Hasil untuk "Fossil man. Human paleontology"

Andrea Villa, Michael Rummel

Rhodanogekko vireti is one of the least known extinct geckos. It was described based on an isolated frontal from the middle Eocene of France, which until now includes the only material assigned to this species. In this contribution, we report an additional isolated frontal, coming from the lower Oligocene of southern Germany, which can be attributed to R. vireti based on a strong middle constriction and a dorsal rugose sculpturing. The new fossil extends the stratigraphic record of the species by about 10 Myr, and it is the first evidence for its presence outside France. The phylogenetic position of Rhodanogekko is still uncertain, but affinities with Sphaerodactylidae were suggested previously. If this is correct, the new frontal from Germany would fit into a stratigraphic gap without recorded confident sphaerodactylids in Europe, spanning the entire Oligocene. However, Rhodanogekko lacks the posterodorsal depressions or grooves apomorphic for frontals of Euleptinae, the subfamily including all European sphaerodactylids, extant and extinct. Additional fossils are needed to understand the relationships between Rhodanogekko and other gekkotans, and we here highlight the potential borne by the late Paleogene fossil record from southern Germany for new discoveries of these reptiles.

Nil-Jana Akpinar, Sandeep Avula, CJ Lee et al.

Large Language Models (LLMs) are increasingly used to generate and edit scientific abstracts, yet their integration into academic writing raises questions about trust, quality, and disclosure. Despite growing adoption, little is known about how readers perceive LLM-generated summaries and how these perceptions influence evaluations of scientific work. This paper presents a mixed-methods survey experiment investigating whether readers with ML expertise can distinguish between human- and LLM-generated abstracts, how actual and perceived LLM involvement affects judgments of quality and trustworthiness, and what orientations readers adopt toward AI-assisted writing. Our findings show that participants struggle to reliably identify LLM-generated content, yet their beliefs about LLM involvement significantly shape their evaluations. Notably, abstracts edited by LLMs are rated more favorably than those written solely by humans or LLMs. We also identify three distinct reader orientations toward LLM-assisted writing, offering insights into evolving norms and informing policy around disclosure and acceptable use in scientific communication.

Marcelo Reguero, María Susana Bargo, Sergio F. Vizcaíno

The process of organizing early collections for the simple sake of storing and retrieving information—for example, assigning identifying numbers to specimens, recording those numbers in a catalog, and, more recently, adding that information to a computerized database—has long been central to museum collections management. In this sense, catalog numbers are vital when specimens are used for research. Particularly the early fossil vertebrate collections (“Old Collections”) of the Museo de La Plata, Argentina, incorporated in the last decades of the 19th Century and the beginning of the 20th century (that is, between 1884 and 1902) to this institution are considered foundational. They hold approximately 35,000 specimens that show diverse and varied ways in the curatorial and cataloging procedures carried out throughout time. In this contribution, we selected the notoungulate mammals Nesodontinae (Toxodontidae) from the Santa Cruz Formation (Early–Middle Miocene) housed in the Vertebrate Paleontology collection, as a sample study. The reasons to study this group are: (1) its scientific importance, as it was one of the best studied between 1887 and 1894; (2) it includes some of the first vertebrates incorporated into the Museo de La Plata in 1884; and (3) there are a large number of specimens in the collection. More than 780 specimens were reviewed, with 84 type specimens registered, several previously reported as lost.

Florian Bouchet, Clément Zanolli, Josep Fortuny et al.

