I explore the impact of extinct lineages and limited morphological character data on the expected delay between the origin time of a clade and the age of its oldest known fossil (the clade-fossil delay). The size of the clade-fossil delay, and variation in its size between clades, fundamentally impacts the extent to which the fossil record is informative about the ages of different clades. The clade-fossil delay is thus a crucial quantity when estimating the timing of branching events in phylogenetic trees (divergence time estimation). I show that both extinct lineages and limited morphological character data increase the clade-fossil delay, especially in datasets with few fossils, which is particularly common when estimating divergence times in flowering plants. Though linked to taphonomic biases, these results are distinct in that they are underpinned by interactions between extinct lineages, limited morphological data, and the nested structure of phylogenetic trees. I discuss the likely impacts of these findings on divergence time analyses and the evolutionary studies that depend on them, and suggest that both a fundamental re-appraisal of the purpose of divergence time estimation, alongside the development of new methods, is required.
The hyperdiverse genus Pheidole Westwood, 1839 is poorly represented in the fossil record. Most species described to date originate from the Dominican and Mexican amber Lagerstätten. In this study, two new species from Oligo-Miocene Mexican amber are described and illustrated. Pheidole ambrata sp. nov. is described based on a syninclusion of one major worker and one minor putative worker, while Pheidole capitomagna sp. nov. is described from a single major worker. This work increases the diversity of the genus in Mexican amber to five species, and the global fossil record to ten. The discovery of these new species provides evidence of the morphological stabilization of the genus in the Neotropics.
Single-use cystoscopes are increasingly adopted in urology, but concerns regarding their environmental footprint persist. Substituting conventional fossil-based plastics with bio-attributed materials may reduce life cycle impacts, yet the magnitude and robustness of this benefit remain uncertain. To evaluate the environmental performance of a single-use flexible cystoscope (aScope™ 4 Cysto; Ambu A/S, Copenhagen, Denmark) incorporating bio-attributed acrylonitrile butadiene styrene (Bio-ABS) using a cradle-to-grave life cycle assessment (LCA). An attributional LCA was performed according to the International Organization for Standardization (ISO) 14040/44 standards, investigating the impact of the introduction of Bio-ABS (50:50 mass balance with fossil feedstock). The functional unit was one cystoscopy procedure. System boundaries included raw material extraction, manufacturing and sterilisation, packaging, distribution, use, and end-of-life treatment. Two geographic scenarios were evaluated (UK and USA). Climate change (kg CO2 equivalents [kg CO2 eq.]) was the primary impact category, with others including human toxicity, particulate matter, and resource use. Sensitivity analyses assessed alternative allocations for bio-circular feedstock and variations in sterilisation utilities. The total carbon footprint of the cystoscope decreased from 1.63 to 1.46 kg CO2 eq. (USA) and from 1.74 to 1.61 kg CO2 eq. (UK) with Bio-ABS, corresponding to reductions of 10% and 7.5%, respectively. Raw material production and sterilisation were the dominant contributors (55-60% of total impact), with packaging accounting for 22-24%. Component-level analysis showed plastics as the primary driver of climate impacts, while electronics and metals contributed disproportionately to resource use and toxicity categories. Sensitivity analyses confirmed the robustness of the Bio-ABS benefit, even when environmental burdens were assigned to bio-feedstock. Incorporating bio-attributed plastics into single-use cystoscopes yields a consistent reduction in life cycle carbon footprint. While material substitution provides measurable benefits, packaging redesign and optimised logistics represent additional opportunities for environmental impact reduction. These findings inform sustainable endoscopic practice and highlight the importance of transparent life cycle modelling in medical device evaluation.
