Functionally mediated cranial allometry evidenced in a genus of rock-wallabies

Biology Letters, Год журнала: 2024, Номер 20(3)

Опубликована: Март 1, 2024

In assessments of skeletal variation, allometry (disproportionate change shape with size) is often corrected to examine size-independent variation for hypotheses relating function. However, size-related trade-offs in functional demands may themselves be an underestimated driver mammalian cranial diversity. Here, we use geometric morphometrics alongside dental measurements assess craniodental the rock-wallaby genus Petrogale (all 17 species, 370 individuals). We identified aspects evolutionary that can both extensions of, and correlated negatively with, static or ontogenetic allometric patterns. Regarding constraints, larger species tended have relatively smaller braincases more posterior orbits, former which might represent a constraint on jaw muscle anatomy. they also anterior dentition zygomatic arches, support hypothesis relaxed bite force accommodation different selective pressures favour facial elongation. By contrast, two dwarf had stouter crania divergent adaptations together suggest increased relative capacity. This likely allows them feed forage mechanically similar consumed by relatives. Our results highlight need nuanced considerations patterns future research

Язык: Английский

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Comparative and functional anatomy of masticatory muscles and bite force in opossums (Didelphimorphia, Didelphidae)

The Anatomical Record, Год журнала: 2025, Номер unknown

Опубликована: Апрель 25, 2025

Abstract Opossums (Didelphidae) are American marsupials traditionally known for their generalized morphology and generalist feeding habits. They include a diversity of similar items in diets, but the proportion types consumed varies between taxa. Thus, ecology shows varying degrees omnivory or food preference that cannot be distinguished into strict dietary categories. With few exceptions, anatomical functional relationship masticatory muscles variation resources used opossums is unknown. Here we provide comparative descriptions jaw adductor muscle anatomy architecture nine Didelphidae genera. The were dissected, weighed, chemically digested separation measurement fascicles. We estimated potential physiological cross‐sectional area (pPCSA) 2D lever arm mechanics to calculate bite force on canine first molar. tested allometric relationships variables forces correlation with diet mechanical challenge (relative frequency hard items). represented by m. temporalis masseter , two layers (superficial deep) each, pterygoideus medialis across sample. zygomaticomandibularis was also identified most genera, except Didelphis Lutreolina . Muscle conserved extent attachment areas, part due differences skull morphology. diversification corresponded pattern which proved efficient adding different diet. mass, average fascicle length, pPCSA scaled isometrically size. Bite molar not correlated challenge. Therefore, quantitative myological data consistent size, increase supports associated increased size opossums.

Язык: Английский

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Copy-cat evolution: Divergence and convergence within and between cat and dog breeds

Proceedings of the National Academy of Sciences, Год журнала: 2025, Номер 122(18)

Опубликована: Апрель 28, 2025

Many domesticated species exhibit remarkable phenotypic diversity. In nature, selection produces not only divergence but also convergence when organisms experience similar selective pressures. Whether artificial during domestication has received little attention. Three-dimensional shape analysis of domestic cat and dog skulls demonstrated at multiple levels. Most broadly, cats dogs have both diversified greatly: equaling or exceeding the morphological disparity among all modern-day their respective families. Moreover, as a result selection, some breeds these two phenotypically distinct species, evolutionarily separated for 50 My, converged to such an extreme extent that they are more each other than many members own ancestors, phenomenon never previously observed in species. Remarkably, this evolved between times within taxon.

Язык: Английский

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Who was the real sabertooth predator: Thylacosmilus or Thylacoleo?

The Anatomical Record, Год журнала: 2024, Номер unknown

Опубликована: Апрель 10, 2024

Abstract Sabertoothed mammalian predators, all now extinct, were almost exclusively feloid carnivorans (Eutheria, Placentalia): here a couple of extinct metatherian predators are considered in comparison with the placental sabertooths. Thylacosmilus (the “marsupial sabertooth”) and Thylacoleo lion”) both relatively large (puma‐sized) carnivores Plio‐Pleistocene Southern Hemisphere (Argentina Australia, respectively). Both have captured public imagination, especially as that somehow analogous to northern forms. But more detailed consideration their morphology shows neither can be simply analogized its supposed counterpart. While did indeed saber‐like canines, many aspects anatomy show it could not killed prey manner proposed for sabertoothed felids such Smilodon . Rather than being an active predator, may been specialized scavenger, using hypertrophied canines open carcasses, perhaps deployed tongue extract innards. lacked supposedly “caniniform” incisors acted like felid's canines. Nevertheless, while mode dispatching remains subject debate, was clearly powerful likely capable bringing down bigger itself hunting alone. In regard, filled ecomorphological role sabertooths, so despite lack nominated true sabertooth” out two taxa.

Язык: Английский

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Prenatal growth patterns of the upper jaw complex with implications for laryngeal echolocation in bats

Journal of Anatomy, Год журнала: 2024, Номер unknown

Опубликована: Окт. 28, 2024

Abstract Craniofacial morphology is extremely diversified within bat phylogeny, however growth and development of the palate in bats remains unstudied. The formation both midline bilateral orofacial clefts laryngeally echolocating bats, morphologically similar to syndromic non‐syndromic cleft humans, are not well understood. Developmental series prenatal samples ( n = 128) adults 10) eight species (two pteropodids, four rhinolophoids, two yangochiropterans), non‐bat mammals Mus musculus Erinaceus amurensis ), were CT‐scanned cranial bones forming upper jaw complex three‐dimensionally visualised assess whether differences can be observed across phylogeny. Volumetric data composing measured quantify growth. premaxilla relatively reduced compared other its shape heterogeneous depending on presence type palatine process premaxillary lacking pteropodids yangochiropterans, whereas a mobile structure which only contact caudally with maxilla by fibrous membrane or suture rhinolophoids. In all maxillary progressively extend bones, some cases split into three branches, so that they completely fused another one medially prior birth. Ossification vomer fusion occur earlier rhinolophoids than yangochiropterans. ossifies bilaterally from different ossification centres uncommon mammals. Analysis ontogenetic allometric trajectories revealed faster maxillary, vomer, yangochiropterans especially Ancestral state reconstruction have higher magnitude change rate E. lower M. bats. This study provides new evidence heterochronic shifts craniofacial phylogeny improve understanding developmental characterising nasal oral emission strategies.

