Sutural complexity and body size in Cretaceous ammonoids: Macroevolutionary decoupling of correlated features

The relationship between sutural complexity (estimated as fractal dimension) and body size is analysed for a sample of 204 genera of Cretaceous ammonoids. Although both characteristics are significantly correlated with each other, their evolutionary dynamics are opposite: i) the duration of genera is not correlated with body size but is correlated with sutural complexity and ii) throughout the Cretaceous there is an increase in the body size of the ammonoids in the sample but no increase in the complexity of their septa is detected. This indicates the difficulty of predicting macroevolutionary patterns for a trait on the basis of its correlation with other features on wide stratigraphic scales.This work has been supported by Campus de Excelencia Internacional Andalucía Tech and funded by the Research Group RNM- 146 (Plan Andaluz de Investigación, Desarrollo e Innovaci on) and the projects UMA18-FEDERJA-188 and P18-FR-3193 (Secretaría General de Universidades, Investigación y Tecnología, Junta de Andalucía). Funding for open access charge: Universidad de Málaga / CBUA. I am grateful to Prof. Dr. Christian Klug and Dr. Kenneth De Baets for their valuable comments and suggestions that greatly helped to improve this work. In memory of Suzana Bengtson

Sobre la complejidad sutural en ammonoideos planiespirales del Cretácico: mayor complejidad no es mayor especialización

La interpretación de muchos aspectos de la paleobiología de los ammonideos está sin duda condicionada por la ausencia de representantes actuales del grupo. Una de las cuestiones más enigmáticas de los mismos es el papel de la complejidad periférica de sus septos. Dicha complejidad, estimada mediante la dimensión fractal de las suturas, fue aumentando desde la aparición del grupo en el Devónico hasta aproximadamente el comienzo del Triásico, tras lo cual se mantuvo en valores medios altos durante el resto del Mesozoico (Boyajian y Lutz,1992). Sin embargo, a pesar de que durante el Cretácico no se observa ninguna tendencia hacia un aumento de la complejidad, aquellos ammonoideos planoespirales con menor complejidad sutural presentan rangos estratigráficos más reducidos, lo cual apunta a que son formas más especializadas (Pérez- Claros y Bengtson, 2017). Aquí presentamos que dicha relación también se mantiene a nivel de superfamilia (r = 0.551, p = 0.05). Además, se observa que en aquellos casos donde las diferencias en complejidad sutural entre parejas de superfamilias antecesora-descendiente resultaron significativas (11 casos de 12), se aprecia una disminución del valor de dimensión fractal (8 casos de 11, χ2 = 6.53, 0.02 < p < 0.01), la cual se acompaña con la disminución correspondiente en rango estratigráfico.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Alometrías intertaxónicas y ontogenéticas entre el área del septo y el volumen del fragmocono en cefalopodos con concha espiral actuales y extintos

La interpretación funcional del replegamiento periférico de los septos de los ammonoideos constituye todo un reto dada la inexistencia de representantes actuales del grupo y, por consiguiente, la imposibilidad de experimentación directa. Por tal motivo las líneas de evidencia se han de basar en gran medida en comparaciones con otros cefalópodos camerados actuales. En este trabajo se comparan las alometrías ontogenéticas que siguen el área septal respecto al volumen del fragmocono en cefalópodos con concha espiral (interna o externa) con las obtenidas para ammonoideos adultos del Jurásico tardío. Las similitudes entre los coeficientes alométricos indican que el aumento de superficie que supone replegar los septos no aparenta ser muy diferente en las primeras etapas del crecimiento de los ammonoideos del de otros cefalópodos con concha espiral. Por el contrario, las discrepancias con los coeficientes alométricos para los ammonoideos adultos parecen apuntar a que la complejidad septal no se alcanza por una mera extrapolación de la ontogenia.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Body mass estimation in amphicyonid carnivoran mammals: A multiple regression approach from the skull and skeleton

