Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation¹

Canadian Journal of Earth Sciences, Journal Year: 2021, Volume and Issue: 58(9), P. 870 - 884

Published: July 1, 2021

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one the most diverse dinosaur faunas, with record favouring large-bodied taxa, in terms number and completeness skeletons. Although small theropods are well documented assemblage, taxonomic assessments frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, morphometric analyses, a focus specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, test whether preserve faunal zonation/turnover patterns similar those previously for megaherbivores. Frontal bones referred therizinosaur (cf. Erlikosaurus), representing among only group Campanian–Maastrichtian (83–66 Ma) fossil North America, plot closely troodontids morphospace, distinct non-DPF therizinosaurs, placement supported by suite troodontid anatomical frontal characters. Postcranial material cf. Erlikosaurus America is also reviewed found morphology caenagnathids, rather than therizinosaurs. Among troodontids, document considerable morphospace biostratigraphic overlap between Stenonychosaurus recently Latenivenatrix, as variable distribution putatively autapomorphic characters, calling validity latter taxon into question. Biostratigraphically, there no broad-scale zonation ornithischians DPF, many ranging throughout much formation overlapping extensively, possibly reflecting lack sensitivity environmental changes, or other cryptic ecological evolutionary factors.

Language: Английский

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Fast production of large, time‐calibrated, informal supertrees with tree.merger

Palaeontology, Journal Year: 2022, Volume and Issue: 65(1)

Published: Jan. 1, 2022

Abstract Assembling informal supertrees inclusive of extinct species is a useful but particularly long and complex procedure. We introduce new, interactive, piece software that allows the fast production large, time‐calibrated supertrees, single‐handedly mixing multiple phylogenetic information from different sources. The software, embodied in tree.merger function available as part RRphylo R package, merging trees into one or adding individual to target phylogeny. Time calibration implemented automatically within according user‐specified, optional age values can be provided for nodes and/or tips. applied two case‐studies. first, hypothetical, case study pertains tree odontocete cetaceans. second regards expansion higher‐level phylogeny dinosaurs proposing sister clade relationship between Ornithoscelida Sauropodomorpha c . 50 357 tree. studies took less than five seconds each complete, on regular personal computer.

Language: Английский

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Functional space analyses reveal the function and evolution of the most bizarre theropod manual unguals

Communications Biology, Journal Year: 2023, Volume and Issue: 6(1)

Published: Feb. 16, 2023

Abstract Maniraptoran dinosaurs include the ancestors of birds, and most used their hands for grasping in flight, but early-branching maniraptorans had extraordinary claws mysterious function. Alvarezsauroids short, strong arms with a stout, rock-pick-like, single functional finger. Therizinosaurians elongate fingers slender sickle-like unguals, sometimes over one metre long. Here we develop comprehensive methodological framework to investigate what functions these bizarre bony are how they formed. Our analysis includes finite element newly established functional-space also involves shape size effects an assessment function evolution. We find distinct divergence among manual unguals maniraptorans, identify complex relationship between structural strength, morphological specialisations, changes. reveals that efficient digging capabilities only emerged late-branching alvarezsauroid forelimbs, rejecting hypothesis vestigial structures like T. rex . results support statement therizinosaurians were herbivores. However, bizarre, huge Therizinosaurus such length no mechanical has been identified; suggest decorative lengthened by peramorphic growth linked increased body size.

Language: Английский

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How Triceratops got its face: An update on the functional evolution of the ceratopsian head

The Anatomical Record, Journal Year: 2023, Volume and Issue: 306(7), P. 1951 - 1968

Published: March 8, 2023

Abstract Ceratopsian dinosaurs arguably show some of the most extravagant external cranial morphology across all Dinosauria. For over a century, ceratopsian have inspired multitude functional studies as more discoveries continued to depict larger picture enormous diversity these animals. The iconic horns and bony frills in many ceratopsians portray plethora shapes, sizes, arrangements taxa, their overall feeding apparatus development unique specializations previously unseen large herbivores. Here, I give brief updated review investigating different aspects head. role is explored, with an overview potential for weaponization or defense either intraspecific anti‐predatory combat, among other things. A pertaining also presented here, analyses exploring beak snout morphology, dentition tooth wear, musculature associated skull anatomy, biomechanics.