Tetratomidae is a small family of fungivorous beetles, comprising approximately 150 extant species in 13 genera and five subfamilies worldwide. Its fossil record is limited, with only seven named species from the Mesozoic and five from the Cenozoic. In the present study, the third species of the extinct eustrophine genus Allostrophus Hsiao, Ślipiński, Yu, Deng & Pang, 2018, A. tuisp. nov., is described from mid-Cretaceous (Cenomanian, ca. 99 Ma) Kachin amber, northern Myanmar. The new species closely resembles A. cretaceus Hsiao, Ślipiński, Yu, Deng & Pang, 2018 in general appearance, but can be distinguished by its characteristic antennae, elytra, tibiae and tarsi. The discovery provides further data for completing the generic definition of Allostrophus and underscores the diversification of this small tenebrionoid family at both generic and species levels by the mid-Cretaceous.
Recent advances in molecular phylogenies have revolutionised our understanding of brittle star systematics and evolutionary history. Although genetic data have provided new grounds for age estimates of phylogenetic divergences, direct fossil evidence is currently the only robust means to determine the minimum age of clades. The present study discusses an exceptional opportunity to robustly pinpoint the minimum age of an extant genus of brittle star. The presumed ophiolepidid brittle star species Ophiolepis? falsa Jagt & Kutscher, in Jagt, 2000, from lower upper Campanian (Upper Cretaceous, c. 79 Ma) deposits in north-east Belgium, is here recorded from coeval strata in the Münsterland Basin (northern Germany) and transferred to the previously monospecific extant hemieuryalid genus Actinozonella Stöhr, 2011. An unusually well-preserved specimen, completely free from mineralised matrix, allows both dorsal and ventral sides of the disc and short arm stumps to be examined. In this way, characters not visible in the holotype of Ophiolepis? falsa could be analysed; these revealed its taxonomic affinity with Actinozonella, dating that genus to at least 79 Ma. The close morphological similarity between Actinozonella and Ophiomisidium Koehler, 1914, and to some species currently assigned to Ophiomastus Lyman, 1878, is discussed.
Australomymar losinnoensesp. nov. is described from a female preserved in Eocene Baltic amber from Poland, which represents the first fossil record of Australomymar Girault. The species is placed in Australomymar based on the combination of 4-segmented tarsi, a 6-segmented funicle with an entire clava, a relatively broad fore wing with long venation, and a distinctly exserted ovipositor. The new species differs from extant congeners in antennal proportions, absence of a diagonal fold or line of setae on the fore wing, and ovipositor sheath length relative to the gaster. This discovery extends the known temporal range of Australomymar to the Eocene and indicates a broader past geographical distribution of the genus.
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Fossils of the Ediacara Biota preserve the oldest macroscopic communities that include animals. Classification of many of these taxa has proved contentious. Instead, studies of ecological characters reveal key insights. Here we examine the Ediacaran fossil Spriggina floundersi from the Ediacara Member, Flinders Ranges and surrounding region. Specimens from Nilpena Ediacara National Park (NENP) and the South Australia Museum (SAM) present significant morphological variation. Fossils found in situ on discrete bedding planes at NENP reveal no systematic orientation of features, suggesting variable morphologies formed via biological processes, rather than external forces. Our results support motility in Spriggina, which involved bending about the long axis, propagation of pedal waves, vertical adjustment of the anterior region and horizontal manipulation of repeated body units. A significant number of fossil specimens are bent to the left (right in life). The nature of these bends does not match expectations of anatomical asymmetry and instead constitutes the oldest described evidence of behavioural handedness. Results are consistent with Spriggina as a bilaterally symmetrical, possibly segmented, benthic organism. These characters are unique compared with known Ediacaran ecologies but are common in various extant bilaterian groups, indicating major animal innovations prior to the Phanerozoic.