Abstract Pliopithecoids are a clade of stem catarrhines represented by multiple Middle to Late Miocene genera in the Vallès-Penedès Basin (NE Iberian Peninsula). The recent description of the crouzeliid Fanchangia (Early Miocene, China) and the recognition that Pliobates (Late Miocene, Spain) is a crouzeliid enable to revisit the taxonomic affinities of some pliopithecoid remains from this basin, namely an M2 from Trinxera del Ferrocarril-Sant Quirze (SQ-TF; ~11.6–11.2 Ma), generally interpreted as a pliopithecid, and a dP4 from Can Feliu 2 (CF2; <11.2 Ma), previously considered a crouzeliid. We redescribe these remains based on both external morphology and enamel-dentine junction (EDJ), and compare them with those of other pliopithecoids. A cladistic analysis of dental features is performed using a dental matrix that includes the dP4 position, while the M2 EDJ shape is compared using landmark-based three-dimensional geometric morphometric (3DGM) analysis. Finally, body mass is estimated based on M2 size using available allometric equations. Our qualitative comparisons show that the M2 resembles in some regards the Asian anapithecines Laccopithecus and Fanchangia but is less derived than Anapithecus, while the 3DGM analysis supports its crouzeliid affinities and hints at differences from crouzeliines. In turn, the dP4 resembles that of crouzeliids, including the anapithecine Fanchangia and the crouzeliines Pliobates and Crouzelia. Given size congruence and close geographic and temporal proximity, it is likely that both specimens belong to a single, medium-sized crouzeliid species. A cladistic analysis of the two specimens simultaneously supports a sister-taxon relationship with Fanchangia within anapithecine crouzeliids. We conclude that the remains from SQ-TF and CF2 belong to the Crouzeliidae and, likely, to a medium-sized anapithecine. Given the scarcity of the material, we refrain from erecting a new species and provisionally refer to this taxon as Anapithecinae nov.—in the hope that future fieldwork will eventually recover additional, more complete material.

Orangel Aguilera, Carlos De Gracia, Félix Rodriguez et al.

Abstract Although lutjanid snappers are widely distributed and diverse marine fishes living in tropical America (the Central Western Atlantic and Central Eastern Pacific), no fossil skeletons of Lutjanidae are reported from the Neogene. Here we describe the first specimens of Lutjanidae from the Chagres Sandstone Member of the late Miocene Chagres Formation, located on the Panamanian Caribbean coast. The skull and the postcranial bones of the specimen indicate that it represents an undescribed species of the genus Etelis. The new taxon is characterized by a moderately deep skull with dorsal surface slanted 29 ͦ relative to the horizontal axis, a large orbit, an opercle with a distal margin forming a wide spine, a posterior margin of the preopercle that is serrated without prominent spines, premaxilla and dentary with a single row of dental alveoli. The mouth is slightly oblique, and the body is elongate and slender. The dorsal fin aligns with the pectoral fins, while the pelvic fin is short and does not reach the anal fin. Oceanic water interchange and species dispersal associated with marine currents flowing eastward through the Central American Seaway appear to have driven the diversification of the American Lutjanidae prior to the complete closure of the Panama Isthmus. The palaeoceanographic changes driven by this geological event triggered a faunal turnover that shaped the extant marine diversity in the Caribbean. The newly described lutjanid is associated to a markedly bathyal (200–500 m) archipelagic and interoceanic seaway strait in central Panama (the Last Interoceanic Central American Deep Strait, LICADS). ZooBank LSI: urn:lsid:zoobank.org:pub:30823570-21C4-4685-AFCF-C1C916577ABC

Jéhan Le Cadre, Jörg U. Hammel, Roland R. Melzer et al.

Abstract Amber resin is known for its exceptional preservations thanks to quick encapsulation of animals and plant material. Fast encapsulation not only helps preserve detailed organisms, but it also offers a glimpse into “frozen behaviors” from up to hundreds of million years, which provide information into the configuration of past ecosystems. We here investigated a syninclusion preserved in Baltic amber (~40 mya) consisting of a fossilized bristly millipede and two mite specimens, located in close proximity to the millipede’s ventral side. The two mites are representatives of Glaesacarus rhombeus, a frequently reported species of mite in Eocene amber whose lineage is considered to be now extinct. The bristly millipede is a female adult identified as a representative of Polyxenus. The specimen exhibits remarkable morphological similarities to the extant species Polyxenus lagurus, indicating the possibility of P. lagurus thriving since the Eocene. The striking persistence of morphological traits over millions of years suggests a stable ecological niche and effective adaptive strategies in Polyxenus. This unexpected association sheds new light on the ecosystem of Eocene forests and the potential effectiveness of defensive mechanisms, already present at that time, since one of the two mites is touching and seemingly surrounded by the posterior defensive setae of the millipede. Together, these findings enhance our understanding of the life of fossil Polyxenida and the evolutionary stability of Polyxenus, highlighting their long-term evolutionary resilience and success.

