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The postcranial skeleton of the gliding neodiapsid reptile Coelurosauravus elivensis (Lower Sakamena Formation, ?upper Permian, southwestern Madagascar) is re-described in detail based on all previously referred specimens. The exquisite preservation of the material provides three-dimensional details of the individual bones, which are missing in the Laurasian weigeltisaurid material. A new skeletal reconstruction of C. elivensis is proposed including the first reconstruction of a weigeltisaurid reptile in lateral view. The re-examination of the material highlights interspecific differences in the postcranium of weigeltisaurids, in particular in the trunk and patagial spars. These animals have long been considered as arboreal and gliding reptiles. However, new information on the postcranium of C. elivensis reveals strong similarities with both extant and extinct quadrupeds specialized for a clinging arboreal lifestyle. Additionally, the presence of an additional phalanx in the fifth digit of the manus is now attested for all weigeltisaurids where this region is preserved. We suggest that this morphology could have allowed weigeltisaurids to grasp their patagium as observed in the extant gliding agamid Draco. Weigeltisaurids are thus the earliest known gliding vertebrates and some of the first tetrapods with an obligatory arboreal lifestyle, but also represent the only known vertebrates with a hyperphalangy aligned with a gliding apparatus.

Altres ajuts: CERCA Programme/Generalitat de Catalunya The Guadalupian was a key epoch for the evolution of tetrapod faunas. It includes the earliest unambiguous occurrences of therapsids and stereospondyls (groups that later became dominant in terrestrial and freshwater environments, respectively) and the late Capitanian mass extinction event. The low-latitude faunas from this time interval, where sufficiently dated, comprise rare tetrapod body fossils whereas the most complete records are provided by ichnoassociations, especially coming from the Provence basins of France. In this paper, we revise the tetrapod ichnoassociation from the Pélitique Formation of the Le Luc Basin of Provence, identifying the following tetrapod ichnotaxa: Batrachichnus salamandroides (temnospondyls/lepospondyls), Capitosauroides talus comb. nov. (therocephalian therapsids), Dicynodontipus isp. (cynodont therapsids), Varanopus isp. (bolosaurian parareptiles), Hyloidichnus bifurcatus (captorhinomorph eureptiles) and Rhynchosauroides isp. (neodiapsid eureptiles). According to our revised ichnotaxonomy and stratigraphic correlations, we date the Pélitique Formation as late Capitanian and assign its tetrapod ichnoassociation to the newly defined Association V (Dicynodontipus sub-biochron of the Erpetopus biochron). The Pélitique Formation ichnoassociation shows a typical composition for a post-dinocephalian extinction ichnofauna, as shown by preliminary multivariate statistics on Guadalupian-Lopingian tetrapod ichnoassociations. It is similar to the contemporaneous skeletal faunas described from the mid- to high-latitude sites of Russia and South Africa and is arguably the earliest evidence of post-dinocephalian extinction recovery at low-latitudes. Our results confirm the global and abrupt impact of the late Capitanian terrestrial mass extinction and the subsequent recovery in the low-latitude realm. This extinction was probably time-equivalent with a global benthic marine mass extinction, and both events may have been linked to climatic perturbation caused by the Emeishian volcanic activity in China, which reached its peak around 260 Ma.

International audience; The Xenacanthiformes from Central and Eastern European deposits have been extensively studied, but the systematics of the species from the French Carboniferous–Permian Autun Basin (Saône-et-Loire) remains debated. Numerous xenacanthiform remains are still identified under the doubtful genus ‘Expleuracanthus’, and many of them consist of isolated dorsal spines which are difficult to identify. Numerous well-preserved specimens are still undescribed and the diversity of the xenacanthiform fauna from the Autun Basin is poorly understood. For example, specimens of the genus Triodus from the Muse oil-shale bed (OSB) of the Autun Basin have no specific attribution, whereas this genus is widely distributed across European Carboniferous–Permian basins. In this study, we describe new specimens of Triodus from the lowermost Permian of the Muse OSB. They allow the erection of a new species, Triodus aeduorum sp. nov., and discussion of the validity of several species from the same locality: ‘Expleuracanthus’ frossardi is considered as a nomen dubium and other Triodus specimens need for the time being to be left in open nomenclature as Triodus sp. These results highlight the endemism of the Triodus species in each European Carboniferous–Permian basin and raise the question of how they migrated from one to another.

The cranial skeleton of the enigmatic gliding neodiapsid reptile Coelurosauravus elivensis (Lower Sakamena Formation, Lopingian, Southwestern Madagascar) is re-described in detail. All previously referred specimens are re-examined under both direct observations and Reflectance Transformation Imaging. Their exquisite preservation yields detailed three-dimensional information on the outline of individual bones and their osteological relationships, which are missing in the Laurasian remains. In contrast to previous studies, the ontogenetic maturity of all specimens is re-affirmed. Previously unidentified elements of the palate, braincase and mandible are described, and a novel reconstruction is proposed, including the first palatal reconstruction in a weigeltisaurid reptile. C. elivensis has the smallest skull of all weigeltisaurids and differs from other species in its facial ornamentation, parietosquamosal frill and larger anterior maxillary dentition. We also provide extensive comparisons with contemporaneous reptiles, possibly closely related taxa and more recent analogs, as well as a preliminary discussion of the functional anatomy of the peculiar cranial morphology of weigeltisaurids. The cranial skeleton is a truss construction with large orbits and temporal fenestrae. By analogy with extant chamaeleonids, the elongate parietosquamosal frill is associated with an increase in length and diameter of the temporal jaw adductors, resulting in an increased gape and/or bite force and speed. Additionally, the spikes and frills of weigeltisaurids most likely served as a display and defensive structure.