A richly fossiliferous sandstone outcrop in the Wasatch Formation, Great Divide Basin, southern Wyoming, has yielded exceptionally well-preserved fossils of three omomyid primates. Here we report new occurrences of two rarely documented omomyids, Arapahovius gazini and Anemorhysis savagei, describe a new species of Tetonius, and perform a phylogenetic analysis of Tetonius and its allies; the two previously described omomyids are new additions to the fossil record of the Great Divide Basin and represent only the second and third occurrences of these species, respectively. Tetonius, Arapahovius, and Anemorhysis are not known to co-occur elsewhere, particularly in the well-documented Bighorn Basin of northwestern Wyoming, where the Tetonius + Pseudotetonius clade is locally extirpated prior to the first appearances of Arapahovius and Anemorhysis. Morphological support for the new species of Tetonius is corroborated by biostratigraphic data suggesting it is younger than Pseudotetonius ambiguus from the Bighorn Basin. However, the new species of Tetonius retains key dental symplesiomorphies that signal a relatively early divergence from the Tetonius + Pseudotetonius clade as it is recorded in the Bighorn Basin. Results from our maximum parsimony analysis indicate that Tetonius varleyorum sp. nov. from the Great Divide Basin is more closely related to P. ambiguus than either of the species of Tetonius known from the Bighorn Basin, underscoring the paraphyletic status of Tetonius with respect to Pseudotetonius proposed by earlier workers. The evolutionary history of the Tetonius + Pseudotetonius clade was more complex than previously recognized, and this added complexity can only be recognized through broader geographic sampling.
Lingulid brachiopods - the namesake "living fossils" of Darwin - have a continuous record from the Cambrian to the present and possess phosphatic valves, rendering them largely unique among extant invertebrates. Due to their poorly understood vital effects and susceptibility to taphonomic breakdown, they have not been widely adopted as geochemical archives. However, inorganic sulfate is abundant in lingulid bioapatite, which may be more resistant to diagenetic alteration than carbonate-based minerals. As such, it is possible that lingulid shells may provide an alternative, independent archive of Phanerozoic sulfate seawater chemistry, provided that the distribution and preservation of sulfur within lingulid shells can be identified. Here, we leverage sulfur K-edge micro X-ray Fluorescence (μ-XRF) imaging, X-ray Absorption Near Edge Structure (XANES) spectroscopy, and petrography to characterize sulfur speciation and distribution within extant and fossil lingulid brachiopods. In modern Lingula anatina, inorganic sulfate is dominant along francolite-rich laminae, whereas organic sulfur species are mostly observed in non-mineralized laminae and the periostracum. In the Cambrian fossil Ungula ingrica, inorganic sulfate is generally dominant in regions with the lowest sulfur abundances, with higher sulfate abundances along compact laminae than on baculate laminae. In contrast, the distribution of diagenetic pyrite is heterogenous, although largely concentrated along shell edges and particular laminae. Notably, the XANES spectrum of francolite-associated sulfate is characterized by a unique post-edge feature at 2494.0 eV. Collectively, these results suggest that carefully selected lingulid specimens - and from intra-valve laminae with minimal diagenetic phases - have the potential to be insightful for reconstructing Phanerozoic sulfate seawater chemistry.