Nils Mandischer, Alexander Atanasyan, Ulrich Dahmen et al.

The digital twin of humans is a relatively new concept. While many diverse definitions, architectures, and applications exist, a clear picture is missing on what, in fact, makes a human digital twin. Within this context, researchers and industrial use-case owners alike are unaware about the market potential of the - at the moment - rather theoretical construct. In this work, we draw a holistic vision of the human digital twin, and derive the specification of this holistic human digital twin in form of requirements, stakeholders, and users. For each group of users, we define exemplary applications that fall into the six levels of functionality: store, analyze, personalize, predict, control, and optimize. The functionality levels facilitate an abstraction of abilities of the human digital twin. From the manifold applications, we discuss three in detail to showcase the feasibility of the abstraction levels and the analysis of stakeholders and users. Based on the deep discussion, we derive a comprehensive list of requirements on the holistic human digital twin. These considerations shall be used as a guideline for research and industries for the implementation of human digital twins, particularly in context of reusability in multiple target applications.

Yi Wen, Meng Xia

Real-time reflection plays a vital role in synchronous communication. It enables users to adjust their communication strategies dynamically, thereby improving the effectiveness of their communication. Generative AI holds significant potential to enhance real-time reflection due to its ability to comprehensively understand the current context and generate personalized and nuanced content. However, it is challenging to design the way of interaction and information presentation to support the real-time workflow rather than disrupt it. In this position paper, we present a review of existing research on systems designed for reflection in different synchronous communication scenarios. Based on that, we discuss design implications on how to design human-AI interaction to support reflection in real time.

Nolan Platt, Ethan Luchs, Sehrish Nizamani

Usability evaluations are essential for ensuring that modern interfaces meet user needs, yet traditional heuristic evaluations by human experts can be time-consuming and subjective, especially early in development. This paper investigates whether large language models (LLMs) can provide reliable and consistent heuristic assessments at the development stage. By applying Jakob Nielsen's ten usability heuristics to thirty open-source websites, we generated over 850 heuristic evaluations in three independent evaluations per site using a pipeline of OpenAI's GPT-4o. For issue detection, the model demonstrated moderate consistency, with an average pairwise Cohen's Kappa of 0.50 and an exact agreement of 84%. Severity judgments showed more variability: weighted Cohen's Kappa averaged 0.63, but exact agreement was just 56%, and Krippendorff's Alpha was near zero. These results suggest that while GPT-4o can produce internally consistent evaluations, especially for identifying the presence of usability issues, its ability to judge severity varies and requires human oversight in practice. Our findings highlight the feasibility and limitations of using LLMs for early-stage, automated usability testing, and offer a foundation for improving consistency in automated User Experience (UX) evaluation. To the best of our knowledge, our work provides one of the first quantitative inter-rater reliability analyses of automated heuristic evaluation and highlights methods for improving model consistency.

Sara Bertelli, Norberto Pedro Giannini, Daniel Alfredo García-López et al.

A new fossil bird is described from the Upper Lumbrera Formation of Northwestern Argentina. Lumbrerornis rougieri gen. et sp. nov. is represented by three-dimensionally preserved elements of the hindlimb of a single individual. Morphological comparative studies and particular characters of the tibiotarsus suggest that the new species might be related to the extinct clades Palaeotididae and Geranoididae of the Northern Hemisphere, which were recently hypothesized to be Paleogene palaeognathous birds. However, the fragmentary preservation of the new fossil prevents a confident systematic position. The Upper Lumbrera Formation is a widely recognized fossiliferous unit with a very rich fauna of mammals and other vertebrates (e.g., fishes, crocodilians, turtles, snakes). This is the first record of a three-dimensionally preserved fossil bird from the Eocene of northwestern Argentina and thus provides fresh evidence of the Eocene faunas from the area and improves our understanding of the poorly known early Paleogene avifaunas from South America.

