Raptorial appendages of the Cambrian apex predatorAnomalocaris canadensisare built for soft prey and speed

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2023, Номер 290(2002)

Опубликована: Июль 5, 2023

The stem-group euarthropod

Язык: Английский

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Pedipalp anatomy of the Australian black rock scorpion, Urodacus manicatus, with implications for functional morphology

Australian Journal of Zoology, Год журнала: 2024, Номер 72(2)

Опубликована: Май 13, 2024

Pedipalps – chelate ‘pincers’ as the second pair of prosomal appendages are a striking feature scorpions and employed in varied biological functions. Despite distinctive morphology ecological importance these appendages, their anatomy remains underexplored. To rectify this, we examined pedipalps Australian black rock scorpion, Urodacus manicatus, using multifaceted approach consisting microcomputed tomography, scanning electron microscopy, energy dispersive X-ray spectroscopy, live pinch force measurements. In doing so, document following aspects pedipalps: (1) musculature three dimensions; (2) cuticular microstructure, focusing on chelae (tibial tarsal podomeres); (3) elemental construction teeth; (4) force. We recognise 25 muscle groups U. manicatus pedipalps, substantially more than previously documented scorpions. The microstructure endo-, meso-, exocuticle is shown to be similar other that mesocuticle reinforces for predation burrowing. Elemental mapping teeth highlights enrichment calcium, chlorine, nickel, phosphorus, potassium, sodium, vanadium, zinc, with marked lack carbon. These elements reinforce teeth, increasing robustness better enable prey capture incapacitation. Finally, data demonstrate can exert high forces (4.1 N), further highlighting application subduing prey, opposed holding envenomation. has an array adaptions functioning sit-and-wait predator primarily uses highly reinforced process prey.

Язык: Английский

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Convergent evolution of giant size in eurypterids

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2024, Номер 291(2027)

Опубликована: Июль 31, 2024

Eurypterids-Palaeozoic marine and freshwater arthropods commonly known as sea scorpions-repeatedly evolved to remarkable sizes (over 0.5 m in length) colonized continental aquatic habitats multiple times. We compiled data on the majority of eurypterid species explored several previously proposed explanations for evolution giant size group, including potential role habitat, surface temperature dissolved oxygen levels, using a phylogenetic comparative approach with new tip-dated tree. There is no compelling evidence that was driven by or nor it coupled invasion environments, latitude local faunal diversity. Eurypterid body best characterized rapid bursts change occurred independently habitat environmental conditions. Intrinsic factors played major determining convergent origin gigantism eurypterids.

Язык: Английский

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Functional Divergence of Scorpion Pedipalps: Musculoskeletal Specialization Toward Opposing Performance Optima

Journal of Morphology, Год журнала: 2025, Номер 286(5)

Опубликована: Май 1, 2025

ABSTRACT When selective pressures for different functions act simultaneously on a structure, morphological diversification can be shaped by adaptation toward distinct functional optima. Systems may evolve along performance gradient, optimizing aspects of function in response to ecological demands. We investigated two scorpion species representing the extremes chela (pincer) shape. Scorpion chelae exhibit remarkable diversity associated with roles, and their varies force‐velocity continuum. To explore how structural muscular adaptations shape performance, we developed biomechanical model integrating synchrotron microtomography, muscle architecture, data. Our findings reveal that these arrangements, each optimized outcome. The short‐fingered maximize closing force through increased mechanical advantage longer sarcomeres, enhancing contraction efficiency. In contrast, slender‐chela optimizes velocity orientations favor rapid acceleration. While additional demands likely influence designs, one morphology appears specialized quickly capturing prey, while other seems adapted prey crushing. These divergent optima have played key role shaping trophic ecology scorpions influencing evolution venom.

Язык: Английский

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An Atlas of Malformed Trilobites from North American Repositories Part 3: The Field Museum of Natural History

American Museum Novitates, Год журнала: 2025, Номер 2025(4035)

Опубликована: Май 29, 2025

Язык: Английский

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Ex Vivo Three-Dimensional Reconstruction of Acutiramus: A Giant Pterygotid Sea Scorpion

American Museum Novitates, Год журнала: 2023, Номер 2023(4004)

Опубликована: Ноя. 17, 2023

Pterygotid eurypterids include some of the largest aquatic arthropods in fossil record and are known from middle Silurian to Middle Devonian deposits across globe. These forms primarily preserve as mostly two-dimensional impressions, a situation that has impacted accurate reconstruction pterygotid ventral structures organization. By documenting specimens displaying important dorsal both Acutiramus—a larger, well-documented genus—and other pterygotids, we reconstruct Acutiramus three-dimensions (3D) more thoroughly understand functional morphology limb arrangement these large eurypterids. With this comprehensive 3D reconstruction, demonstrate much anterior insertion appendages II–V, near-horizontal orientation II–VI coxae, presence reduced appendage II, labrum epistomel region. The sections identified locality for cheliceral articulation. This model also uncovers streamlined nature low-profile Acutiramus. We use our explore morphofunctionality eurypterids, including their feeding strategies, addressing conundrum inherent previous reconstructions.

Язык: Английский

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Novel pterygotid sea scorpions from the Silurian and Devonian of Gondwana

Gondwana Research, Год журнала: 2024, Номер 135, С. 282 - 292

Опубликована: Авг. 17, 2024

Язык: Английский

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Novel coprolitic records from the Silurian (Přídolí) Wallace Shale of New South Wales

Alcheringa An Australasian Journal of Palaeontology, Год журнала: 2023, Номер 47(1), С. 24 - 30

Опубликована: Янв. 2, 2023

Evidence of successful predation or scavenging in the fossil record represents important palaeobiological data to more thoroughly understanding extinct ecosystems. Shelly coprolites are particularly useful indications durophagous deposits, as they can have a higher preservational potential than their producers. Here we present new shelly coprolite from Silurian (Přídolí) Wallace Shale New South Wales, Australia. This specimen contains abundant fragments trilobite Denckmannites rutherfordi Sherwin, 1968 that show limited disarticulation across exoskeletal sections. We propose pterygotid eurypterid was most likely producer this coprolite, although trilobites and fishes not completely excluded possible trace-makers. In documenting specimen, highlight preserves complex palaeoecosystem previously thought renewed efforts understand deposit needed light insight.R.D.C. Bicknell [[email protected]], Palaeoscience Research Centre, School Environmental Rural Science, University England, Armidale, 2351, Australia;P.M. Smith [[email protected]], Palaeontology Department, Australian Museum Institute, Sydney, 2010, Australia; Department Biological Sciences, Macquarie University, 2109, Australia;J. Kimmig [[email protected]], Abteilung Geowissenschaften, Staatliches für Naturkunde Karlsruhe, 76133, Germany.

Язык: Английский

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Shelly coprolites record durophagous predation in the Late Ordovician Bohdalec Formation (Katian; Prague Basin, Czech Republic)

Geobios, Год журнала: 2023, Номер 82, С. 1 - 11

Опубликована: Ноя. 10, 2023

Язык: Английский

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The earliest pterygotid record (Arthropoda, Chelicerata) from the Lower Silurian Majiaochong Formation of South China

Historical Biology, Год журнала: 2024, Номер unknown, С. 1 - 5

Опубликована: Май 26, 2024

In this paper, we describe new materials of pterygotid eurypterid Erettopterus sp. excavated from the lower Silurian (Llandovery) Majiaochong Formation Guizhou Province, China. Those represent one earliest records genus Erettopterus, thereby indicating their long-lived history within South Chinese region, and might have accomplished global distribution earlier than previous estimated.

Язык: Английский

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