A new crocodylomorph from the upper Barremian Incigez Formation of Zonguldak (NW Turkey) is described for the first time based on jaw and limb bone elements from the collection of the Istanbul Technical University. The material is attributed to Turcosuchus okani gen. et sp. nov. according to a unique combination of character states, such as a strong heterodonty, composed of non-spatulated teeth, a maximum of 10 teeth posterior to the symphysis, a sigmoidal dorsal margin of the dentary in lateral view, and a splenial excluded from the symphysis. An updated phylogenetic analysis of crocodylomorphs confirms that this new taxon belongs to the Hylaeochampsidae, and that it forms a relatively robust clade with the derived Unasuchus, Acynodon, Iharkutosuchus and Hylaeochampsa. Turcosuchus also presents some anatomical convergence with bernissartids, allodaposuchids, basal globidontans and other crocodylians. Turcosuchus okani is one of the earliest, but not basal hylaeochampsids, and the first known Early Cretac...

The two vertebrate fossil assemblages from the ?Middle Triassic Ntawere Formation have been known since the 1960s, but little new work has been done since the description of novel taxa in the 1960s and 1970s. Three recent field seasons have increased vertebrate diversity in the upper Ntawere assemblage and expanded biostratigraphic connections between the lower and upper Ntawere assemblages and assemblages in fossiliferous basins across southern Pangea. The upper Ntawere contains hybodontoid sharks, ptychoceratodontid lungfish, large- and small-bodied stereospondyl amphibians (Cherninia, ‘Stanocephalosaurus’ Batrachosuchus, a new taxon), stahleckeriid dicynodonts (Sangusaurus, Zambiasaurus), traversodontid and trirachodontid cynodonts (Luangwa, a new species, Cricodon), and at least four archosauromorphs, including a large loricatan pseudosuchian, a shuvosaurid poposauroid, and silesaurid dinosauriforms (Lutungutali), whereas the lower Ntawere contains the cynodonts Cynognathus and Diademodon and species of the dicynodont Kannemeyeria. The lower and upper Ntawere assemblages have been correlated with the middle and upper subzones of the Cynognathus Assemblage Zone of the Karoo Basin, South Africa, into a network of connections between assemblages in modern day Tanzania, Argentina, Brazil, Namibia, Antarctica, and India. Although lower Ntawere correlations are reinforced by the occurrence of Cynognathus, new observations from the upper Ntawere, in combination with field work in Tanzania, Namibia, and Brazil, have shifted the geographic focus of biostratigraphic connection away from the Karoo later in the Triassic. A recent radiometric date from Argentina from below the horizon correlated with both the Karoo and the lower Ntawere places these, and all higher assemblages, into the Carnian Stage of the Late Triassic.

Trematosaurids form a very large and remarkable clade of Triassic tetrapods (Temnospondyli: Stereospondyli) with a worldwide geographical distribution. Compared with specimens from Europe, Australia or North America, they remain relatively scarce in African rocks, where they are mainly known in the Early Triassic of Madagascar and South Africa. Longirostrine trematosaurids were only known from Madagascar, represented by the genus Wantzosaurus. However, we describe herein a new species of the longirostrine trematosaurid Aphaneramma, Aphaneramma gavialimimus sp. nov., from the Olenekian (Lower Triassic) of Madagascar. This genus was previously known from the Early Triassic of Europe and Asia. Based on a new nearly complete skull, the new species is characterized by a premaxilla-nasal suture anteriorly directed, not contacting the nostrils; choanae completely included within the palatines; the ventral opening of the orbits in the anterior part of the interpterygoid vacuities; a very elongated nasal covering ...

In response to predation pressure, some insects have developed spectacular plant mimicry strategies (homomorphy), involving important changes in their morphology. The fossil record of plant mimicry provides clues to the importance of predation pressure in the deep past. Surprisingly, to date, the oldest confirmed records of insect leaf mimicry are Mesozoic. Here we document a crucial step in the story of adaptive responses to predation by describing a leaf-mimicking katydid from the Middle Permian. Our morphometric analysis demonstrates that leaf-mimicking wings of katydids can be morphologically characterized in a non-arbitrary manner and shows that the new genus and species Permotettigonia gallica developed a mimicking pattern of forewings very similar to those of the modern leaf-like katydids. Our finding suggests that predation pressure was already high enough during the Permian to favour investment in leaf mimicry., Many insects mimic plants in order to avoid detection by predators. Here, Garrouste and colleagues describe a katydid fossil that extends the record of leaf mimicry to the Middle Permian, more than 100 million years earlier than previously known fossil specimens of plant mimicry.

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International audience; The dicynodonts are an emblematic group of herbivorous therapsids that survived the Permo-Triassic (P-Tr)crisis. Laotian dicynodonts from stratigraphically constrained beds, recently dated using the U-Pb zircon method, yield newinsights into terrestrial faunas of Southeast Asia during the latest Permian and earliest Triassic. Summarily described, theywere originally attributed to the genus Dicynodon. We provide a new phylogenetic analysis for Laotian dicynodonts, basedon three well-preserved skulls, indicating that they belong to two new taxa: Counillonia superoculis, gen. et sp. nov., andRepelinosaurus robustus, gen. et sp. nov. Our phylogenetic analysis of Dicynodontia indicates that (1) Counillonia is closelyrelated to some ‘Dicynodon’-grade taxa and (2) Repelinosaurus is a kannemeyeriiform. The phylogenetic affinities of thesenew Laotian dicynodonts allow discussion of the survivorship of multiple lineages (Kannemeyeriiformes and ‘Dicynodon’-grade dicynodontoids) across the P-Tr crisis. The Laotian dicynodonts also shed new light on the paleobiogeography ofSoutheast Asia from the late Paleozoic to the early Mesozoic, particularly the timing of collisions between the Indochina,the South China, and the North China blocks. The presence of dicynodonts in Laos, most likely in the Early Triassic, thusimplies that the connection between the Indochina Block and the South China Block occurred no later than the latestPermian or earliest Triassic (i.e., when the dicynodonts provide direct evidence for a connection).