Shreyas Bhat, Joseph B. Lyons, Cong Shi et al.

With the advent of AI technologies, humans and robots are increasingly teaming up to perform collaborative tasks. To enable smooth and effective collaboration, the topic of value alignment (operationalized herein as the degree of dynamic goal alignment within a task) between the robot and the human is gaining increasing research attention. Prior literature on value alignment makes an inherent assumption that aligning the values of the robot with that of the human benefits the team. This assumption, however, has not been empirically verified. Moreover, prior literature does not account for human's trust in the robot when analyzing human-robot value alignment. Thus, a research gap needs to be bridged by answering two questions: How does alignment of values affect trust? Is it always beneficial to align the robot's values with that of the human? We present a simulation study and a human-subject study to answer these questions. Results from the simulation study show that alignment of values is important for trust when the overall risk level of the task is high. We also present an adaptive strategy for the robot that uses Inverse Reinforcement Learning (IRL) to match the values of the robot with those of the human during interaction. Our simulations suggest that such an adaptive strategy is able to maintain trust across the full spectrum of human values. We also present results from an empirical study that validate these findings from simulation. Results indicate that real-time personalized value alignment is beneficial to trust and perceived performance by the human when the robot does not have a good prior on the human's values.

Zhenzhi Wang, Yixuan Li, Yanhong Zeng et al.

Human image animation involves generating videos from a character photo, allowing user control and unlocking the potential for video and movie production. While recent approaches yield impressive results using high-quality training data, the inaccessibility of these datasets hampers fair and transparent benchmarking. Moreover, these approaches prioritize 2D human motion and overlook the significance of camera motions in videos, leading to limited control and unstable video generation. To demystify the training data, we present HumanVid, the first large-scale high-quality dataset tailored for human image animation, which combines crafted real-world and synthetic data. For the real-world data, we compile a vast collection of real-world videos from the internet. We developed and applied careful filtering rules to ensure video quality, resulting in a curated collection of 20K high-resolution (1080P) human-centric videos. Human and camera motion annotation is accomplished using a 2D pose estimator and a SLAM-based method. To expand our synthetic dataset, we collected 10K 3D avatar assets and leveraged existing assets of body shapes, skin textures and clothings. Notably, we introduce a rule-based camera trajectory generation method, enabling the synthetic pipeline to incorporate diverse and precise camera motion annotation, which can rarely be found in real-world data. To verify the effectiveness of HumanVid, we establish a baseline model named CamAnimate, short for Camera-controllable Human Animation, that considers both human and camera motions as conditions. Through extensive experimentation, we demonstrate that such simple baseline training on our HumanVid achieves state-of-the-art performance in controlling both human pose and camera motions, setting a new benchmark. Demo, data and code could be found in the project website: https://humanvid.github.io/.

Marc Roig Vilamala, Jack Furby, Julian de Gortari Briseno et al.

Effective communication is essential in collaborative tasks, so AI-equipped robots working alongside humans need to be able to explain their behaviour in order to cooperate effectively and earn trust. We analyse and classify communications among human participants collaborating to complete a simulated emergency response task. The analysis identifies messages that relate to various kinds of interactive explanations identified in the explainable AI literature. This allows us to understand what type of explanations humans expect from their teammates in such settings, and thus where AI-equipped robots most need explanation capabilities. We find that most explanation-related messages seek clarification in the decisions or actions taken. We also confirm that messages have an impact on the performance of our simulated task.

Priscila Morales-Ortega, Gerardo Gon´zalez-Barba, Mariana Díaz-Santana-Iturrios et al.

