Palaeobiology and osteohistology of South African sauropodomorph dinosaurs

Journal of Anatomy, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

Abstract Several sauropodomorph dinosaurs have been excavated from the Elliot Formation (EF) of Southern Africa which include important taxa such as Massospondylus , Melanorosaurus and Antetonitrus . The study bone microstructure smaller, bipedal Sauropodomorpha larger, quadrupedal Sauropoda allow us to infer how growth dynamics changed during evolution gigantism. Historically, osteohistological studies tended focused on either early diverging (e.g. Plateosaurus & ) or derived (diplodocids titanosaurs), whereas transitionary groups (i.e. Sauropodiformes Sauropoda) are poorly known. Here, we assess palaeobiology two sauropodiformes an sauropod by analysing their histology. Thin sections long bones indeterminate NMQR 3314 1551, SAM–PK–K382 were prepared. general histology all three similar. Rapid through deposition fibrolamellar tissue characterised respective ontogenies. Lines arrested (LAGs) commonly located in mid outer cortex signalling onset uninterrupted growth. Differences these principally related pathological evident femur sauropodiform 1551 formation annuli around LAGs indet., well location compacta. number varied among but generally regions showed accumulation LAGs. our similar sauropods It appears that abundance at later ontogenetic stages likely key traits gigantism Sauropoda, supports occurrence a mosaic dynamic patterns Sauropodomorpha.

Language: Английский

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Biostratigraphy of theMassospondylusAssemblage Zone (Stormberg Group, Karoo Supergroup), South Africa

South African Journal of Geology, Journal Year: 2020, Volume and Issue: 123(2), P. 249 - 262

Published: June 1, 2020

Abstract The Massospondylus Assemblage Zone is the youngest tetrapod biozone in Karoo Basin (upper Stormberg Group, Supergroup) and records one of oldest dinosaur dominated ecosystems southern Gondwana. Recent qualitative quantitative investigations into biostratigraphy lower upper Elliot formations (lEF, uEF) Clarens Formation main resulted first biostratigraphic review this stratigraphic interval nearly four decades, allowing us to introduce a new scheme, (MAZ). MAZ expands upon Range by including crocodylomorph Protosuchus haughtoni ornithischian Lesothosaurus diagnosticus as two co-occurring index taxa alongside taxon, sauropodomorph carinatus. With maximum thickness ~320 m southeastern portion basin, our contained within uEF Group), however, based on vertebrate ichnofossils evidence, it may potentially extend sedimentary units lowermost Drakensberg Group. We do not propose any further subdivisions, consider Tritylodon Acme (TAZ) temporal marker MAZ. currently accepted range age between Hettangian Pliensbachian, however faunal turnover, which observes an increase diversity clades, crocodylomorph, mammaliaform uEF, could reflect effects end-Triassic extinction event (ETE).

Language: Английский

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A new international initiative for facilitating data-driven Earth science transformation

Geological Society London Special Publications, Journal Year: 2020, Volume and Issue: 499(1), P. 225 - 240

Published: Jan. 1, 2020

Abstract Data-driven techniques including machine-learning (ML) algorithms with big data are re-activating and re-empowering research in traditional disciplines for solving new problems. For geoscientists, however, what matters is we do the rather than amount of it. While recent monitoring will help risk resource assessment, long-earth record fundamental understanding processes. Thus, how technologies can facilitate geoscience a question most organizations geoscientists. A quick answer that technology may fundamentally change direction research. In view challenges faced by governments professional contributing to transformation Earth science era, International Union Geological Sciences has established initiative: IUGS-recognized Big Science Program. This paper elaborates on main opportunities benefits utilizing data-driven approaches geosciences facilitating earth transformation. The include from human learning alone integration AI, ML, as well known questions seeking answers formulating as-yet unknown answers. key be associated intelligent acquisition massive, heterogeneous automated comprehensive discovery complex problem solving.

Language: Английский

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The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds

PeerJ, Journal Year: 2018, Volume and Issue: 6, P. e5976 - e5976

Published: Dec. 19, 2018

The homology of the tridactyl hand birds is a still debated subject, with both paleontological and developmental evidence used in support alternative identity patterns avian fingers. With its simplified phalangeal morphology, Late Jurassic ceratosaurian Limusaurus has been argued to II-III-IV digital complex pattern homeotic transformations three-fingered (tetanuran) theropods. We report new large-bodied theropod, Saltriovenator zanellai gen. et sp. nov., based on partial skeleton from marine Saltrio Formation (Sinemurian, lowermost Jurassic) Lombardy (Northern Italy). Taphonomical analyses show bone bioerosion by invertebrates (first record for dinosaurian remains) suggest history carcass before being deposited well-oxygenated well-illuminated sea bottom. shows mosaic features seen four-fingered theropods basal tetanurans. Phylogenetic analysis supports sister taxon relationships between Italian theropod younger Early Berberosaurus Morocco, lineage which basalmost Ceratosauria. Compared atrophied later members Ceratosauria, demonstrates that fully functional hand, well-adapted struggling grasping, was primitively present ceratosaurians. Ancestral state reconstruction along stem 2-3-4-1-X 2-3-4-0-X as manual formulae at roots Ceratosauria Tetanurae, confirming I-II-III Accordingly, peculiar represents derived condition restricted late-diverging ceratosaurians cannot help elucidating origin evolution explained step-wise lateral simplification among non-tetanuran dinosaurs, followed single primary axis shift digit position 4 3 root Tetanurae once fourth finger completely lost, allowed independent losses vestigial metacarpal allosaurians, tyrannosauroids, maniraptoromorphs. an estimated body length 7.5 m, largest most robust Jurassic, pre-dating occurrence mass approaching 1,000 Kg over 25 My. radiation larger relatively stockier averostran earlier than previously known may represent one factors ignited trend toward gigantism sauropods.

Language: Английский

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Skull remains of the dinosaur Saturnalia tupiniquim (Late Triassic, Brazil): With comments on the early evolution of sauropodomorph feeding behaviour

PLoS ONE, Journal Year: 2019, Volume and Issue: 14(9), P. e0221387 - e0221387

Published: Sept. 6, 2019

Saturnalia tupiniquim is a sauropodomorph dinosaur from the Late Triassic (Carnian-c. 233 Ma) Santa Maria Formation of Brazil. Due to its phylogenetic position and age, it important for studies focusing on early evolution both dinosaurs sauropodomorphs. The osteology has been described in series papers, but cranial anatomy remains mostly unknown. Here, we describe skull bones one paratypes (only type-series possess such remains) based CT Scan data. newly elements allowed estimating length provide additional support presence reduced (i.e. two thirds femoral length) this taxon, as typical later Skull reduction could be related an increased efficiency predatory feeding behaviour, allowing fast movements head order secure small elusive prey, hypothesis also supported by data tooth brain morphology. A principal co-ordinates analysis jaw apparatus shows marked shifts morphospace occupation different stages first 30 million years their evolutionary history. One these observed between non-plateosaurian plateosaurian sauropodomorphs, suggesting that, despite having omnivorous diet, behaviour some Carnian Saturnalia, was markedly that taxa. second shift, Early Jurassic taxa, congruent with floral turnover across Triassic-Jurassic boundary.

Language: Английский

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