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International audience; Chroniosuchians were a clade of non-amniotic tetrapods known from the Guadalupian (middle Permian) to Late Triassic, mainly from Russia and China. The rarity of complete or articulated remains means that relatively little is known about this group in terms of its anatomy, palaeobiology, or evolutionary history. Based on a nearly complete skull with a left hemimandible, we describe the first chroniosuchian from Laos from rocks preserving the Permian-Triassic boundary in the Luang Prabang Basin, which is located on the tectonic Indochina Block. This specimen is referred to a new genus and species, Laosuchus naga, based on numerous diagnostic features, including an extremely reduced pineal foramen; absence of palatal dentition; well-developed transverse flange of the pterygoid that contacts the maxilla; internal crest on and above the dorsal side the palate; otic notch closed by the tabular horn and the posterior part of the squamosal, forming a continuous wall; thin and high ventromedial ridge on parasphenoid. A phylogenetic analysis of 51 characters and 25 taxa reveals a basal position for Laosuchus naga among Chroniosuchia. In addition, CT scan data reveal internal structures and provide new insights about the anatomy and palaeobiology of chroniosuchians. Laosuchus naga was likely amphibious and spent most of its time in water, rather than in terrestrial environments. As chroniosuchians are nonmarine tetrapods previously known on the North 2 China Block, South China Block, and Laurussia, the occurrence of Laosuchus naga on the Indochina Block supports the hypothesis of physical connections between all these tectonic plates by the time of the Permo-Triassic boundary.

A new ichnofauna from the Permian of Morocco is described in details: it is the first Palaeozoic ichnofauna from the Zat Valley in Marrakech High Atlas. The new tracksite was found in the Tighdouine region, in the middle-upper Permian of the Cham-el-Houa Siltstone Formation. An abundant and diverse ichnoassemblage composed of both protostomian (probably arthropods and annelids) traces and vertebrate tracks is recorded. The presence of protostomian burrows and traceways, associated with tetrapod tracks corresponds to the Scoyenia ichnofacies. Protostomian traces are ascribed to Diplichnites gouldi, Diplopodichnus biformis, Scoyenia cf. gracilis and Spongeliomorpha carlsbergi. Tetrapod tracks include more than 70 tracks attributed to Amphisauropus, Erpetopus, Hyloidichnus, Characichnos, and indeterminate tracks. The co-occurrence of tetrapod tracks (both walking and swimming tracks), protostomian traces, mudcracks, ripple marks, as well as the lithological features of the track-bearing levels, indicate regularly inundated depositional environments during periods of high discharge under a local seasonal climate. A sedimentological analysis shows that the depositional environments evolved from braided-meandering systems to alluvial floodplains. The track-bearing surfaces are mainly preserved in crevasse splays, levees and pond deposits. This newly discovered ichnofauna helps to better reconstruct the palaeoenvironments of the Marrakech High Atlas in Morocco during the Permian, and enlarges the palaeogeographic distribution of important ichnotaxa.

Pangaean paleogeographic models place the Tim Mersoi basin of northern Niger in a 5000-km-wide corridor between Gondwana and Laurasia approximately 15 degrees south of the paleoequator. Late Permian paleoclimate models position this basin between tropical summer-wet to the north and desert to the south. Recent investigations of the fossil vertebrates and paleosols in the late Permian (Lopingian) Moradi Formation confirm that the climate was warm and hyperarid with highly seasonal monsoonal rainfall. Possibly as a result of these unusual “wet desert” conditions, the tetrapod fauna shows a high degree of endemism. This study tests existing paleoclimate models by providing additional data on sedimentary environments and vertebrate taphonomic processes. The Moradi red bed sequences accumulated in a gently subsiding sag basin to the west of the tectonically active Massif de l'Air. Low angle gravelly alluvial fans prograded westward from the massif and at times impinged on a large stable northward flowing meandering channel system. The interchannel mudrock sequences are over-thickened by the accumulation of loessic silts and preserve isolated skull and post crania of amphibians (Nigerpeton and Saharastega) as well as semi-articulated captorhinids (Moradisaurus). Detailed surface mapping of a fossil-rich exposure revealed an anastomosed network of loess-filled distributary channels incised into the floodplain mudrocks. This provided a locus for the accumulation and rapid burial of at least 15 associated skeletons of the pareiasaurian Bunostegos. Semi-permanent ponds are evidenced by patches of fissile red mudstone containing rare bivalves and spiral coprolites. In the distal floodplains away from the main river channels, the combination of a generally high groundwater table, warm mean annual temperatures, and deflation of fines from the floodplain surface promoted the formation of gypsiferous paleosols and end-point playa lakes. Carbonate-rich mud accumulated around the lake margins and provided ideal conditions for the imprinting and preservation of tetrapod trackways.

