Heterochrony and Oophagy Underlie the Evolution of Giant Filter‐Feeding Lamniform Sharks DOI Creative Commons
Joel H. Gayford, Duncan J. Irschick, Andrew Chin

et al.

Evolution & Development, Journal Year: 2024, Volume and Issue: 27(1)

Published: Nov. 30, 2024

ABSTRACT Evolutionary transitions toward gigantic body sizes have profound consequences for the structure and dynamics of ecological networks. Among elasmobranchs (sharks rays), gigantism has evolved on several occasions, most notably in iconic Megalodon ( Otodus megalodon †) extant whale shark Rhincodon typus ), basking Cetorhinus maximus megamouth Megachasma pelagios all which reach total lengths exceeding 6 m and, some cases, 21 or more. Comparative phylogenetic studies suggest that filter feeding heterothermy provide two alternative evolutionary pathways leading to sharks. These selection‐based explanations are important; however, our understanding size is fundamentally constrained without a proximate, mechanistic how suite adaptations necessary facilitate evolved. Here we propose heterochrony hypothesis evolution giant filter‐feeding ecomorphotype. We craniofacial oophagy embryonic stages lamniform sharks retained through ontogeny C. M. by paedomorphosis, resulting an enlarged head mouth relative rest body, even adulthood. This change developmental timing enables these taxa optimize prey acquisition, thought be limiting factor marine vertebrates. discuss concordance this with current developmental, morphological, data, future means could tested.

Language: Английский

Drivers of diversification in sharks and rays (Chondrichthyes: Elasmobranchii) DOI Creative Commons
Joel H. Gayford, Patrick L. Jambura

Frontiers in Ecology and Evolution, Journal Year: 2025, Volume and Issue: 12

Published: Jan. 10, 2025

Elasmobranchs (sharks and rays) are a charismatic lineage of unquestionable ecological importance in past present marine ecosystems. Represented by over 1200 species, elasmobranchs have undergone substantial shifts taxonomic diversity since their origin. Quantifying these diversification trends underlying causes improves our understanding macroevolutionary processes the factors influencing community composition through deep time. Studies addressing drivers Elasmobranchii yielded conflicting results; some report clear relationships between specific traits events, whilst others fail to find support for such relationships. There is also evidence suggest that biotic interactions or environmental (global climatic change tectonic events) shaped elasmobranch dynamics. In this review, we summarise dynamics evolutionary history, before considering three principal hypothesised clade: trait evolution, interactions, change. Finally, discuss major limitations field, how discordant methodologies data sources hamper current Elasmobranchii. Whilst future studies will undoubtedly be required further unravel complex relationship, no single factor can considered sole satisfactory explanation observed time exclusion other.

Language: Английский

Citations

1
Bioluminescence and repeated deep-sea colonization shaped the diversification and body size evolution of squaliform sharks DOI
A. Marion, Fabien L. Condamine, Guillaume Guinot

et al.

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2042)

Published: March 1, 2025

Understanding the underlying mechanisms that have generated striking biodiversity inhabiting deep-sea ecosystems remains a challenge in evolutionary biology. Here, we addressed this topic by studying macroevolutionary dynamics shaped diversification of squaliform sharks, an iconic clade vertebrates. Using phylogenetic comparative methods and fossil-based Bayesian estimates, both at species level, combined fossil record data with molecular phylogenies to provide quantitative framework for understanding history Squaliformes. We reveal early lineages originated shallow water during Early Cretaceous experienced multiple independent shifts toward deep sea Late Cretaceous. Importantly, show these were likely facilitated acquisition bioluminescence, which significantly impacted body size evolution among lineages. Furthermore, colonization events coincide periods climate warming marine transgression Cenomanian-Turonian Palaeocene-Eocene transitions. Following colonizations, diversified over last 30 Myr, resulting one richest radiations sharks. These results demonstrate how complex interplay between key innovation new habitats drove major ecological transition, highlighting importance integrative when deep-time dynamics.

Language: Английский

Citations

1
The ancestor of sharks and rays laid eggs, but ancestral state reconstructions need empirically supported traits and transparent reporting: a comment on Katona et al. (2023) DOI
Daniel F. Hughes, Daniel G. Blackburn

Journal of Evolutionary Biology, Journal Year: 2025, Volume and Issue: unknown

Published: March 29, 2025

Language: Английский

Citations

0
Three-dimensional fossils of a Cretaceous collared carpet shark (Parascylliidae, Orectolobiformes) shed light on skeletal evolution in galeomorphs DOI Creative Commons
Richard P. Dearden, Zerina Johanson, Helen L. O’Neill

et al.

Royal Society Open Science, Journal Year: 2025, Volume and Issue: 12(4)

Published: April 1, 2025

A rich fossil record of teeth shows that many living shark families' origins lie deep in the Mesozoic. Skeletal fossils sharks to whom these belonged are far rarer and when they preserved often flattened, hindering understanding evolutionary radiation groups. Here we use computed tomography describe two articulated Upper Cretaceous skeletons from Chalk UK preserving three-dimensional neurocrania, visceral cartilages, pectoral vertebrae. These display skeletal anatomies characteristic Parascylliidae, a family Orectolobiformes now endemic Australia Indo Pacific. However, differ having more heavily mineralized braincase tri-basal fin endoskeleton, while their can be attributed new species problematic taxon Pararhincodon. Phylogenetic analysis confirms Pararhincodon is stem-group parascylliid, providing insight into evolution parascylliids' distinctive anatomy during late Mesozoic-Cenozoic shift orectolobiform biodiversity Northern Atlantic Meanwhile both extant parascylliids have vertebral morphology previously described only Carcharhiniformes, contributing perspective picture emerging macroevolutionary analyses coastal, small-bodied for galeomorphs.

Language: Английский

Citations

0
Heterochrony and Oophagy Underlie the Evolution of Giant Filter‐Feeding Lamniform Sharks DOI Creative Commons
Joel H. Gayford, Duncan J. Irschick, Andrew Chin

et al.

Evolution & Development, Journal Year: 2024, Volume and Issue: 27(1)

Published: Nov. 30, 2024

ABSTRACT Evolutionary transitions toward gigantic body sizes have profound consequences for the structure and dynamics of ecological networks. Among elasmobranchs (sharks rays), gigantism has evolved on several occasions, most notably in iconic Megalodon ( Otodus megalodon †) extant whale shark Rhincodon typus ), basking Cetorhinus maximus megamouth Megachasma pelagios all which reach total lengths exceeding 6 m and, some cases, 21 or more. Comparative phylogenetic studies suggest that filter feeding heterothermy provide two alternative evolutionary pathways leading to sharks. These selection‐based explanations are important; however, our understanding size is fundamentally constrained without a proximate, mechanistic how suite adaptations necessary facilitate evolved. Here we propose heterochrony hypothesis evolution giant filter‐feeding ecomorphotype. We craniofacial oophagy embryonic stages lamniform sharks retained through ontogeny C. M. by paedomorphosis, resulting an enlarged head mouth relative rest body, even adulthood. This change developmental timing enables these taxa optimize prey acquisition, thought be limiting factor marine vertebrates. discuss concordance this with current developmental, morphological, data, future means could tested.

Language: Английский

Citations

1