Osteohistological insight into the growth dynamics of early dinosaurs and their contemporaries

PLoS ONE, Journal Year: 2024, Volume and Issue: 19(4), P. e0298242 - e0298242

Published: April 3, 2024

Dinosauria debuted on Earth’s stage in the aftermath of Permo-Triassic Mass Extinction Event, and survived two other Triassic extinction intervals to eventually dominate terrestrial ecosystems. More than 231 million years ago, Upper Ischigualasto Formation west-central Argentina, dinosaurs were just getting warmed up. At this time, represented a minor fraction ecosystem diversity. Members tetrapod clades, including synapsids pseudosuchians, shared convergently evolved features related locomotion, feeding, respiration, metabolism could have risen later dominance. However, it was that radiated Mesozoic most significantly terms body size, diversity, global distribution. Elevated growth rates are one adaptations set apart, particularly from their contemporary crocodilian mammalian compatriots. When did elevated first evolve? How strategies earliest known compare with those tetrapods ecosystems? We studied femoral bone histology an array early alongside non-dinosaurian contemporaries order test whether oldest exhibited novel strategies. Our results indicate vertebrate fauna collectively exhibits relatively high rates. Dinosaurs among fastest growing taxa sample, but they occupied niche crocodylomorphs, archosauriformes, large-bodied pseudosuchians. Interestingly, these grew at least as quickly, more continuously sauropodomorph theropod Mesozoic. These data suggest that, while ancestral for likely played significant role dinosaurs’ ascent within ecosystems, not them apart contemporaries.

Language: Английский

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Early Jurassic origin of avian endothermy and thermophysiological diversity in dinosaurs

Current Biology, Journal Year: 2024, Volume and Issue: 34(11), P. 2517 - 2527.e4

Published: May 15, 2024

A fundamental question in dinosaur evolution is how they adapted to long-term climatic shifts during the Mesozoic and when developed environmentally independent, avian-style acclimatization, becoming endothermic.

Language: Английский

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Palaeoecological deductions from osteohistology

Biology Letters, Journal Year: 2023, Volume and Issue: 19(8)

Published: Aug. 1, 2023

Palaeoecological deductions are vital for understanding the evolution and diversification of species within prehistoric environments. This review highlights multitude ways in which microanatomy microscopic structure bones enables palaeoecological deductions. The occurrence growth marks is discussed, their usefulness deducing ontogenetic status age individuals considered, as well how such permit assessment dynamics species. Here osteohistology shown to provide insight into past populations, ecological relationships between individuals. In addition, response trauma, disease moulting considered. Finally, I explore can give ecomorphological adaptations, filter feeding, probe feeding saltatorial locomotion. Methodological advances three-dimensional microtomography synchrotron scanning bodes future studies despite some compromises terms tissue identity, circumvents crucial issue destructive analyses.

Language: Английский

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Growing with dinosaurs: a review of dinosaur reproduction and ontogeny

Biology Letters, Journal Year: 2025, Volume and Issue: 21(1)

Published: Jan. 1, 2025

Since the start of twenty-first century, there has been a notable increase in annual publications focusing on dinosaur reproduction and ontogeny with researchers using these data to address range macroevolutionary questions about dinosaurs. Ontogeny, which is closely tied osteological morphological variation, impacts several key research areas, such as taxonomic diversity, population dynamics, palaeoecology, macroevolution, well physiological reproductive factors driving ecological success. While broad studies have significantly advanced our understanding evolution, they also revealed important challenges areas needing further investigation. In this review, we aim outline some major linked ontogeny, namely biology, osteohistological growth strategies, variation link between macroevolution. We offer recommendations for best practices promising future directions. These include increasing sample sizes through fieldwork exhaustive use pre-existing fossil collections, micro-computed tomography (μCT) scanning methods dataset non-destructive manner, methodical collection reposition μCT scan data, assessing ontogenetic maturity, establishing consistency terminology building comprehensive extant comparative datasets.

Language: Английский

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Disparate life histories in coeval Triassic cynodonts and their implications for the evolution of mammalian life histories

Paleobiology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 19

Published: March 24, 2025

Abstract The evolution of mammalian innovations like elevated growth rates, endothermy, and live birth has been the subject paleobiological work for decades. Bone histology provides one best lines evidence assessing rates life-history traits in fossil record. However, little ontogenetic information is available nonmammalian cynodonts, stock lineage that eventually gave rise to mammals. Here, I report bone two traversodontid cynodonts from Triassic Manda Formation Tanzania. Using femoral size series, correlate tissue composition limb Scalenodon angustifrons Luangwa drysdalli. Fifteen individuals were analyzed seven penecontemporaneous localities assess intraspecific histovariation within development first time. My results show have disparate life histories despite being similarly sized contemporaries. characterized by parallel-fibered transitions woven-parallel early ontogeny, interpreted as a spurt. This increase rate seen small- middle-sized but resorbed remodeled largest, skeletally mature individual. By contrast, ontogeny. femur not correlated with changes composition, multiple peripheral slower-growing regardless size, highly developmentally plastic growth. Together, these demonstrate coeval members Traversodontidae histories. underlying mechanisms explain different taxa are likely due (1) intrinsic differences (2) varying degrees flexible implication this variation dynamics may be more widespread than currently understood good indicator maturity some species.

