Pampean megamammals in Europe: the fossil collections from Santiago Roth.

Santiago Roth was a Swiss fossil finder, naturalist, and paleontologist that emigrated to Argentina in 1866. His work largely influenced the discipline in the country at the end of the twentieth century, particularly the stratigraphy of the Pampean region. Some of his collections of Pampean fossils were sold to museums and private collectors in Europe and were accompanied by elaborated catalogues. Fossils in the Roth's catalogues N° 2 and 3 are housed today in the Natural History Museum of Denmark, fossils from catalogues N° 4 to 6, were sold to Swiss museums, with Catalogue N° 5 currently housed at the Department of Paleontology, Universität Zürich. Here, we provide a general framework on the stratigraphy from the Roth's Pampean fossil sites, summarize the history of the Pampean fossils in Europe originally collected by Roth, and provide historical and curatorial details of the Roth's collection at the Department of Paleontology, Universität Zürich. Supplementary Information: The online version contains supplementary material available at 10.1186/s13358-023-00283-5.

Santiago Roth fue un buscador de fósiles, naturalista y paleontólogo suizo que emigró a la Argentina en 1866. Su obra influyó en gran medida en la disciplina del país a fines del siglo XX, con algunos aportes que son pilares, en particular aquellos para la comprensión de la estratigrafía de la Región Pampeana. Algunas de sus colecciones de fósiles pampeanos fueron vendidas a museos y coleccionistas privados en Europa y estaban acompañadas de catálogos elaborados. Los fósiles de los catálogos N° 2 y 3 de Roth se encuentran hoy en el Museo de Historia Natural de Dinamarca, los fósiles de los catálogos N° 4 a 6 fueron vendidos a museos suizos, mientras que el Catálogo N° 5 en particular está alojado actualmente en el Departamento de Paleontología, Universidad de Zurich. Aquí proporcionamos un marco general sobre la estratigrafía de los sitios de los fósiles pampeanos de Roth, resumimos la historia de los fósiles pampeanos en Europa colectados originalmente por Roth y brindamos detalles históricos y curatoriales de la colección de Roth del Departamento de Paleontología, Universidad de Zurich.

How to tuna fish: constraint, convergence, and integration in the neurocranium of pelagiarian fishes.

Morphological evolution of the vertebrate skull has been explored across a wide range of tetrapod clades using geometric morphometrics, but the application of these methods to teleost fishes, accounting for roughly half of all vertebrate species, has been limited. Here we present the results of a study investigating 3D morphological evolution of the neurocranium across 114 species of Pelagiaria, a diverse clade of open-ocean teleost fishes that includes tuna and mackerel. Despite showing high shape disparity overall, taxa from all families fall into three distinct morphological clusters. Convergence in shape within clusters is high, and phylogenetic signal in shape data is significant but low. Neurocranium shape is significantly correlated with body elongation and significantly but weakly correlated with size. Diet and habitat depth are weakly correlated with shape, and nonsignificant after accounting for phylogeny. Evolutionary integration in the neurocranium is high, suggesting that convergence in skull shape and the evolution of extreme morphologies are associated with the correlated evolution of neurocranial elements. These results suggest that shape evolution in the pelagiarian neurocranium reflects the extremes in elongation found in body shape but is constrained along relatively few axes of variation, resulting in repeated evolution toward a restricted range of morphologies.

Ontogenetic changes of diploic channels in modern humans.

OBJECTIVES: The diploic channels are bony passages of veins, running within frontal, parietal, and occipital bones. In this study, we investigate ontogenetic changes of these channels in a sample of nonadult and adult modern humans. MATERIALS AND METHODS: Using computed tomography scans of dried crania, we provide quantitative comparisons of lumen size, branch length, volume, and vascular asymmetries, and correlations with age, cranial size, and bone thickness. RESULTS: The vascular system displays progressive but nonlinear changes throughout ontogeny, becoming even more complex with adulthood. Vascular variables are significantly different in frontal, parietal, and occipital bones for most of the postnatal ontogeny. Diploic channels of the left and right sides are developed similarly. Vascular variables display a nonlinear association with age and cranial size in modern humans. Cranial bone thickness is shown to be a major determinant of lumen size, branch length, and volume. CONCLUSIONS: A previous radiographic survey suggested that diploic channels are more developed in adult modern humans than in nonadults. Recent advances in digital anatomy have been used in this study to investigate this craniovascular structure. The complexity of the channels increases during development, with a noticeable boost in adults. Taking into account the potential metabolic differences and constraints associated with modern human brain size and shape, the vascular differences found might be related to endocranial thermoregulation.

