Skull Characters Research Articles

Calvarial Thickening in Tuberous Sclerosis Complex

IntroductionTuberous sclerosis complex (TSC)-related skeletal abnormalities are under-studied. Awareness of skull thickening in TSC patient is important from the surgical standpoint because thick skull might complicate craniotomy. This study, aimed at revealing if TSC patients are generally prone to skull thickening, had led us to retrospectively investigate the frequency and characteristics of skull thickening in these patients. MethodTSC patients aged 10 to 60 years who underwent MRI were identified from the neurosurgery, dermatology or pediatrics clinic between 2010 and 2021. Two control groups were used for comparison: one with unruptured intracranial aneurysms to serve as control without anti-seizure medications (ASMs) exposure and another with non-TSC epilepsy as control with ASM exposure. Thickness of frontal, parietal, temporal, and occipital bones was measured at a fixed location of each bone across patients on T2-weighted axial images. Result29 patients fulfilled the inclusion criteria. Frontal and temporal bones of the TSC group were significantly thicker than those of either control group. Skull thickening was significantly associated with intracerebral calcification, but not with age, sex, or ASM exposure. Focal skull thickening was associated with the presence of a subcortical calcification. ConclusionsTSC patients have thickened skull that is often linked to intracerebral calcification. The presence of skull thickening may require modification of surgical approach during craniotomy. Skull thickening and the underlying intracerebral calcification likely share a common precipitating factor given their relationship. Future studies are warranted to clarify the genetic underpinnings of this relationship and even broader skeletal abnormalities in TSC.

Anatomy, digital radiography and cone-beam computed tomography of Western European hedgehog (Erinaceus europaeus) skull

BackgroundEuropean hedgehogs (Erinaceus europaeus) are small insectivorous mammals common in Europe. With increased urbanization, the species become more frequent in the cities and near other human dwellings. The anatomy of the species with the use of diagnostic imaging techniques along with the classical anatomical methodology has not been researched before. In addition to the description of this species' skull, the data may contribute to progress in hedgehog medicine, delivering a basis for diagnosing and treating head trauma in this species.ResultsCadavers of 30 European hedgehogs have been used to study the anatomy of the head of the species. Along with classical anatomical techniques – latex and corrosion cast specimens, x-ray, and cone-bean computed tomography scans were performed. The methods were then compared, and the detailed anatomy of the head was described. The skull of the Western European hedgehog was elongated and oval in shape, and could be divided into two distinct regions: one formed of neurocranial bones and the other of facial bones. The neurocranium was composed of the following bones: the occipital, interparietal, parietal, frontal, temporal, sphenoid, ethmoid, and pterygoid bones. The following facial bones were identified: the incisive, nasal, maxilla, zygomatic, palatine, vomer, and the mandible. The most important findings include the primitive tympanic bullae, the absence of a supraorbital foramen, and the lacrimal bones, which were indistinguishably fused with the maxillae.ConclusionsThe results of the study may be used in future research on the comparative anatomy of the other members of the Eulipotyphla order. With the increase of hedgehogs in the cities, it is important to establish new diagnostic and treatment protocols for wildlife rehabilitation centers. Anatomical and radiological descriptions may be used as a base for such work. The anatomical features of the hedgehog skull described in the study may prove useful for further studies from a comparative anatomical perspective. Additionally, the data may serve as a basis for developing identification guidelines for archaeological studies and forensic research.

A new species of Platypterygius (Ophthalmosauridae) from the lower Barremian of Colombia and assessment of the species composition of the genus

