When the lung invades: a review of avian postcranial skeletal pneumaticity

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 380(1920)

Published: Feb. 27, 2025

Birds are unique among extant tetrapods in exhibiting air-filled cavities that arise from the respiratory system and invade postcranial bones, a phenomenon called skeletal pneumaticity (PSP). These intraosseous originate diverticula of ventilatory air sacs or directly gas-exchanging lung. Despite long history study, many basic characteristics this remain poorly understood. In hybrid review, we synthesize insights anatomical, developmental, biomechanical paleontological literature to review functional evolutionary significance PSP. Leveraging new data, confirm skeletons pneumatic birds not less heavy for their mass than those apneumatic birds. Pneumatic may nonetheless be lightweight with respect body volume, but is hypothesis remains empirically tested. We also use micro-computed tomography scanning deep learning-based segmentation produce pilot model pneumatized spaces neck Mallard ( Anas platyrhynchos ). This approach facilitates accurate modelling bone architecture quantitative comparative analysis within between taxa. Future work on PSP should focus cellular mechanisms developmental processes govern onset extent pneumatization, which essentially unknown. article part theme issue ‘The biology avian system’.

Language: Английский

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The influence of soft tissue volume on estimates of skeletal pneumaticity: implications for fossil archosaurs

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 380(1920)

Published: Feb. 27, 2025

Air space proportion (ASP), the volume fraction in bone that is occupied by air, frequently applied as a measure for quantifying extent of skeletal pneumaticity extant and fossil archosaurs. Nonetheless, ASP estimates rely on key assumption: soft tissue mass within pneumatic bones negligible, an assumption has rarely been explicitly acknowledged or tested. Here, we provide first comparisons between estimated air (where internal cavity assumed to be completely air-filled) true (ASPt, where tissues present cavities fresh specimens are considered). Using birds model archosaurs exhibiting postcranial pneumaticity, find ASPt significantly lower than ASP, raising important consideration should investigations evolution bulk density extinct archosaurs, well volume-based archosaur body mass. We advocate difference studies seeking quantify avoid risk systematically overestimating composed air. This article part theme issue ‘The biology avian respiratory system’.

Language: Английский

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New sauropod teeth from the Upper Jurassic of Portugal and their implications for sauropod dental evolution

Papers in Palaeontology, Journal Year: 2025, Volume and Issue: 11(1)

Published: Jan. 1, 2025

Abstract The Upper Jurassic of Portugal is well known for its dinosaurian fauna, which includes five sauropod species. Although only one these species preserves associated dental material, isolated teeth are commonly found in the units Portugal. morphological diversity Portuguese has already been described and attributed to four morphotypes. Here, we report an additional 24 heart‐shaped teeth, 9 spatulate 16 compressed chisel‐shaped 10 pencil‐shaped hitherto unstudied collection Museu da Lourinhã. All morphotypes clades from fossil record, based on morphology tooth slenderness. statistical tests show a clear relation between widely used Slenderness Index (SI) taxonomy, proves be necessary correctly interpret any usage SI as taxonomic tool. As such, when it comes attribute Turiasauria, Camarasauridae, Titanosauriformes indet., Flagellicaudata. A reassessment evolution shows general trend increasing slenderness all studied groups, disappearance broad‐crowned taxa with developed tooth‐to‐tooth occlusion by end Early Cretaceous. We suggest that this may correlated batteries ornithischians, were more efficient oral food processing.

Language: Английский

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Novel report of an osteogenic tumor in a late Jurassic Mamenchisaurid from Thailand

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

Published: April 24, 2025

Abstract Here we report on an osseous abnormality and multiple fractures in ulna of a subadult basal Eusauropod (Mamenchisauridae) from the Late Jurassic Phu Kradueng Formation Thailand. The anatomical deformities were studied using multi‐method approach that included assessment its gross morphology, computed tomography (CT), osteohistology to aid diagnosis. intracortical lesion bone is irregularly shaped, has well‐defined margins with scattered irregular bony trabeculae especially center, it surrounded by sclerotic spiculated periosteal reactive tissue. analysis radiology histopathological characteristics indicates osteogenic tumor, although are unable confidently commit more specific CT scan data indicated evident occurred postmortem unrelated pathology. This first tumor Eusauropoda.

