Ngwevu intloko: a new early sauropodomorph dinosaur from the Lower Jurassic Elliot Formation of South Africa and comments on cranial ontogeny inMassospondylus carinatus

PeerJ, Год журнала: 2019, Номер 7, С. e7240 - e7240

Опубликована: Авг. 5, 2019

Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation South Africa has increased markedly recent years with discovery new fossils, re-assessments previously collected material and a better understanding Stormberg Group stratigraphy. Here, Ngwevu intloko, genus basal sauropodomorph is named on basis complete skull partial skeleton (BP/1/4779) assigned to Massospondylus carinatus. It can be distinguished from all other sauropodomorphs by combination 16 cranial six postcranial characters. The species compared small ontogenetic series M. carinatus as well range closely related taxa. Taphonomic deformation, sexual dimorphism ontogeny are rejected possible explanations for morphological differences present between BP/1/4779 Osteohistological examination reveals that had nearly reached adult size at time its death minimum age 10 years.

Язык: Английский

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Ten more years of discovery: revisiting the quality of the sauropodomorph dinosaur fossil record

Palaeontology, Год журнала: 2020, Номер 63(6), С. 951 - 978

Опубликована: Июль 18, 2020

Abstract Spatiotemporal changes in fossil specimen completeness can bias our understanding of a group's evolutionary history. The quality the sauropodomorph record was assessed decade ago, but number valid species has since increased by 60%, and 17% taxa from that study have undergone taxonomic revision. Here, we assess how 10 years additional research changed outlook on record. We quantified all 307 currently considered using skeletal metric, which calculates proportion complete skeleton preserved for each taxon. Taxonomic stratigraphic age revisions, rather than new species, are drivers most significant differences between current results those previous assessment. No statistical appeared when use dataset to generate temporal curves based solely known 2009 or 1999. now observe severe drop mean values across Jurassic–Cretaceous boundary never recovers pre‐Cretaceous levels. Explaining this pattern is difficult, as find no convincing evidence it related environmental preferences body size changes. Instead, might result from: (1) reduction terrestrial preservation space due sea level rise; (2) ecological specificities relatively high diagnosability Cretaceous species; and/or (3) sampling newly explored sites with many previously unknown taxa. Revisiting patterns manner allows us test longevity conclusions made quantitative studies.

Язык: Английский

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A quantitative method for inferring locomotory shifts in amniotes during ontogeny, its application to dinosaurs and its bearing on the evolution of posture

Palaeontology, Год журнала: 2019, Номер 63(2), С. 229 - 242

Опубликована: Ноя. 6, 2019

Abstract Evolutionary transitions between quadrupedal and bipedal postures are pivotal to the diversification of amniotes on land, including in our own lineage (Hominini). Heterochrony is suggested as a macroevolutionary mechanism for postural but understanding evolution deep time hindered by lack methods inferring posture extinct species. Dinosaurs an excellent natural laboratory because they demonstrate at least four instances quadrupedality evolving from bipedality, heterochronic processes have been put forward explanatory model these transitions. We extend quantitative method reliably tetrapods study ontogenetic using measurements proportional limb robusticity. apply this series living amniotes, focusing dinosaurs. Our correctly predicts general pattern conservation many amniote species infers same some Furthermore, it shift crawling walking humans. also infer transition early late‐ontogenetic bipedality transitional sauropodomorph dinosaur Mussaurus patagonicus possibly branching ceratopsian Psittacosaurus lujiatunensis not Massospondylus carinatus . The phylogenetic positions shifts suggest that heterochrony may play role macroevolution posture, has substantial potential testing evolutionary locomotor modes, especially elucidating mechanisms like heterochrony.

Язык: Английский

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The evolutionary biomechanics of locomotor function in giant land animals

Journal of Experimental Biology, Год журнала: 2021, Номер 224(11)

Опубликована: Июнь 1, 2021

ABSTRACT Giant land vertebrates have evolved more than 30 times, notably in dinosaurs and mammals. The evolutionary biomechanical perspectives considered here unify data from extant extinct species, assessing current theory regarding how the locomotor biomechanics of giants has evolved. In terrestrial tetrapods, isometric allometric scaling patterns bones are evident throughout history, reflecting general trends lineage-specific divergences as animals evolve giant size. Added to on other supportive tissues neuromuscular control, these illuminate lineages tetrapods each into robust forms adapted constraints gigantism, but with some morphological variation. Insights leverage limbs maximal speed reinforce idea that, beyond 100–300 kg body mass, reduce their abilities, eventually may lose entire behaviours such galloping or even running. Compared prehistory, megafaunas depauperate diversity disparity; therefore, turning fossil record can tell us about tetrapods. Interspecific variation uncertainty unknown aspects form function living taxa still render it impossible use first principles theoretical tightly bound limits gigantism. Yet sauropod demonstrate that >50 tonne masses repeatedly evolved, plans quite different those mammalian giants. Considering largest bipedal dinosaurs, disparity modern megafauna, this shows there is flexibility allowing divergent specialisations.