In this paper, we describe a new ophthalmosaurid specimen found in the lower Barremian beds of the Paja Formation at Villa de Leiva, Boyacá, Colombia. The specimen represents a new species of Platypterygius, P. elsuntuoso sp. nov. defined by three unique features within the genus: a small ventral peg in the anterior ventral border of the extracondylar area of the basioccipital; a supratemporal groove in the quadrate; and a shallow neck at the base of the acellular cementum ring on the teeth root. In support of our taxonomic determination, in this contribution we also assess the species composition of the genus Platypterygius, comparing the known anatomy of the type species P. platydactylus with that of the other species previously assigned to the genus. We found that a great morphological affinity in the forelimb of the species P. americanus, P. australis, P. hercynicus, and P. sachicarum (lower Barremian to lower Cenomanian) with that of the type species (Aptian) is unquestionable and differentiate them from all other ophthalmosaurids. Three new diagnostic features (synapomorphies of the genus) support their inclusion in Platypterygius. Consequently, the genus name “Kyhytysuka”, recently proposed to differentiate P. sachicarum from the genus Platypterygius is here rejected. A careful comparison of the cranial characteristics of Platypterygius specimens preserving associated cranial and fin remains demonstrate that Platypterygius is a genus distinguishable from other ophthalmosaurids not only by a typical forelimb but also by a particular combination of skull features. In this context, the skull morphology of “Simbirskiasaurus” concurs with that defining Platypterygius and its minor differences are not sufficient to support its generic distinction. The morphological comparisons and our phylogenetic analysis show the new species P. elsuntuoso more closely related to the Colombian species P. sachicarum than to other species of Platypterygius. Given that the new species came from the lower Barremian and P. sachicarum came from the upper Barremian, the minor differences in dentition found between the two species suggest a speciation by adaptation to new food sources in the Cretaceous epicontinental sea of Colombia.

The osteology of the lacertid genus Darevskia Arribas, 1999 (Squamata, Lacertidae)

A total of 230 cleared and alizarin stained and 136 radiographed specimens of Darevskia belonging to 47 nominal taxa (species, subspecies or singular clades) including the seven parthenogenetic ones and a triploid hybrid were studied. Sixteen osteological characters in all the tried species were analyzed. These characters by corporal regions were: skull characters: 1.—number of premaxillary teeth; 2.—number of maxillary teeth; 3.—number of dentary teeth; 4.—teeth morphology; 5.—presence of anterolateral process in the postfrontal bone; 6.—presence of anteromedial process in the postorbital bone; 7.—comparative lengths of the postorbital and postfrontal bones; 8.—overlap degree between the postorbital and the squamosal bones. Postcranial characters: 9.—existence of visible (ossified) ribs associated with the third presacral vertebrae; 10.—sternal/xiphisternal costal formula and presence of inscriptional ribs; 11.—number of presacral vertebrae; 12.—number of posterior dorsal vertebrae (short presacral ribs); 13.—presence and form of the sternal fontanelle; 14.—form of the clavicles (emarginated or marginated); 15.—interclavicle form; 16.—morphology of first autotomic vertebrae of the tail. Our goals were to characterize osteologically the different species of Darevskia, to contrast their relationships traced from osteological traits with the available genetic-derived phylogenies of the group, to compare the osteological characteristics of the parthenogenetic species with their bisexual parental species, and to comment on their parentage and character polarity. Finally, we aimed to search for osteological characteristics of the different groups within Darevskia, diagnosing them for the first time. The results, commented on by characters, are available in the main text, and taxa characteristics are easily consultable and condensed in Table 1. Osteological characteristics of Darevskia, together with available phylogenetic trees, have permitted us to define some new groups within Darevskia (raddei, chlorogaster, defilippi, and parvula new groups) (Appendix 3), which are reciprocally monophyletic and have diagnostic characteristics. All of them are diagnosed and named as subgenera to be used if necessary, instead of the partial, old and not always comprehensive groups.

Infant Hydrocephalus.

Hydrocephalus is a neurosurgical condition that is highly prevalent in pediatric medicine. In the infant population, there is a distinct set of features that all primary pediatricians would benefit from understanding. Infant hydrocephalus can present prenatally on imaging and postnatally with symptomatic enlargement of the head and associated skull features and raised intracranial pressures. The 2 major pathophysiology models of infant hydrocephalus are the bulk flow and the intracranial pulsatility models. The most common acquired forms of hydrocephalus include posthemorrhagic hydrocephalus, postinfectious hydrocephalus, and brain tumor. The most common congenital forms of hydrocephalus include those due to myelomeningocele, aqueductal stenosis, and posterior fossa malformations. There are various evaluation and treatment algorithms for these different types of hydrocephalus, including cerebrospinal fluid shunting and endoscopic third ventriculostomy. The aim of this review was to elaborate on those features of hydrocephalus to best equip primary pediatricians to diagnose and manage hydrocephalus in infants.