The fish-to-tetrapod transition—followed later by terrestrialization—represented a major step in vertebrate evolution that gave rise to a successful clade that today contains more than 30,000 tetrapod species. The early tetrapod Ichthyostega was discovered in 1929 in the Devonian Old Red Sandstone sediments of East Greenland (dated to approximately 365 million years ago). Since then, our understanding of the fish-to-tetrapod transition has increased considerably, owing to the discovery of additional Devonian taxa that represent early tetrapods or groups evolutionarily close to them. However, the aquatic environment of early tetrapods and the vertebrate fauna associated with them has remained elusive and highly debated. Here we use a multi-stable isotope approach (δ13C, δ18O and δ34S) to show that some Devonian vertebrates, including early tetrapods, were euryhaline and inhabited transitional aquatic environments subject to high-magnitude, rapid changes in salinity, such as estuaries or deltas. Euryhalinity may have predisposed the early tetrapod clade to be able to survive Late Devonian biotic crises and then successfully colonize terrestrial environments. An approach using multiple stable isotopes reveals that early tetrapods of the Devonian period were euryhaline animals that inhabited aquatic environments of highly variable salinity.

Permian and Triassic tetrapods are very rare in Turkey. Yet this group bears important paleoenvironmental and paleogeographical signals to better understand Pangean models, and especially the geodynamic history of the Permian and Triassic in Turkey, which remains highly debated. Here we present and describe the first temnospondyls from Turkey (SE Anatolia) which consist of a Middle Permian branchiosaurid and an Early Triassic stereospondyl. The branchiosaurid is the first representative of its group in Gondwana and the first from the Middle Permian: it therefore brings important paleogeographic implications and supports the hypothesis that anamniotic tetrapods may have used trans-Pangean migration routes between Europe and Gondwana. It also brings new data to the debated depositional environment of the Permian of SE Anatolia. The Triassic stereospondyl represents one of the few tetrapods known from paleoequatorial areas and confirms a relatively rapid faunal turnover of the anamniotic fauna after the Permian-Triassic mass extinction.

The only true living endothermic vertebrates are birds and mammals, which produce and regulate their internal temperature quite independently from their surroundings. For mammal ancestors, anatomical clues suggest that endothermy originated during the Permian or Triassic. Here we investigate the origin of mammalian thermoregulation by analysing apatite stable oxygen isotope compositions (δ18Op) of some of their Permo-Triassic therapsid relatives. Comparing of the δ18Op values of therapsid bone and tooth apatites to those of co-existing non-therapsid tetrapods, demonstrates different body temperatures and thermoregulatory strategies. It is proposed that cynodonts and dicynodonts independently acquired constant elevated thermometabolism, respectively within the Eucynodontia and Lystrosauridae + Kannemeyeriiformes clades. We conclude that mammalian endothermy originated in the Epicynodontia during the middle-late Permian. Major global climatic and environmental fluctuations were the most likely selective pressures on the success of such elevated thermometabolism. DOI: http://dx.doi.org/10.7554/eLife.28589.001, eLife digest School textbooks often refer to “cold-blooded” and “warm-blooded” animals, but these terms are misleading. Rather than being cold, animals like reptiles have body temperatures that are mostly determined by their external environment and can actually achieve high body temperatures, for example, by basking in the sun. By contrast, “warm-blooded” mammals produce their own heat and typically maintain a body temperature that is warmer than their environment. As such, so-called warm-blooded animals are more accurately referred to as “endotherms” and cold-blooded animals as “ectotherms”. Endothermic animals share several characteristics, including insulating layers – like fur or feathers – that keep the body warm, and a secondary palate that separates the mouth and nose for continuous breathing, even while eating. Many of these traits are seen in fossils belonging to a group of animals called the therapsids. Also known as the “mammal-like reptiles”, these animals are descended from ectothermic reptiles but are the ancestors of the endothermic mammals. They dominated the land between 270 and 220 million years ago, during periods of time called the Permian and the Triassic. They also survived two major mass extinction events, including the most devastating mass extinction in all of Earth’s history. However, when the ancestors of mammals became truly endothermic remains an open question. Previous studies that have tried to determine this by focusing on the physical characteristics of therapsids have not yet given a consistent date. Rey et al. took a new approach to answer when endothermy first evolved in the mammal-like reptiles, and instead looked at the chemical makeup of minerals in over 100 fossils. Oxygen can exist in different forms called stable isotopes: oxygen-16 and the rarer and heavier oxygen-18. The ratio of these two isotopes in a fossil will depend on, among other things, where the animal lived and, importantly, its body temperature. Therefore, Rey et al. compared oxygen-containing minerals in the bones and teeth of therapsids to those of other animals that lived alongside them to look for signatures that indicated differences in body temperature and how it was regulated. It appears that two different branches of the therapsid’s family tree independently became endothermic. One branch includes the mammals and their direct ancestors, while the second is more distantly related to mammals. Both became endothermic towards the end of the Permian Period, between about 259 and 252 million years ago. Based on these findings, Rey et al. suggest that endothermy allowed these animals to better cope with fluctuating climates, which helped them to be among the few species that survived the mass extinction event at the end of the Permian. Going forward, these new findings can help scientists to understand which physical characteristics were necessary for endothermy to first develop and which helped to optimize it afterwards. Furthermore, they also suggest that endothermic animals are more able to survive fluctuations in climate, which could guide efforts to protect modern-day endangered species that are most at risk from the ongoing effects of climate change. DOI: http://dx.doi.org/10.7554/eLife.28589.002

International audience; Temnospondyls form a large clade of extinct non-amniotic tetrapods. Although their external cranial anatomy is relatively well known, their endocranium (i.e. internal structures of the skull) remains poorly known due to the lack of well-preserved material with conservation of the original anatomic volume. Internal structures are generally crushed under the skull roof due to the frequent flattening of skulls during fossilization. Yet this region is of great paleobiological interest with respect to the hearing, nervous, and vascular systems. In addition, endocranial characters have already been shown to be phylogenetically very informative in various vertebrate groups (e.g. mammals, dinosaurs). An exquisite skull belonging to Stanocephalosaurus amenasensis from the Lower-Middle Triassic of the Zarzaïtine Series (Algeria) has been investigated by X-ray micro-CT (computed tomography) scan. The resulting 3-D reconstruction of this unique specimen reveals highly detailed anatomy of the endocranial region, which is described herein. In addition, both columellar cavity and stapes morphologies lead to a new functional hypothesis for the stapes as part of an underwater hearing system. This endocranium description increases our knowledge of temnospondyl paleobiology and endocranial structure variability. The hearing system postulated in S. amenasensis provides an evolutionary scenario which is also compared with that of extant anurans.

