Usili Formation

Usili Formation
Stratigraphic range: Lopingian
~259–252 Ma
TypeGeological formation
Unit ofSongea Group
UnderliesManda Formation
OverliesRuhuhu Formation
Thickness260 m (850 ft)
Lithology
PrimarySandstone, conglomerate
OtherSiltstone, mudstone
Location
Coordinates10°18′S 35°06′E / 10.3°S 35.1°E / -10.3; 35.1
Approximate paleocoordinates55°06′S 15°12′E / 55.1°S 15.2°E / -55.1; 15.2
RegionRuvuma Region
Country Tanzania
ExtentRuhuhu Basin
Type section
Named forUsili Mountain
Named byStockley
Year defined1932
Usili Formation is located in Tanzania
Usili Formation
Usili Formation (Tanzania)

The Usili Formation is a Late Permian geologic formation in Tanzania. It preserves fossils of many terrestrial vertebrates from the Permian, including temnospondyls, pareiasaurs, therapsids and the archosauromorph Aenigmastropheus.[1][2]

  1. ^ Sidor, C. A.; Vilhena, D. A.; Angielczyk, K. D.; Huttenlocker, A. K.; Nesbitt, S. J.; Peecook, B. R.; Steyer, J. S.; Smith, R. M. H.; Tsuji, L. A. (2013). "Provincialization of terrestrial faunas following the end-Permian mass extinction". Proceedings of the National Academy of Sciences. 110 (20): 8129–33. Bibcode:2013PNAS..110.8129S. doi:10.1073/pnas.1302323110. PMC 3657826. PMID 23630295.
  2. ^ Ezcurra, M. N. D.; Scheyer, T. M.; Butler, R. J. (2014). "The Origin and Early Evolution of Sauria: Reassessing the Permian Saurian Fossil Record and the Timing of the Crocodile-Lizard Divergence". PLOS ONE. 9 (2): e89165. Bibcode:2014PLoSO...989165E. doi:10.1371/journal.pone.0089165. PMC 3937355. PMID 24586565.