Traditionally, saber-toothed cats, particularly species of the genus Smilodon, were considered unable to bite through bones due to the apparent fragility of their teeth. We analyze here megafauna fossil remains of Salto de Piedra palaeontological site (Humid Pampas), one of the few extensively radiometrically dated Pleistocene sites in Argentina and systematically excavated. Salto de Piedra is located near contemporary human occupation sites that have yielded megafauna remains. This spatial and chronological proximity provides an exceptional scenario to compare the prey ranges hunted by humans and by Smilodon. Here we provide Smilodon populator tooth mark patterning on their megaherbivore preys. Mark morphology demonstrates that Smilodon canines penetrated and processed cortical bone, refuting interpretations that considered them functionally fragile. These tooth marks have been compared with other carnivores and saber-toothed felid fossil sites. This spatial and chronological control provides direct evidence of predatory activity and constrains its temporal span, enabling evaluation of the ecological role of this hypercarnivore. This extraordinary discovery provides direct evidence of Smilodon 's predation, and confirms that it was an apex predator, focused almost exclusively on megafauna. These tooth marks can be identified and extrapolated to other fossil sites. Furthermore, this diagnostic tooth-mark pattern enables reconstruction of prey preferences. Our results indicate that Smilodon exerted sustained predatory pressure across a broad range of megaherbivores. Despite the spatial proximity and temporal overlap between Smilodon predation (22.2-13.3 ka BP) at Salto de Piedra and human arrival to this area (~ 14 ka BP), no interactions between these two predators has been observed indicating certain avoidance between them. The complex predator-prey trophic interactions during the Late Pleistocene-Holocene transition in the Pampas region of South America, support multicausal models, integrating ecological and anthropogenic drivers. Evidence from the iconic saber-toothed cat, Smilodon, reveals that megafauna was shared by them and human hunting. The Salto de Piedra site, located in the Humid Pampas of Argentina, has yielded an exceptional find: a key contribution, as no study of this kind had ever been carried out on Smilodon before. In this paper, we describe and characterise the diagnostic pattern of bite marks attributable to Smilodon populator (saber-toothed) on the bones of its prey. Until now, no bite marks on their prey bones had ever been described for this iconic predator, which was thought to have particularly fragile canines for marking bone. Our study shows that Smilodon fed on a wide range of megaherbivores, far greater than that found in contemporary human settlements near Salto de Piedra.
Total-evidence phylogenetic analyses combine multiple data types, but the relative influence of different partitions can be difficult to assess. This is especially true in morphological studies that analyse traditional discrete characters together with geometric morphometric (GM) landmarks, because these partitions differ in structure, scale and completeness. Here, we test how varying the weight of a cranial landmark configuration relative to craniodental discrete characters affects tree length contribution and topology in parsimony analyses of extant primates and fossil hominins. We performed two iterative weighting series: one including all available GM and discrete data, and another excluding discrete characters for two fossil hominins so they were represented only by GM data. In both series, increasing GM weight produced stepwise, not continuous, topological change, with multiple iterations yielding identical most parsimonious trees before new topologies emerged. GM contribution to total tree length increased nonlinearly, suggesting diminishing returns. Topological shifts were concentrated among fossil hominins and were most pronounced when some taxa were represented only by heavily weighted landmark data. These results show that GM data can meaningfully affect parsimony-based phylogenetic inference, but their impact depends strongly on weighting and missing data distribution.
Despite the important advances made in the taxonomy of water fleas (Crustacea: Cladocera), many taxa have not yet been revised. The genus Simocephalus Schoedler, 1858 (Anomopoda: Daphniidae) belongs to understudied groups. During the last forty years, several attempts have been made to use genetic approaches to estimate species diversity within Simocephalus. At the same time, investigations on morphology almost stopped after the last revision of Orlova-Bienkowskaja (2001). The lack of morphological data, even on the most widespread taxa, makes it difficult to apply the remains of this group to paleoecological reconstructions, although Simocephalus ephippia are common in subfossil sediments and fossils of different geological ages. We investigated more than 80 ephippia of recent representatives of the genus from Eurasia and North America, and 45 ephippia from Pleistocene sites of different ages on these two continents. For the first time, we have distinguished three main morphotypes based on the sculpture of the ephippia among the recent representatives. Ephippia of the vetulus-type are covered by polygonal hillocks of moderate height and with prominent processes. This morphotype is the most common in Eurasia, but it could be found on other continents, considering the distribution patterns of the S. vetulus species complex. Ephippia of the vetuloides-mixtus-type are covered by hillocks with processes strongly protruding above the ephippium surface. This morphotype is found only in the Asian part of Russia; it has more localized distribution than the vetulus-type. Ephippia of the serrulatus-type are covered by almost flat hillocks, or with hillocks of moderate height. This morphotype is found in both Eurasia and North America, which may confirm previous genetic data on a close relationship between serrulatus populations from the Eastern Palearctic and North America. Ephippia of the vetulus- and serrulatus-types are found in several Pleistocene localities. Due to lack of information about ornamentation patterns of Simocephalus ephippia of pre-Cenozoic age, we could not estimate the precise time of the morphotype separation. However we may conclude that in the Late Pleistocene the vetulus- and serrulatus-types were broadly distributed in Northern Eurasia and North America. Simocephalus ephippia demonstrate a morphological stasis at least since the Late Pleistocene, or even during longer time. In Maly Chukochiy Cape deposits (Republic Yakutia) we found a sole ephippium presumably belonging to an extinct taxon of Simocephalus. Eastern parts of Northern Eurasia had diverse communities of Simocephalus at the Pleistocene-Holocene boundary, and these then changed analogously to the transformation of Daphnia communities. In the course of our work, we obtained a large set of illustrations of Simocephalus ephippium morphology in different populations. We hope that our study will attract more attention to the taxonomy of modern Simocephalus and its Pleistocene-earlier Holocene subfossil ephippia.