Permian tetrapods from Zambia are best known from the Luangwa Basin, which was the subject of sporadic geological and paleontological work throughout the 20th century (Wallace, 1907; Dixey, 1937; D...

The Triassic was first defined based on the characteristic three-fold sequence of rocks that crops out across much of Europe, and many of the first records of Triassic dinosaurs, crocodile-line arc...

We describe a new capitosauroid temnospondyl, Antarctosuchus polyodon, gen. et sp. nov., on the basis of a large and relatively complete skull from the upper Fremouw Formation of Antarctica. The ne...

Temnospondyls from the Middle–Late Triassic of Madagascar are problematic and scarce: ‘Metoposaurus hoffmani’ was erected on the basis of poor material, and this taxon has never been revised. Other remains were also reported and assigned to Temnospondyli indet., but they have never been described, nor figured. Here, we (re)describe in detail this historical material from the Folakara area of Madagascar (Isalo Group, Morondava Basin): the specimens include cranial and postcranial remains, most of them being referred to Metoposauridae indet. and a few to Stereospondyli indet. We also confirm that ‘M. hoffmani’ is a nomen dubium owing to the absence of any clear autapomorphy of the fragmentary type material. The material referred here to Metoposauridae indet. is incorporated in an updated paleobiogeographic analysis of the group: interestingly, it suggests a connection with Indian metoposaurids during the Late Triassic.

Recent discoveries have shown that non-dinosaurian dinosauromorphs were morphologically diverse, globally distributed, and have a stratigraphic range extending into the Upper Triassic. Silesauridae, the sister group to Dinosauria, contains at least seven species. Here we describe Lutungutali sitwensis, gen. et sp. nov., the first silesaurid from the upper portion of the Ntawere Formation of the Luangwa Basin, Zambia. The upper Ntawere Formation has been correlated with subzone C of the Cynognathus Assemblage Zone of the Karoo Basin in South Africa and the Lifua Member of the Manda beds in the Ruhuhu Basin in Tanzania, both of which are considered Anisian in age and the latter has yielded the silesaurid Asilisaurus kongwe. The results of our phylogenetic analysis, including a new pelvic character, allies Lutungutali with Upper Triassic silesaurids such as Silesaurus, Sacisaurus, and Eucoelophysis rather than with the possibly coeval Asilisaurus. The Zambian silesaurid shares a laterally oriented b...

We describe newly recovered cranial material of Bunostegos akokanensis, a pareiasaurian reptile known from the Upper Permian Moradi Formation of northern Niger. Bunostegos is highly autapomorphic, with diagnostic cranial features including two or three hemispherical bosses located above and between the external nares; laterally projecting supraorbital ‘horn’ formed by an enlarged postfrontal; large foramen present on ventral surface of postfrontal; and hemispherical supratemporal boss located at posterolateral corner of skull roof. We addressed the phylogenetic position of Bunostegos by incorporating it into a cladistic analysis of 29 parareptilian taxa (including all 21 currently valid pareiasaurs) and 127 cranial and postcranial characters. The results of this analysis place Bunostegos as more derived than middle Permian forms such as Bradysaurus and as the sister taxon to the clade including Deltavjatia plus Velosauria. Certain characters, such as the pattern of cranial ornamentation and the s...

In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence on the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether the end-Permian mass extinction (252.3 Ma) affected the distribution of tetrapod faunas within the southern hemisphere and apply quantitative methods to analyze four components of biogeographic structure: connectedness, clustering, range size, and endemism. For all four components, we detected increased provincialism between our Permian and Triassic datasets. In southern Pangea, a more homogeneous and broadly distributed fauna in the Late Permian (Wuchiapingian, ∼257 Ma) was replaced by a provincial and biogeographically fragmented fauna by Middle Triassic times (Anisian, ∼242 Ma). Importantly in the Triassic, lower latitude basins in Tanzania and Zambia included dinosaur predecessors and other archosaurs unknown elsewhere. The recognition of heterogeneous tetrapod communities in the Triassic implies that the end-Permian mass extinction afforded ecologically marginalized lineages the ecospace to diversify, and that biotic controls (i.e., evolutionary incumbency) were fundamentally reset. Archosaurs, which began diversifying in the Early Triassic, were likely beneficiaries of this ecological release and remained dominant for much of the later Mesozoic.