Language: Английский

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Osteohistology of the unusually fast‐growing theropod dinosaur Ceratosaurus

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

Published: Feb. 5, 2025

Abstract Ceratosaurus is a large‐bodied non‐avian theropod dinosaur known from the Upper Jurassic Morrison Formation of North America and remarkable both for its exceptionally fast annual growth rate status as only currently with postcranial osteoderms. We describe osteohistology three hind limb bones, two dorsal ribs, one osteoderm representing four individuals . In addition to describing tissues these we compared rates in our sample those five other ceratosaurians. fit seven models specimens results best‐fit model(s) ceratosaurians ( Masiakasaurus knopfleri Majungasaurus crenatissimus ) which sufficient data were available. The bone tissue limbs highly vascularized, dense plexiform or reticular vascular complexes alternating strips parallel woven‐fibered matrix. Few lines arrested recorded prior achieving asymptotic body size. Both sampled ribs are remodeled, small portions primary visible each section, revealing parallel‐fibered sparse osteons. contain numerous throughout cortex that allowed more accurate estimates individual age when paired limbs. composed core large Haversian canals perimeter lamellar Sharpey's fibers along internal surface bone. Multiple LAGs also present within exterior margins. Maximum on average nine‐fold faster than Our lacks juveniles so confidence inferred limited. Thus, begin constrain patterns, averaged all possessed an Akaike Information Criterion score corrected size (AICc) 10 lowest scoring model. found monomolecular model exhibited AICc value, von Bertalanffy Gompertz possessing values units it. contrast, logistic confidently selected , respectively. Irrespective model, maximum relative several‐fold greater Majungasaurus. histological life history support evolutionary trend towards prolonged development Ceratosauria through time.

Language: Английский

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Microstructural characterization and growth dynamics in Notosuchus terrestris, a Mesoeucrocodylia crocodyliform from the Upper Cretaceous of Northern Patagonia, Argentina

Cretaceous Research, Journal Year: 2023, Volume and Issue: 150, P. 105607 - 105607

Published: June 8, 2023

Language: Английский

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I believe I can fly… New implications for the mode of life and palaeoecology of the Late Triassic Ozimek volans based on its unique long bone histology

Palaeontology, Journal Year: 2024, Volume and Issue: 67(3)

Published: May 1, 2024

Abstract The small diapsid reptile Ozimek volans is one of the most enigmatic representatives Late Triassic fauna Krasiejów, Poland. Phylogenetically, was identified as a ‘protorosaurian’ related to tanystropheids, but extremely elongated limbs and presumed gliding abilities are unusual for this group. This raises question whether lifestyle inferred taxon reflected in its bone histology. Two long bones from single association (humerus UOPB 1148a femur 1148b) were sectioned at midshaft obtain details histological framework. A large medullary cavity, thin walls lamellar with numerous lamellae, only very few simple vascular canals shared by both bones. Application modified 3‐front model (introducing fourth front) cortical growth reveals that ontogenetically younger when compared humerus. limb bones, their diameter, compact structure, low vascularization, no remodelling, lack pneumaticity, histologically similar those modern bats. characteristic cortex may have been well suited withstand high loads while limiting weight. well‐ordered collagen fibres successive lamellae along be key adaptation better distribution load generated during gliding. © 2024 Palaeontological Association.

Language: Английский

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Skeletally immature individuals nest together in the phylogenetic tree of early dinosaurs

Anais da Academia Brasileira de Ciências, Journal Year: 2024, Volume and Issue: 96(suppl 1)

Published: Jan. 1, 2024

The phylogenetic affinities of early dinosaurs are a controversial topic. There disputing scenarios aiming to explain the evolutionary tree these reptiles. A number factors play role on this issue. High levels intraspecific variation experienced by earliest forms pointed distinct authors as one main sources biases. In present study, we performed experimental analyses incorporating skeletally immature individuals operational taxonomic units in order investigate effect ontogeny phylogeny and morphospace Late Triassic sauropodomorphs. results support an "artificial" grouping trees, which is controlled ontogenetic development. Such interpreted control states certain morphological characters, producing false synapomorphies. addition, disparity analysis indicated significant difference between mature individuals, corroborating previous assumptions. At point, suggest caution during scoring process dinosaurs. Some approaches that avoid ontogenetically sensitive characters revealed putative solution. Nevertheless, additional specimens alternative tools mandatory properly deal with

Language: Английский

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Ontogenetic mechanisms of size change: implications for the Lilliput effect and beyond

Paleobiology, Journal Year: 2023, Volume and Issue: 50(1), P. 130 - 149

Published: Dec. 4, 2023

Abstract Body size has a long history of study in paleobiology and underlies many important phenomena macroevolution. Body-size patterns the fossil record are often examined by utilizing data alone, which hinders our ability to describe biological meaning behind change on macroevolutionary timescales. Without reflecting geologic factors that drive change, we cannot assess its mechanistic underpinnings. Existing frameworks for studying ontogeny phylogeny can remedy this problem, particularly classic age–size–“shape” space originally developed studies heterochrony. When evaluated based metrics age, size, phenotype populations, proposed mechanisms be outlined theoretically tested empirically record. Using framework, compare ontogenetic trajectories within between species determine how changes emerge. Here, outline evolutionary such as heterochrony, well apparent, non-biological (e.g., taphonomic sorting). To demonstrate utility framework actual paleobiological problems, apply it Lilliput effect, compelling widely documented pattern decrease during extinction events. However, little is known about underlying pattern. We provide brief effect refine definition mechanistically tested. Processes likely produce effects include allometric sequence repatterning (including heterochrony) size-selective sorting. these highlight relevant examples feasible empirical tests possible.

Language: Английский

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