We here describe a fossil jaw fragment from the middle Eocene (Lutetian) Uzunçarşıdere Formation in Anatolia, pertaining to a pleurodontan iguanian. This region during most of the Eocene was part of an isolated insular landmass, called Balkanatolia, that is mostly known for its peculiar and diverse insular mammalian fauna. The lizard specimen represents the first evidence of Eocene reptiles from Balkanatolia, providing a first glimpse into the herpetofaunas of this, now lost, insular landmass. The fossil material is rather fragmentary, precluding a more precise identification, but its distinctive tooth morphology confirms the presence of pleurodontan iguanians in the region for the first time. The presence of a distinct mesiodistal groove along the apical crest of the central cusp in the teeth of the Anatolian pleurodontan is of particular interest, as this feature is otherwise observed only in the Eocene genera Cadurciguana from Western Europe and Parasauromalus from North America, plus the extant American lineages of Dactyloidae, Leiocephalidae, and Polychrotidae. Interestingly, this feature seems to be absent from all other pleurodontans, including the abundant Eocene corytophanid Geiseltaliellus. The new find indicates another successful overseas dispersal of pleurodontans, a group that has repeatedly colonized distant landmasses, including oceanic islands, throughout its evolutionary history. Taking into consideration the diversity and abundance of pleurodontans in the Eocene of Europe and the total absence of the group from coeval Africa and Asia, it is likely that the new Anatolian iguana arrived from the former continent sometime between the early and early middle Eocene.
Anthropogenic climate change presents significant health challenges for older people with care needs across all care settings, from private homes and supported living arrangements to institutional care facilities. Those particularly at risk include individuals with limited mobility, multimorbidity, or social isolation. Care and support systems therefore need to implement measures for both climate change mitigation and adaptation. Mitigation encompasses reducing energy and water consumption, minimising waste, decreasing reliance on fossil fuels, managing chemicals, and strengthening political and regulatory cooperation. Adaptation involves capacity building, technological innovation, financial management, education and research, monitoring and evaluation, as well as institutional and social support. The effectiveness of structural, organisational, and social measures, such as thermally resilient buildings, efficient ventilation and cooling systems, emergency power supply, secure water and waste infrastructure, hygiene standards, and community-based support services, is well documented. Good practice examples, including community-based support in home settings, structural and technical modernisation in care facilities, and strategic instruments in procurement and governance, demonstrate that climate-resilient strategies enhance care security, support the prevention of care dependency, improve the quality of life of older people, and simultaneously achieve ecological and economic objectives. Climate mitigation and adaptation are integral components of future-oriented, needs-based care, positioning care facilities and community structures as key levers for sustainable transformation. Der menschengemachte Klimawandel stellt ältere, pflegebedürftige Menschen in allen Versorgungssettings, von zu Hause über betreute Wohnformen bis hin zu Pflegeeinrichtungen, vor