Ronan Allain

Muséum National d'Histoire Naturelle · Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements

Paleophysiology is an emergent discipline. Organismic (integrative) approaches seem more appropriate than studies focusing on the variation of specific features because traits are tightly related in actual organisms. Here, we used such an organismic approach (including lifestyle, thermometabolism, and hunting behavior) to understand the paleobiolog...

Coprolites (fossil droppings) are common in the Mesozoic fossil record. However, coprolite assemblages from continental settings have more rarely been quantitatively analysed than the marine ones. The excavation of the Berriasian continental Lagerstätte of Angeac-Charente (France) during the last decade has resulted in unearthing a vast number of f...

Various terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight‐bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick...

Sexual dimorphism is challenging to detect among fossils due to a lack of statistical representativeness. The Angeac-Charente Lagerstätte (France) represents a remarkable ‘snapshot’ from a Berriasian (Early Cretaceous) ecosystem and offers a unique opportunity to study intraspecific variation among a herd of at least 61 coeval ornithomimosaurs. Her...

In the palaeogeographical context of the opening of the South Atlantic Ocean at the end of the Early Cretaceous, we document here the first microvertebrate fauna recorded from the Aptian deposits of Gadoufaoua, Niger. A systematic study of the fauna has resulted in a significant expansion of the existing faunal list and increase our knowledge of t...

Jeddaherdan aleadonta Apesteguía et al., 2016 is currently known as the first and single Mesozoic iguanian lizard from Africa. The original description and age of the holotype and only known specimen (i.e. a dentary fragment bearing five teeth) are revised here. We show that this fragmentary specimen was misinterpreted anatomically, does not come f...

Sexual dimorphism is challenging to detect among fossils, due to a lack of statistical representativeness. The Angeac-Charente Lagerstatte (France) represents a remarkable snapshot from a Berriasian (Early Cretaceous) ecosystem and offers a unique opportunity to study intraspecific variation among a herd of at least 61 coeval ornithomimosaurs. Here...

This contribution describes the continental micro- and macrovertebrate fauna of Angeac-Charente (Berriasian, Early Cretaceous). The rich and diversified fauna includes at least 38 different vertebrate taxa from all major clades, and is represented by more than 50 000 specimens. The Angeac-Charente locality includes the most diverse earliest Cretace...

The Ksar Metlili Formation, from the Jurassic – Cretaceous transition (Tithonian – Berriasian) of eastern High Atlas Mountains, Morocco, has yielded one of the richest microvertebrate assemblages from the Mesozoic of Gondwana. With at least 19 species, mammaliaforms are particularly diverse. ‘Dryolestoidea’ are the most abundant and the most divers...

Dinosaur remains found at the Vaches Noires cliffs (Calvados, Normandy) have usually been discovered by amateur palaeontologists. The bones come from carcasses which drifted away from a nearby land (Armorican Massif) during the upper Callovian and lower Oxfordian. Most of these bones belong to private collections and are hardly accessible. Conseque...

Sauropodomorph dinosaurs include the largest terrestrial animals that ever lived on Earth. The early representatives of this clade were, however, relatively small and partially to totally bipedal, conversely to the gigantic and quadrupedal sauropods. Although the sauropod bauplan is well defined, notably by the acquisition of columnar limbs, the ev...

This contribution describes the continental micro- and macrovertebrate fauna of Angeac- Charente (Berriasian, Early Cretaceous). The rich and diversified fauna includes at least 38 different vertebrate taxa from all major clades, and is represented by more than 50 000 specimens. The Angeac–Charente locality includes the most diverse earliest Cretac...

Terrestrial ecosystems from the Lower Cretaceous of Europe and bonebeds formed in swampy environments are poorly known. The Berriasian‐early Valanginian Angeac‐Charente site in France represents an example of both. Nine field campaigns have yielded thousands of fossils of over a hundred taxa, including 16 taxa from vertebrate macroremains with nume...

Dinosaurs remains found at the Vaches Noires cliffs (Calvados, Normandy) are usually discovered by amateurs in palaeontology. Those bones come from carcasses drifted away from nearby land (Armorican Massif). Most of them belongs to theropods. This over-representation is enigmatic because it is not found in other similar deposits. Most of those bone...

