Exploring the diversity and disparity of rhabdodontomorph ornithopods from the Late Cretaceous European archipelago

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: April 30, 2025

The origin and early diversification of ornithopods, a major clade ornithischian dinosaurs, remain poorly understood, with conflicting phylogenetic hypotheses regarding rootward neornithischian relationships. Some topological stability is inferred near the basal divergence Iguanodontia, though ingroup relationships unclear. For instance, Rhabdodontidae, Late Cretaceous European ornithopods 'traditionally' considered to include eight nine species, presents significant taxonomic challenges. We explore diversity disparity Rhabdodon-lineage iguanodontians. assembled novel dataset comprising morphological morphometric data obtained from rhabdodontomorph dentaries, which are abundant, well-preserved in majority taxa, distinctive. Special attention given Rhabdodon septimanicus, known taxon upper Campanian lower Maastrichtian southern France, established based on particularly robust dentary bone that has been subjected interpretations. Our restudy specimen, combined multivariate assessment, shows this clear outlier among rhabdodontomorphs, providing basis for its assignment new genus, Obelignathus. Although further large-scale studies, especially detailed osteological descriptions, needed clarify significance certain our results indicate group exhibits greater than currently recognized, several sympatric taxa co-occurring, at least France possibly also Romania.

Language: Английский

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Ornithopod tracks and bones: Paleoecology and an unusual evidence of quadrupedal locomotion in the Lower Cretaceous of eastern Iberia (Teruel, Spain)

Cretaceous Research, Journal Year: 2023, Volume and Issue: 144, P. 105473 - 105473

Published: Jan. 6, 2023

Language: Английский

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Evidence of large-sized ankylopollexian dinosaurs (Ornithischia: Iguanodontia) in the Upper Jurassic of Portugal

Journal of Systematic Palaeontology, Journal Year: 2025, Volume and Issue: 23(1)

Published: April 2, 2025

Language: Английский

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New perspectives on body size and shape evolution in dinosaurs

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 8, 2025

ABSTRACT Diversity in the body shapes and sizes of dinosaurs was foundational to their widespread success during Mesozoic era. The ability quantify size form reliably is therefore critical study dinosaur biology evolution. Body mass estimates for any given fossil animal are, theory, most informative when derived from volumetric models that account three‐dimensional entire body. In addition providing total mass, approaches can be used determine inertial properties specific segments overall distribution throughout body, each which are essential modelling interpretation form–function relationships associations with ecology. However, determination volumes taxa often subjective, may sensitive varied artistic inference. This highlights need an approach estimation segment systematically constrained by quantitative scaling between hard tissues fossilise soft only observable extant taxa. To this end, we recently published skeletal tissue factors CT data sauropsids estimate 52 non‐avian representing majority major clades plans. masses estimated range less than 200 g tiny avialan Yixianornis over 60 tonnes giant sauropod Patagotitan , currently largest known mostly complete remains. From our models, infer many previous reconstructions envelopes too small, were heavier estimates. Our generally overlap limb bone shaft dimensions, but considerable variability among clades. suggests different either differed volume ratios, or dimensions relative perhaps related differences locomotor dynamics postural also allowed us investigate variation proportions across a perspective grounded anatomical data, framing long‐standing hypotheses about form, function, behaviour context. For example, reconstructed disparity whole‐body centres reflects broad array postures clades, while lack strong positive allometry weight‐bearing corroborates studies suggesting decrease performance as increased.

Language: Английский

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Ornithischian dinosaurs in Southeast Asia: a review with palaeobiogeographic implications

Fossil record, Journal Year: 2023, Volume and Issue: 26(1), P. 1 - 25

Published: Jan. 10, 2023

Ornithischian dinosaurs have been discovered in Thailand, Laos, and Malaysia. These bird-hipped herbivores remain relatively rare by comparison with saurischian dinosaurs. In the Late Jurassic, stegosaurs basal neornithischians from Thailand showed similarities to Middle-Late Jurassic taxa China. Ornithischians appeared fossil record again during late Early Cretaceous (Aptian-Albian) of Laos. They are represented non-hadrosaurid iguanodontians ceratopsians. A few specimens reported poorly dated rocks Here, we illustrate diversity ornithischian assemblages Southeast Asia discuss their palaeobiogeographical implications.

Language: Английский

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An early-diverging iguanodontian (Dinosauria: Rhabdodontomorpha) from the Late Cretaceous of North America

PLoS ONE, Journal Year: 2023, Volume and Issue: 18(6), P. e0286042 - e0286042

Published: June 7, 2023

Intensifying macrovertebrate reconnaissance together with refined age-dating of mid-Cretaceous assemblages in recent decades is producing a more nuanced understanding the impact Cretaceous Thermal Maximum on terrestrial ecosystems. Here we report discovery new early-diverging ornithopod, Iani smithi gen. et sp. nov., from Cenomanian-age lower Mussentuchit Member, Cedar Mountain Formation Utah, USA. The single known specimen this species (NCSM 29373) includes well-preserved, disarticulated skull, partial axial column, and portions appendicular skeleton. Apomorphic traits are concentrated frontal, squamosal, braincase, premaxilla, including presence three premaxillary teeth. Phylogenetic analyses using parsimony Bayesian inference posit as North American rhabdodontomorph based enlarged, spatulate teeth bearing up to 12 secondary ridges, maxillary lacking primary ridge, laterally depressed process jugal, posttemporal foramen restricted among other features. Prior discovery, neornithischian paleobiodiversity Member was primarily isolated teeth, only hadrosauroid Eolambia caroljonesa named remains. Documentation possible assemblage, along published reports an as-of-yet undescribed thescelosaurid, fragmentary remains ankylosaurians ceratopsians confirms minimum five, cohabiting clades earliest Late ecosystems America. Due poor preservation exploration Turonian–Santonian assemblages, timing extirpation Western Interior Basin is, yet, unclear. However, documents survival all major Early neornithischians (Thescelosauridae, Rhabdodontomorpha, Ankylopollexia) into dawn

