Manda Formation

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Manda Formation
Stratigraphic range: Anisian? - Carnian?
Lifua Member of the Manda beds.png
Map of the outcropping Manda Formation
Type Geological formation
Unit of Songea Group
Sub-unitsKingori Sandstone Member, Lifua Member
UnderliesNone
Overlies Usili Formation
Lithology
Primary Sandstone
Other Mudstone, siltstone, marl
Location
Coordinates 10°18′S35°12′E / 10.3°S 35.2°E / -10.3; 35.2
Approximate paleocoordinates 53°42′S23°00′E / 53.7°S 23.0°E / -53.7; 23.0
Region Iringa & Ruvuma Regions
CountryFlag of Tanzania.svg  Tanzania
Extent Ruhuhu Basin
Tanzania relief location map.svg
Pink ff0080 pog.svg
Manda Formation (Tanzania)

The Manda Formation (also known as the Manda Beds) is a Middle Triassic (Anisian?) or possibly Late Triassic (Carnian?) geologic formation in Tanzania. It preserves fossils of many terrestrial vertebrates from the Triassic, including some of the earliest dinosauromorph archosaurs. [1] The formation is often considered to be Anisian in age according to general tetrapod biochronology hypotheses and correlations to the Cynognathus Assemblage Zone of South Africa. [2] However, some recent studies cast doubt to this age, suggesting that parts deposits may actually be younger (Carnian) in age. [3] [4] [5]

Contents

History of study

One of the first to study rocks of the Manda Formation was British geologist G. M. Stockley. In 1932, Stockley explored the geology of the Ruhuhu Basin in Tanzania. He called a series of layers dating from the Late Carboniferous to the Middle Triassic the Songea Series and divided it into eight units labelled K1-K8. Stockley was also the first to describe fossils from these rocks, naming an older layer the "Lower Bone Bed" and a younger layer the "Upper Bone Bed".

In 1957, paleontologist Alan J. Charig described many more fossils from the bone beds in his Ph.D. thesis for the University of Cambridge. [6] [7] Charig renamed the youngest of Stockley's units in 1963, calling unit K6 the Kawinga Formation, K7 the Kingori Sandstones, and K8 the Manda Formation. Fossils were identified in many strata, invalidating Stockley's division into two distinct bone beds. Since Charig's description, the Kawinga Formation has been renamed the Usili Formation, the Kingori Sandstones have become the Kingori Sandstone Member of the Manda Formation, and Charig's original Manda Formation has become a subunit of the formation called the Lifua Member. [1] Six formations and one informal unit are currently recognized in the Songea Group (Ruhuhu basin) rocks range in age from Pennsylvanian to Anisian, including the Idusi (K1), Mchuchuma (K2), Mbuyura (K3), Mhukuru (K4), Ruhuhu (K5), and Usili (K6) formations and the informal Manda Beds, which include the Kingori Sandstone (K7) and Lifua Member (K8). [8]

Paleobiota

Tetrapods

Color key
Taxon Reclassified taxonTaxon falsely reported as presentDubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Temnospondyls

TaxonSpeciesMemberMaterialNotesImages
Stanocephalosaurus S. pronus [9] LifuaRemains of a temnospondyl amphibian previously referred either to Parotosuchus or Eryosuchus [10]

Parareptiles

TaxonSpeciesMemberMaterialNotesImages
Ruhuhuaria R. reiszi [11] LifuaCAMZM T997, poorly preserved but complete skull and mandibleAn owenettid

