Proconsul meswae
| Proconsul meswae | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Miocene | ||||||||||||
| 20 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Proconsul meswae | ||||||||||||
| Harrison & Andrews , 2009 | ||||||||||||
Proconsul meswae is an extinct species of the genus Proconsul that was foundin East Africa during the early Miocene . Fossils assigned to this genus were dated to at least 20 million years ago. The only location so far is Meswa Bridge , an excavation site in the west of Kenya , 1.5 kilometers north of Muhoroni (0 ° 8 '14 south, 35 ° 12' 21 east). The genus Proconsul is one of the earliest known representatives of the human species (Hominoidea).
Naming
The name of the genus Proconsul ("before the Consul") was chosen in 1933 by Arthur Tindell Hopwood (1897-1969), probably in allusion to the chimpanzee Consul , who lived in the London Zoo in the 1930s . The epithet meswae refers to the site of Meswa Bridge in Kenya.
Initial description
The first description of the species in 2009 was based on around two dozen teeth (mainly milk teeth), two upper jaw fragments, one lower jaw fragment and another piece of skull bone from at least four individuals. The holotype is the fossil KNM-ME 11, a fragment from the upper jaw of a child with dentition consisting of partly deciduous and partly permanent teeth. The fossils KNM-ME 1 to 10, 19, 24, 25 and 8529 were named as paratypes. The location of the finds is the headquarters of the National Museums of Kenya in Nairobi .
These fossils come exclusively from very young individuals and were mostly discovered between 1978 and 1980 and scientifically described in 1981. Already in this first description of the find it was pointed out that the size of the teeth is most likely to be compared with that of Proconsul nyanzae , but that their structure differs considerably from this and is reminiscent of Proconsul major . Therefore, the teeth cannot be assigned to one or the other species. However, since too few milk teeth of these species were available for comparative studies, it was decided in 1981 not to ascribe the fossils to a specific species, but only to the genus Proconsul .
In 2009, however, in the first description of the species Proconsul meswae, it was argued that the combination of the morphological features of deciduous teeth and permanent teeth allowed a diagnosis to be made . The demarcation of Proconsul nyanzae and Proconsul major took place both on the basis of differences in the nature of the dental crowns and the roots . Overall, in comparison with other Proconsul finds , the teeth were interpreted as original and Proconsul meswae therefore as the “original sibling taxon of the other Proconsul species”.
Dating
Exact dating of the finds turned out to be difficult due to soil relocation. A K-Ar dating yielded a maximum age for the found layer 22.5 to 26 million years ago, the minimum is specified at 19.5 ± 0.3 million years ago. The authors of the first description also referred to fossil finds of other animal species, which also referred to a dating to the early Miocene and cautiously referred to the hominine fossils as "at least 20 million years old". Why only remains of children and adolescent individuals were discovered remained unexplained.
Web links
- Entry Proconsul meswae on paleobiodb.org
Individual evidence
- ↑ Terry Harrison and Peter Andrews : The anatomy and systematic position of the early Miocene proconsulid from Meswa Bridge, Kenya. In: Journal of Human Evolution. Volume 56, No. 5, 2009, pp. 479-496, doi : 10.1016 / j.jhevol.2009.02.005
- ^ Arthur Tindell Hopwood: Miocene Primates from Kenya. J. Linn. Soc. (Zool.), Vol. 30, 1933, pp. 437-464.
- ↑ According to Robert N. Proctor, Finding Life in Old Bones, shortly after 1900 there was also a chimpanzee named Consul in Paris .
- ^ Peter Andrews et al .: Hominoid primates from a new Miocene locality named Meswa Bridge in Kenya. In: Journal of Human Evolution. Volume 10, No. 2, 1981, pp. 123–128, doi : 10.1016 / S0047-2484 (81) 80009-7 , full text (PDF; 3.1 MB) ( Memento from March 2, 2014 in the Internet Archive )
- ^ WW Bishop, JA Miller and FJ Fitch: New potassium-argon age determinations relevant to the Miocene fossil mammal sequence in east Africa. In: American Journal of Science. Volume 267, 1969, pp. 669-699; doi : 10.2475 / ajs.267.6.669