The body masses of sixteen species of amphicyonids (Mammalia, Carnivora, Amphicyonidae) from the New and Old World were estimated on the basis of 86 osteological variables measured from the craniodental (N = 44) and postcranial (N = 42) skeleton of living species of Canidae and Ursidae. Given the absence of complete and well preserved skeletons of amphicyonids in the fossil record, multiple regression functions were derived separately from measurements taken from the mandible, the cranium and the major limb bones. The accuracy of the regression functions was evaluated using the percentage prediction error and the percentage standard error of the estimates. Mass values were calculated with these equations using measurements taken in adult individuals from a number of daphoenine and amphicyonine species. Results obtained show that three distinct size classes of amphicyonids emerged through the evolutionary history of the “beardog” family and that these size classes correlate with presumably different ecomorphs. Quantitative estimates of body size of amphicyonids are critical for deciphering the paleobiology of this poorly understood family of large fissiped carnivorans and can be used for placing it within a broader ecological context

The influence of skull shape modularity on internal skull structures: a 3D-Pilot study using bears

In order to capture the phenotypic variation of the internal skull structures, such as the sinuses or the brain, it is necessary to perform CT scans in a large number of specimens, which is difficult and expensive. Therefore, while the external morphology of the mammalian cranium has been the subject of many morphometric studies, the internal structures of the cranium have been comparatively less studied. Here, we explore how the variation of external shape reflects the morphology of internal structures. We use the family Ursidae (Carnivora, Mammalia) as a case study because bears have a wide variability of cranial morphologies in part associated with different trophic ecologies. To do this, we digitized a set of landmarks in 3D with a Microscribe G2X from the external surface of the cranium in a wide sample of bears. Additionally, the crania of seven bear species were CT-scanned and prepared digitally to visualize the 3D models of the external cranium morphology and of internal structures. Subsequently, we divided the landmarks into two modules, splanchnocranium and neurocranium, and we perform a two-block partial least squares analysis (2B PLS) to explore the intraspecific (static) morphological changes associated with the covariation between them. These morphological changes were visualized using the morphing technique with the 3D models, looking at both the external shape and the internal structures. In addition, we inferred the volume of the sinuses and of the brain in each hypothetical model. Our results show that the first two PLS axes are associated externally with changes in the basicranial angle, face length and cranium height and width. Concerning the internal structures, there are parallel changes in dorso-ventral and medio-lateral expansion of sinuses and brain, accompanied by their corresponding changes in volume. In contrast, the third PLS axis is related to opposite changes in the volume of sinuses and brain. These preliminary results suggest that the opposite relationship between sinuses and brain volumes in the bear cranium is not as evident as expected, at least at intraspecific level.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A morphometric characterization of cranial shape in terrestrial carnivorans based on fourier analysis

A number of studies have shown that skull morphology reflects the ecological adaptations of terrestrial carnivores as well as their phylogenetic legacy. Here we use Fourier shape analysis for describing the dorsal outline of the cranium in a number of extant and extinct species in the order Carnivora. To evaluate to what extent the shapes of the outlines analyzed reflect phylogeny and/or adaptation, a principal components analysis was performed with the harmonic amplitudes of the Fourier analyses. Results obtained show that cranial morphology is highly constrained by the phylogenetic legacy of each carnivoran family, as those species belonging to the same family tend to be placed in the same region of the morphospace. However, a functional signal is also present. In particular, after controlling for size effects, there is a weak but significant correlation between an axis of morphological variation and the estimates of bite force at the level of the upper canine, while another independent axis is related to bite force measurements at the carnassial. The wide distribution of canids in the empirical morphospace reflects their ecological disparity, while the restricted dispersal on the plot of saber-tooth predators probably results from biomechanical constraints posed by their highly specialized, hypertrophied upper canines. Moreover, there is a general allometric trend for all carnivoran families, which is associated with the lateral expansion of the zygomatic arches, and two different allometric trends exclusive to canids and felids, respectively, which are linked to snout length. Our results show that phylogeny constrains to a large extent the morphological adaptive zone which carnivoran species can inhabit.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A comparison of the taphonomic attributes of quarries VM3 and VM4 of the Early Pleistocene site of Venta Micena (Baza Basin, SE Spain)