Geometric morphometric analysis of new zealand rabbit cranium

This study, aimed to determine the shape features of the New Zealand rabbit skull and to reveal the differences between individuals and genders in terms of shape features. For this purpose, the geometric morphometry method was used. A total of 10 female and 10 male New Zealand Rabbit craniums were used. The skulls were photographed in a dorsal, ventral and lateral view, and the mandible was photographed in a lateral view. Homologous landmarks were marked on the photographs. Consensus graphs were created by the TpsRelw (Version 1.70) program. Additionally, principal component analysis and relative warp analysis were performed. As a result of the study, principal components explained 34.813%, 57.225% and 42.427% of the total shape difference in the dorsal, ventral and lateral views of the skull, respectively. In the first principal component graph obtained as a result of principal component analysis, no significant clustering was observed between genders. According to the graphics obtained in the MorphoJ program, inter-individual variation was detected mainly in the viscerocranium, followed by the neurocranium. This study will contribute to morphological and archaeological studies on rabbit skulls.

Nonmetric population‐specific sex estimation based on the skull using logistic regression for Flemish samples

AbstractThere are very few sex estimation methods specifically designed for or tested on Belgian skulls. The currently used methods for European populations have been developed using North American collections where individuals are categorized as White and/or having European ancestry. These frequently show discordance between the pelvic sex and cranial sex estimations highlighting the need for population specific methods. To fill this gap in our knowledge, several sex estimation methods, using 15 qualitative skull features, were tested on two Flemish (northern Belgium) skeletal collections; one archaeological (15th–17th century) and one forensic (20th century). The features were tested by themselves as well as in different combinations using logistic regression. The glabella is considered the best lone feature with a minimal accuracy of 78.4% and a sex bias of −5.2%. Furthermore, four sex estimation equations were developed for the skull, the cranium, the mandible, and the frontal bone separately. The skull has an accuracy of 89.3% and a bias of 0.8%. For the cranium, this is 87.5% and −0.3%, respectively, for the mandible 85.1% and −0.1%, and for the frontal bone it is 80.4% and −4.6%. The various tests confirm that many skull features can be used for sex estimation and can generate high sex estimation accuracy.

Digital skull anatomy of the Oligocene North American tortoise Stylemys nebrascensis with taxonomic comments on the species and comparisons with extant testudinids of the Gopherus–Manouria clade

The anatomy of North American tortoises is poorly understood, despite a rich fossil record from the Eocene and younger strata. Stylemys nebrascensis is a particularly noteworthy turtle in this regard, as hundreds of specimens are known from Oligocene deposits, and as this species is one of the earliest fossil turtles to have been described in the scientific literature. Since its initial description based on a shell, many specimens with more complete material have been referred to Stylemys nebrascensis. Here, we review and confirm the referral of an important historic specimen to Stylemys nebrascensis, which includes shell, non-shell postcranial, and skull material. This allows us to document unique skull features of Stylemys nebrascensis (e.g., an unusual ‘poststapedial canal’ that connects the posterior skull surface with the cavum acustico-jugulare) and to refer another well-preserved skull to the species. Based on computed-tomography scanning of these two skulls, we provide a detailed description of the cranial and mandibular osteology of Stylemys nebrascensis. Stylemys nebrascensis has a combination of plesiomorphic skull characteristics (e.g., retention of a medial jugal process) and derived traits shared with extant gopher tortoises (e.g., median premaxillary ridge) that suggest it may be a stem-representative of the gopher tortoise lineage. This supports the hypothesis that extant and fossil tortoises from North America form a geographically restricted clade that split from Asian relatives during the Paleogene.

A new Mexican endemic species of yellow-eared bat in the genus Vampyressa (Phyllostomidae, Stenodermatinae)

Abstract Bats from the genus Vampyressa Thomas, 1900 are known from a relatively small number of individuals in Mexico. Through recent collecting efforts in southwestern Mexico, we detected several previously unknown populations of Vampyressa, which appeared to represent a lineage independent from but closely related to V. thyone. Here, we describe this lineage as a new species of the genus Vampyressa from the Mexican states of Guerrero and Oaxaca. The new species is currently known from at least 8 collected specimens and 3 released individuals from 8 localities, and can be differentiated from V. pusilla and V. thyone based on pelage and skull characters, size, mitochondrial Cytochrome b, and nuclear Recombination-activating gene 2 sequence data. The new species has been captured mainly in the lowlands but occurs along a wide altitudinal range from 150 to 2,200 m above sea level. Most of the records of the new species are from west of the Isthmus of Tehuantepec, which evidences a new case of a phylogenetic break at this biogeographic barrier. The genus Vampyressa now includes 6 species, and Mexico expands its position as the country with the largest number of endemic bats in the Neotropics, totaling 20 endemics.