Language: Английский

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Dots on a screen: The past, present, and future of morphometrics in the study of nonavian dinosaurs

The Anatomical Record, Journal Year: 2023, Volume and Issue: 306(7), P. 1896 - 1917

Published: March 15, 2023

Using morphometrics to study nonavian dinosaur fossils is a practice that predates the origin of word "dinosaur." By 1970s, linear had become established as valuable tool for analyzing intra- and interspecific variation in dinosaurs. With advent more recent techniques such geometric advanced statistical approaches, morphometric analyses dinosaurs have proliferated, granting unprecedented insight into many aspects their biology evolution. I outline past, present, future applied zeroing on five paleobiology where has been widely utilized advance our knowledge: systematics, sexual dimorphism, locomotion, macroevolution, trackways. Morphometric methods are especially susceptible taphonomic distortion. As such, impact distortion original fossil shape discussed current quantifying accounting with goal reducing noise biological signal ratio. Finally, paleobiologists move "virtual paleobiology" framework, whereby digital renditions captured via photogrammetry computed tomography. These primary data form basis three-dimensional (3D) along slew other forms analyses. 3D specimen part extended help democratize paleobiology, unlocking from physical museum making available researchers across world.

Language: Английский

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Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2021, Volume and Issue: 288(1944), P. 20202938 - 20202938

Published: Feb. 3, 2021

Socio-sexual selection is predicted to be an important driver of evolution, influencing speciation, extinction and adaptation. The fossil record provides a means testing these predictions, but detecting its signature from morphological data alone difficult. There are, nonetheless, some specific patterns growth variation which are expected traits under socio-sexual selection. distinctive parietal-squamosal frill ceratopsian dinosaurs has previously been suggested as display trait, evidence for this limited. Here, we perform whole-skull shape analysis unprecedentedly large sample specimens Protoceratops andrewsi using high-density landmark-based geometric morphometric approach test four predictions regarding potential signalling role the frill. Three predictions—low integration with rest skull, significantly higher rate change in size during ontogeny, variance than other skull regions—are supported. One prediction, sexual dimorphism shape, not supported, suggesting that differences P. likely small. Together, findings consistent mutual mate choice or quality more general social interactions, support hypothesis functioned signal dinosaurs.

Language: Английский

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Modularity and heterochrony in the evolution of the ceratopsian dinosaur frill

Ecology and Evolution, Journal Year: 2020, Volume and Issue: 10(13), P. 6288 - 6309

Published: May 22, 2020

Abstract The fossil record provides compelling examples of heterochrony at macroevolutionary scales such as the peramorphic giant antlers Irish elk. Heterochrony has also been invoked in evolution distinctive cranial frill ceratopsian dinosaurs Triceratops . Although frills vary size, shape, and ornamentation, quantitative analyses that would allow for testing hypotheses are lacking. Here, we use geometric morphometrics to examine shape variation across diversity within four species preserving growth series. We then test whether constitutes an evolvable module both species, compare trajectories taxa with ontogenetic series identify heterochronic processes. Evolution consisted primarily progressive expansion its caudal caudolateral margins, morphospace occupation following taxonomic groups. taphonomic distortion represents a complicating factor, our data support modularity species. Peramorphosis played important role evolution, acceleration operating early neoceratopsian followed by progenesis later diverging cornosaurian ceratopsians. Peramorphic may have facilitated decoupling this structure from jaw musculature, inference predicts higher evolutionary rates among ceratopsids indeed borne out data. However, denser sampling meager early‐diverging is required further.

