Ntawere Formation

Coordinates: 10°48′S 33°06′E / 10.8°S 33.1°E / -10.8; 33.1
Source: Wikipedia, the free encyclopedia.
Ntawere Formation
Ma
Type
Approximate paleocoordinates
53°36′N 20°36′E / 53.6°N 20.6°E / 53.6; 20.6
RegionEastern Province
Country Zambia
ExtentLuangwa Basin

The Ntawere Formation is a

temnospondyls.[1]

Geology

Several different facies are present in the Ntawere Formation, reconstructing a floodplain environment. The coarsest facies are trough cross-bedded conglomeratic sandstone full of mineral concretions. These coarse deposits formed in ancient channels such as riverbeds. Another type of facies involves thick beds of mudstone interbedding with thinner layers of fine-grained sandstone, indicating alternating low- and high-energy water flow within the channels. Graded sandstone to mudstone overbank deposits (complete with ripple marks) occur near channel deposits. Extensive successions of laminated or massive mudstone are common, often containing slickensides, calcareous nodules or layers (marls), and/or hematite nodules. These types of thick mud/marl layers likely formed in more quiet parts of the floodplain isolated from turbulent channels.[1]

The floodplain was seemingly more active during the deposition of the Lower Ntaware Formation, as coarser sandstone channel fills are prevalent in that section while extensive mudstone layers are more common in the Upper Ntaware Formation. Fossils are typically found preserved in calcareous nodules in the mudstone of the Upper Ntaware, although they occur in some parts of the Lower Ntaware as well. The Ntaware Formation is an example of red beds, which are typically deposited in warm environments with seasonal ponds and rivers tied to wet and dry seasons.[1]

Paleobiota

Invertebrates

Invertebrates of the Ntawere Formation
Taxon Member Material Notes
Unio karooensis Upper Ntaware Shells A freshwater
bivalve

Fish

Fish of the Ntawere Formation
Taxon Member Material Notes
Hybodontoidei indet. Upper Ntaware Fin spines An indeterminate non-
hybodontid hybodontoid shark, similar to Lissodus and Lonchidion
Ptycoceratodontidae indet. Lower Ntaware, Upper Ntawere Tooth plates An indeterminate lungfish, similar to Ptychoceratodus

Amphibians

Amphibians of the Ntawere Formation
Taxon Member Material Notes Images
Batrachosuchus concordi
Upper Ntaware A skull and forelimbs A
stereospondyl
Batrachosuchus
Cherninia
Cherninia megarhina
Upper Ntaware A partial skull A
stereospondyl
"Stanocephalosaurus" pronus Upper Ntaware A skull A new species of
capitosauroid
, likely not part of the genus Stanocephalosaurus
Stereospondyli indet. Upper Ntaware Vertebrae and part of a jaw Indeterminate stereospondyl material. The jaw fragment may belong to a
rhytidosteid

Synapsids

Synapsids
of the Ntawere Formation
Taxon Member Material Notes Images
Cricodon metabolus
Upper Ntaware A partial skeleton A
cynodont
Cynognathus
Diademodon
Cynognathus crateronotus
Lower Ntaware Teeth,
vertebrae, partial humerus, ilium
A
cynodont
Diademodon tetragonus
Lower Ntaware A skull A
cynodont
"Kannemeyeria" latirostris Lower Ntaware A skull A
dicynodont, possibly a species of Kannemeyeria or Dolichuranus
Kannemeyeria lophorhinus
Lower Ntaware A skull A
dicynodont
Luangwa drysdalli
Upper Ntaware Skulls and postcranial material A
cynodont
Sangusaurus edentatus
Upper Ntaware A partial skull A
dicynodont
Traversodontidae sp. Upper Ntaware Skulls and postcranial material An unnamed species of
cynodont
Zambiasaurus submersus
Upper Ntaware A skull fragment A
dicynodont

Archosauromorphs

Archosauromorphs
of the Ntawere Formation
Taxon Member Material Notes Images
Archosauriformes indet. Upper Ntaware Teeth Various indeterminate large carnivorous archosauriforms, likely loricatans
Lutungutali
Archosauromorpha indet. Upper Ntaware A neck vertebra An indeterminate archosauromorph, possibly an
allokotosaur
Dinosauriformes
indet.
Upper Ntaware A partial fibula A large
silesaurid
Loricata indet. Upper Ntaware Vertebrae An indeterminate large archosaur, similar to Stagonosuchus
Lutungutali sitwensis
Upper Ntaware An ilium A basal
silesaurid
Shuvosauridae indet. Upper Ntaware Part of a femur An indeterminate
poposauroid
"
Silesauridae indet. Upper Ntaware A maxilla, femurs, and material from the hip, ankle, and foot Indeterminate basal
silesaurid material comparable to Asilisaurus and Lutungutali

See also

References

  1. ^
    S2CID 133878741
    .

Further reading

  • K. D. Angielczyk, J. S. Steyer, C. A. Sidor, R. H. H. Smith, R. L. Whatley and S. Tolan. 2014. Permian and Triassic Dicynodont (Therapsida: Anomodontia) Faunas of the Luangwa Basin, Zambia: Taxonomic Update and Implications for Dicynodont Biogeography and Biostratigraphy. In C. F. Kammerer, K. D. Angielczyk and J. Fröbisch (eds.), Early Evolutionary History of the Synapsida 93-138
  • A. R. Drysdall and J. W. Kitching. 1963. A re-examination of the Karroo succession and fossil localities of part of the Upper Luangwa Valley. Memoir of the Geological Survey of Northern Rhodesia 1:1-62