Chomateri (Miocene of Greece)

Also known as Kisdari

Where: Attiki, Greece (38.0° N, 24.0° E: paleocoordinates 37.7° N, 23.6° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Chomateri Member (Pikermi Formation), Late/Upper Miocene (11.6 - 5.3 Ma)

• Here we reconstruct environmental conditions from the two Graecopithecus-bearing sediment successions using grain-texture analysis, end-member modelling of grain-size distributions, geochemistry of soluble salts and provenance analysis of U-Pb ages of detrital zircons. We then provide age constraints on fossils and document environmental changes on the basis of combined bio-magnetostratigraphy and cyclostratigraphy.

Environment/lithology: fluvial; paleosol/pedogenic, red, yellow siltstone and carbonaceous claystone

• For the first time we demonstrate that C4 grasses were the dominant herbaceous element of the Pikermi Formation. Our habitat reconstruction suggests fire-prone woody grasslands and woodlands within a savannah biome for Pikermi and Pyrgos and, thus, provides unambiguous evidence for the early environmental conjectures of Gaudry.

• The classical Pikermi fauna is terminated at the beginning of the Messinian (7.25–7.10 Ma) by a significant faunal turnover (post-Pikermi turnover), accompanied by massive increase of Saharan dust and salt accumulation with profound effects on soil salinity and nutrition.

• Furthermore, mineral dust in Attica was rich in soluble evaporites (halite, gypsum) in the earliest Messinian and especially during two pronounced insolation seasonality minima at 7.18 and 7.157 Ma, which suggests an orbitally driven progressive Sahara desertification. We suppose that a latest Tortonian to early Messinian dust- and salt-laden atmosphere over the Mediterranean may have further accelerated cooling and aridification via absorption of incoming solar radiation and, thus, may partially explain regionally accentuated Mediterranean cooling

• We subdivide Upper Miocene sediments of the Athens and the Mesogea Basins (Figs 1 and 2) into the terrestrial to alluvial Pikermi Formation (new formation) and the palustrine to lacustrine Rafina Formation (new formation). The Pikermi Formation represents an up to 30-mthick sequence of predominantly reddish silts with subordinate clastic channels of conglomerates and sandstones, which contains a rich and exclusively terrestrial vertebrate fauna. The formation rests discordantly upon the ‘lower limestone unit’[9] (palustrine to lacustrine grey marls and coals) and is concordantly overlain by the Rafina Formation (palustrine to lacustrine clay, coal, and platy limestone). Based on transport mechanisms, sediment colour, and palaeosol development, the Pikermi Formation can be subdivided into two members: the Red Conglomeratic Member (new member) characterized by debris flows and the fluvio-alluvial Chomateri Member (new member). The lower part of the Pikermi Formation (Red Conglomeratic Member) represents an alternation of red silts with a weak pedogenic overprint and debris flow deposits (Fig 3). These debris flows contain clasts of the nearby Attica unit of Mt. Pendeli, which indicates a strong topographic gradient. Silts from the lower Red Conglomeratic Member include the classical Pikermian bone accumulations. The upper Pikermi Formation (Chomateri Member) represents an alternation of reddish to yellowish silts with fluvial channels and channel-fill trains (Fig 3) that are indicative of small migrating streams during times of increased surface run-off. Away from channels, silts can contain well developed calcareous palaeosols rich in mammalian fossils. In both basins, the Pikermi Formation is concordantly overlain by palustrine clays and coals, and lacustrine marls and limestones of the Rafina Formation

Size class: macrofossils

Primary reference: M. Böhme, N. Spassov, M. Ebner, D. Geraads, L. Hristova, U. Kirscher, S. Kötter, U. Linnemann, J. Prieto, S. Roussiakis, G. Theodorou, G. Uhlig, and M. Winklhofer. 2017. Messinian age and savannah environment of the possible hominin Graecopithecus from Europe . In R. Macchiarelli (ed.), PLoS One 12(5) [E. Vlachos/P. Kampouridis/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 195562: authorized by Evangelos Vlachos, entered by Panagiotis Kampouridis on 13.08.2018, edited by Evangelos Vlachos

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Rodentia - Hystricidae
Hystrix primigenia2 Wagner 1848 porcupine
 Rodentia - Gliridae
Myomimus cf. dehmi1 de Bruijn 1966 dormouse
Muscardinus sp.1 Kaup 1829 dormouse
 Rodentia - Muridae
? Occitanomys provocator n. sp.1 de Bruijn 1976 mouse
? Occitanomys neutrum n. sp.1 de Bruijn 1976 mouse
Parapodemus gaudryi1 Dames 1883 mouse
 Rodentia - Cricetidae
"Kowalskia aff. lavocati" = Neocricetodon lavocati1, Byzantinia pikermiensis n. gen. n. sp.1
"Kowalskia aff. lavocati" = Neocricetodon lavocati1 Hugueney and Mein 1965 mouse
Byzantinia pikermiensis n. gen. n. sp.1 de Bruijn 1976 mouse
 Primates - Cercopithecidae
Mesopithecus pentelicus2 Wagner 1839 monkey
 Perissodactyla - Chalicotheriidae
Chalicotherium goldfussi5 Kaup 1833 chalicothere
maxilla with right and left P3-M3
 Perissodactyla - Equidae
Hipparion mediterraneum2 Roth and Wagner 1855 hipparionine horse
 Artiodactyla - Suidae
 Artiodactyla - Cervidae
 Artiodactyla - Bovidae
Palaeoreas lindermayeri2 Wagner 1848 antelope
Tragoportax gaudryi2 Kretzoi 1941 antelope
 Artiodactyla - Giraffidae
Palaeotragus rouenii2 Gaudry 1861 giraffe
 Carnivora - Felidae
Metailurus parvulus2 Hensel 1862 cat
 Proboscidea - Gomphotheriidae
Anancus lehmanni3 Gaziry 1997 gomphothere
Konidaris G. 2013. PhD Thesis
 Proboscidea - Choerolophodontidae
Aves
 Galliformes - Phasianidae
Pavo archiaci4 Gaudry 1862 peafowl
proximal humerus, distal humerus