Sauropodomorph dinosaurs constitute a well-studied clade of dinosaurs, notably because of the acquisition of gigantism within this group. The genus Plateosaurus is one of the best-known sauropodomorphs, with numerous remains from various localities. Its tumultuous taxonomic history suggests the relevance of addressing its intrageneric shape variabi...

Most Notosuchia were active terrestrial predators. A few were semi-aquatic, or were insectivorous, omnivorous or herbivorous. A question relative to their thermometabolism remains to be answered: were Notosuchia warm-blooded? Here we use quantitative bone palaeohistology to answer this question. Two variables were used as proxies to infer thermomet...

Major evolutionary transitions, in which animals develop new body plans and adapt to dramatically new habitats and lifestyles, have punctuated the history of life. The origin of cetaceans from land-living mammals is among the most famous of these events. Much earlier, during the Mesozoic Era, many reptile groups also moved from land to water, but t...

A dozen non-sauropodan sauropodomorph genera are currently known from southern Africa. The vast majority of the specimens were unearthed in South Africa, but a few were found in Lesotho. We provide here the first complete anatomical description of a historical specimen from Lesotho: ‘the Maphutseng dinosaur.’ The first remains of this animal were u...

The Middle Jurassic – Early Cretaceous period witnessed the emergence of some major representatives of modern continental vertebrate groups (stem lissamphibians, squamates, therian mammals and birds) and angiosperms, at a time when fragmentation of Pangaea was underway. The successive Moroccan microvertebrate faunas of Ksar Metlili (?Berriasian) an...

The Ksar Metlili site, Anoual Syncline, Eastern Morocco, has been resampled. More than 24,500 identified specimens provide key palaeontological data for the understanding of the African and Gondwanan vertebrate evolution around the Jurassic-Cretaceous boundary. Some remarkable taxa were discovered that allow to reassess the dating of the Ksar Metli...

Opportunity to study ecology and behavior of extinct vertebrates within their past ecosystem is exceedingly rare. Moreover, Lower Cretaceous terrestrial ecosystems of Europe are poorly known. The Berriasian (Lower Cretaceous) French paleontological site of Angeac-Charente, have fossilized a rich Mesozoic terrestrial swampy ecosystem. From 2010, 8 e...

The new material from the Ksar Metlili site, Anoual Syncline, Eastern Morocco, provides key palaeontological data for the understanding of the African and Gondwanan vertebrate evolution around the Jurassic-Cretaceous boundary. Some remarkable taxa were discovered that allow to reassess the dating of the Ksar Metlili site and have several major chro...

Large predators are overabundant in mid-Cretaceous continental dinosaur assemblages of North Africa. Such unbalanced ecosystem structure involves, among predatory dinosaurs, typical abelisaurid or carcharodontosaurid theropods co-occurring with long-snouted spinosaurids of debated ecology. Here, we report calcium (Ca) isotope values from tooth enam...

Few neotaphonomic studies of trampling on bones have been made, especially in fine and soft sediments. However, trampling is an important taphonomical agent that can considerably modify a bone assemblage. Moreover, resulting bone modifications can be mistaken with other taphonomical agents, including human butchery behavior that can have great cons...

A new genus and new species of ginglymodian is described from the Aptian Grès supérieurs Formation of the Savannakhet Basin, Laos (Lao People's Democratic Republic), found at the Ban Lamthouay locality. The fish is known from a single isolated head, which shows enough diagnostic characters to characterize a new taxon. It represents the first named...

Octobre 2010, coup de tonnerre dans le monde de la paléontologie et dans les médias les restes d'un des plus grands dinosaures connus au monde venait d'être découvert en France. Et plus précisément en Charente. Et il n'était pas tout seul... Crocodiles. Tortues, poissons. Reptiles volants et toutes sortes de dinosaures vivaient il y a 140 millions...

Palaeogeography of the carbonated Jura platform during the upper Oxfordian–lower Kimmeridgian Map modified after Cariou (2013). Abbreviated locations for: (1) truncations: O, Ornans (Enay, Contini & Boullier, 1988), BP, Bonnevaux-le-Prieuré (Lathuiliere et al., 2005), Damparis (this study); and (2) fossil woods: BC, Besançon (Citadelle) (Bulle et a...