The site of Venta Micena (Guadix-Baza Depression, SE Spain), a rich Fossil-Lagerstätten of late Early Pleistocene age (1.6-1.5 Ma), preserves a diverse assemblage of large mammals. Up to date, >24,000 skeletal remains have been unearthed from the surface excavated (~400 m2) in the two main quarries of the site, VM3 and VM4, which represents a density of fossils of >60/m2. Although this density is not homogeneously recorded across the 80-120 cm thick VM stratum, which outcrops over ~2.5 km, it suggests that tens of millions of fossils were preserved in the micritic limestones of this lithological unit. VM3 has been interpreted as a den of the giant hyena Pachycrocuta brevirostris in the plain that surrounded the Baza paleolake. Taphonomic analyses showed that the hyenas: (i) scavenged the prey hunted by the hypercarnivores, sabertoothed felids and wild dogs; (ii) transported the remains to their communal den as whole carcasses or selected anatomical parts; and (iii) fractured the skeletal parts according to their marrow contents and mineral density, which resulted in well-defined consumption sequences. In the case of VM4, an excavation quarry ~350 m distant from VM3, preliminary taphonomic analyses of the assemblage showed several differences, including: (i) a higher frequency of elements in anatomical connection than in VM3; (ii) a lower proportion of bones tooth-marked by carnivores (5.5%) compared with their frequency in VM3 (29.4%); (iii) a lower proportion of remains with salivary and gastric alterations (0.06% in both cases) than in VM3 (0.34% and 0.15%, respectively); and (iv) a less advanced degree of weathering (90.8% of bones show weathering stage 0 in VM4 compared to 75.9% in VM3).ICAZ Taphonomy Working Group, CSIC, MNCN Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p&lt;0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (&lt;1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (&lt;1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

Body Mass Estimation in Amphicyonid Carnivoran Mammals: A Multiple Regression Approach from the Skull and Skeleton

The body masses of sixteen species of amphicyonids (Mammalia, Carnivora, Amphicyonidae) from the New and Old World were estimated on the basis of 86 osteological variables measured from the craniodental (N = 44) and postcranial (N = 42) skeleton of living species of Canidae and Ursidae. Given the absence of complete and well preserved skeletons of amphicyonids in the fossil record, multiple regression functions were derived separately from measurements taken from the mandible, the cranium and the major limb bones. The accuracy of the regression functions was evaluated using the percentage prediction error and the percentage standard error of the estimates. Mass values were calculated with these equations using measurements taken in adult individuals from a number of daphoenine and amphicyonine species. Results obtained show that three distinct size classes of amphicyonids emerged through the evolutionary history of the “beardog” family and that these size classes correlate with presumably different ecomorphs. Quantitative estimates of body size of amphicyonids are critical for deciphering the paleobiology of this poorly understood family of large fissiped carnivorans and can be used for placing it within a broader ecological context

Sobre el uso de los mínimos cuadrados parciales de dos bloques para el estudio de los patrones integración entre el neurocráneo y el esplacnocráneo en homínidos actuales y homínidos extintos

Many biological structures that interact in development and/or function tend to evolve in a concertedly fashion and thus become integrated forming modules. The two most prominent modules of the mammalian cranium are the cerebral capsule (i.e., the neurocranium) and the face (i.e., the splanchnocranium), as inferred from both developmental processes and functional reasons. The relative importance of both cranial complexes was estimated here by means of their relative sizes, which were measured in the five extant hominoid species and also in a huge sample of extinct hominins using six standard cranial measurements as proxies of the length, width, and height of each cranial module. Several two-block partial least-squares analyses (2B-PLS) were performed for adults of the extant and extinct species using size standardized and non-standardized variables, as well as pooled and non-pooled within-species correlation matrices. When no size standardization was performed, pooled and non pooled within-species analyses showed a common pattern of developmental integration for all living hominoid species, on the one hand, and very different patterns of evolutionary integration, on the other, in which each species exhibited a distinct relationship between the relative sizes of their modules. On the contrary, when cranial size was removed, ontogenetic and evolutionary integration run in the same direction, which indicates that the relative sizes of the splanchnocranium and the neurocranium relate inversely both within and between species. Australopiths, the extinct representatives of the genus Homo and the anatomical modern humans (AMH) seem to lie in a different trend than the great apes, although the pattern of covariation between their cranial modules is basically the same. This difference suggests that a great ape cannot reach the morphology of an AMH simply by increasing the size of its neurocranium. Similarly, an AMH cannot be transformed to the face/neurocranium proportions of an ape simply by reducing its neurocranium. We thank the Universidad de Malaga. Campus de Excelencia Internacional Andalucia Tech and the Ministerio de Ciencia e Innovacion (Ref. CGL2011-30334).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Ciencia e Innovacion (Ref. CGL2011-30334)