria, she knew she was looking at something special. Compared to fragments, an intact
partial skeleton can tell paleoanthropologists about a creature’s body proportions and how its anatomy might have functioned. A relative newcomer to the field and a paleoclimatologist by trade, Böhme enlisted Begun’s expertise in analyzing the
fossil ape.
Böhme and colleagues determined that the bones they found came from a dryopithecine ape, an extinct ancestor of humans and great apes that once lived in the Miocene epoch. The fossils are approximately 11.6 million years old and came from at least four
individual apes, including one partial skeleton. The team described the newfound ancestor, named Danuvius guggenmosi, in a study published today in Nature.
New Ancient Ape Species Rewrites the Story of Bipedalism
An illustration of Danuvius guggenmosi, supporting itself with both its forelimbs and hindlimbs. Velizar Simeonovski
D. guggenmosi was likely a small primate about the size of baboon, with long arms like a bonobo. The creature had flexible elbows and strong hands capable of grasping, which suggests that it could have swung from tree to tree like a modern great ape. But
the similarities with known apes stop there. The animal’s lower limbs have much more in common with human anatomy. With extended hips and knees, D. guggenmosi was capable of standing with a straighter posture than that of living African apes, and its
knees and ankles were adapted to bear weight. The animal’s locomotion would have therefore shared similarities with both human and ape movement, and D. guggenmosi may have been able to navigate the forest by swinging from tree limbs and walking on two
legs.
“There is no reason to think it would not have used all four limbs when that made sense, for example, on smaller branches where balance was an issue,” Begun says. “But it was also capable of both suspension and unassisted bipedalism.”
This hybrid form of locomotion, which Böhme and colleagues dubbed “extended limb clambering,” was previously unheard of. Begun says before this discovery, scientists in the field used models of motion employed by living quadruped primates to inform
how our early ancestors may have moved. “Here, we have something that doesn't exist today,” he says. “It's totally new and different, and you couldn't imagine it. It would have been silly to even suggest it unless you found fossils that told you
that there was an animal like this.”
Unlike suspensory great apes that favor their forelimbs and bipedal hominins which prefer their hindlimbs, the anatomy of D. guggenmosi indicates that the ancient primate used both sets of limbs equally. The curvature of the big toe suggests that this
animal would have been able to walk flat-footed on branches, using its longest toe to grasp and balance.
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" Walk bipedally flat-footed on branches using longest toe to grasp & balance ".
Why did hominoids braoden their bodies: lateral movements of arms & legs? Did they have habitually vertical bodies, cf.central spine?
Climbing arms overhead? surface-swimming? bipedal wading?
Danuvius answers your questions.
Peter Andrews gives an *excellent* description of Mio-Pliocene hominid+pongid fossils.
But yes, his interpretation is incredibly ridiculous, not less ridiculous as your "upright arboreal bipeds".
What did he say about Danuvius, meine kleine tochter?
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