Samuel Ginot

University of Bonn | Uni Bonn · Institute of Evolutionary Biology and Ecology

In this report we compare two geometric morphometric methods (Outline-based vs. Virtual Modeling-based) aiming to analyze the ammonoid whorl profile shape (designated as whorl cross-section shape in previous contributions). A dataset including 50 ammonoid whorl profiles is used to evaluate the two approaches, and the resulting morphospaces are comp...

Biodiversity is not just the number of species but one of its major aspects is the observable (or phenotypic) diversity of forms, present within and between species. This relates to biological evolution, natural selection, ecosystem functions and services, and conservation. However important it may be, phenotypic diversity is still underlooked in c...

Bilateral symmetry is widespread across animals, yet, among bilaterians, many cases of conspicuous asymmetries evolved. This means that bilaterally homologous structures on the left and right sides display divergent phenotypes. The evolution of such divergent phenotypes between otherwise similarly shaped structures can be thought to be favored by m...

Performance traits such as bite forces are crucial to fitness and relate to the niche and adaptation of species. However, for many insects it is not possible to directly measure their bite forces because they are too small. Biomechanical models of bite forces are therefore relevant to test hypotheses of adaptation in insects and other small organis...

Log Size Index (LSI) has been developed and used in archaeozoology to perform biometric studies of often small datasets, a recurrent limitation of archaeological faunal assemblages. This approach consists of aggregating measurements taken on different anatomical parts by standardisation, using a reference to which the studied measurements are scale...

Fossils of Devonian ammonoids are abundant and well-preserved in the Anti-Atlas of Morocco; as such they provide an invaluable record of regional morphological disparity changes (diversity of shapes) that characterise the first steps of ammonoid evolution. However, they were rarely analysed quantitatively with respect to their morphological spectru...

Fitness-related traits tend to have low heritabilities. Conversely, morphology tends to be highly heritable. Yet, many fitness-related performance traits such as running speed or bite force depend critically on morphology. Craniofacial morphology correlates with bite performance in several groups including rodents. However, within species, this rel...

Publicly available image data (2D and 3D) from biological specimens is becoming extremely widespread, notably following digitization efforts from natural history institutions worldwide. To deal with this huge amount of data, high-throughput phenotyping methods are being developed by researchers, to extract biologically meaningful data, in correlati...

Taxonomy is the very first step of most biodiversity studies, but how confident can we be in the taxa delineation? One may hypothesize that the more abundant the material, the more accurate the description of morphological variability and hence the better the taxonomic delineation. Yet, as we shall see, in the case of numerous transitional forms, t...

Fitness-related traits tend to have low heritabilities. Conversely, morphology tends to be highly heritable. Yet, many fitness-related performance traits such as running speed or bite force depend critically on morphology. Craniofacial morphology correlates with bite performance in several groups including rodents. However, within species, this rel...

Ammonoids constitute an invaluable fossil record for documenting macroevolutionary patterns. Our study investigates the morphological evolution of ammonoids during their initial radiation through the Early and Middle Devonian. Previous morphological disparity analyses were restricted to conch geometry; here we have also explored the evolutionary pa...

The ammonoids appeared during the Lower Devonian (ca. 405 Ma); they derived from the Bactritida which root in the Orthocerida in the latest Silurian or earliest Devonian. Earliest forms are found in Morocco (e.g., Praechebbites debaetsi) in early Emsian deposits. In the Anti-Atlas of Morocco, the Emsian ammonoids are abundant and well preserved. Th...

Free download link for 50 days : https://authors.elsevier.com/a/1bsT13HcE1cwvI Conodonts, one of the longest-lived early groups of vertebrates, have a very complete fossil record ranging from the late Cambrian to the end of the Triassic and persisted through many global climatic and biotic events. In this paper, we analyse a large dataset harveste...

The ammonoids appeared during the Lower Devonian (c. 405 Ma); they derived from the Bactritida which root in the Orthocerida in the latest Silurian or earliest Devonian. Earliest forms are found in Morocco (e.g. Praechebbites debaetsi) in early Emsian deposits. In the Anti-Atlas of Morocco, the Emsian ammonoids are abundant and well preserved. Thes...