Language: Английский

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Early‐diverging Titanosauriform (Dinosauria, Sauropoda) Teeth from the Lower Cretaceous Yixian Formation of Southeastern Inner Mongolia, Northeast China

Acta Geologica Sinica - English Edition, Journal Year: 2024, Volume and Issue: 98(2), P. 303 - 310

Published: April 1, 2024

Abstract Three eusauropod teeth (SDUST‐V1064, PMOL‐AD00176, PMOL‐ADt0005) are reported from the Lower Cretaceous Yixian Formation of Ningcheng, southeastern Inner Mongolia, China. Two them PMOL‐AD00176) assigned to early‐diverging titanosauriforms in having slightly mesiodistal expansion at base tooth crown, a slenderness index value >2.0 and <4.0, D‐shaped cross section. Furthermore, SDUST‐V1064 PMOL‐AD00176 referred as an Euhelopus ‐like titanosauriform on basis sub‐circular boss lingual surface asymmetrical crown‐root margin which slants apically, respectively. CT scan data reveals new dental information titanosauriforms, for example, enamel labial side thicker than that side, enamel/dentine ratio 0.26 present dentine crown.

Language: Английский

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Dinosaur teeth from the Lower Cretaceous Jiufotang Formation of western Liaoning, China

PeerJ, Journal Year: 2025, Volume and Issue: 13, P. e19013 - e19013

Published: Feb. 20, 2025

Here, two dinosaur teeth are discovered from the Lower Cretaceous Jiufotang Formation in Longcheng, Chaoyang, western Liaoning, China. This discovery marks a new fossil site for Jehol Biota, characterized by three-dimensionally preserved fossils. Based on comprehensive morphological comparisons, can be assigned to Theropoda and early-diverging Titanosauriformes. The theropod tooth, with length of 47.8 mm, represents distinct taxon separate Sinotyrannus, which is only known large Formation. titanosauriform tooth youngest sauropod record within Biota. These findings contribute an increased diversity ten taxa 12.

Language: Английский

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The influence of soft tissue volume on estimates of skeletal pneumaticity: implications for fossil archosaurs

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 11, 2024

Abstract Air space proportion (ASP), the volume fraction in bone occupied by air, is frequently applied as a measure for quantifying extent of skeletal pneumaticity extant and fossil archosaurs. Nonetheless, ASP estimates rely on key assumption: that soft tissue mass within pneumatic bones negligible, an assumption has rarely been explicitly acknowledged or tested. Here, we provide first comparisons between estimated air (where internal cavity assumed to be completely air-filled) true (ASPt, where tissues present cavities fresh specimens are considered). Using birds model archosaurs exhibiting postcranial pneumaticity, find ASPt significantly lower than ASP, raising important consideration should investigations evolution bulk density extinct archosaurs, well volume-based archosaur body mass. We advocate difference studies seeking quantify avoid risk systematically overestimating composed air.

Language: Английский

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Patterns and function of pneumaticity in the vertebrae, ribs, and ilium of a titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of TexasCitation for this article: Fronimos, J. A. (2023) Patterns and function of pneumaticity in the vertebrae, ribs, and ilium of a titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Texas. Journal of Vertebrate Paleontology . https://doi.org/10.1080/02724634.2023.2259444

Journal of Vertebrate Paleontology, Journal Year: 2023, Volume and Issue: 43(2)

