The Madumabisa Mudstone Formation is a geologic formation in the Middle to Late Permian of Zambia and Zimbabwe. It comprises ancient lake and river mudstone exposed in two sedimentary basins: the Mid-Zambezi Basin (on the Zambia-Zimbabwe border) and the Luangwa Basin (in northeast Zambia).
Though understudied for many years, the exposures of the Luangwa Basin are among the best records of Late Permian fossils in the world. The upper member of the Madumabisa Mudstone Formation has produced many species of synapsids (animals distantly related to mammals). Dicynodonts (herbivores with tusks and beaks) and gorgonopsians (saber-toothed predators) are particularly common. Similar species are found in the even more fossil-rich Karoo Basin of South Africa, assisting age correlation between the two regions.
Age and regional correlations The age of the Madumabisa Mudstone must be estimated from its fossil fauna, which can then be compared to the strata of the Karoo Basin in South Africa.
Lower member The lower member of the Madumabisa Mudstone has rare fossils of tapinocephalids, similar to the Tapinocephalus Assemblage Zone (TAZ) of the Karoo, about 265–260 million years ago (Ma). In other words, from the Capitanian stage of the Middle Permian (Guadalupian) epoch. The early dicynodont Abajudon is also found in the R1 member of the Ruhuhu Formation in Tanzania.
Upper member The upper member of the Madumabisa Mudstone seems to have two distinct fossil-rich intervals in the Luangwa Basin, a lower and upper assemblage. The lower assemblage has an abundance of Oudenodon, Diictodon, and Pristerodon, alongside other dicynodonts such as Kembawacela, Endothiodon, and Odontocyclops. In the Karoo, Endothiodon and Odontocyclops only coexist near the end of the Endothiodon Assemblage Zone (EAZ), a little older than 256 Ma. In other words, about mid-way through the Wuchiapingian stage of the Late Permian (Lopingian) epoch. EAZ taxa such as Endothiodon and Gorgonops have also been found in the Mid-Zambezi Basin. Aulacephalodon is only found in a narrow band of strata between the two major assemblages. A distinct middle assemblage may be supported or refuted by future sampling. If valid, it will probably be equivalent to the Karoo's Cistecephalus Assemblage Zone (CAZ, about 256–255 Ma).
The upper assemblage has an abundance of Dicynodon, alongside other dicynodonts (Daptocephalus, Compsodon, Digalodon) and other distinctive synapsids (Theriognathus, Procynosuchus). These fossils are most consistent with the Karoo's Dicynodon–Theriognathus subzone of the Daptocephalus Assemblage Zone (DAZ), about 255–254 Ma. The DAZ extends from the later part of the Wuchiapingian stage into the succeeding Changhsingian stage. Lystrosaurids (Euptychognathus, Madumabisa) are more common than other dicynodonts in the youngest layers of the formation, hinting at a slight overlap with the Lystrosaurus maccaigi subzone of the DAZ. There is no direct evidence that the Permian-Triassic boundary is preserved in the Madumabisa Mudstone Formation
Paleobiota From Peecook et al. (2025) unless cited otherwise:
Synapsids
Dinocephalians Dinocephalians of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesAnteosauridae indet.Lower MMFMid-Zambezi Basin (Zimbabwe)A snout fragment, possibly from an anteosaurid dinocephalian.CriocephalosaurusC. gunyankaensisLower MMFMid-Zambezi Basin (Zimbabwe)A dubious dinocephalian based on poorly-preserved skull material which is now missing.Tapinocephalidae indet.Lower MMFMid-Zambezi Basin (Zambia, Zimbabwe)Teeth and jaw fragments from tapinocephalid dinocephalians. A partial skull has also been found in Zimbabwe.Munyikwa, Darlington. (2001). Cranial Morphology of a Primitive Dinocephalian from the Madumabisa Mudstone Formation, Zimbabwe (Order No. 31795564). Available from ProQuest Dissertations & Theses Global. (3159933623).
Biarmosuchians Biarmosuchians of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesBiarmosuchia indet.Upper MMF (lower assemblage)Luangwa Basin (Zambia)A medium-sized biarmosuchian skull similar to Herpetoskylax and Lycaenodon.BondocerasB. bulborhynchusLower MMFMid-Zambezi Basin (Zambia)A burnetiid biarmosuchian.IsengopsI. luangwensisUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized burentiamorph biarmosuchian with tall horns above its eyes.MobacerasM. zambezienseLower MMFMid-Zambezi Basin (Zambia)A burnetiid biarmosuchian.WantulignathusW. gwembensisLower MMFMid-Zambezi Basin (Zambia)An unusual blunt-snouted biarmosuchian.