Language: Английский

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Osteological comparison of casque ontogeny in palaeognathous and neognathous birds: insights for selecting modern analogues in the study of cranial ornaments from extinct archosaurs

Zoological Journal of the Linnean Society, Journal Year: 2023, Volume and Issue: 199(1), P. 10 - 25

Published: March 2, 2023

Abstract Birds, along with their dinosaurian precursors, possess a variety of bony cranial expansions. A deep understanding the phenotypic complexity these structures would be useful for addressing development, evolution, and function hard-tissue ornamentation. Yet, evolutionary significance have gone largely unaddressed because no unifying conceptual framework interpreting expansions currently exists. To provide such framework, we examine osseous ornament variation in modern birds, using µ-CT imaging to casque components, structural composition, developmental changes two neognathous (Numida meleagris, Macrocephalon maleo) one palaeognathous species (Casuarius casuarius) survey avian osteology literature 11 orders containing members Our anatomical analyses suggest broad configuration categories: (i) geminal, which ornaments consist paired elements only (i.e. within Neognathae) (ii) disunited, unpaired, midline bones Palaeognathae). Ornament contribute elevation (proximal support), elaboration (distal shape), or both. results hold utility unravelling selection processes, particularly difficult-to-decipher display roles, that shaped casques, as well use extant avians comparative analogues non-avian dinosaurs ornamental head structures.

Language: Английский

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A new juvenile Yamaceratops (Dinosauria, Ceratopsia) from the Javkhlant Formation (Upper Cretaceous) of Mongolia

PeerJ, Journal Year: 2022, Volume and Issue: 10, P. e13176 - e13176

Published: April 5, 2022

Here we report a new articulated skeleton of Yamaceratops dorngobiensis (MPC-D 100/553) from the Khugenetjavkhlant locality at Shine Us Khudag (Javkhlant Formation, ?Santonian-Campanian) eastern Gobi Desert, Mongolia, which represents first substantially complete and juvenile individual this taxon. The specimen includes nearly cranium large portions vertebral column appendicular skeleton. Its skull is about 2/3 size holotype specimen, based on mandibular length. ontogenetic stage confirmed by multiple indicators skeletal morphological immaturity known in ceratopsians, such as long-grained surface texture long bones, smooth external postorbital, open neurocentral sutures all caudal vertebrae, orbit relative to postorbital jugal, low angle lacrimal ventral ramus maxillary teeth row, narrow frontal, straight edge dentary. Osteohistological analysis MPC-D 100/553 recovered three lines arrested growth, implying around 3 years age when it died, verified specimen’s immature stage. adds autapomorphy , anteroventral margin fungiform dorsal end being excluded antorbital fossa. Furthermore, shows unique combination diagnostic features some other basal neoceratopsians: ventrally hooked rostral bone Aquilops americanus very tall middle neural spines or more than four times high centrum Koreaceratops hwaseongensis Montanoceratops cerorhynchus Protoceratops andrewsi . jugal with subtemporal deeper suborbital also shared A. Liaoceratops yanzigouensis P. Adding 38 scorings into recent comprehensive data matrix Neoceratopsia taking account ontogenetically variable characters Y. sister taxon Euceratopsia (Leptoceratopsidae plus Coronosauria). A second phylogenetic another for Ceratopsia supported position. position important ceratopsian evolution, one basalmost neoceratopsians broad, thin frill hyper-elongated while still bipedal.

Language: Английский

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Biomechanical skull performance in the meiolaniid Niolamia argentina (Testudinata: Meiolaniidae) using Finite Element AnalysisCitation for this article: Degrange, F. J., Nieto, M. N., Sterli, J., & Vlachos, E. (2024) Biomechanical skull performance in the meiolaniid Niolamia argentina (Testudinata: Meiolaniidae) using Finite Element Analysis. Journal of Vertebrate Paleontology . https://doi.org/10.1080/02724634.2024.2357315

Journal of Vertebrate Paleontology, Journal Year: 2023, Volume and Issue: 43(6)

Published: Nov. 2, 2023

The use of horns and frills for sexual display attack has been proposed demonstrated in extinct taxa on several occasions, with the ceratopsian dinosaurs as most iconic example. Niolamia argentina is a large meiolaniid turtle from Patagonia, characterized by presence extensive massive skull. Here, Finite Element Analysis (FEA) applied only known adult skull N. to assess cranial performance simulating defensive/aggressive movements. We tested five different scenarios: (1) hitting snout, (2) forehead, (3) struggling notch between frill horn, (4) stabbing lateral horns, (5) caudal torsion frills, last two being damaging stressful scenarios. Together lack features related head-hitting/fighting, we find that, although structures studied here may indicate priori that they were engaging combat males, each other trying stab represent highly In this sense, propose seems be more suitable than behavior.

Language: Английский

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