Archosauromorphs

TaxonSpeciesMemberMaterialNotesImages
Asperoris Asperoris mnyama LifuaNHMUK PV R36615, incomplete skullA non-crurotarsan archosauriform of uncertain phylogenetic placement Asperoris.png
"Stagonosuchus"S. tanganyikaensis [12] Lifua MemberSAM 11754, right humerus An indeterminate archosauromorph; possibly a rhynchosaur unrelated to Stagonosuchus nyassicus.
Stenaulorhynchus S. stockleyiLifuaA rhynchosaur
Unnamed Archosauromorph [9] Indeterminate.LifuaNHMUK PV R36619, incomplete skull and partial postcranial skeletonA non-archosaurian archosauriform
Archosaurs
TaxonSpeciesMemberMaterialNotesImages
Asilisaurus A. kongweLifuaA silesaurid dinosauriform Asilisaurus.jpg
Hypselorhachis H. mirabilisLifuaNHMUK R16586, a complete dorsal vertebra A sail-backed archosaur possibly belonging to the family Ctenosauriscidae
Mambawakale M. ruhuhu [13] Lifua MemberNHMUK R36620, partial skull and some postcranial fragmentsA paracrocodylomorph; previously informally known as "Pallisteria angustimentum".
Mambawakale dorsal.gif
Mandasuchus M. tanyauchen [14] Lifua MemberNHMUK R6792, partial mandible and postcranial skeletonsA paracrocodylomorph
Nundasuchus N. songeaensis [9] [15] LifuaNMT RB48, partial skeleton and skullA pseudosuchian of uncertain affinities, possibly a suchian
 Nundasuchus Songeaensis.png 
Nyasasaurus N. parringtoni [2] LifuaNHMUK R6856, a right humerus, three partial presacral vertebrae and three sacral vertebrae. SAM-PK-K10654 is also potentially referable - see "Thecodontosaurus" alophos below.A theropod or an ornithischian or the most advanced non-dinosaurian dinosauriform. Possibly the oldest dinosaur. [2]
Stagonosuchus S. nyassicusA loricatan closely related to Prestosuchus, and sometimes considered a species within that genus.
Teleocrater T. rhadinusLifuaNHMUK R6795, vertebrae, limb bones and other elements. Additional material referred from two other individuals.An early avemetatarsalian in the group Aphanosauria. [16]
 Teleocrater v1.png 
"Thecodontosaurus""T." alophos [2] Lifua MemberSAM-PK-K10654, three neck vertebrae and two rear presacral vertebraeA probable subjective senior synonym of Nyasasaurus, initially identified as a sauropodomorph dinosaur. [2]
Unnamed archosaur [17] Unidentified.LifuaNearly complete skull and partial skeletonA stem-aetosaur

Therapsids

Dicynodonts
TaxonSpeciesMemberMaterialNotesImages
Angonisaurus A. cruickshankiLifuaA kannemeyeriiform
Kannemeyeria K. simocephalusLifuaA kannemeyeriid kannemeyeriiform Kannemeyeria NT small.jpg
Sangusaurus S. parringtoniiLifuaA stahleckeriid kannemeyeriiform
Shansiodon IndeterminateLifuaSkullA shansiodontid kannemeyeriiform
Tetragonias T. njalilusLifuaA shansiodontid kannemeyeriiform Tetragonias njalilus 01.jpg
Cynodonts
TaxonSpeciesMemberMaterialNotesImages
Aleodon A. brachyrhamphusLifuaA possible chiniquodontid
Cricodon C. metabolusLifuaA trirachodontid
Cynognathus C. crateronotus [18] LifuaA cynognathid Cynognathus NT small.jpg
Diademodon D. tetragonasLifuaA diademodontid Diademodon.jpg
Scalenodon S. angustifronsLifuaA traversodontid
S? attridgeiLifuaA traversodontid; may fall outside the genus Scalenodon and may be a synonym of "Scalenodon" charigi
S? charigiLifuaA traversodontid; may fall outside the genus Scalenodon
Mandagomphodon M. hirschoniLifuaA traversodontid; originally classified in the genus Scalenodon; named after the Manda Beds

Age and correlations

The upper Manda Beds have been assigned to the Perovkan LVF based on reports that Eryosuchus, [19] Shansiodon, [20] Angonisaurus, and Scalenodon [21] were present. [22] Angonisaurus does seem to tie the Manda Beds to subzone C of the Cynognathus Assemblage Zone in the Karoo Basin. [23] However, the relations of the other Tanzanian taxa are more ambiguous. Purported Tanzanian "Eryosuchus" and "Shansiodon" specimens likely represent new genera unrelated to their supposed namesakes, [24] [23] while Scalenodon may be endemic to Africa due to the uncertain relations of non-African "Scalenodon" species. [25] One Upper Manda cynodont, Aleodon , has also been found in the Dinodontosaurus assemblage zone of the Santa Maria Formation in Brazil. [26]

See also

Related Research Articles

<i>Nyasasaurus</i> Extinct genus of reptiles

Nyasasaurus is an extinct genus of avemetatarsalian archosaur from the putatively Middle Triassic Manda Formation of Tanzania that may be the earliest known dinosaur. The type species Nyasasaurus parringtoni was first described in 1956 in the doctoral thesis of English paleontologist Alan J. Charig, but it was not formally described until 2013.

<span class="mw-page-title-main">Prestosuchidae</span> Extinct family of reptiles

Prestosuchidae is a polyphyletic grouping of carnivorous archosaurs that lived during the Triassic. They were large active terrestrial apex predators, ranging from around 2.5 to 7 metres in length. They succeeded the Erythrosuchidae as the largest archosaurs of their time. While resembling erythrosuchids in size and some features of the skull and skeleton, they were more advanced in their erect posture and crocodile-like ankle, indicating more efficient gait. "Prestosuchids" flourished throughout the whole of the middle, and the early part of the late Triassic, and fossils are so far known from Europe, India, Africa (Tanzania), Argentina, and Paleorrota in Brazil. However, for a long time experts disagree regarding the phylogenetic relationships of the group, what genera should be included, and whether indeed the "Prestosuchidae" constitute a distinct family.