Fig. 1 Jean-Claude Rage climbing a rope ladder during a palaeontological excavation campaign in Quercy (southwestern France) in 1976 (photo EB). Jean-Claude Rage has been recognized for several decades as one of the leading and international experts in the field of palaeontology, which he largely contributed to develop and which could be called “micro-palaeoherpetology”. As an introduction to a collection of papers in his honour, this short biographical sketch, authored by two colleagues of Jean-Claude (one of whom also is a former PhD student of his) is meant to convey our appreciation of his remarkable scientific and personal achievements. Jean-Claude Rage is currently Emeritus Research Director at the CNRS (National Centre of Scientific Research) and is based at the Museum National d'Histoire Naturelle in Paris. He is married to Pr. Agnes Lauriat-Rage (an expert on fossil molluscs and retired MNHN Professor). Jean-Claude was born on 1st March, 1943 at Lyon, France. After attending high school at Saint-Etienne, in central France, he returned to Lyon in 1963 to study at the university, while keeping links with Saint-Etienne, where he worked as an auxiliary teacher until 1965. He became assistant reader at the University of Lyon (1965-1968), where he obtained his Master Degree in 1967. His third cycle thesis (“these de 3eme cycle” – a now defunct French degree) on Quaternary anurans, prepared under the supervision of Prof. Louis David, was defended in 1968. Then Jean-Claude left (temporarily) fossil amphibians (and the city of Lyon) for reptiles (and the city of Paris), where he defended in 1976 his Ph-D (“Doctorat d'Etat”) on snake anatomy, origins and evolution, under the supervision of Prof. Robert Hoffstetter (University Paris 6). Jean-Claude's long association with the Centre National de la Recherche Scientifique (CNRS) began in 1968, when he obtained a temporary position there, which soon turned …

A new vertebrate locality from the Lower Permian (Cisuralian) of the Bourbon-l'Archambault basin (Massif Central, France) is reported and its associated flora and fauna preliminarily described. This locality corresponds to a mass mortality assemblage deposited in an aquatic environment. Interestingly, it has yielded hundreds of exceptionally well preserved seymouriamorph specimens, all referred to Discosauriscus austriacus. This exquisite assemblage corresponds to the first seymouriamorph Lagerstätte and the first record of D. austriacus outside the Boskovice basin in Czechia. It enlarges the geographical distribution of the species during the Early Permian, and has new palaeoenvironmental implications regarding the Palaeozoic Bourbon-l'Archambault basin.

Macroevolutionary, palaeoecological and biomechanical analyses in deep time offer the possibility to decipher the structural constraints, ecomorphological patterns and evolutionary history of extinct groups. Here, 3D comparative biomechanical analyses of the extinct giant early amphibian group of stereospondyls together with living lissamphibians and crocodiles, shows that: i) stereospondyls had peculiar palaeoecological niches with proper bites and stress patterns very different than those of giant salamanders and crocodiles; ii) their extinction may be correlated with the appearance of neosuchians, which display morphofunctional innovations. Stereospondyls weathered the end-Permian mass extinction, re-radiated, acquired gigantic sizes and dominated (semi) aquatic ecosystems during the Triassic. Because these ecosystems are today occupied by crocodilians and stereospondyls are extinct amphibians, their palaeobiology is a matter of an intensive debate: stereospondyls were a priori compared with putative living analogous such as giant salamanders and/or crocodilians and our new results try to close this debate.

The continental Permian–Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New stratigraphic, sedimentological and paleontological analyses from Middle–Upper Permian to Lower–Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian–Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attributed to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula—one of the few reported from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus–Rotodactylus), an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic–early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and related to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by high-energy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Tethys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the oldest continental records of the Western Tethys, providing new keys to decipher the Triassic faunal biogeography and recovery., E. Mujal and J. Fortuny received funding from the SYNTHESYS Project http://www.synthesys.info/ (DE-TAF-2560, FR-TAF-3621, FR-TAF-4808 to E. Mujal and FR-TAF-435 and FR-TAF-3353 to J. Fortuny) which is financed by European Community Research Infrastructure Action under the FP7 “Capacities” Program. E. Mujal acknowledges “Secretaria d'Universitats i de Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya” (E.M., expedient number 2013 CTP 00013, at ISE-M, Université Montpellier-2) for funding used for visiting collections. E. Mujal obtained financial support from the PIF grant of the Geology Department at UAB. A. Arche, J. Barrenechea, R. De la Horra, J.B. Diez and J. López-Gómez received support from the CGL2011-24408 and CGL2014-52699 research projects of the Spanish Ministerio de Economía y Competitividad. This paper is also a contribution to the following research projects: “Sistemas Sedimentarios y Variabilidad Climática” (642853) of the CSIC, and Basin Analysis (910429), and Palaeoclimatology and Global Change (910198) of the Universidad Complutense de Madrid. J. Fortuny acknowledges the support of the Generalitat de Catalunya postdoc grant 2014 – BP-A 00048. Fieldwork campaigns have been developed under the projects “Vertebrats del Permià i el Triàsic de Catalunya i el seu context geològic” and “Evolució dels ecosistemes amb faunes de vertebrats del Permià i el Triàsic de Catalunya” (ref. 2014/100606), based by the Institut Català de Paleontologia and carried out thanks to the financial support of the Departament de Cultura (Generalitat de Catalunya).

Lasasaurus beltanae nov. gen. nov. sp., a new procolophonid (Reptilia, Parareptilia) from the Lower Triassic of Madagascar, is represented by a single partial skeleton preserved in a ferro-calcareous nodule from the Middle Sakamena Formation, in the North of the island. This new taxon is unique in possessing peculiar, fine and dendritic crests running along the posterolateral side of the squamosal, widely spaced maxillary teeth, subparallel mesiodistal ridges connecting maxillary teeth to the tooth row, and a strongly acute anterior margin of the copula (hyoid bone). This well-preserved specimen belongs to a juvenile individual. The inclusion of L. beltanae nov. gen. nov. sp. in a phylogenetic analysis suggests that it is close to Theledectinae, Procolophoninae, and Leptopleurinae, though their respective relationships are uncertain. This specimen is the first procolophonid described from Madagascar and represents a minor terrestrial component of a coastal vertebrate assemblage dominated by amphibious to fully-aquatic taxa.

