Saadanius
| Saadanius | ||||||||||
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View from the front of the type specimen by Saadanius |
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| Temporal occurrence | ||||||||||
| Middle Oligocene | ||||||||||
| 29 to 28 million years | ||||||||||
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| Scientific name | ||||||||||
| Saadanius | ||||||||||
| Zalmout et al., 2010 | ||||||||||
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Saadanius is an extinct genus of primates that was foundin the Arabian Peninsula during the mid Oligocene . Fossils discoveredin Saudi Arabia that were assigned to this genus, dated their discoverers in the first description of the genus and type species Saadanius hijazensis in 2010 using radiometric methods to at least 26 to 21 million years and using biostratigraphic analyzes - including animals from the group of the Anthracotheriidae - around 29 to 28 million years ago. The fossils were placed by their discoverers in the vicinity of the last common ancestors of vervet monkeys (Cercopithecoidea) and humans (Hominoidea). At the same time, their find wasassessedas confirmation of the hypothesis that the early evolution of the Old World monkeys took place in the African - Arab region.
Naming
This name Saadanius is derived from the Arabic sa'adan /سَعدان / saʿdān / 'monkey'. The epithet of the so far only scientifically described species Saadanius hijazensis refers to the location in the Hejaz region (الحجاز al-Hijāz , DMG al-Ḥiǧāz ), in the English-speaking area Al Hijaz . Saadanius hijazensis therefore means "monkey from Hejaz".
In the first description of genus and type species, these were assigned to the Saadaniidae family , which was also newly introduced in 2010, and the also newly introduced superfamily Saadanioidea within the Old World monkeys (Catarrhini).
Initial description
In the first description of the genus and also the type species Saadanius hijazensis, the holotype was identified as the fragment of the facial skull of a presumably adult male individual (archive number SGS-UM 2009-002), which is kept in the paleontological department of the Saudi Geological Survey in Jeddah . Fragments of bones from the eye sockets and nose, the almost completely preserved palate and parts of the upper jaw with some preserved molars , incisors and a canine could be assigned to this fossil .
The fossil bones were uncovered in 2009 on the northwestern edge of Harrat Al Ujayfa in the Hejaz region, Saudi Arabia, above an oolithic iron ore formation during the search for fossil whale and dinosaur bones. Its discoverer, Iyad S. Zalmout, was a postdoc in the group of Philipp D. Gingerich, University of Michigan .
features
Saadanius hijazensis was believed to be the size of a Siamang during his lifetime and weighed around 15 to 20 kilograms. All special features that make it possible to distinguish vervet monkeys and humans from one another are missing. According to the first description, the shape of his face is intermediate between Aegyptopithecus and the later species of the Miocene ; it probably looked more like the face of today's baboons than the face of gibbons . Outstanding features are in particular his relatively elongated face and the snout-like protrusion of the facial bones; Furthermore, the absence of a frontal sinus , the presence of very small canine teeth, as well as the construction of the relatively wide large molars covered with only thin enamel , assessed as an “original” feature . On the other hand, the conspicuous “newly acquired” feature is the structure of the external auditory canal, which can be derived from the preserved temporal bone . A deep bite mark in the middle area of the face and a puncture point further to the right that may lead to death can also be seen.
According to the remains of plants found in the same layers of earth, the habitat of Saadanius hijazensis includes mangrove forests .
Importance of the find
Finds of fossil Old World monkeys from the Oligocene - around 34 to 21 million years ago - are so far relatively rare. However, they are considered to be particularly important for the reconstruction of the tribal history of the human species , since their lineage separated from that of the vervet monkey relatives in this epoch . The primate fossils of this epoch include, for example, the species of the superfamily Propliothecoidea, dated to an age of 35 to 30 million years, the genus Aegyptopithecus (34 to 28 million years old) and the much younger genus Kamoyapithecus , which lived 27 to 24 million years ago . With an age of approximately 29 to 28 million years, Saadanius thus fills a gap in the sequence of traditional fossils of the Middle Oligocene.
According to the reconstruction in the first description, Saadanius hijazensis combines certain original features and newly acquired features , from which it was concluded that the separation of the human from the vervet relatives - as other fossil finds had previously suggested - in the period between 29-28 and 24 million years ago took place; the lower limit of 24 million years was derived from the classification of Kamoyapithecus among the humans. With the help of the so-called molecular clock - the calibration of which is, however, controversial - it was calculated that the separation took place between 34.5 and 29.2 million years.
Web links
- nature.com illustration of the fossil
- nature.com Diagram showing the alleged relationship between Saadanius and other primates
- Saadanius entry in the Paleobiology Database
Individual evidence
- ↑ Iyad S. Zalmout et al .: New Oligocene primates from Saudi Arabia and the divergence of apes and Old World monkeys. In: Nature . Volume 466, 2010, pp. 360-364, doi: 10.1038 / nature09094
- ^ Fossil find puts a face on early primates. On: eurekalert.org of July 14, 2010
- ↑ Lucas Laursen: Fossil skull fingered as ape-monkey ancestor. On: nature.com from July 14, 2010, doi: 10.1038 / news.2010.354 (full text)
- ↑ Michael E. Steiper et al: Genomic data support the hominoid slowdown and an Early Oligocene estimate for the hominoid-cercopithecoid divergence. In: PNAS . Volume 101, No. 49, 2004, pp. 17021-17026, doi: 10.1073 / pnas.0407270101