erhebliche gesundheitliche Herausforderungen. Besonders vulnerabel sind Personen mit eingeschränkter Mobilität, Multimorbidität oder sozialer Isolation. Pflege- und Betreuungsstrukturen müssen daher Maßnahmen zur Klimawandelminderung (Mitigation) und Klimawandelanpassung (Adaptation) umsetzen. Mitigation umfasst die Reduktion von Energie- und Wasserverbrauch, Abfallminimierung, Senkung fossiler Brennstoffnutzung, Chemikalienmanagement sowie politische und regulatorische Kooperation. Adaptation beinhaltet Kapazitätsaufbau, technologische Innovation, finanzielle Steuerung, Bildung und Forschung, Monitoring, Evaluation sowie institutionellen und sozialen Support. Die Wirksamkeit baulicher, organisatorischer und sozialer Maßnahmen, etwa thermisch robuste Gebäude, effiziente Belüftungs- und Kühlsysteme, Notstromversorgung, sichere Wasser- und Abfallinfrastruktur, Hygienestandards und kommunale Unterstützungsangebote, ist gut dokumentiert. Good-Practice-Beispiele wie kommunale Unterstützungsangebote im häuslichen Umfeld, bauliche und technische Modernisierungen in Pflegeeinrichtungen sowie strategische Instrumente im Beschaffungs- und Governancebereich zeigen, dass klimaresiliente Strategien die Versorgungssicherheit erhöhen, Pflegebedarfsprävention fördern, die Lebensqualität älterer Menschen verbessern und gleichzeitig ökologische sowie ökonomische Ziele erreichen. Klimaschutz und Klimaanpassung sind integrale Bestandteile einer zukunftsfähigen, bedarfsgerechten Versorgung und machen Pflegeeinrichtungen sowie kommunale Strukturen zu Hebeln für nachhaltigen Wandel.
Sludge resource recovery is a promising strategy for mitigating carbon emissions from wastewater treatment plants (WWTPs). However, decision-making for carbon reduction strategies faces significant uncertainties, due to the coupling between wastewater and sludge treatment processes, as well as the inherent variability in sludge characteristics. To systematically quantify the carbon reduction potential of sludge resource recovery and mitigate decision-making risks, an integrated methodological framework was developed in this study by combining dynamic modeling and life cycle assessment (LCA), applied to a typical Anaerobic-Anoxic-Oxic process case. The dynamic model provided a calibrated, site-specific simulation of wastewater treatment processes, providing daily estimates of CH4, N2O, and fossil-derived CO2 emissions, as well as sludge production and characteristics. The site-specific data generated by the model showed 89.11%-91.55% lower variability in sludge characteristics compared to generic literature data. These model-derived site-specific inputs reduced the uncertainty ranges in the LCA of sludge resource recovery, revealing that under current electricity conditions, emission offsets are limited to 41%-57% of the plant-wide carbon footprints. Under the assumed future cleaner electricity scenarios, sludge land use and anaerobic digestion coupled with land-use strategies were projected to approach or reach plant-wide net-zero emissions for the investigated WWTP, with net emissions as low as -2,744 t CO2-eq by 2050..Furthermore, cleaner electricity mixes reduced the carbon reduction potential of sludge-to-energy conversion by 18% and 22% for anaerobic digestion with land use and pyrolysis alone, respectively. The integrated dynamic model-LCA framework substantially reduced decision-making risks for sludge-based carbon reduction by generating high-precision site-specific data. The study provides a scientific basis for optimizing plant-wide low-carbon strategy.