A new species of the temnospondyl tetrapod, Sclerocephalus stambergi n. sp., is described from the early Permian deposits of the Boskovice Basin in Moravia (Czech Republic). The length of the skull of the only known specimen is about 50 mm. Characters including the well-ossified quadrate, septomaxilla and scapulocoracoid, presence of the maxilla-nasal suture and a free posterolateral margin of the supratemporal suggest an early adult age. This new species of Sclerocephalus is distinguished from the others on the basis of the following characters: nasal and maxillary processes of the premaxilla of equal width; absence of the alary process of the premaxilla; distinct pointed process on the lacrimal between the maxilla and jugal; narrow interclavicle; and very peculiar tabular presenting a quadrangular, plate-like process extending from its posterolateral portion, an almost right angle between its lateral and posterior margins, and a long posteromedial process. The new species represents the smallest and possibly the most basal Sclerocephalus species. The specimen described here sheds new light on the anatomy and taxonomy of Sclerocephalus. It completes the biodiversity of the tetrapod fauna from the Boskovice Basin, and our knowledge on the evolution of the European Paleozoic temnospondyls.

Three basic paleosol morphologies, named Type A, Type B and Type C, are described from the middle–upper Permian strata of the Moradi Formation, Tim Mersoi Basin, northern Niger. The Moradi Formation is a typical alluvial redbed succession dominated by red mudrocks with fine to coarse-grained pebbly channel sandstones and matrix-breccias. Type A paleosols are hosted by well-sorted fine to medium grained trough cross bedded and massive sandstones and preserve abundant vertical to horizontal micritic and microspar calcite tubules, interpreted as rhizoliths. Lateral variability of rhizoliths in Type A paleosols, and their close association with fluvial channel-fill sediments suggests they are the roots of grove stands of phreatophytic vegetation that grew within unstable anabranching stream systems. Type B paleosols are hosted by mudrocks and preserve well-developed ped structure, abundant micritic calcite nodules and vertically-stacked micritic calcite nodular bodies, as well as rare calcite with satin-spar texture interpreted as a pseudomorphic replacement of pedogenic gypsum. The morphology of Type B paleosols suggests they were formed in well-drained floodplain deposits on stable landforms. Type C paleosols are similar to Type B but preserve pedogenic structures indicative of soil volume expansion and contraction, as well as more abundant Stage II pedogenic carbonate nodules. The morphology of Type C paleosols suggests that they developed periodically rather than seasonally in poorly-drained deposits that nevertheless occupied a relatively stable part of the landscape such as the plains flanking ephemeral lakes or sabkhas. X-ray diffraction analysis of the The range of morphologies, petrographic textures and mineralogy of the paleosol profiles indicates semi-arid to hyper-arid climatic setting. This paleoclimatic reconstruction is in agreement with Middle and Late Permian conceptual paleoclimate models and quantitative general circulation models. Nevertheless, and in spite of an arid climate, Moradi paleosols and their host strata also indicate a relatively shallow groundwater table. Importantly, this shallow groundwater resource undoubtedly helped to support the moderately diverse fossil vertebrate assemblage and large-stature macrophytes preserved in the Moradi Formation.

Apateon, a key genus among Branchiosauridae from the Carboniferous--Permian of Europe, is often considered closely related to salamanders on the basis of developmental similarities, anatomical features, and life history. The current work deals with recognition of heterochronies among three "time-averaged populations" of Apateon based on inference from histological features already studied in extant urodeles. Our study is performed on the long bones of 22 specimens of Apateon pedestris and Apateon caducus. Histological observations show that diaphyseal and epiphyseal ossification patterns of Apateon are similar to those of urodeles. From skeletochronological analysis, the identification of the age of sexual maturity allows us to discriminate juveniles from adults and to confirm the previous hypothesis of a paedomorphic condition based on anatomical data among these species. The current study also suggests a paedomorphic condition of each "population" at the histological level. This heterochrony may have been linked to peculiar ecological conditions such as hypoxic and fresh water environment. Functional reasons may also be invoked to explain differences of ossification between fore- and hindlimbs of the "populations" from Odernheim and Niederkirchen because paleoecological conditions are very different from one locality to another. This study illustrates the role that the acquisition of heterochronic features plays at the microevolutionary scale.

The amniotes generally lay eggs on land and are thereby differentiated from lissamphibians (salamanders, frogs and caecilians) by their developmental pattern. Although a number of 330–300-Myr old fossils are regarded as early tetrapods placed close to amniotes on the basis of anatomical data, we still do not know whether their developmental pattern was more similar to those of lissamphibians or amniotes. Here we report palaeohistological and skeletochronological evidence supporting a salamander-like development in the seymouriamorph Discosauriscus . Its long-bone growth pattern, slow diaphyseal growth rate and delayed sexual maturity (at more than 10 years old) are more comparable with growth features of extant salamanders rather than extant amniotes, even though they are mostly hypothesized to be phylogenetically closer to living amniotes than salamanders.

5 pages; International audience; A well-preserved vertebral column from the Late Permian of Southern France (Lopingian, La Lieude Formation, Lodève Basin) is described. It is composed of diplospondylous vertebrae and is most comparable with the temnospondyl Tupilakosaurus previously known from the Early Triassic of Greenland and Russia. This new specimen therefore represents the earliest occurrence of a diplospondylous tupilakosaur, and extends the geographic range of the group to Western Europe. It is an aquatic temnospondyl that used the anguilliform undulatory mode of swimming.

