Aquatic Ape Human Ancestor Theory

Aquatic Ape Theory - What is it?

A Brief Summary of AAT - key arguments

A Brief History and Key Proponents of AAT

When / Where / How?

Ape to Human Evolution Timeline

Alternative theories of human evolution

Wikipedia and the scientific community

... Anatomical Evidence
... Bipedalism
... Birth and babies
... Brain
... Breath control
... Descended larynx
... Diet
... Diseases
... Fat
... Fingers, toes and feet
... Furlessness
... Hair and baldness
... Human ailments
... Kidneys
... Language & Song
... Menopause
... Nose
... Olfactory sense
... Pachyostosis
... Paranasal Sinuses
... Platycephaly
... Reverse osmosis
... Sexual features
... Sleep (USWS)
... Surfer's ear
... Sweating
... Tears
... Underwater vision
... Viruses
... Waterside environments

. Homo Ancestors
... Trachillos bipedal hominids
... Homo erectus
... Homo neanderthalensis
... Sea Gypsies/ the Moken
... Homo sapiens - water afinity
... Coastal Migration
... Pan and Gorilla ancestry
... Semi-Aquatic Animals

. Testable Hypotheses
. Fossil evidence
. Genetic evidence
. Paleoecological evidence
. Retroviral marker in apes
. Acheulean handaxes

A call to scientists...

Recent News and Updates

Books and publications

Articles

Videos links

Links

Contact

Graecopithecus

Greacopithecus (G. freybergi) may have been the oldest direct ancestor of the Homo clade, or possibly the LCA of humans and chimpanzees, and has been classed as perhaps "the oldest known hominin". [1]

"Given the potential hominin affinity of Graecopithecus, our results suggest that the Pan-Homo split predated the Messinian and that the chimpanzee–human last common ancestor thrived in the Mediterranean region." [2]

Known from a specimen mandible (nicknamed El Graeco] found in 1944 near Athens, some researchers believe the species to possibly belong to the same taxon as Ouranopithecus macedoniensis, but differences in dental morphology make this unlikely. [3] A single ape tooth found in Bulgaria in 2012 and believed to be 7 million years old*, is also believed to have come from Graecopithecus, at a time when Europe's ancestral apes were in decline. [4]

*"On the basis of orbital tuning of the Pikermi Formation and the bio-magnetostratigraphy of Azmaka, Graecopithecus can be dated to 7.24 Ma (tooth from Azmaka) and 7.18–7.17 Ma (type mandible from Pyrgos) and is, thus, of earliest Messinian age. The levels that contain a classical Pikermi mammal fauna can now be dated to between 7.33 and 7.29 Ma. Therefore, the transition from the Pikermi to post-Pikermi fauna appears to coincide with the Tortonian-Messinian boundary.

"Analysis of both potential hominin sites indicates that Graecopithecus inhabited different habitats, be it open braided-river landscapes in Azmaka, or the wooded grassland of Pyrgos. [5]

The jaw fossil suggests that Graecopithecus had relatively small canines which is a hominin trait shared with humans and pre-humans, but not chimps, suggesting that the species may have existed after the split with chimpanzees.

“While great apes typically have two or three separate and diverging roots, the roots of Graecopithecus converge and are partially fused – a feature that is characteristic of modern humans, early humans and several pre-humans,” said lead researcher Professor Madelaine Böhme of the University of Tübingen. The lower jaw, has additional dental root features, suggesting that the species was a hominid.

Clearly, more fossil specimens need to be found before the picture becomes clearer.

Professor Böhme added: “Our findings may eventually change our ideas about the origin of humanity. I personally don’t think that the descendants of Graecopithecus died out, they may have spread to Africa later. The split of chimps and humans was a single event. Our data support the view that this split was happening in the eastern Mediterranean – not in Africa." [6]

According to the scientists’ data, the population north of the Sahara evolved into hominins, says Bohme. No fossil ape remains from 7 or 8 million years ago have been found (at least not yet) in Africa, but she speculates that the southern crowd stuck below the Sahara became Pan, the genus that includes the chimps and bonobos.

The Trachillos footprints found in Crete and dating to approximately 5.7 million years ago, [7] may be related to Graecopithecus [8] from around the time of the Messinian Salinity Crisis (MSC) when Crete was still connected to the Greek mainland. The footprints lacked claws, were pentadactyl, plantigrade, and clearly the track-maker was a bipedal hominin.

“Later, perhaps half million years after El Graeco, the Sahara Desert disappeared again. It was probably quite a humid period,” says Bohme. Fossil river beds indicate massive flows of water, including in today’s arid Libya. Lake Chad existed and was high enough to overflow. In short, the area was inviting and the man-apes, either El Graeco itself or its descendent, moved southward into this lovely landscape. The earliest-known African hominid is a good 200,000 years later than our Graeco: Sahelanthropus tchadensis.

If Graecopithecus really was a bipedal, plantigrade hominin, with small canines, living in and around the Tethys sea in the late Miocene, we have to assume that either the species followed a convergent evolutionary path with homo, or was in fact a direct ancestor to Homo, which would mean that the oldest known hominin ancestor of the Homo clade lived in Europe and not Africa. [9]


Potential hominin affinities of Graecopithecus from the Late Miocene of Europe

Jochen Fuss, Nikolai Spassov, David Begun & Madelaine Böhme 2017
PLoS https://doi.org/10.1371/journal.pone.0177127

The split of our own clade from the Panini is undocumented in the fossil record. To fill this gap, we investigated the dento-gnathic morphology of Graecopithecus freybergi (Pyrgos Vassilissis, Greece) & cf.Graecopithecus sp. (Azmaka, Bulgaria), using new μCT & 3D reconstructions of the 2 known specimens.

Pyrgos Vassilissis & Azmaka are currently dated to the early-Messinian at 7.175 & 7.24 Ma. Mainly based on its external preservation & the previously vague dating, Graecopithecus is often referred to as nomen dubium.

The examination of its previously unknown dental root & pulp canal morphology confirms the taxonomic distinction from the significantly older N-Greek hominine Ouranopithecus. It shows features that point to a possible phylogenetic affinity with hominins. G.freybergi uniquely shares p4 partial root fusion & a possible canine root reduction with this hominins, therefore, it provides intriguing evidence of what could be the oldest known hominin.

Fig 1. Studied specimens and virtual reconstructions of the holotype of Graecopithecus.

Fig 1. Studied specimens and virtual reconstructions of the holotype of Graecopithecus.

a, Type mandible of Gfreybergi from Pyrgos, Greece. b, RIM 438/387 –Left P4 of cf. Graecopithecus sp. from Azmaka, Bulgaria.
From left to right: distal, mesial, lingual, buccal, occlusal and apical. c-i, μCT based 3D reconstructions of the type mandible showing the partially preserved roots and pulp canals from c-m3 and the crowns of right p4-m2. Further images with a magnification of the virtually isolated teeth and pulp canals are provided in S1 Figc, Occlusal view. d-e, Apical view. f, Buccal view of the left hemimandible. g, Buccal view of the right hemimandible. h, Lingual view of the left hemimandible. i, Lingual view of the right hemimandible. Scale bars, 10 mm. [10]


 
Website: F. Mansfield, 2015

Disclaimer: This site is currently under construction. Every effort has been (will be!) made to trace the copyright owners of any images or text used on this site to request permission and to give proper credit. If you are the copyright holder of any images, files or text and have not been contacted, please contact the webmaster in order to rectify this.