A Neural Implant Design Toolbox for Nonhuman Primates.

This paper describes an in-house method of 3D brain and skull modeling from magnetic resonance imaging (MRI) tailored for nonhuman primate (NHP) neurosurgical planning. This automated, computational software-based technique provides an efficient way of extracting brain and skull features from MRI files as opposed to traditional manual extraction techniques using imaging software. Furthermore, the procedure provides a method for visualizing the brain and craniotomized skull together for intuitive, virtual surgical planning. This generates a drastic reduction in time and resources from those required by past work, which relied on iterative 3D printing. The skull modeling process creates a footprint that is exported into modeling software to design custom-fit cranial chambers and headposts for surgical implantation. Custom-fit surgical implants minimize gaps between the implant and the skull that could introduce complications, including infection or decreased stability. By implementing these pre-surgical steps, surgical and experimental complications are reduced. These techniques can be adapted for other surgical processes, facilitating more efficient and effective experimental planning for researchers and, potentially, neurosurgeons.

3D Transcranial ultrasound localization microscopy reveals major arteries in the sheep brain.

Cerebral circulation ensures the proper functioning of the entire human body, and its interruption, i.e. stroke, leads to irreversible damage. However, tools for observing cerebral circulation are still lacking. Although MRI and CT scans serve as conventional methods, their accessibility remains a challenge, prompting exploration into alternative, portable, and non-ionizing imaging solutions like ultrasound with reduced costs. While Ultrasound Localization Microscopy (ULM) displays potential in high-resolution vessel imaging, its 2D constraints limit its emergency utility. This study delves into the feasibility of 3D ULM with multiplexed probe for transcranial vessel imaging in sheep brains, emulating human skull characteristics. Three sheep underwent 3D ULM imaging, compared with angiographic MRI, while skull characterization was conducted in vivo using ultrashort bone MRI sequences and ex vivo via micro CT. The study showcased 3D ULM's ability to highlight vessels, down to the Circle of Willis, yet within a confined 3D field-of-view. Future enhancements in signal, aberration correction, and human trials hold promise for a portable, volumetric, transcranial ultrasound angiography system.

A Morrison stem gekkotan reveals gecko evolution and Jurassic biogeography.

Geckos are a speciose and globally distributed clade of Squamata (lizards, including snakes and amphisbaenians) that are characterized by a host of modifications for nocturnal, scansorial and insectivorous ecologies. They are among the oldest divergences in the lizard crown, so understanding the origin of geckoes (Gekkota) is essential to understanding the origin of Squamata, the most species-rich extant tetrapod clade. However, the poor fossil record of gekkotans has obscured the sequence and timing of the assembly of their distinctive morphology. Here, we describe the first North American stem gekkotan based on a three-dimensionally preserved skull from the Morrison Formation of western North America. Despite its Late Jurassic age, the new species already possesses several key characteristics of the gekkotan skull along with retained ancestral features. We show that this new stem gekkotan, and several previously named species of uncertain phylogenetic relationships, comprise a widespread clade of early crown lizards, substantiating faunal homogeneity in Laurasia during the Late Jurassic that extended across disparate ecological, body-size and physiological classes.

Biomechanical skull performance in the meiolaniid Niolamia argentina (Testudinata: Meiolaniidae) using finite element analysis

ABSTRACT The use of horns and frills for sexual display and attack has been proposed and demonstrated in extinct taxa on several occasions, with the ceratopsian dinosaurs as the most iconic example. Niolamia argentina is a large meiolaniid turtle from Patagonia, characterized by the presence of extensive frills and massive horns in the skull. Here, Finite Element Analysis (FEA) is applied in the only known adult skull of N. argentina to assess the cranial performance simulating defensive/aggressive movements. We tested five different scenarios: (1) hitting with the snout, (2) hitting with the forehead, (3) struggling with the notch between the frill and the horn, (4) stabbing with lateral horns, and (5) caudal torsion of the frills, the last two being the most damaging and stressful scenarios. Together with the lack of skull features related to head-hitting/fighting, we find that, although the cranial structures of Niolamia argentina studied here may indicate a priori that they were for engaging in combat between males, hitting each other with the caudal frills and trying to stab each other may represent highly stressful scenarios. In this sense, we propose that the presence of frills and horns in N. argentina seems to be more suitable for sexual display than for combat behavior.