Language: Английский

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THE OSTEOLOGY OF THE HOLOTYPE OF THE BRITISH IGUANODONTIAN DINOSAURMANTELLISAURUS ATHERFIELDENSIS

Monographs of the Palaeontographical Society, Journal Year: 2023, Volume and Issue: 177(665), P. 1 - 63

Published: Jan. 2, 2023

Iguanodontian dinosaurs are known from Middle Jurassic to Late Cretaceous deposits worldwide and historically important because they include the first fossils be identified as giant extinct reptiles that later became dinosaurs. Due historical taxonomic practices fragmentary nature of many specimens, discoveries 19th century were referred Iguanodon with little appraisal, resulting in genus becoming something a 'wastebasket taxon'. Reinterpretations holotype specimens an step attempting understand evolutionary history iguanodontian Here, we redescribe Mantellisaurus atherfieldensis, one most complete British dinosaur Barremian/Aptian Isle Wight, UK, assess its phylogenetic position. We find atherfieldensis is valid taxon distinct based on three autapomorphies premaxilla, maxilla, scapula, resolves early diverging hadrosauroid styracosternan, representing ornithopods.

Language: Английский

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A new small-bodied ankylosaurian dinosaur from the Upper Cretaceous of North Patagonia (Río Negro Province, Argentina)

Journal of Systematic Palaeontology, Journal Year: 2022, Volume and Issue: 20(1)

Published: Dec. 1, 2022

The most representative ankylosaurian remains from Argentina have been found in sediments of the Allen Formation (Campanian–Maastrichtian) Salitral Moreno, Río Negro Province. Several authors discussed identity and history these remains. In this study, we review all published material along with some new order to summarize knowledge about ankylosaurs. Previously includes a tooth, dorsal anterior caudal vertebrae, femur several osteoderms. include synsacral elements, partial anatomy synsacrum, mid-caudal vertebra, osteoderms, histology post-cervical support nodosaurid identification, as proposed previous descriptions Moreno material. Patagopelta cristata gen. et sp. nov. is ankylosaur characterized by presence unique cervical half-ring femoral anatomies, including high-crested lateral osteoderms half rings strongly developed muscular crest surface femur. ∼2 m body length estimated for very small an ankylosaur, comparable dwarf Struthiosaurus. We recovered within Nodosaurinae, related nodosaurids 'mid'-Cretaceous North America, contrasting topologies that Panoplosaurini (Late Cretaceous American nodosaurids). These results palaeobiogeographical context which Argentina, are part allochthonous fauna migrated into South America during late Campanian First Biotic Interchange.https://zoobank.org/urn:lsid:zoobank.org:pub:FBA24443-F365-49FD-A959-10D2848C2400

Language: Английский

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Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile

Science Advances, Journal Year: 2023, Volume and Issue: 9(24)

Published: June 16, 2023

In the dusk of Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present first species a from subantarctic region, Gonkoken nanoi, early Maastrichtian age Magallanes, Chile. Unlike duckbills further north Patagonia, descends North American forms diverging shortly before origin Hadrosauridae. However, at time, non-hadrosaurids America had become replaced by hadrosaurids. We propose ancestors arrived earlier and reached south, into regions where never arrived: All alleged Antarctic remains could belong non-hadrosaurid like Gonkoken. Dinosaur faunas world underwent qualitatively different changes Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability.

Language: Английский

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Dental microwear texture analysis reveals a likely dietary shift within Late Cretaceous ornithopod dinosaurs

Palaeontology, Journal Year: 2023, Volume and Issue: 66(6)

Published: Nov. 1, 2023

Abstract Dinosaurs were the dominant megaherbivores during Cretaceous when angiosperms, flowering plants, emerged and diversified. How herbivorous dinosaurs responded to increasing diversity of angiosperms is largely unknown due lack methods that can reconstruct diet directly from body fossils. We applied dental microwear texture analysis (DMTA), an approach quantifies microtopography diet‐induced wear marks on tooth surfaces, ornithopods, dinosaur clade includes taxa with most sophisticated masticatory system. found Late ornithopods have significantly rougher (DMT) compared pre‐Late DMT variation increased in hadrosaurids, a derived ornithopod clade. These changes indicate likely temporal dietary shift towards more abrasive foodstuffs within probably ingestion phytoliths (amorphous silica bodies plants). Phytoliths are main source rough modern herbivores, along exogenous dust grit, generally concentrated than other major plant groups. Our results show DMTA occlusal enamel surface be used diets dinosaurs, resolution superior conventional methods.

Language: Английский

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