Systematics of Miocene apes:
State of the art of a neverending controversy
Alessandro Urciuoli & David M Alba 2023 JHE 175,103309

Hominoids diverged from cercopithecoids during the Oligocene in Afro-Arabia, initially radiating in that continent and subsequently dispersing into Eurasia.
(?? more likely in coastal forests of the Indian island archipels of the Tethys Ocean then, see my 2022 book p.299 --mv)
From the Late-Miocene onward, the geographic range of hominoids progressively shrank, except for hominins, which dispersed out of Africa during the Pleistocene.
(?? most likely much earlier out of the Red Sea swamp forests: Gorilla c 8 Ma via the N-Rift into Afar, Homo & Pan c 5 Ma when the Red Sea opened into the Gulf, ibid. --mv)
Although the overall picture of hominoid evolution is clear, based on available fossil evidence,
(geogr.distribution of apes (hylobatids & Pongo in SE.Asia, Pan & Gorilla in Africa, H.erectus on Java etc.) is at least as important IMO --mv)
many uncertainties persist re.the phylogeny & paleo-bio-geography of Miocene apes (non-hominin hominoids), owing to their sparse record, pervasive homoplasy & the decimated current diversity of this group.
(yes, parallel & convergent evolutions are more frequent than we use to think, google "aquarboreal" --mv)
We review Miocene ape systematics & evolution, by focusing on the most parsimonious cladograms published during the last decade.
1) we provide a historical account of the progress made in Miocene ape phylogeny & paleo-bio-geography,
we report an updated classification of Miocene apes,
we provide a list of Miocene ape species-locality occurrences + an analysis of their paleo-biodiversity dynamics,
2) we discuss various critical issues of Miocene ape phylogeny & paleo-bio-geography (hylobatid & crown hominid origins + the relationships of Oreopith.) cf the highly divergent results obtained from cladistic analyses of cranio-dental & post-cranial characters separately.
We conclude:
cladistic efforts to disentangle Miocene ape phylogeny are potentially biased by a long-branch attraction problem, caused by the numerous post-cranial similarities shared between hylobatids & hominids - despite the increasingly held view that they are likely homoplastic to a large extent (as illustrated by Siva- & Pierolapith.)
(what is "large" here? most likely, early Hominoidea were already upright & bipedal waders-climbers in mangrove forests, google "aquarboreal" --mv)
- and further aggravated by abundant missing data, owing to incomplete preservation.
We argue (besides the recovery of additional fossils, the retrieval of paleo-proteomic data & a better integration between cladistics & geometric morphometrics):
Miocene ape phylogenetics should take advantage of total-evidence (tip-dating) Bayesian methods of phylogenetic inference combining morphologic, molecular& chronostratigraphic data.
This would hopefully help ascertain: was hylobatid divergence more basal than currently supported?

Very interesting paper IMO.
There were probably a lot of parallel evolutions & convergences,
e.g. was Oreopith a cercopith with aquarboreal adaptations??
https://www.gondwanatalks.com/l/the-waterside-hypothesis-wading-led-to-upright-walking-in-early-humans/