Язык: Английский

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Triassic sauropodomorph dinosaurs from South America: The origin and diversification of dinosaur dominated herbivorous faunas

Journal of South American Earth Sciences, Год журнала: 2021, Номер 107, С. 103145 - 103145

Опубликована: Янв. 13, 2021

Язык: Английский

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Impact of the Jenkyns Event (early Toarcian) on dinosaurs: Comparison with the Triassic/Jurassic transition

Earth-Science Reviews, Год журнала: 2022, Номер 234, С. 104196 - 104196

Опубликована: Сен. 28, 2022

The Early Jurassic Jenkyns Event (∼183 Ma) was characterized in terrestrial environments by global warming, perturbation of the carbon cycle, enhanced weathering and wildfires. Heating acid rain on land caused a loss forests affected diversity composition plant assemblages rest trophic web. We suggest that Event, triggered activity Karoo-Ferrar Large Igneous Province, pivotal remodelling ecosystems, including plants dinosaurs. Macroplant palynological data show reductions richness conifers, cycadophytes, ginkgophytes, bennetitaleans, ferns, continuation seasonally dry warm conditions. Major changes occurred to sauropodomorph dinosaurs, with extinction diverse basal families formerly called ‘prosauropods’ as well some sauropods, diversification derived Eusauropoda Toarcian South America, Africa, Asia, wider new families, Mamenchisauridae, Cetiosauridae Neosauropoda (Dicraeosauridae Macronaria) Middle Jurassic, showing massive increase size feeding modes. Ornithischian dinosaurs patchy records; heterodontosaurids scelidosaurids disappeared, major clades (Stegosauridae, Ankylosauridae, Nodosauridae) emerged soon after Bajocian Bathonian worldwide. Among theropod Coelophysidae Dilophosauridae died out during theropods (Megalosauroidea, Allosauroidea, Tyrannosauroidea) this event substantial increases size. then crisis marked especially floral origins clades, increasing body Comparison end Triassic Mass Extinction helps understand incidence climatic driven large igneous provinces ecosystems their great impacts early dinosaur evolution.

Язык: Английский

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Climatic controls on the ecological ascendancy of dinosaurs

