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Raoellidae are small fossil cetartiodactyls closely related to the Cetacea. Until now undisputable raoellid remains were reported only from the early Middle Eocene of the Indian Subcontinent, although this Indo-Pakistani endemism has been challenged by several recent works describing potential raoellids from Mongolia, Myanmar and China. In this contribution we address the question of raoellid taxonomic content and definition, through a revision of the dental features of the family. This work, which includes a revision of the putative raoellid material from outside Indo-Pakistan, is primarily based on a re-examination of ‘suoid’ specimens from Shanghuang (Middle Eocene, coastal China). Our results indicate that the Shanghuang material both substantiates the youngest and easternmost occurrence of Raoellidae and represents the only unquestionable record of raoellids outside the Indian Subcontinent at present. This significantly extends the geographical and chronological range of the family. The occurrence of a raoellid species in the Middle Eocene of coastal China implies that raoellids dispersed from the Indian Subcontinent to eastern Asia during Early or Middle Eocene time. This tempers classical hypotheses of Middle Eocene Indian endemism and eastern Asian provincialism. [ABSTRACT FROM PUBLISHER]

Modern humans have populated Europe for more than 45,000 years 1,2 . Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period 3 . Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe 4 , but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants., (© 2023. The Author(s).)

Domestication has led to many changes in domestic animal biology, including their anatomy. The shape of the inner ear, part of the mammalian ear, has been found particularly relevant for discriminating domesticated species, their hybrids or differentiating the wild and domestic populations of a single species. Here we assessed the use of the size and shape of the semicircular canals (SCC) of the inner ear as a marker of pig domestication. We studied a total of 63 petrosal bones belonging to wild boar (Sus scrofa, two populations) and domestic pigs (extensively and intensively reared specimens) that were µCT-scanned and from which the size and the shape of the inner ear were quantified through geometric morphometrics, analyzing the 3D coordinates of 6 landmarks and 60 sliding semilandmarks localized on the SCC and the common crus. The domestic pigs have larger SCC than the wild boar from which they also strongly differ in shape (correct cross validation of 95.5%, confidence interval: 92.3%-98.1%). Strong shape differences were detected between the two populations of wild boar, as well as a sexual size dimorphism. All together the results highlight the taxonomic discriminant power of the SCC of the inner ear shape, and its relevance for domestication studies., (© 2022 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution published by Wiley Periodicals LLC.)

Endothermy underpins the ecological dominance of mammals and birds in diverse environmental settings 1,2 . However, it is unclear when this crucial feature emerged during mammalian evolutionary history, as most of the fossil evidence is ambiguous 3-17 . Here we show that this key evolutionary transition can be investigated using the morphology of the endolymph-filled semicircular ducts of the inner ear, which monitor head rotations and are essential for motor coordination, navigation and spatial awareness 18-22 . Increased body temperatures during the ectotherm-endotherm transition of mammal ancestors would decrease endolymph viscosity, negatively affecting semicircular duct biomechanics 23,24 , while simultaneously increasing behavioural activity 25,26 probably required improved performance 27 . Morphological changes to the membranous ducts and enclosing bony canals would have been necessary to maintain optimal functionality during this transition. To track these morphofunctional changes in 56 extinct synapsid species, we developed the thermo-motility index, a proxy based on bony canal morphology. The results suggest that endothermy evolved abruptly during the Late Triassic period in Mammaliamorpha, correlated with a sharp increase in body temperature (5-9 °C) and an expansion of aerobic and anaerobic capacities. Contrary to previous suggestions 3-14 , all stem mammaliamorphs were most probably ectotherms. Endothermy, as a crucial physiological characteristic, joins other distinctive mammalian features that arose during this period of climatic instability 28 ., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Africa has played a pivotal role in the evolution of early proboscideans (elephants and their extinct relatives), yet vast temporal and geographical zones remain uncharted on the continent. A long hiatus encompassing most of the Eocene (Ypresian to the Early Priabonian, around 13 Myr timespan) considerably hampers our understanding of the early evolutionary history of the group. It is notably the case with the origin of its most successful members, the Elephantiformes, i.e. all elephant-like proboscideans most closely related to modern elephants. Here, we describe a proboscidean lower molar discovered in Lutetian phosphate deposits from Togo, and name a new genus and species, Dagbatitherium tassyi . We show that Dagbatitherium displays several elephantiform dental characteristics such as a three-layered Schmelzmuster, the presence of a mesoconid, transversely enlarged buccal cusps and the individualization of a third lophid closely appressed to a minute distal cingulid. Dagbatitherium represents a stem Elephantiformes, pushing back the origin of the group by about 10 Myr, i.e. a third of its currently known evolutionary history. More importantly, Dagbatitherium potentially unlocks the puzzle of the origin of the unique elephantiform tooth crown organization by bridging a critical temporal and morphological gap between early bunodont incipiently bilophodont proboscidean taxa and more derived elephantiforms.