The examination of chitons (Polyplacophora) associated with sandy bioclastic sediments collected in the southwestern Adriatic Sea (Mediterranean Basin) revealed the presence of three previously undescribed species: Leptochiton elisabettaesp. nov., L. gaiaesp. nov., and Ischnochiton falkorisp. nov. The latter two species preserve dried soft parts, allowing preliminary anatomical observations, particularly of the girdle. In addition, the studied sediments yielded valves of rare and recently described taxa (Leptochiton antondhorni, L. salicensis and Ischnochiton sigwartae), enabling refinement of their shell morphological characters. Notably, some species identified in these submerged deposits known only from disarticulated valves (L. salicensis and I. sigwartae) had been previously recorded exclusively from onshore Pleistocene deposits of Italy. Their presence in the Recent Mediterranean fauna remains unconfirmed and has so far been interpreted as representing palimpsest late Pleistocene fossils within this basin. The Polyplacophoran fauna of the Mediterranean basin presently comprises approximately 50 species, including a few taxa known only from putative last-glacial fossil records. It is foreseeable that this number will increase further, owing to more in-depth investigation of previously poorly explored habitats, not only in deep-sea environments, and to the increasingly widespread use of molecular techniques.
Here we describe two new fossil species and one new genus of pseudoscorpions, found in the late Eocene Baltic amber. Baltochthonius andrushchenkoi gen. et sp. nov. and Heterolophus eridanus sp. nov. are assigned to the subfamily Tridenchthoniinae (Pseudoscorpiones: Chthoniidae). We present an updated diagnostic key for the tribes, genera and subgenera of Tridenchthoniinae. The biogeographic, paleohabitat and ecological features of new species are presented and compared to the related extinct and extant species of the subfamily Tridenchthoniinae.
Propane upgrading is fundamentally constrained by the high energy demand of conventional dehydrogenation and the reliance of hydroformylation on fossil-derived syngas, limiting both efficiency and sustainability. We redesign this architecture by establishing a carbon dioxide (CO2)-assisted oxidative dehydrogenation-hydroformylation (CO2-ODH-HF) cascade that replaces propane dehydrogenation (PDH) with a CO2-ODH reactor and circulates CO2 to generate carbon monoxide (CO) and dihydrogen (H2) internally. Aspen Plus simulations show that this shift in reaction route creates a syngas self-sufficient system in which propylene formation, CO2 utilization, and hydroformylation become directly coupled. The integrated cascade enhances carbon-utilization efficiency, eliminates external CO procurement, and substantially reduces total production costs compared with PDH-HF. Life-cycle assessment further indicates ~42% lower greenhouse-gas emissions per kilogram of aldehyde produced, without triggering economic-environmental trade-offs. Sensitivity analyses reveal strong robustness against fluctuations in the feed price of liquefied petroleum gas (LPG) containing propane compounds, CO cost, and hydroformylation catalyst loss. By restructuring underlying reaction pathways and carbon flows, the CO2-ODH-HF cascade establishes a scalable and carbon-efficient route for propane upgrading and aldehyde synthesis.
While in humans, the flexed position of the fetus and its rotating course down the birth canal are well documented, in other primates the mechanism of labor is unknown. Despite the lack of comparative data, it is commonly assumed that the human obstetric mechanism is unique, and anthropologists have disputed when and why the transition to the modern human mechanism occurred. The purpose of this study is to establish the mechanism of labor in two species of nonhuman primates. The data in this study consist of a series of radiographs taken throughout labor in unanesthetized, unrestrained, spontaneously laboring Papio anubis (n = 4) and Saimiri boliviensis (n = 7), pelvimetric radiographs, and neonatal cephalometry. In both species, the fetus normally presents in extension, with the face or brow dilating the cervix, and the head being delivered with the mentum anterior. Contra popular assumption, fetal rotation during labor was observed, and was analogous to rotation in human face presentations. Dramatic pelvic deformation, but not fetal head molding, was recorded. I suggest that previously published cephalopelvic ratios of nonhuman primates do not accurately represent the obstetric situation. Here, measurements of the actually constrictive diameters of the nonhuman primate pelvis and functionally significant measures of the fetal head are presented. The implications of this study for the obstetric evaluation of fossil hominid pelves are discussed.