Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2021, Номер 288(1944), С. 20202938 - 20202938

Опубликована: Фев. 3, 2021

Socio-sexual selection is predicted to be an important driver of evolution, influencing speciation, extinction and adaptation. The fossil record provides a means testing these predictions, but detecting its signature from morphological data alone difficult. There are, nonetheless, some specific patterns growth variation which are expected traits under socio-sexual selection. distinctive parietal-squamosal frill ceratopsian dinosaurs has previously been suggested as display trait, evidence for this limited. Here, we perform whole-skull shape analysis unprecedentedly large sample specimens Protoceratops andrewsi using high-density landmark-based geometric morphometric approach test four predictions regarding potential signalling role the frill. Three predictions—low integration with rest skull, significantly higher rate change in size during ontogeny, variance than other skull regions—are supported. One prediction, sexual dimorphism shape, not supported, suggesting that differences P. likely small. Together, findings consistent mutual mate choice or quality more general social interactions, support hypothesis functioned signal dinosaurs.

Язык: Английский

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Spatial variation in antler investment of Apennine red deer

Ecology and Evolution, Год журнала: 2021, Номер 11(12), С. 7850 - 7864

Опубликована: Май 3, 2021

Abstract Heterogeneity in resource availability and quality can trigger spatial patterns the expression of sexually selected traits such as body mass weaponry. While relationships between habitat features phenotypic are well established at broad geographical scales, information is poor on finer, intrapopulation scales. We analyzed biometric data collected 1965 red deer Cervus elaphus males over 20 years from a nonmigratory population living two sides mountainous ridge, with substantial differences land cover but similar climate density. investigate (i) mass, (ii) antler (iii) investment. also tested for site‐ age‐specific allometric relationship mass. Statistically significant fine‐scale variations and, to lesser extent, allocation matched cover. All three were greater northern slope, characterized by higher heterogeneity open habitats, than southern slope. Moreover, differed among age‐classes, pattern that was consistent mountain slopes. Our results support occurrence individual attributes fine, scale. findings emphasize role environmental shaping key life‐history traits, potential consequences reproductive success.

Язык: Английский

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Selection on weapon allometry in the wild

Evolution, Год журнала: 2023, Номер 77(9), С. 2090 - 2099

Опубликована: Июль 3, 2023

Abstract Allometry is the scaling relationship between a trait and body size. This can often explain considerable morphological variation within among species. Nevertheless, much remains unknown about factors that underlie allometric patterns. For example, when different relationships are observed amongst closely related species, these differences regularly considered to be products of selection. However, directional selection on allometry (particularly slope) has rarely been tested in natural populations. Here, we investigate weapon size (i.e., allometry) wild population giant mesquite bugs, Pachylis neocalifornicus (previously Thasus neocalifornicus). Males this species use their weapons (enlarged femurs) compete with one another over access resources females. We found large males relatively successfully secured mates. also small could mates as well. These two patterns together increase slope sexually selected weapon, suggesting straightforward process by which evolve.

Язык: Английский

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Modularity and heterochrony in the evolution of the ceratopsian dinosaur frill

Ecology and Evolution, Год журнала: 2020, Номер 10(13), С. 6288 - 6309

Опубликована: Май 22, 2020

Abstract The fossil record provides compelling examples of heterochrony at macroevolutionary scales such as the peramorphic giant antlers Irish elk. Heterochrony has also been invoked in evolution distinctive cranial frill ceratopsian dinosaurs Triceratops . Although frills vary size, shape, and ornamentation, quantitative analyses that would allow for testing hypotheses are lacking. Here, we use geometric morphometrics to examine shape variation across diversity within four species preserving growth series. We then test whether constitutes an evolvable module both species, compare trajectories taxa with ontogenetic series identify heterochronic processes. Evolution consisted primarily progressive expansion its caudal caudolateral margins, morphospace occupation following taxonomic groups. taphonomic distortion represents a complicating factor, our data support modularity species. Peramorphosis played important role evolution, acceleration operating early neoceratopsian followed by progenesis later diverging cornosaurian ceratopsians. Peramorphic may have facilitated decoupling this structure from jaw musculature, inference predicts higher evolutionary rates among ceratopsids indeed borne out data. However, denser sampling meager early‐diverging is required further.

Язык: Английский

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Male crayfish (Faxonius obscurus, Decapoda: Cambaridae) claws are longer and stronger yet comparable in shape during the reproductive season

Biological Journal of the Linnean Society, Год журнала: 2023, Номер 139(1), С. 57 - 69

Опубликована: Март 31, 2023

Abstract Animal weapons are diverse and often exaggerated structures associated with sexual selection male–male combat. Despite their diversity, our knowledge of these comes primarily from studies that focus on the size neglect other components, such as shape or performance. Furthermore, can exhibit species-level plasticity based nutrition ecological variables, but few have documented seasonal variation in weapon plasticity. Here, we investigate how size, performance differ across adult male reproductive non-reproductive Allegheny crayfish, Faxonius obscurus. Given F. obscurus cambarid crayfishes cyclical moulting between states, they provide an ideal system which to questions. We found claws all three components investigated; males were longer, stronger different compared males. Wielding longer is likely confer greater competitive success during mating season, demonstrates unexplored pattern discuss results considering seasonality phenotypes propose several avenues future research using crayfish a model system.

Язык: Английский

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