Studying ontogeny in both extant and extinct species can unravel the mechanisms underlying mammal diversification and specialization. Among mammalian clades, Cetartiodactyla encompass species with a wide range of adaptations, and ontogenetic evidence could clarify longstanding debates on the origins of modern specialized families. Here, we study the evolution of dental eruption patterns in early diverging cetartiodactyls to assess the ecological and biological significance of this character and shed new light on phylogenetic issues. After investigation of the ontogenetic dental series of 63 extinct genera, our parsimony reconstructions of eruption state evolution suggest that the eruption of molars before permanent premolars represents a plesiomorphic condition within Cetartiodactyla. This result substantially differs from a previous study based on modern species only. As a result, the presence of this pattern in most ruminants might represent an ancestral condition contributing to their specialized herbivory, rather than an original adaptation. In contrast, the late eruption of molars in hippopotamoids is more likely related to biological aspects, such as increases in body mass and slower pace of life. Our study mainly shows that eruption sequences reliably characterize higher level cetartiodactyl taxa and could represent a new source of phylogenetic characters, especially to disentangle the origin of hippopotamoids and cetaceans.

Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility., (© 2017 The Authors.)

The affinities of the Hippopotamidae are at the core of the phylogeny of Cetartiodactyla (even-toed mammals: cetaceans, ruminants, camels, suoids, and hippos). Molecular phylogenies support Cetacea as sister group of the Hippopotamidae, implying a long ghost lineage between the earliest cetaceans (approximately 53 Ma) and the earliest hippopotamids (approximately 16 Ma). Morphological studies have proposed two different sister taxa for hippopotamids: suoids (notably palaeochoerids) or anthracotheriids. Evaluating these phylogenetic hypotheses requires substantiating the poorly known early history of the Hippopotamidae. Here, we undertake an original morphological phylogenetic analysis including several "suiform" families and previously unexamined early Miocene taxa to test previous conflicting hypotheses. According to our results, Morotochoerus ugandensis and Kulutherium rusingensis, until now regarded as the sole African palaeochoerid and the sole African bunodont anthracotheriid, respectively, are unambiguously included within the Hippopotamidae. They are the earliest known hippopotamids and set the family fossil record back to the early Miocene (approximately 21 Ma). The analysis reveals that hippopotamids displayed an unsuspected taxonomic and body size diversity and remained restricted to Africa during most of their history, until the latest Miocene. Our results also confirm the deep nesting of Hippopotamidae within the paraphyletic Anthracotheriidae; this finding allows us to reconstruct the sequence of dental innovations that links advanced selenodont anthracotheriids to hippopotamids, previously a source of major disagreements on hippopotamid origins. The analysis demonstrates a close relationship between Eocene choeropotamids and anthracotheriids, a relationship that potentially fills the evolutionary gap between earliest hippopotamids and cetaceans implied by molecular analyses.