Plate tectonics was apparently important in hominoid evolution:

India approaching S-Asia 40 or 30 Ma first formed island archipels.
Catarrhini that reached these islands became the Hominoidea, who waded bipedally in the coastal forests, and climbed arms overhead in the branches above the water: they became "aquarboreal" (aqua=water, arbor=tree): this explains why Hominoidea differ
from Cercopithecoidea, e.g.
- larger bodies (hylobatids - smaller again, see below - still have remarkably long gestation periods),
- much wider body, esp.the thorax ventrally (Hominoidea = Latisternalia: very broad sternum=breast-bone), which turned the scapulas from lateral to dorsal = arms (>legs) from ventral to lateral (for climbing vertically? for swimming?),
- centrally-placed spine esp. the lumbar & cervical spine (vs. the dorsally-placed spine of monkeys & most mammals, A.Schultz), suggesting a more vertical body posture, for wading bipedally & for climbing arms overhead,
- tail loss, very unexpected in purely arboreal mammals, but not in BP waders.

-- When India got further underneath Asia, this split the lesser apes (E) in SE.Asia & the great apes (W) along the Tethys Sea-coasts.
-- The terminal closure c 14 Ma of the Mesopotamian Seaway then split pongids-sivapiths along the Indian Ocean (E) & hominids-dryopiths along the Med.Sea (W), explaining e.g. the Trachilos bipedal footprints c 6 Ma (2021 Scient.Reports 11,19427), google "
aquarboreal ancestors":
-The pongids along the Indian Ocean forced the hylobatids higher into the trees (becoming smaller brachiators, still below-branch) in SE.Asia.
-The Mediterranian hominids died out (Messinian Salinity Salinity Crisis c 5.6 Ma? Zanclean Mega-Flood c 5,3 Ma?), but Red Sea hominids (Gorilla & Homo-Pan) survived.
The Red Sea opened into the Gulf c 5 Ma:
--Pan went right, initially along the E.African coastal forests -> inland: S.Afr.apiths africanus->robustus,
--Homo went left, along the S.Asian coasts -> H.erectus in Java after c 2 Ma, google "coastal dispersal Pleistocene Homo".
--Gorilla c 8 Ma already had followed the incipient Rift -> E.Africa: E.Afr.apiths afarensis->boisei (// S.Afr.).

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