Rise and diversification of chondrichthyans in the Paleozoic

Paleobiology, Journal Year: 2024, Volume and Issue: 50(2), P. 271 - 284

Published: March 14, 2024

Abstract The Paleozoic represents a key time interval in the origins and early diversification of chondrichthyans (cartilaginous fishes), but their diversity macroevolution are largely obscured by heterogenous spatial temporal sampling. predominantly cartilaginous skeletons pose an additional limitation on preservation potential hence quality fossil record. Here, we use newly compiled genus-level dataset application sampling standardization methods to analyze global total-chondrichthyan dynamics through from first appearance Ordovician end Permian. Subsampled estimates chondrichthyan genus richness were initially low Silurian increased substantially Early Devonian. Richness reached its maximum middle Carboniferous before dropping across Carboniferous/Permian boundary gradually decreasing throughout Sampling is higher both Devonian compared with most Permian stages. Shark-like scales too limited allow for some subsampling techniques. Our results detect two radiations diversity: earliest Devonian, led acanthodians (stem-group chondrichthyans), which then decline rapidly Late second Carboniferous, holocephalans, increase greatly Devonian/Carboniferous boundary. Dispersal chondrichthyans, specifically into deeper-water environments may reflect niche expansion following faunal displacement aftermath Hangenberg extinction event at

Language: Английский

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Molecular Dating of the Teleost Whole Genome Duplication (3R) Is Compatible With the Expectations of Delayed Rediploidization

Genome Biology and Evolution, Journal Year: 2024, Volume and Issue: 16(7)

Published: June 24, 2024

Abstract Vertebrate evolution has been punctuated by three whole genome duplication events that have implicated causally in phenotypic evolution, from the origin of novelties to explosive diversification. Arguably, most dramatic these is 3R event associated with teleost fishes which comprise more than half all living vertebrate species. However, tests a causal relationship between and diversification proven difficult due challenge establishing timing phenomena. Here we show, based on molecular clock dating concatenated gene alignments, occurred early–middle Permian (286.18 267.20 million years ago; Ma), 52.02 12.84 (Myr) before divergence crown-teleosts latest Permian–earliest Late Triassic (254.36 234.16 Ma) long major pulses Ostariophysi Percomorpha (56.37 100.17 Myr at least 139.24 183.29 later, respectively). The extent this temporal gap putative cause effect precludes as deterministic driver age constraints remain compatible expectations prolonged rediploidization process following which, through effects chromosome rearrangement loss, remains viable mechanism explain

Language: Английский

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Sampling biases obscure the early diversification of the largest living vertebrate group

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2022, Volume and Issue: 289(1985)

Published: Oct. 19, 2022

Extant ray-finned fishes (Actinopterygii) dominate marine and freshwater environments, yet spatio-temporal diversity dynamics following their origin in the Palaeozoic are poorly understood. Previous studies investigate face-value patterns of richness, with only qualitative assessment biases acting on actinopterygian fossil record. Here, we palaeogeographic trends, reconstruct local richness apply estimation techniques to a recently assembled occurrence database for fishes. We identify substantial record biases, such as geographical bias sampling centred around Europe North America. Similarly, estimates skewed by extreme unevenness distributions, reflecting historical taxonomic practices, extent that evenness has an overriding effect estimates. Other than genuine rise Tournaisian end-Devonian mass extinction, actinopterygians appear lack biological signal, heavily biased highly dependent sampling. Increased represented regions expanding beyond literature include museum collection data will be critical obtaining accurate diversity. In conjunction, applying well-sampled regional subsets ‘global’ dataset may trends.

Language: Английский

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The skeletal completeness of the Palaeozoic chondrichthyan fossil record

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(1)

Published: Jan. 1, 2024

Chondrichthyes (sharks, rays, ratfish and their extinct relatives) originated diversified in the Palaeozoic but are rarely preserved as articulated or partly remains because of predominantly cartilaginous endoskeletons. Consequently, evolutionary history is perceived to be documented by isolated teeth, scales fin spines. Here, we aim capture analyse quality chondrichthyan fossil record using a variation skeletal completeness metric, which calculates how complete skeletons individuals compared estimates original entirety. Notably, significantly lower than any published vertebrate group: low throughout Silurian Permian peaking Devonian Carboniferous. Scores increase range similar pelycosaurs parareptiles only when taxa identified solely from spines excluded. We argue that environmental influences probably played an important role completeness. Sea level negatively correlates with records resembles patterns already evident ichthyosaurs, plesiosaurs sauropodomorphs. Such observed variations highlight impact different sampling biases on need acknowledge these inferring macroevolution.

Language: Английский

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The Evolution and Biological Activity of Metazoan Mixed Lineage Kinase Domain-Like Protein (MLKL)

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(19), P. 10626 - 10626

Published: Oct. 2, 2024

In mammals, mixed lineage kinase domain-like protein (MLKL) is the executor of necroptosis. MLKL comprises an N-terminal domain (NTD), which alone suffices to trigger necroptosis by forming pores in plasma membrane, and a C-terminal that inhibits NTD activity. Evolutionarily, poorly conserved animals not found Protostomia. Although orthologs exist invertebrate Deuterostomia, biological activity unknown. Herein, we examined 34 metazoan phyla detected only Deuterostomia but also Protostomia (Rotifera). The Rotifera exhibited low identities with non-Rotifera shared relatively high non-metazoan MLKL. invertebrates, formed two phylogenetic clades, one was represented Rotifera. vertebrates, expression tissue-specific generally rich immune organs. When expressed human cells, MLKL-NTD Rotifera, Echinodermata, Urochordata, Cephalochordata induced strong necroptotic depended on number residues. Together these findings provided new insights into evolution Metazoa revealed

Language: Английский

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Fitting fangs in a finite face: A novel fang accommodation strategy in a 280‐million‐year‐old ray‐finned fish

Journal of Anatomy, Journal Year: 2022, Volume and Issue: 242(3), P. 525 - 534

Published: Nov. 26, 2022

Abstract Though Paleozoic ray‐finned fishes are considered to be morphologically conservative, we report a novel mode of fang accommodation (i.e., the fitting fangs inside jaw) in Permian actinopterygian † Brazilichthys macrognathus , whereby teeth lower jaw insert into fenestrae upper jaw. To better understand how have accommodated through geologic time, synthesize multitude ways living and extinct osteichthyans housed large mandibular dentition. While precise structure seen has not been reported any other osteichthyans, alternate strategies fenestration fit present some extant fishes—the needlejaws Acestrorhynchus gars genus Lepisosteus . Notably, out our survey, only two aforementioned neopterygians bear for fangs. We implicate kinetic jaws this trend, more easily between palatal bones. The restricted space available early osteichthyan may led proliferation accommodate recommend greater survey morphology, light these results recent reevaluations fossil ray‐fins.

Language: Английский

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