Several cephalopods from the Eocene have been recorded along the Pacific coast of North America. Each new record incorporates relevant knowledge to infer the paleobiology of this group. In this study, we report two nautiloids (subclass Nautiloidea) from the Ypresian found in the Tepetate Formation. One specimen was identified as Eutrephoceras hannai, and the other was designated as species nova, Nautilus sudcalifornianus. We found that the suture shape, especially in the lateral lobe, is the most conspicuous diagnostic feature to discriminate nautiloids. Moreover, the biological material evaluated in our study constitutes the southernmost geographic distribution of the two species and the most ancient record of Nautilidae for the Eocene. Due to the characteristics detected in the specimens analyzed here and previous studies that describe the faunal diversity of the formation, we hypothesize that this area was an idoneous site for spawning and growth of young stages of E. hannai and N. sudcalifornianus sp. nov. during the Eocene. Thus, our study supports the hypothesis that extant nautiloids migrate towards warm shallow water areas for spawning and growth of the juvenile stage and suggests that this migratory behavior is ancient within the subclass. With this research, we provide new insights into the taxonomy, biology, ecology, and biogeography of nautiloids from the Eocene. Additionally, the Tepetate Formation has great geological and paleontological relevance given the faunal diversity discovered in this area increases the malacological record for the northeastern Pacific.

JEREMÍAS R.A. TABORDA, M. BELEN VON BACZKO, JULIA B. DESOJO

Ornithosuchids are a Late Triassic pseudosuchian archosaur group, consisting of four species (three from South America, and one from Scotland). All of them have triangular skulls with a protruding premaxilla, large nostrils, an extensive diastema in their narrow snout, a short jaw that does not reach the anterior end of the skull, and serrated posteriorly curved teeth. For this clade, carnivorous and scavenger habits have been previously proposed. Within the Ornithosuchidae, Riojasuchus tenuisceps (from Argentina) has the most morphologically extreme characteristics. Based on CT scans of the preserved skulls we generated a 3D model, and over this, we estimated the volumes of the adductors and abductor muscles and the force exerted by each. From these data we built the finite element model and measured the bite force (1.8–2.3 kN). Lateral, tractive, and torsional forces were applied to the end of the snout to evaluate the structural response of the skull during feeding. The results show that R. tenuisceps could resist tractive and torsional stresses better than lateral stress. Additionally, we analysed the peculiar morphological characteristics of the skull and their functional implications. We observed that the upper and lower dental rows were laterally separated from each other, preventing the generation of a cutting line during occlusion, and therefore, R. tenuisceps would have fed on small-sized prey that it could swallow whole. The curved premaxilla and the short mandible would not allow it to bite with the tip of the snout (ruling out the scavenging hypothesis), but were instead more adequate to capturing prey suspended in a fluid. This set of results allows us to propose that R. tenuisceps could have had a zoophagous diet and a wading habit, being able to feed on fish, amphibians, or any small animals that they could catch from the shoreline.

Sofia Yfantidou, Marios Constantinides, Dimitris Spathis et al.

This paper explores the intersection of Artificial Intelligence and Machine Learning (AI/ML) fairness and mobile human-computer interaction (MobileHCI). Through a comprehensive analysis of MobileHCI proceedings published between 2017 and 2022, we first aim to understand the current state of algorithmic fairness in the community. By manually analyzing 90 papers, we found that only a small portion (5%) thereof adheres to modern fairness reporting, such as analyses conditioned on demographic breakdowns. At the same time, the overwhelming majority draws its findings from highly-educated, employed, and Western populations. We situate these findings within recent efforts to capture the current state of algorithmic fairness in mobile and wearable computing, and envision that our results will serve as an open invitation to the design and development of fairer ubiquitous technologies.

Dominik R. G. Schleicher, Juan Pablo Hidalgo, Daniele Galli

Chemically peculiar Ap and Bp stars host strong large-scale magnetic fields in the range of $200$~G up to $30$~kG, which are often considered to be the origin of fossil magnetic fields. We assess the evolution of such fossil fields during the star formation process and the pre-main sequence evolution of intermediate stars, considering fully convective models, models including a transition to a radiative protostar and models with a radiative core. We also examine the implications of the interaction between the fossil field and the core dynamo. We employ analytic and semi-analytic calculations combined with current observational constraints. For fully convective models, we show that magnetic field decay via convection can be expected to be very efficient for realistic parameters of turbulent resistivities. Based on the observed magnetic field strength - density relation, as well as the expected amount of flux loss due to ambipolar diffusion, it appears unlikely that convection could be suppressed via strong enough magnetic fields. On the other hand, a transition from a convective to a radiative core could very naturally explain the survival of a significant amount of flux, along with the presence of a critical mass. We show that in some cases, the interaction of a fossil field with a core dynamo may further lead to changes in the surface magnetic field structure. In the future, it will be important to understand in more detail how the accretion rate evolves as a function of time during the formation of intermediate-mass protostars, including its impact on the protostellar structure. The latter may even allow to derive quantitative predictions concerning the expected population of large scale magnetic fields in radiative stars.