Язык: Английский

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Complexity and weak integration promote the diversity of reef fish oral jaws

Communications Biology, Год журнала: 2024, Номер 7(1)

Опубликована: Ноя. 4, 2024

Abstract Major trade-offs often manifest as axes of diversity in organismal functional systems. Overarching may result high trait integration and restrict the trajectory diversification to be along a single axis. Here, we explore feeding mechanism coral reef fishes establish role complexity spectacular ecological radiation. We show that primary axis variation measured musculo-skeletal traits is aligned with trade-off between mobility force transmission, spanning species capture prey suction those bite attached prey. found weak or no covariation about half traits, reflecting deviations from The dramatic trophic range among occurs axis, numerous departures use mosaic combinations adapt diverse challenges. suggest morphological evolution both independent major widespread complex systems where global shapes patterns diversity. Significant additional emerges assemble units many meet varying demands.

Язык: Английский

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Skull evolution and lineage diversification in endemic Malagasy carnivorans

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Март 29, 2024

Abstract Madagascar is one of the world’s foremost biodiversity hotspots with more than 90% its species endemic to island. Malagasy carnivorans are only four extant terrestrial mammalian clades Madagascar. Although there eight species, these exhibit remarkable phenotypic and ecological diversity that often hypothesized have diversified through an adaptive radiation. Here, we investigated evolution skull in tested if they exhibited characteristics convergence We found their disparity exceeds any other feliform family, as skulls vary widely strikingly capture a large amount morphological variation across all feliforms. also evidence shared zones cranial shape between euplerid subclades felids, herpestids, viverrids. Lastly, contrary predictions radiation, do not rapid lineage diversification marginally faster rates mandibular evolution, lesser extent compared These results reveal exceptional necessary generate striking evolved after dispersal isolation on

Язык: Английский

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Sizing Up Skull Allometry

Опубликована: Март 21, 2024

In this seminar, I discuss how the overall size of an animal influences function its skull, and role can play in diversity skull shapes seen mammals. outline recent developments our understanding allometry (size-related changes) function, emphasise that is underestimated driver functional adaptation. Because variation often extracted from shape data to examine adaptive patterns, some size-correlated relating might frequently be missed. latest publication with *Biology Letters*, we analysed skulls teeth 370 Australian rock-wallabies (Macropodidae: *Petrogale*), representing all 17 species. We show across species correlated positively, or negatively, within at different parts these regions related biomechanics feeding. suggest allometric patterns receive more scrutiny regarding their function.

Язык: Английский

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Beyond CREA: Evolutionary patterns of non‐allometric shape variation and divergence in a highly allometric clade of murine rodents

Ecology and Evolution, Год журнала: 2024, Номер 14(7)

Опубликована: Июнь 28, 2024

Abstract The shared functions of the skull are thought to result in common evolutionary patterns mammalian cranial shape. Craniofacial allometry (CREA) is a particularly prominent pattern where larger species display proportionally elongate facial skeletons and smaller braincases. It was recently proposed that CREA arises from biomechanical effects scaling when diets similar. Thus, deviations should occur with changes biomechanics, for example due dietary change. Here, we test this using 3D geometric morphometric analysis dataset Australian murine crania, which highly allometric. We contrast allometric non‐allometric variation cranium by comparing mode, allometry, ordinations, as well integration, modularity functional modules. found evidence stabilising selection allometry‐containing size‐free shape, substantial aligned specialisation parallel CREA. Integration among modules higher, lower, size included, but integration between rostrum vault, involved pattern, dropped dramatically after removal. Our results thus support hypothesis composite arising on function, shape occurring alongside impacts gnawing function. This emphasises need research evolution context

Язык: Английский

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Postnatal Skull Development Reveals a Conservative Pattern in Living and Fossil Vizcachas Genus Lagostomus (Rodentia, Chinchillidae)

Journal of Morphology, Год журнала: 2024, Номер 285(9)

Опубликована: Сен. 1, 2024

ABSTRACT The plains vizcacha, Lagostomus maximus , is the only living species in genus, being notably larger than fossil congeneric species, such as incisus from Pliocene of Argentina and Uruguay. Here, we compare skull growth allometric pattern sexual dimorphism L. relating shape size changes with function. We also test whether ontogenetic trajectories trends between both sexes follow same pattern. A common was elongation skull, a product lengthening rostrum, chondrogenesis on spheno‐occipitalis synchondrosis coronalis suture. detected low proportion suture fusion. In some variables, older male specimens did not represent simple linear extension female trajectory, all dimorphic traits were related to development masticatory muscles. Sexual previously attributed would indicate that this phenomenon present genus since early suggests social behaviors polygyny male‐male competition. Ontogenetic similar showing conservative condition genus. Only two different ontogeny which appeared earlier compared : frontal process nasals square shape, straight occipital bone lateral view. Juveniles close adult morphospace, suggesting peramorphic process. sequence synchondroses fusion showed minor differences temporozygomatica frontonasalis sutures, indicating major mechanical stress size. suggest generalized path Chinchillidae, but further analyses are necessary at an evolutionary level, including Lagidium Chinchilla .

Язык: Английский

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