Dicynodonts Dicynodonts of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesAbajudonA. kaayaiLower MMFMid-Zambezi Basin (Zambia)A small endothiodont.AulacephalodonA. kapoliwacelaUpper MMF (both assemblages?)Luangwa Basin (Zambia)A large geikiid cryptodont.CompsodonC. helmoediUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small emydopid emydopoid.DaptocephalusD. sp.Upper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized dicynodontoid.DicynodonD. angielczykiUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized dicynodontoid.D. cf. D. lacerticepsUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized dicynodontoid.DicynodontoidesD. cf. D. nowackiUpper MMF (both assemblages)Luangwa Basin (Zambia)A medium-sized kingoriid emydopoid.DigalodonD. cf. D. rubidgeiUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small emydopoid.DiictodonD. felicepsUpper MMF (both assemblages)Luangwa Basin (Zambia)A small pylaecephalid.EmydopsE. sp.Upper MMF (lower assemblage)Luangwa Basin (Zambia)A small emydopid emydopoid.Emydorhinus?E.? sp.Upper MMF (lower assemblage)Luangwa Basin (Zambia)A small emydopoid.EndothiodonE. sp.Lower–Upper MMF (lower assemblage)Mid-Zambezi Basin (Zambia, Zimbabwe),Luangwa Basin (Zambia)A large endothiodont.EuptychognathusE. kingaeUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized lystrosaurid.cf. Katumbiacf. K. parringtoniUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized elphid bidentalian.KembawacelaK. kitchingiUpper MMF (lower assemblage)Luangwa Basin (Zambia)A small cistecephalid emydopoid.KitchinganomodonK. crassusUpper MMF (upper assemblage)Luangwa Basin (Zambia)A large rhachiocephalid cryptodont.MadumabisaM. opainionUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized lystrosaurid.OdontocyclopsO. whaitsiUpper MMF (lower assemblage)Luangwa Basin (Zambia)A very large cryptodont.OudenodonO. bainiiUpper MMF (lower assemblage)Luangwa Basin (Zambia)A large oudenodontid cryptodont.PristerodonP. mackayiLower–Upper MMF (lower assemblage)Mid-Zambezi Basin (Zimbabwe),Luangwa Basin (Zambia)A small dicynodont.SyopsS. vanhoepeniUpper MMF (both assemblages)Luangwa Basin (Zambia)A large bidentalian, endemic to the Luangwa Basin.
Gorgonopsians Gorgonopsians of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesAelurognathusA. tigricepsUpper MMF (lower assemblage)Luangwa Basin (Zambia)A large rubidgein gorgonopsian.A. sp.Upper MMF (upper assemblage)Luangwa Basin (Zambia)A large rubidgein gorgonopsian. This upper assemblage specimen may be referred to either Aelurognathus or Smilesaurus.ArctognathusA. curvimolaUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small gorgonopsian.ArctopsA. umulunshiUpper MMF (lower assemblage)Luangwa Basin (Zambia)A medium-sized gorgonopsian.CyonosaurusC. sp.Upper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized gorgonopsian.DinogorgonD. sp.Upper MMF (upper assemblage)Luangwa Basin (Zambia)A very large rubidgein gorgonopsian.cf. Dixeyacf. D. sp.Upper MMF (upper assemblage)Luangwa Basin (Zambia)A small gorgonopsian.GorgonopsG. sp.Upper MMF (lower assemblage)Mid-Zambezi Basin (Zambia)A medium-sized gorgonopsian.LycaenopsL. sp.Upper MMF (lower assemblage)Luangwa Basin (Zambia)A medium-sized gorgonopsian.RubidgeaR. atroxUpper MMF (upper assemblage)Luangwa Basin (Zambia)A large rubidgein gorgonopsian.ScylacocephalusS. sp.Upper MMF (both assemblages)Luangwa Basin (Zambia)A small gorgonopsian.SycosaurusS. laticepsUpper MMF (lower assemblage)Luangwa Basin (Zambia)A very large rubidgein gorgonopsian. Sycosaurus-like gorgonopsian material has also been reported from Zimbabwe.
Therocephalians Therocephalians of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesIchibengopsI. munyamadziensisUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small chthonosaurid therocephalian.IctidosuchoidesI. longicepsUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small baurioid therocephalian.cf. I. sp.Upper MMF (lower assemblage)Luangwa Basin (Zambia)A small baurioid therocephalian.MupashiM. migratorUpper MMF (upper assemblage)Luangwa Basin (Zambia)A small karenitid therocephalian.TheriognathusT. micropsUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized whaitsiid therocephalian.
Cynodonts Cynodonts of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesNshimbodonN. muchingaensisUpper MMF (lower assemblage)Luangwa Basin (Zambia)A small charassognathid cynodont.ProcynosuchusP. delaharpeaeUpper MMF (upper assemblage)Luangwa Basin (Zambia)A medium-sized procynosuchid cynodont.
Other tetrapods Other tetrapods (reptiles and amphibians) of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesAmenoyengiA. mpunduensisUpper MMF (lower assemblage)Mid-Zambezi Basin (Zambia)A small moradisaurine captorhinid.PareiasuchusP. nasicornisUpper MMF (both assemblages)Luangwa Basin (Zambia)A large pareiasaur."Protocaptorhinus""P." sp.Upper MMFMid-Zambezi Basin (Zimbabwe)A captorhinid similar to Saurorictus.RhinecepsR. karibaensisUpper MMFLuangwa Basin (Zambia)A medium-sized rhinesuchid temnospondyl.
Fish Fish of the Madumabisa Mudstone FormationGenus / TaxonSpeciesStrataLocationNotesImagesActinopterygiiindet.Lower–Upper MMFLuangwa Basin, mid-Zambezi Basin (Zambia)Ray-finned fish material, including scales and skull fragments from a large (~30 cm) Bethesdaichthys-like fish. Other scales are more consistent with fish similar to Kompasia, Namaichthys, or coelacanths.cf. AtherstoniaLuano Basin (Zambia)A ray-finned fish.Elasmobranchiiincertae sedisUpper MMFLuangwa Basin (Zambia)Fin spines from shark-like fish, including possible xenacanthids, hybodonts, ctenacanths, and synechodontiforms.IschnolepisI. bancroftiLuano Basin (Zambia)A common redfieldiiform.Pygopterus?Luano Basin (Zambia)A ray-finned fish.
Plants Several species of Glossopteris have been found in the Madumabisa Mudstone Formation, along with other "seed ferns" (Gangamopteris, Noeggerathiopsis) and true ferns (Neomariopteris. Phyllotheca). Petrified wood is also known from the formation, including large trunks of "Dadoxylon" (Agathoxylon), up to 4 feet in diameter. Palynomorphs (spore and pollen forms) are similar to those found in the Lower Sakamena Formation of Madagascar.
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