Current Biology, Год журнала: 2022, Номер 33(1), С. 206 - 214.e4

Опубликована: Дек. 16, 2022

The ascendancy of dinosaurs to become dominant components terrestrial ecosystems was a pivotal event in the history life, yet drivers their early evolution and biodiversity are poorly understood.1Brusatte S.L. Benton M.J. Ruta M. Lloyd G.T. first 50 Myr dinosaur evolution: macroevolutionary pattern morphological disparity.Biol. Lett. 2008; 4: 733-736https://doi.org/10.1098/rsbl.2008.0441Crossref PubMed Scopus (105) Google Scholar,2Irmis R.B. Evaluating hypotheses for diversification dinosaurs.Earth Environ. Sci. Trans. R. Soc. Edinb. 2010; 101: 397-426https://doi.org/10.1017/S1755691011020068Crossref (94) Scholar,3Benton Forth J. Langer M.C. Models rise dinosaurs.Curr. Biol. 2014; 24: R87-R95https://doi.org/10.1016/j.cub.2013.11.063Abstract Full Text PDF (93) Scholar During Late Triassic, were initially rare geographically restricted, only attaining wider distributions greater abundance following end-Triassic mass extinction event.4Brusatte Superiority, competition, opportunism evolutionary radiation dinosaurs.Science. 321: 1485-1488https://doi.org/10.1126/science.1161833Crossref (334) Scholar,5Langer Ezcurra M.D. Bittencourt J.S. Novas F.E. origin dinosaurs.Biol. Rev. Camb. Philos. 85: 55-110https://doi.org/10.1111/j.1469-185X.2009.00094.xCrossref (212) Scholar,6Langer Godoy P.L. So volcanoes created dinosaurs? quantitative characterization pan-aves.Front. Earth 2022; 10https://doi.org/10.3389/feart.2022.899562Crossref (3) This is consistent with an opportunistic expansion model, initiated by co-occurring groups such as aetosaurs, rauisuchians, therapsids.4Brusatte Scholar,7Tucker M.E. Triassic environments, climates reptile evolution.Palaeogeogr. Palaeoclimatol. Palaeoecol. 1982; 40: 361-379https://doi.org/10.1016/0031-0182(82)90034-7Crossref (89) Scholar,8Benton Dinosaur success triassic: noncompetitive ecological model.Q. 1983; 58: 29-55Crossref (170) However, this could instead be response changes global climatic through Jurassic transition, especially given increasing evidence that climate played key role constraining distributions.7Tucker Scholar,9Whiteside J.H. Lindström S. Irmis Glasspool I.J. Schaller M.F. Dunlavey Nesbitt S.J. Smith N.D. Turner A.H. Extreme ecosystem instability suppressed tropical dominance 30 million years.Proc. Natl. Acad. USA. 2015; 112: 7909-7913https://doi.org/10.1073/pnas.1505252112Crossref (61) Scholar,10Bernardi Gianolla P. Petti F.M. Mietto linked Carnian pluvial episode.Nat. Commun. 2018; 9: 1499https://doi.org/10.1038/s41467-018-03996-1Crossref (87) Scholar,11Lovelace D.M. Hartman S.A. Mathewson P.D. Linzmeier B.J. Porter W.P. Modeling Dragons: using mechanistic physiological microclimate models explore environmental, physiological, constraints on dinosaurs.PLoS One. 2020; 15e0223872https://doi.org/10.1371/journal.pone.0223872Crossref (8) Scholar,12Mancuso A.C. Benavente C.A. Mundil Evidence episode Gondwana: new multiproxy records bearing diversification.Gondwana Res. 86: 104-125https://doi.org/10.1016/j.gr.2020.05.009Crossref (35) Scholar,13Mancuso Pedernera T.E. Gaetano L.C. Breeden III B.T. Paleoenvironmental biotic late triassic Argentina: testing abiotic forcing at basin scale.Front. 10https://doi.org/10.3389/feart.2022.883788Crossref (4) Scholar,14Kent D.V. Clemmensen L.B. Northward dispersal from Gondwana Greenland mid-Norian (215–212 Ma, Triassic) dip atmospheric pCO2.Proc. 2021; 118e2020778118https://doi.org/10.1073/pnas.2020778118Crossref (16) Scholar,15Griffin C.T. Wynd B.M. Munyikwa D. Broderick T.J. Zondo Tolan Taruvinga H.R. Africa's oldest reveal suppression distribution.Nature. 609: 313-319https://doi.org/10.1038/s41586-022-05133-xCrossref Scholar,16Olsen Sha Fang Y. Chang C. Whiteside Kinney Sues H.-D. Kent Vajda V. Arctic ice dinosaurs.Sci. Adv. 8eabo6342https://doi.org/10.1126/sciadv.abo6342Crossref (5) Here, we test hypothesis elucidate how influenced distribution quantitatively examining tetrapod "climatic niche space" across Triassic-Jurassic boundary. Statistical analyses show sauropodomorph occupied more restricted space than other tetrapods dinosaurs, being excluded hottest, low-latitude zones. A subsequent, earliest geographic preferred conditions. Evolutionary model-fitting provide important shift cooler warmer niches during Sauropoda. These results facilitated change support dinosaurs.

Язык: Английский

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

South African Journal of Geology, Год журнала: 2020, Номер 123(2), С. 249 - 262

Опубликована: Июнь 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).

Язык: Английский

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

Geological Society London Special Publications, Год журнала: 2020, Номер 499(1), С. 225 - 240

Опубликована: Янв. 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.

Язык: Английский

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The postcranial anatomy and osteohistology of Terrestrisuchus gracilis (Archosauria, Crocodylomorpha) from the Late Triassic of Wales

Papers in Palaeontology, Год журнала: 2024, Номер 10(4)

Опубликована: Июль 1, 2024

Abstract The earliest crocodylomorphs, known as non‐crocodyliform first appeared during the Late Triassic. In contrast to extant crocodylians, which are all semi‐aquatic, early crocodylomorphs represent terrestrial taxa with a fully erect posture and in most cases small body size. Their gracile skeletons suggest an active mode of life, possibly similar contemporaneous, bipedal theropod dinosaurs. Despite this remarkable plan, postcranial morphology has rarely been documented detail, restricting our ability infer aspects their functional evolution. Here, we provide detailed description postcranium Terrestrisuchus gracilis , small‐bodied crocodylomorph from Triassic Pant‐y‐Ffynnon Quarry (southern Wales, UK), including long bone tissues based on histological thin sections. Almost elements skeleton have preserved. is highly gracile, even for crocodylomorph. Osteological correlates appendicular that had digitigrade, quadrupedal posture. A quantitative analysis limb robustness corroborates was quadruped. Histological suggests sampled specimens were skeletally immature fast growth at time death, indicated by lack external fundamental system predominance fibrolamellar bone. tissue recently described Saltoposuchus connectens certain non‐crocodylomorph pseudosuchians, but differs Hesperosuchus agilis crocodyliforms, parallel‐fibred more prevalent.

Язык: Английский

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