<i>Teleocrater</i> Extinct genus of reptiles

Teleocrater is a genus of avemetatarsalian archosaur from the Middle Triassic Manda Formation of Tanzania. The name was coined by English paleontologist Alan Charig in his 1956 doctoral dissertation, but was only formally published in 2017 by Sterling Nesbitt and colleagues. The genus contains the type and only species T. rhadinus. Uncertainty over the affinities of Teleocrater have persisted since Charig's initial publication; they were not resolved until Nesbitt et al. performed a phylogenetic analysis. They found that Teleocrater is most closely related to the similarly enigmatic Yarasuchus, Dongusuchus, and Spondylosoma in a group that was named the Aphanosauria. Aphanosauria was found to be the sister group of the Ornithodira, the group containing dinosaurs and pterosaurs.

<i>Ticinosuchus</i> Extinct species of reptile

Ticinosuchus is an extinct genus of suchian archosaur from the Middle Triassic of Switzerland and Italy.

<i>Cynognathus</i> Assemblage Zone Biozone which correlates to the Burgersdorp Formation of the Beaufort Group

The Cynognathus Assemblage Zone is a tetrapod biozone utilized in the Karoo Basin of South Africa. It is equivalent to the Burgersdorp Formation, the youngest lithostratigraphic formation in the Beaufort Group, which is part of the fossiliferous and geologically important Karoo Supergroup. The Cynognathus Assemblage Zone is the youngest of the eight biozones found in the Beaufort Group, and is considered to be late Early Triassic (Olenekian) to early Middle Triassic (Anisian) in age. The name of the biozone refers to Cynognathus crateronotus, a large and carnivorous cynodont therapsid which occurs throughout the entire biozone.

Yarasuchus is an extinct genus of avemetatarsalian archosaur that lived during the Anisian stage of the Middle Triassic of India. The genus was named and described in 2005 from a collection of disarticulated but fairly complete fossil material found from the Middle Triassic Yerrapalli Formation. The material is thought to be from two individuals, possibly three, with one being much more complete and articulated than the other. The type and only species is Y. deccanensis. Yarasuchus was a quadruped roughly 2–2.5 metres (6.6–8.2 ft) long, with an elongated neck and tall spines on its vertebrae. Unlike other quadrupedal Triassic reptiles, the limbs and shoulders of Yarasuchus were slender, and more like those of ornithodirans.

Sangusaurus is an extinct genus of large dicynodont synapsid with two recognized species: S. edentatus and S. parringtonii. Sangusaurus is named after the Sangu stream in eastern Zambia near to where it was first discovered + ‘saur’ which is the Greek root for lizard. Sangusaurus fossils have been recovered from the upper parts of the Ntawere Formation in Zambia and of the Lifua Member of the Manda Beds in Tanzania. The earliest study considered Sangusaurus a kannemeyeriid dicynodont, but more recent phylogenetic analyses place Sangusaurus within the stahleckeriid clade of Dicynodontia. Until recently, little work had been done to describe Sangusaurus, likely due to the fact that only four incomplete fossil specimens have been discovered.

<i>Tetragonias</i> Extinct genus of dicynodonts

Tetragonias is an extinct genus of dicynodont from the Anisian Manda Beds of Tanzania. With tetra meaning “four,” and goni meaning “angle,” the name references the square shape of the Tetragonias skull when viewed dorsally. Not to be confused with the plant Tetragonia,Tetragonias were dicynodont anomodonts discovered in the late 1960s by paleontologist A. R. I. Cruickshank in the Manda Formation. Only the type species, T. njalilus, has been recognized.

Sterling Nesbitt is an American paleontologist best known for his work on the origin and early evolutionary patterns of archosaurs. He is currently an associate professor at Virginia Tech in the Department of Geosciences.

<i>Mandasuchus</i> Extinct genus of reptiles

Mandasuchus is an extinct genus of loricatan pseudosuchian from the Manda Formation of Tanzania, which dates back to the Anisian stage of the Middle Triassic. Although this genus was first mentioned by Alan Charig in 1956, a formal description was not published until 2018.

Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and Collections at the Burke Museum of Natural History and Culture. His research focuses on Permian and Triassic tetrapod evolution, especially on therapsids.