R. Barrena, G. Chon, H. Böhringer et al.

We present a detailed kinematical and dynamical study of the galaxy cluster RXCJ1111.6+4050 (RXCJ1111), at z = 0.0756 using 104 new spectroscopic redshifts of galaxies observed at the TNG 3.5m telescope and SDSS DR16 public archive. Our analysis is performed in a multiwavelength context in order to study and compare mainly optical and X-ray properties using XMM-Newton data. We find that RXCJ1111 is a galaxy cluster showing a velocity distribution with clear deviations from Gaussianity, that we are able to explain by the presence of a substructure within the cluster. The two cluster components show velocity dispersions of $644 \pm 56$ km/s and $410 \pm 123$ km/s, which yield dynamical masses of M$_{200}$=$1.9 \pm 0.4 \times10^{14}$ M$_{\odot}$ and $0.6 \pm 0.4 \times 10^{14}$ M$_{\odot}$ for the main system and substructure, respectively. RXCJ1111 presents an elongation in the North-South direction and a gradient of 250-350 km/s/Mpc in the velocity field, suggest that the merger axis between the main system and substructure is slightly tilted with respect to the line-of-sight. The substructure is characterized by a magnitude gap $Δm_{12} \ge 1.8$, so it fits the "fossil-like" definition of a galaxy group. Mass estimates derived from X-ray and optical are in good agreement when two galaxy components are considered separately. We propose a 3D merging model and find that the fossil group is in an early phase of collision with the RXCJ1111 main cluster and almost aligned with the line-of-sight. This merging model would explain the slight increase found in the T$_X$ with respect to what we would expect for relaxed clusters. Due to the presence of several brightest galaxies, after this collision, the substructure would presumably lose its fossil condition. Therefore, RXCJ1111 represents the observational evidence that the fossil stage of a system can be temporary and transitional.

STEPHEN R. WESTROP, ALYCE A. DENGLER

Species of Catillicephala are known from sites around the mid-Cambrian margin of Laurentian North America, including Vermont, Quebec, Newfoundland and North Greenland. Catillicephala cifellii sp. nov. is from the Downes Point Member of the Shallow Bay Formation (Cow Head Group) in western Newfoundland. It occurs in three shelf margin-derived boulders in debris flow conglomerates that accumulated in a continental slope setting. The associated trilobites and agnostoid arthropods, including Ptychagnostus aculeatus and Megagnostus glandiformis, indicate a correlation with the Lejopyge laevigata Zone. As such, C. cifellii is among the oldest representatives of the genus, and is early Guzhangian in age.

Zulma Gasparini, Leonardo Salgado, Alberto Carlos Garrido

Los estudios realizados en reptiles fósiles de las colecciones del museo “Prof. Dr. Juan A. Olsacher” de la ciudad de Zapala (Neuquén) se orientaron hacia formas marinas del Jurásico y formas continentales del Cretácico Inferior y Cretácico Superior en la Cuenca Neuquina. Vinculado a la Dirección Provincial de Minería de la provincia desde sus orígenes, el museo Olsacher prestó colaboración logística con grupos de investigación nacional e internacionales, entre los que sobresalen el grupo de reptiles marinos del Museo de La Plata. Desde 2008, el museo cuenta con personal de investigación encargado del estudio del contexto geológico y tafonómico de los restos fósiles hallados. Como resultado de las campañas realizadas en los últimos 50 años, las cuales contaron con el apoyo logístico del museo Olsacher, la institución incorporó a sus colecciones una gran cantidad de especímenes, entre ellos 15 holotipos, 7 de reptiles marinos y 8 de dinosaurios.