R function to compute LSI (Simpson 1941), VSI (Uerpmann 1982), and VSI* (Escarguel 2008). Bootstraped values and confidence intervals can be computed using parametric or non-parametric approaches. To find and use the code of functions please go to https://github.com/sginot/MorphoInd

The link between performance, morphology and their sources of variation is a major target of evolutionary functional biology. In vertebrates, many studies have linked in vivo bite force to skull morphology, mostly at the interspecific level. Within species, however, the ontogeny of bite force, in relation to the development of the mandible, remains...

The Devonian ammonoids are particularly abundant and well preserved in the Anti-Atlas of Morocco. These rich faunas are well documented in the literature, and can provide an interesting record of the morphological disparity changes that characterize the macroevolution of the early Ammonoidea during the Devonian period. The present study aims to inv...

Conodonts are among the first vertebrates to have evolved mineralized tooth-like structures. Among these, the so-called P 1 elements are known to have been used to break down food and display a wide variety of morphologies. In particular, the repeated independent evolution of platform-like P 1 elements have been suggested to correspond to similar f...

Morphological traits are frequently used as proxies for functional outputs such as bite force performance. This allows researchers to infer and interpret the impacts of functional variation, notably in adaptive terms. Despite their mechanical bases, the predictive power of these proxies for performance is not always tested. In particular, their acc...

Mice from the Orkney archipelago exhibit an important diversity regarding molar shape. While on some islands mice display a usual dental pattern, teeth from other islands display additional cusplets and unusual phenotypes that may constitute case studies for evaluating the potential functional relevance of dental changes. We developed a multifacete...

In rodents, and other vertebrates in general, the morphology of tarsal bones, especially the astragalus and calcaneus, has been shown to be tightly linked to locomotor movements. As a result, it has been used to infer locomotor behaviors in extinct species. Recent expeditions in Peruvian Amazonia have led to the discovery of the oldest caviomorph r...

The present 3D Dataset contains the 3D models analyzed in the article entitled "One skull to rule them all? Descriptive and comparative anatomy of the masticatory apparatus in five mice species based on traditional and digital dissections" (Ginot et al., Journal of Morphology, https://doi.org/10.1002/jmor.20845).

Developmental instability, as measured by fluctuating asymmetry is generally considered to increase with genetic and environmental stresses. Few studies have, however, addressed the role of asymmetry in altering organism performance. Here, we measured bite force performance in three strains of inbred and outbred mice derived from wild ancestors. We...

Murine rodents display a unique cranial morphology and masticatory musculature. Yet detailed myological descriptions are scarce, especially considering the great diversity of the subfamily and the use of the house mouse and brown rat as model organisms. The masticatory musculature in these two species has been thoroughly described, which allows com...

Rodentia is a species-rich group with diversified modes of life and diets. Although rodent skull morphology has been the focus of a voluminous literature, the functional significance of its variations has yet to be explored in live animals. Myomorphous rodents, including murids, have been suggested to represent “high-performance generalists.” We me...

Closely related syntopic species have been shown to avoid competition by differentiating in the type of food they process. This can be achieved by changes in size or in the masticatory apparatus that produce modifications in bite force. The wood mouse (Apodemus sylvaticus (Linnaeus, 1758)) and Western Mediterranean mouse (Mus spretus Lataste, 1883)...

Cette thèse porte sur l'anatomie et la morphologie du complexe crânien chez les murinés. Ses objectifs sont de démontrer et de décrire le lien morpho-fonctionnel entre le crâne et la force de morsure, représentant la performance, d'identifier les sources génétiques de la variation de la performance et de la morphologie, et de comprendre comment la...

Differences in biological performance, at both intra- and inter-specific levels, have often been linked to morphology but seldom to behavioural or genotypic effects. We tested performance at the intraspecific level by measuring bite force in the African pygmy mouse, Mus minutoides. This species displays an unusual sex determination system, with sex...

Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the...