<span class="mw-page-title-main">Paracrocodylomorpha</span> Clade of reptiles

Paracrocodylomorpha is a clade of pseudosuchian archosaurs. The clade includes the diverse and unusual group Poposauroidea as well as the generally carnivorous and quadrupedal members of Loricata, including modern crocodylians. Paracrocodylomorpha was named by paleontologist J. Michael Parrish in 1993, although the group is now considered to encompass more reptiles than his original definition intended. The most recent definition of Paracrocodylomorpha, as defined by Sterling Nesbitt in 2011, is "the least inclusive clade containing Poposaurus and Crocodylus niloticus. Most groups of paracrocodylomorphs became extinct at the end of the Triassic period, with the exception of the crocodylomorphs, from which crocodylians such as crocodiles and alligators evolved in the latter part of the Mesozoic.

<i>Stenaulorhynchus</i> Extinct genus of reptiles

Stenaulorhynchus is an extinct genus of hyperodapedontid rhynchosaur known from the Middle Triassic deposits of Tanganyika Territory, Tanzania. It was found in the Lifua Member of the Manda Formation in the Karoo Supergroup. It was named and first described by Sidney Henry Haughton in 1932. The type species is Stenaulorhynchus stockleyi, a beaked herbivore measuring 1–6 meters in length.

<span class="mw-page-title-main">Epipophyses</span> Bony projections of neck vertebrae in certain reptiles

Epipophyses are bony projections of the cervical vertebrae found in archosauromorphs, particularly dinosaurs. These paired processes sit above the postzygapophyses on the rear of the vertebral neural arch. Their morphology is variable and ranges from small, simple, hill-like elevations to large, complex, winglike projections. Epipophyses provided large attachment areas for several neck muscles; large epipophyses are therefore indicative of a strong neck musculature.

Francis Rex Parrington was a British vertebrate palaeontologist and comparative anatomist at the University of Cambridge. A Fellow of the Royal Society, he was director of the Cambridge University Museum of Zoology and past president of the zoology section of the British Association for the Advancement of Science.

Mandagomphodon is an extinct genus of traversodontid cynodonts from the Middle Triassic Lifua Member of the Manda Beds of Ruhuhu Valley, Tanzania. The type species Mandagomphodon hirschsoni was named by Crompton in 1972 as a species referable to Scalenodon. Later studies, including a 2003 phylogenetic analysis of traversodontid relationships, did not find the species of Scalenodon from the Manda Formation to form a single clade, meaning that many were not referable to the genus. The study suggested that S. hirschsoni had more in common with other traversodontids like Luangwa. S. attridgei was viewed as a possible synonym of S. charigi, which was also found to be only distantly related to S. angustifrons. Therefore, a new generic name Mandagomphodon was erected for S. hirschsoni by James A. Hopson in 2013.

<i>Lutungutali</i> Extinct genus of reptiles

Lutungutali is an extinct genus of silesaurid dinosauriform from the Middle Triassic of Zambia. The single type species of the genus is Lutungutali sitwensis. Lutungutali was named in 2013 and described from a fossil specimen, holotype NHCC LB32, including hip bones and tail vertebrae. The specimen was collected in 2009 from the upper Ntawere Formation, which dates to the Anisian stage of the Middle Triassic. Lutungutali is the first known silesaurid from Zambia and, along with the Tanzanian silesaurid Asilisaurus and dinosauriform Nyasasaurus, the oldest bird-line archosaur known from body fossils.

<span class="mw-page-title-main">Usili Formation</span> Geologic formation in 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.

<i>Ufudocyclops</i> Extinct genus of dicynodonts

Ufudocyclops is an extinct genus of stahleckeriid dicynodont from the Middle Triassic of South Africa. It was found in the Burgersdorp Formation, part of the uppermost Cynognathus Assemblage Zone of the Beaufort Group in the Karoo Basin. The type and only known species is U. mukanelai. It was a large, beaked herbivore like other Triassic dicynodonts, lacking tusks, and is mostly characterised by unique features of the skull. It is known from three specimens, two of which were previously referred to the Tanzanian dicynodont Angonisaurus. The separation of Ufudocyclops from Angonisaurus indicates that the Middle Triassic fauna of the Beaufort Group in South Africa was not part of a larger shared fauna with those of the Manda Beds in Tanzania, as was previously supposed, and suggests that they were separated as more localised faunas, possibly by geographic barriers or in time. Ufudocyclops then would have been a unique part of the uppermost Cynognathus Assemblage Zone in South Africa. It is also the oldest known member of the family Stahleckeriidae, and implies that the family was already diversifying in the Middle Triassic alongside other kannemeyeriiforms, not just in the Late Triassic after other families died out.

The Ntawere Formation is a Middle Triassic (Anisian) geological formation in Zambia, preserving fossils of synapsids, archosaurs, and temnospondyls.

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