Craniovascular traits in anthropology and evolution: from bones to vessels.

Many aspects of human biology can be reconstructed from skeletal and fossil remains. The endocranial vasculature runs through cerebral, connective, and bone elements, where it is influenced by the functional and structural relationships among these different components of the endocranial system. The imprints and traces of these vessels can be used to analyze the craniovascular features of extinct species or historical samples. These traits can supply information about evolutionary adaptation, the mutual relationships between and within populations, and individual life history. In particular, bioarchaeology considers individual morphological variants as indicators of temporal and spatial relatedness and population structure, whereas paleoanthropology studies functional aspects to consider evolutionary changes and phylogenetic processes. Forensic science can investigate the cause of death associated with craniovascular pathologies by relying on morphological variations for individual identification. In this review, we consider the imprints of middle meningeal vessels, dural venous sinuses, emissary veins, and diploic veins. We summarize the most relevant morphological and functional information about craniovascular features and their applications in retrospective anthropological and medical fields, as well as describing the methodological issues associated with the sampling and quantitative evaluation of these elusive vascular remnants imprinted in the cranial bones.

Parietal Bone Thickness and Vascular Diameters in Adult Modern Humans: A Survey on Cranial Remains.

Cranial bone thickness varies among modern humans, and many factors influencing this variability remain unclear. Growth hormones and physical activity are thought to influence the vault thickness. Considering that both systemic factors and energy supply influence the vascular system, and taking into account the structural and biomechanical interaction between endocranial vessels and vault bones, in this study we evaluate the correlation between vascular and bone diameters. In particular, we tested the relationship between the thickness of the parietal bone (which is characterized, in modern humans, by a complex vascular network) and the lumen size of the middle meningeal and diploic vessels, in adult modern humans. Our results show no patent correlation between the thickness of parietal bone and the size of the main vascular channels. Values and distributions of the branching patterns, as well as anatomical relationships between vessels and bones, are also described in order to provide information concerning the arrangement of the endocranial vascular morphology. This information is relevant in both evolutionary and medical contexts. Anat Rec, 299:888-896, 2016. © 2016 Wiley Periodicals, Inc.

Diploic vessels and computed tomography: Segmentation and comparison in modern humans and fossil hominids.

OBJECTIVES: The diploic channels appear to be more developed in humans than in nonhuman primates, suggesting they may be relevant in evolutionary biology. This study is aimed at providing a segmentation procedure for diploic channels and CT analysis, a quantitative description of their variation in modern humans, and paleoanthropological case-studies. MATERIALS AND METHODS: CT data were used for the 2D and 3D visualization, rendering, and measure, of diploic channels in modern and fossil hominids. We analyzed 20 modern human skulls and three Neanderthals. The effect of different resolution factors was evaluated. A specific protocol was designed to segment the vascular network and localize the main branches, reducing the noise of the cancellous bone. RESULTS: We provide a quantitative description of the frontal, parietal, and occipital diploic networks in modern humans and in three Neanderthals. There is a correlation in the degree of vascularization among the different vault areas. No side differences can be detected. The diploic network is commonly connected with the meningeal artery at the temporal fossa, with the emissary veins at the occipital bone, and with the venous sinuses at the parieto-occipital areas. The channels are more developed in the parietal areas. The three Neanderthals show a vascular development, which is in the lower range of the modern human variation. CONCLUSIONS: Modern humans display a large variation in their morphological patterns, being the parietal area the most vascularized. The pattern of the diploic channels may be relevant in anthropology, medicine, and paleontology, taking into account their possible involvement in thermoregulation.

Midsagittal brain variation and MRI shape analysis of the precuneus in adult individuals.

Recent analyses indicate that the precuneus is one of the main centres of integration in terms of functional and structural processes within the human brain. This neuroanatomical element is formed by different subregions, involved in visuo-spatial integration, memory and self-awareness. We analysed the midsagittal brain shape in a sample of adult humans (n = 90) to evidence the patterns of variability and geometrical organization of this area. Interestingly, the major brain covariance pattern within adult humans is strictly associated with the relative proportions of the precuneus. Its morphology displays a marked individual variation, both in terms of geometry (mostly in its longitudinal dimensions) and anatomy (patterns of convolution). No patent differences are evident between males and females, and the allometric effect of size is minimal. However, in terms of morphology, the precuneus does not represent an individual module, being influenced by different neighbouring structures. Taking into consideration the apparent involvement of the precuneus in higher-order human brain functions and evolution, its wide variation further stresses the important role of these deep parietal areas in modern neuroanatomical organization.