Sexual dimorphism in skull size and shape of Laticauda colubrina (Serpentes: Elapidae).

Sexual dimorphism in size and shape is widespread among squamate reptiles. Sex differences in snake skull size and shape are often accompanied by intersexual feeding niche separation. However, allometric trajectories underlying these differences remain largely unstudied in several lineages. The sea krait Laticauda colubrina (Serpentes: Elapidae) exhibits very clear sexual dimorphism in body size, with previous studies having reported females to be larger and to have a relatively longer and wider head. The two sexes also differ in feeding habits: males tend to prey in shallow water on muraenid eels, whereas females prey in deeper water on congerid eels. I investigated sexual dimorphism in skull shape and size as well as the pattern of skull growth, to determine whether males and females follow the same ontogenetic trajectories. I studied skull characteristics and body length in 61 male and female sea kraits. The sexes differ in skull shape. Males and females follow distinct allometric trajectories. Structures associated with feeding performance are female-biased, whereas rostral and orbital regions are male-biased. The two sexes differ in allometric trajectories of feeding-related structures (female biased) that correspond to dietary divergence between the sexes. Sea kraits exhibit clear sexual dimorphism in the skull form that may be explained by intersexual differences in the feeding habits as well as reproductive roles. The overall skull growth pattern resembles the typical pattern observed in other tetrapods.

Microtomographic investigation of a large corpus of cichlids.

A large collection of cichlids (N = 133) from Lake Victoria in Africa, with total lengths ranging from 6 to 18 cm was nondestructively imaged using micro-computed tomography. We present a method to efficiently obtain three-dimensional tomographic datasets of the oral and pharyngeal jaws and the whole skull of these fishes to accurately describe their morphology. The tomographic data we acquired (9.8 TB of projection images) yielded 1.5 TB of three-dimensional image stacks used for extracting the relevant features of interest. Herein we present our method and outlooks on analyzing the acquired data; a morphological description of the oral and pharyngeal jaws, a three-dimensional geometric morphometrics analysis of landmarked skull features, and a robust method to automatically extract otoliths from the tomographic data.

Craniofacial and dental features in children aged 3-5years with congenital Zika syndrome.

Zika virus infection has been associated to congenital zika syndrome (CZS) in newborns and is characterized by microcephaly, central/axial motor and sensory dysfunction, dysphagia among other previously described severe health complications. CZS is usually diagnosed postpartum by evident/apparent neural development problems. Although there are some reports of craniofacial/dentition development in CZS, several clinical oral aspects are still unknown. This study describes some structural and functional characteristics of facial and cranial growth and deciduous dentition in CZS-affected children. Some cranial, facial and dental characteristics were determined in 14 children with CZS aged 3-5years and compared them against 12 apparently healthy children paired by age and gender. Fourteen CZS cases presented microcephaly, maxillary prognathism, altered facial thirds, asymmetric pupillary line, bruxism (p = 0.006), deep and anterior open bite and distal step decidual molar relationship (p = 0.031). CZS children cannot feed by themselves and most cannot walk and have not develop coordinated and intelligible language according to their chronological age. In contrast, controls presented normal skull features, have autonomous locomotion skills, speak intelligible language, feed by themselves, presented a harmonic intermaxillary relationship and have symmetrical facial thirds. Microcephaly, dysphagia, bruxism, mandibular retrognathia, altered facial proportions and malocclusion are the main craniofacial and oral features at CZS. The complications of CZS including those related with the face and the oral cavity are still being identified. This study revealed some cranial, facial and oral features in children affected by CSZ. Interdisciplinary rehabilitation protocols must address these syndromic features that could improve children and parents living conditions.

Exceptional X-Ray contrast: Radiography imaging of a Middle Triassic mixosaurid from Svalbard.

