The reconstructed cranium of Pierolapithecus and the evolution of the great ape face
Kelsey D Pugh, Santiago A Catalano, Miriam Pérez de los Ríos & Sergio Almécija 2023
PNAS 120, e2218778120 doi org/10.1073/pnas.2218778120

Pierolap.catalaunicus (c 12 Ma NE-Spain) is key to understanding the mosaic nature of hominid (gr.ape+human) evolution,
its skeleton indicates: an orthograde body-plan preceded suspensory adaptations in hominid evolution,
but is ongoing debate about this species: the sole known cranium, preserving a nearly complete face, suffers from taphonomic damage.
1) We carried out a microCT, based virtual reconstruction of the Pierolapithecus cranium,
2) we assessed its morphological affinities, using a series of 2D & 3D morphometric analyses,
3) we modeled the evolution of key aspects of ape face form.
The reconstruction clarifies many aspects of the facial morphology of Pierolapithecus:
it is most similar to gr.apes (fossil & extant) in overall face shape & size, morphologically distinct from other mid-Miocene apes.
Crown-gr.apes can be distinguished from other taxa in several facial metrics (e.g. low mid-facial prognathism, rel.tall faces),
only some of these features are found in Pierolapithecus, which is most cons.x a stem-hominid position.
The inferred morphology at all ancestral nodes within the hominoid (ape+human) tree is closer to gr.apes than to hylobatids (gibbons+siamangs, convergent with other smaller anthropoids).
Our analyses support a hominid ancestor that was distinct from all extant & fossil hominids in overall facial shape, and shared many features with Pierolapithecus.
This reconstructed ancestral morpho-type represents a testable hypothesis, that can be re-evaluated as new fossils are discovered.

:-) This perfectly confirms our aquarboreal hypothesis:
Miocene Hominoidea were already vertical waders-climbers in coastal forests along the N-Tethys Ocean:
wading bipedally + climbing arms overhead in the branches above the water,
google "aquarboreal" &
https://www.gondwanatalks.com/l/the-waterside-hypothesis-wading-led-to-upright-walking-in-early-humans/

It also confirms our view that hylobatids (gibbons+siamangs) secondarily reduced body-size (but still have rel.long gestation).

See also:

The nasal and paranasal architecture of the Middle Miocene ape Pierolapithecus catalaunicus (primates: Hominidae):
Phylogenetic implications
Miriam Pérez de los Ríos, Salvador Moyà-Solà & David M Alba 2012 JHE
doi org/10.1016/j.jhevol.2012.05.012

The internal cranial anatomy of the mid-Miocene (11.9 Ma) gr.ape Pierolap.catalaunicus (Hominidae: Dryopithecini) is described (CT-scans of the holotype spm IPS21350) with particular emphasis on its phylogenetic implications:
- an anteriorly-restricted maxillary sinus, that posteriorly spreads towards the ethmoidal area (resembling the pongine condition), but is situated well above the molar roots (as in kenyapithecins, other dryopithecins & pongines);
- lack of frontal sinus (a synapomorphy of derived pongines, independently acquired by both cercopithecoids & hylobatids);
- posteriorly-situated turbinals (as in Pongo);
- anteriorly-projecting naso-lacrimal canal (as in Pongo);
- probably (bone damage!) stepped nasal floor, with non-overlapping premaxillary–maxillary contact, as in dryopiths & stem-hominoids. Overall, Pierolap displays a mosaic of primitive hominid & derived pongine features, incons.x being a hominine (as previously suggested).
2 alternative phylogenetic interpretations: Pierolap
= stem member of the Hominidae as previously suggested in its original description?
= stem member of the Ponginae s.l. (with the European dryopithecines being the sister taxon to the Asian pongines).

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Extinct ape gets a facelift, 12 million years later
New study reconstructs the face of Pierolapithecus catalaunicus, a key fossil in the story of great ape & human evolution
16.10.23 Am.Mus.Nat.Hist.
A new study has reconstructed the well-preserved but damaged skull of a gr.ape species c 12 Ma:
Pierolap.catalaunicus may be crucial to understanding gr.ape & human evolution.

A new study has reconstructed the well-preserved, but damaged skull of gr.ape Pierolap.catalaunicus from NE-Spain (PNAS), first described in 2004, one of a diverse group of now-extinct ape spp that lived in Europe c 15-7 Ma.
It is key to understanding the mosaic nature of hominid (gr.ape+human) evolution:
it is known from a cranium + partial skeleton of the same individual (a rarity in the fossil record).
Kelsey Pugh:
"Features of the skull & teeth are extremely important in resolving the evol.relationships of fossil spp:
when we find this material in ass.x bones of the rest of the skeleton, it gives the opportunity to
- accurately place the species on the hominid family tree +
- learn more about the biology of the animal in terms of how it was moving around its environment."

Previous work on Pierolapithecus suggests: an upright body-plan preceded adaptations that allowed hominids to hang from tree branches and move among them. But debate persists about the species' evol. place, partly due to damage to the cranium.
Ashley Hammond, co-author:
"One of the persistent issues in studies of ape & human evolution is: the fossil record is fragmentary, many spms are incompletely preserved & distorted. This makes it difficult to reach a consensus on the evol.relationships of key fossil apes that are essential to understanding ape+human evolution."

The researchers used CT-scans to virtually reconstruct Pierolap's cranium, compare it to other primate spp, and model the evolution of key features of ape facial structure:
Pierolap shares similarities in overall face shape & size with fossilized & living gr.apes,
but it also has distinct facial features, not found in other mid-Miocene apes.
The results are cons.x the idea that this species represents one of the earliest members of the gr.ape+human family.
Sergio Almécija, co-author:
"An interesting output of the evol.modeling in the study is:
Pierolap's cranium is closer in shape & size to the ancestor from which living gr.apes & humans evolved.
OTOH, gibbons & siamangs (the 'lesser apes') seem to be secondarily derived in relation to size reduction."