Published: March 4, 2023

ABSTRACTMany sauropod dinosaurs exhibit extensive postcranial skeletal pneumaticity that may have facilitated the evolution of extreme body sizes. Among titanosauriforms, complex, irregularly branching camellate chambers are found throughout presacral vertebral column, often invading ribs and ilium as well. To explore function these camellae, including reduction in bone volume, was examined a titanosaur from Upper Cretaceous Black Peaks Formation Big Bend National Park, Texas, includes pneumatic dorsal ilia. Using natural breaks to non-destructively observe internal structure, patterns described for vertebrae, ribs, ilium. The space occupied by camellae is quantified airspace proportion, which reported here first time. Airspace proportions exceed 70% parts vertebrae ilium, with lower values near cotyles centra acetabulum. Values decrease distally. These not appreciably different those sauropods simpler camerate pneumaticity. If did offer greater weight than camerae, they enhanced structural strength, appear align stress Apneumatic trabecular around acetabulum, preacetabular process, postzygapophyses, however, indicate stresses too great bear, although an ontogenetic influence cannot be ruled out. ACKNOWLEDGMENTSI thank T. M. Lehman opportunity work on specimen guiding initial direction project. Collection material assisted A. Brink, J. Browning, D. Evans, Schubert, S. Wick. C. Schulte prepared here. cross sections were digitized analyzed Cutler, Grosjean, Leaphart, Mayes. I am grateful Brown, Sagebiel, Rowe access specimens now reposited at Texas Memorial Museum, University Austin. also acknowledge park service staff Park their continued stewardship fossil resources made this possible. Editors Schwarz, D'Emic reviewers provided thoughtful guidance improved manuscript.DISCLOSURE STATEMENTNo potential conflict interest author(s).AUTHOR CONTRIBUTIONSJAF designed executed data collection, results, wrote edited manuscript.SUPPLEMENTARY FILESSupplementary File 1: section image files used analysis (Figs. S1–19) table taxa ASP measurements available (Table S1).

Language: Английский

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Revealing the use of dental indices to infer taxonomic variation in sauropod dinosaurs

Palaeontology, Journal Year: 2024, Volume and Issue: 67(5)

Published: Sept. 1, 2024

Abstract Sauropod teeth are commonly categorized taxonomically by two well‐established measurement indices: slenderness index (SI; apicobasal height/mesiodistal width), which quantifies breadth, and compression (CI; labiolingual width/mesiodistal cross‐sectional circularity. Although both indices used to infer high‐level taxonomic affinities, little is known about the linear relationships between constituent measurements or how vary intra‐cranially at lower levels. Here, we evaluate these using a novel dataset of sauropod (N = 898) spanning all major groups. Results for indicate significant differential scaling within Sauropodomorpha, in slope elevation. Broad‐crowned sauropods mostly display positive allometry SI compared isometry narrow‐crowned sauropods. However, this distinction less clear with CI as most isometry, whilst non‐sauropod sauropodomorphs (e.g. Plateosauridae) allometry. An anova reveals varies significantly genus tooth position. Specifically, jaw type (maxilla dentary) Plateosauridae, position titanosaurs. Overall, variation restricted genus. Our findings reveal that have utility, there caveats. The calculate exhibit allometry, indicating values size‐dependent. Furthermore, may not accurately reflect size heterodont conditions present among early‐branching sauropodomorphs. study highlights importance quantifying data, can be inform hypotheses regarding physiological palaeoecological drivers influencing shape evolution.

Language: Английский

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Cranial anatomy of Bagualia alba (Dinosauria, Eusauropoda) from the Early Jurassic of Patagonia and the implications for sauropod cranial evolution

Journal of Systematic Palaeontology, Journal Year: 2024, Volume and Issue: 22(1)

Published: Oct. 14, 2024

Sauropods are the largest terrestrial vertebrates ever known. During their evolution, they underwent numerous morphological changes, some of which occurred at end Early Jurassic. However, current knowledge Jurassic dinosaurs is scarce, especially cranial information. Here we describe skull basal eusauropod Bagualia alba from Cañadón Asfalto Formation (Toarcian; Jurassic) Patagonia, Argentina, represents most complete late worldwide. The osteological description and phylogenetic relationships allowed us to determine acquisition common bauplan eusauropods Jurassic: a tall robust rostrum with great retraction external nares; deep narial fossa; reduced antorbital fenestra; verticalization lacrimal; prefrontal without an anterior process; anteroposterior shortening frontal; supratemporal fenestra visible laterally; braincase; 'U'-shaped jaws in dorsal view; reduction number teeth dentary; crown occlusion; development lateral plates premaxilla maxilla; dorsoventral expansion dentary symphysis. These characteristics were recently suggested be related change diet sauropods toward mainly hard vegetation. In this context, contributes filling gap evolution between gracile skulls Sauropodiformes highly widely represented Middle taxa.

Language: Английский

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