The skull of the temnospondyl amphibian Saharastega moradiensis, from the Upper Permian Moradi Formation (Izegouandane Group, Izegouandane Basin) of northwestern Niger, is described in detail. Saharastega mo- radiensis is the most primitive known temnospondyl from Gondwana and possesses a combination of plesiomorphic and apomorphic character states, which suggest affinities with the Edopoidea, a clade of basal temnospondyls from the Upper Carboniferous and Lower Permian of Euramerica. These include the exclusion of the lacrimal from the orbital margin, the exclusion of the vomers and palatines from the interpterygoid vacuities, and the presence of an intertemporal ossification. Autapomorphies of the new taxon include the presence of narrow and elongated, transversely oriented nostrils; an extensive tongue-and-groove contact between the premaxillae and maxillae; tabulars that possess exception- ally large, laterally and ventrally directed 'horns'; and an extraordinary 'occipital plate' that may be formed, at least in part, by a supraoccipital ossification. A phylogenetic analysis of select Paleozoic temnospondyls indicates that S. mora- diensis is the sister taxon to the edopoids, represented in this analysis by Chenoprosopus and Edops. This suggests that S. moradiensis represents a late-surviving member of a clade that is the sister group of the Edopoidea. Members of this clade may have been restricted to equatorial northwest Africa during the Late Carboniferous and Early Permian, an area that was not affected by the extensive glaciation that covered much of southern Pangea.

We describe the edopoid temnospondyl Nigerpeton ricqlesi from the Upper Permian Moradi Formation of northern Niger on the basis of two partial skulls and tentatively associated postcranial material. This crocodile-like taxon displays several edopoid characters states such as a long prenarial region with enlarged premaxillae, elongated vomers, large, posteriorly tapering choanae, and a jugal that broadens anteriorly. Nigerpeton possesses a unique carnivorous dentition. It is autapomorphic in its possession of an extremely elongate snout bearing a maxillary bulge that accommodates three hypertrophied caniniform teeth, inner premaxillary tusks, and anterior paired fenestrae, which pierce the skull roof. In addition, both the maxilla and dentary tooth rows show the sporadic appearance of ‘doubled’ tooth positions. The lateral-line system is present at the adult stage, which suggests an aquatic habitat for this taxon. A phylogenetic analysis of Edopoidea and its relatives places Nigerpeton as the sist...

A jaw fragment of a giant temnospondyl from the Upper Triassic or Lower Jurassic of Lesotho (southern Africa), initially regarded as a Triassic mastodonsaurid because of its size, is redescribed in detail and considered to be a member of the Brachyopoidea (Brachyopidae + Chigutisauridae sensu Warren and Marsicano [2000]) based on its dental morphology, presence of a well-developed ectopterygoid tusk, and the concavity of the ventral margin of the skull in lateral view. Recognition of the specimen as a brachyopid, rather than as a chigutisaurid, is of palaeobiogeographical significance in representing one of the youngest known brachyopids from Gondwana. The Lesotho specimen is also of palaeobiological interest in that an estimate of its overall size indicates that it represents one of the largest amphibians sensu lato ever known.

The “capitosaurs” from the Lower Triassic of Madagascar are revised. Benthosuchus madagascariensis Lehman, 1961, and Wetlugasurus milloti Lehman, 1961, are combined in the new combination Watsonisuchus madagascariensis on the basis of the most complete growth series among capitosaurians. A phylogenetic analysis showed that the genus Watsonisuchus is justified, although its species W. madagascariensis is not the most derived within the genus. The skull growth of W. madagascariensis clearly shows an allometric trend, but the fact that adults have more dermo-sensory grooves than juveniles suggests surprisingly that they may have become progressively more aquatic during growth. The ontogeny of W. madagascariensis is compared with that of other temnospondyls. Different longi-rostrine conditions are observed in Permian and Triassic stereospondylomorphs (archegosaurians and capitosaurians, respectively). They are interpreted as convergences rather than are a synapomorphy of the clade.

The temnospondyl Wantzosaurus elongatus Lehman, 1961, from the Lower Triassic of Madagascar, is redescribed on the basis of a new specimen, which is the most complete trematosaur ever found. Detailed osteological observations and comparisons provide new data on the anatomy, ontogeny, palaeobiology and palaeoecology of this peculiar marine ‘amphibian’. The morphology of this aquatically readapted taxon is compared to that of marine ‘reptiles’: Wantzosaurus might have been able to swim by undulation. A phylogenetic analysis of the trematosaurs is performed for the first time and suggests that Wantzosaurus is a derived taxon within the clade Trematosauridae. The family is defined on the basis of derived character states and is shown to be monophyletic.

The temnospondylCheliderpeton vranyi Fritsch, 1877 from the Lower Permian Ruprechtice horizon (Rotliegend) of the Intrasudetic Basin (Bohemia, Czech Republic) is redescribed. Many features of the skeleton permit a new understanding of the type species and consequently of the genus. Diagnostic characters are the narrow and round-tipped snout, straight to convex outline of the skull roof, narrow and long otic notch, posteriorly expanded quadratojugal, and the relatively wide and short rhombic interclavicle. The ilium with a short, expanded dorsal branch and the missing contact of nasal/maxilla are features shared with the related Upper PermianIntasuchus from Russia and the Eryopidae.Actinodon germanicus is a junior synonym ofCheliderpeton vranyi.

New fossils from the ?uppermost Carboniferous-Lower Permian have been found at Buxieres-les-Mines (Massif central, France). In this preliminary article we report on algae, stromatolites, palynomorphs, macroflora, ostracods, insects, elasmobranchs, acanthodians, actinopterygians and amphibians. Elasmobranchs and amphibians are diversified compared with those of other European localities. Most taxa indicate lacustrine deposits and an Asselian age, and permit us to address the question of the palaeoecosystem evolution of the Bourbon-l'Archambault Basin, during the Lower Permian.