The Jebel Qatrani Formation (also Gebel Qatrani) is a palaeontological and geologic formation located in the Faiyum Governorate of central Egypt. Conformably overlying the Qasr el Sagha Formation. It is exposed namely between the Jebel Qatrani escarpment and the Qasr el Sagha escarpment, north of

Birket Qarun Lake Moeris ( grc, Μοῖρις, genitive Μοίριδος) is an ancient lake in the northwest of the Faiyum Oasis, southwest of Cairo, Egypt. In prehistory, it was a freshwater lake, with an area estimated to vary between and . It persists ...

lake near Faiyum.

Geology

These rocks were laid down in the Eocene-

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

period (

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of t ...

- Rupelian). This formation was originally thought to be between 35.4 and 33.3 million years old, based on initial analysis of the formation. However, analysis by Erik Seiffert in 2006 concluded that the age of the Jebel Qatrani Formation should be revised. His assessment of more recent evidence indicates an age for most of the formation of between 30.2 and 29.5 million years ago, placing it almost entirely in the Early Oligocene. Seiffert states that only the lowest 48 metres was laid down in the Eocene, but recent opinion holds the original hypothesis of a sediment straddling the Eocene-Oligocene boundary to be correct. Mostly sandstones deposited by meandering rivers and seasonal lakes, the lower (Eocene) part of the formation represents a woodlanded ecosystem of which much petrified wood also remains. In contrast, the upper (Oligocene) layers present indication of much drier and cooler conditions, with savanna replacing the woodland for several million years before the climate turned wetter and warmer again and the forests regrew. The fauna changes also notably during this time, seemingly coincident with the Eocene–Oligocene extinction event recorded in Eurasia.

Fossils

Mammals

* ''

Arsinoitherium zitteli ''Arsinoitherium'' is an extinct genus of paenungulate mammals belonging to the extinct order Embrithopoda. It is related to elephants, sirenians, hyraxes and the extinct desmostylians. Arsinoitheres were superficially rhinoceros-like herbiv ...

'', an arsinoitheriid * '' Bothriogenys fraasi'', an anthracotheriid * ''Herodotius pattersoni'', a

pseudoungulate Pseudoungulata, or "false hoofed mammals", is a possible clade made up of two subgroups, aardvarks and paenungulates ( hyraxes, elephants, and sirenians). Before this group was proposed, it was thought that aardvarks were more closely related to ...

* '' Plesiopithecus'', an enigmatic lemur-like primate * Pliohyracidae, large

hyrax Hyraxes (), also called dassies, are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between long and weigh between . They are superficially simil ...

es * Ptolemaiida, carnivorous afrothere mammals * ''

Qatranilestes ''Qatranilestes'' is an extinct genus of afrosoricid which existed in Fayum, Egypt during the earliest Oligocene period (Rupelian The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene ...

'' and ''

Widanelfarasia ''Widanelfarasia'' is an extinct genus of placental mammals known from the Late Eocene Jebel Qatrani Formation of Egypt. Two species are known: ''W. bowni'' and the smaller ''W. rasmusseni''. Described in 2000 by E. R. Seiffert and Elwyn L. Simon ...

'', relatives of golden moles, otter shrews, and tenrecs * Several

hyaenodontid Hyaenodontidae (" hyena teeth") is a family of extinct predatory mammals from extinct superfamily Hyaenodontoidea within extinct order Hyaenodonta. Hyaenodontids arose during the early Eocene and persisted well into the early Miocene. Fossils of ...

s ('' Akhnatenavus cf. leptognathus, Metapterodon'') * Several hystricognath rodents (e.g. '' Acritophiomys bowni, A. woodi, Elwynomys lavocati, Gaudeamus hylaeus'') * A primitive marsupial, maybe related to '' Peratherium'' * Primitive Old World

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...

s (e.g. ''

Aegyptopithecus zeuxis ''Aegyptopithecus'' ("Egyptian ape", from Greek ''Αίγυπτος'' "Egypt" and ''πίθηκος'' "ape") is an early fossil catarrhine that predates the divergence between hominoids (apes) and cercopithecids (Old World monkeys). It is known ...

, Biretia fayumensis'' & ''B. megalopsis'')

Birds

* '' Eremopezus'', an enigmatic large groundbird * '' Goliathia'', a large shoebill relative * ''

Palaeoephippiorhynchus Palaeoephippiorhynchus is an extinct genus of large stork from the Oligocene of Africa: its closest living relative is the Saddle-billed stork The saddle-billed stork or saddlebill (''Ephippiorhynchus senegalensis'') is a large wading bird in t ...

dietrichi'', a large stork * ''Xenerodiops'', an unusual

heron The herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera ''Botaurus'' and ''Ixobrychus ...

* A

cormorant Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven ge ...

-like bird, possibly related to genus ''Piscator'' * Several jacanas * One or two species of primitive osprey and another bird of prey (possibly an ancestral sea eagle) * A turaco

Other animals

* '' Albertwoodemys'', a side-necked turtle * '' "Crocodylus" megarhinus'', an ancestral crocodile * ''

Eogavialis africanum ''Eogavialis'' is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles ''Tomistoma schlegelii'', the extant false gharial, and consequently material from the genus was originally ...

'', a primitive gharial * ''

Parachanna fayumensis ''Parachanna fayumensis'', is an extinct member of the snakehead fish family (Channidae) known from fossil records only. It is the oldest member of this family known from Africa. It differs from ''Parachanna insignis'', '' P. africana'' and '' P ...

'', a snakehead fish * ''Pterosphenus'', a snake *

African tetras African tetras (family Alestidae, formerly spelled Alestiidae) are a group of characiform fish exclusively found in Africa. This family contains about 18 genera and 119 species. Among the best known members are the Congo tetra, and African tigerf ...

(Alestidae) or similar Characiformes * Catfish, perhaps of genus ''Fajumia''

References