The black shales of the Middle Triassic Botneheia Formation in Svalbard are known for their fossil richness with abundant ichthyosaur remains and beds of the bivalve Daonella. Vertebrate remains from the Muen Mountain on Edgeøya are shown to have exceptional X-ray contrast due to a combination of sulphide and sulphate permineralisation and pseudomorphing. Radiography imaging of a previously described specimen, PMO 219.250, revealed new and spectacular details such as more carpals, teeth, and skull sutures. Teeth and skull characters are taxonomically significant. supporting the referral of PMO 219.250 to Phalarodon and further suggesting an affinity to P. atavus. Three sulphur phases were identified, with the sulphide sphalerite (ZnS) being the highest temperature phase, followed by the sulphate baryte (BaSO4), and the sulphide pyrite (FeS2). Sulphate permineralisation is also seen in specimens from the Upper Jurassic on Svalbard. We suggest that sulphur-rich fluids have flowed and dissolved barium from the shales and deposited the sphalerite and baryte, and that this could be linked to the Cretaceous HALIP. The Jurassic specimens are only permineralised by baryte, while the Triassic specimens have also been permineralised, but mainly pseudomorphed by baryte with crystals of sphalerite. Lithology differences appear to have controlled the compaction of the Triassic specimens, while the Jurassic specimens have retained their three-dimensional shape due to the baryte emplacement relatively earlier in their depositional history. Although soft tissues are not preserved, the excellent X-ray contrast in the Middle Triassic specimens is reminiscent of pyritised fossil sites such as the Hunsrück Slate (Devonian), Beecher's Trilobite Bed (Ordovician), and the La Voulte-sur-Rhône marls (Jurassic).

Temporal Trends in Skull Morphology of the European Bison from the 1950s to the Present Day

The shape and size of the skull are determined by various factors. These factors act not only on single individuals in their ontogenesis, but can affect entire populations in the long term, thus determining developmental trends. The aim of this study was to determine whether the craniometric features of the European bison skull and their proportions are constant or change over time. In total, 1097 European bison skulls from the Mammal Research Institute of the Polish Academy of Sciences and Warsaw University of Life Sciences were examined. It has been shown that almost all examined skull dimensions tend to decrease. The opposite phenomenon was observed for the height of the skull in males. The results of the work prove that European bison adapt to changing environmental conditions related to climate warming, food availability, and population density.

A new species of the genus Liotyphlops Peters, 1881 (Serpentes, Anomalepididae) from Colombia and the synonymization of Liotyphlopsbeui (Amaral, 1924) with Liotyphlopsternetzii (Boulenger, 1896).

A new species of Liotyphlops Peters, 1881, Liotyphlopspalauophissp. nov., is described from the neighborhoods of Bogota, Colombia from a previous syntype of L.anops, and a lectotype is designated for the latter species. The new species is readily distinguished from congeners by having the frontal scale divided (vs single), and a central foramen in the parabasisphenoid (vs foramen absent). High-resolution x-ray computed tomography (HRXCT) was used to study and present data on the skull of the holotype of the new species, the lectotype of L.anops, and the holotype of L.ternetzii. Additionally, extensive study of skull characters and external morphology failed to find diagnostic characters to differentiate L.beui and L.ternetzii, and the former is here considered a junior synonym of L.ternetzii, which is also redescribed.

Human Peopling and Population Dynamics in Sicily: Preliminary Analysis of the Craniofacial Morphometric Variation from the Paleolithic to the Contemporary Age

The geographic position, isolation, and the long and dynamic history of colonization created a human context in Sicily that allows for a particular anthropological study; information about “migratory flow” and “population influx” could be investigated in the cranial morphology of a localized geographical region. The research goals are the identification of temporal trends in facial morphology in order to assess the adaptations and the microevolutionary trends and to verify if the cranial morphology of humans was modified by the various genetic contributions and more or less related to the intense and significant migratory flows. This work includes a diachronic morphometrics study of 3D models of 95 Sicilian skulls coming from 19 populations (from the Paleolithic to the Contemporary Age), providing an overview of human biodiversity and variability in Sicily. To achieve this, a geometric morphometrics analysis of the facial features of adult human skulls was performed. The approach used allows for the identification of the main micro-anatomical and micro-evolutionary features. Considering sample size/composition, it has been possible to discriminate between prehistorical and historical populations. The results highlight a series of morphological changes related to different migratory flows that have followed one another with different intensities and effectiveness starting from the Prehistory up to the Contemporary Age. The human peopling of Sicily is a subject of continuous debate; however, this study points to the coexistence of microevolutionary patterns and population dynamics, with the latter being one of the main causes of the morphological variations.