Geological correlation scheme Correlation scheme of the lithological units of Damparis with both synthetic geological successions of Franche-Comté region and of north-western Switzerland.

Biostratigraphical distinction of the geological formations from the late Middle and Upper Oxfordian in Franche-Comté (France) Taxon names and stratigraphical ranges have been updated from original publications and different sources respectively. Only two taxa (highlighted in yellow) are still affected by taxonomic vs. stratigraphic inconsistencies...

Data matrix (TNT and Mesquite)

Supplementary Information

Brachiosauridae is a clade of titanosauriform sauropod dinosaurs that includes the well-known Late Jurassic taxa Brachiosaurus and Giraffatitan. However, there is disagreement over the brachiosaurid affinities of most other taxa, and little consensus regarding the clade’s composition or inter-relationships. An unnamed partial sauropod skeleton was...

Titanosauriforms represent the most diverse clade of sauropod dinosaurs, with >120 species, a global distribution, and a Late Jurassic to end-Cretaceous temporal range. Interrelationships of this clade are poorly understood, especially for derived titanosaurs; however, a wealth of new data provides an opportunity to remedy this problem. Based on fi...

Spinosaurs represent a group of peculiar theropod dinosaurs that have often been described as “crocodile-mimic”, predominantly fish-eating predators, and recently claimed to have been semi-aquatic animals. Here we report a suite of craniodental characters unexpectedly shared by spinosaurs and pike conger eels. Pike conger eels are predatory, mainly...

Taphonomic studies of pre-Quaternary vertebrate assemblages, especially from open-air and swampy environments, are rare. However, they are useful to characterize non-anthropic process at the origin of bonebeds formation and modification, helping archeoezoologists to distinguish cultural to non-cultural action on archaeological site, as the distinct...

The enigmatic crocodyliform ‘Elosuchus’ felixi from the Echkar Formation (upper Albian to lower Cenomanian, Early–Late Cretaceous boundary) west of In Abangharit, Agadez District, Niger, is here re-described. Our assessment of the material shows that there are at least two taxa amongst the referred material: ‘E.’ felixi, including the holotype (an...

Melanorosaurus is a genus of basal sauropodomorph that currently includes two species from Southern Africa. In this paper, we redescribe the holotype femur of Melanorosaurus thabanensis from the Elliot Formation of Lesotho, as well as associated remains. The stratigraphic position of this taxon is reviewed, and it is clear that it comes from the Lo...

Sigilmassasaurus brevicollis is an enigmatic theropod dinosaur from the early Late Cretaceous (Cenomanian) of Morocco, originally based on a few isolated cervical vertebrae. Ever since its original description, both its taxonomic validity and systematic affinities were contentious. Originally considered to represent its own family, Sigilmassasaurid...

Metriorhynchids were a widely distributed group of marine crocodylomorphs that thrived during the Middle Jurassic–Early Cretaceous. Within this group there is a subclade, Geosaurini, that evolved craniodential characteristics indicative of macrophagy (feeding on large-bodied prey items). When this subclade evolved and began to diversify into the my...

Metriorhynchids were a widely distributed group of marine crocodylomorphs that thrived during the Middle Jurassic–Early Cretaceous. Within this group there is a subclade, Geosaurini, that evolved craniodential characteristics indicative of macrophagy (feeding on large-bodied prey items). When this subclade evolved and began to diversify into the my...

The holotype of the sauropod dinosaur Rebbachisaurus garasbae was discovered in infra-upper Cenomanian horizons of the Kem Kem region of southeastern Morocco in the 1940s and 1950s. The original materials included part of a vertebral column, some of which was found in articulation, and a scapula, a humerus, and an ischium. Of these remains, only th...

The relationships among basal sauropodomorphs are controversial. Results of cladistic analyses vary from a fully paraphyletic assemblage to a monophyletic core-prosauropod. We apply the comparative cladistics method to three published cladistic analyses of sauropodomorph dinosaurs, in order to identify root causes for differences between phylogenet...

We report the discovery in Mesozoic continental “red beds” of Anoual Syncline, Morocco, of the new Guelb el Ahmar (GEA) fossiliferous sites in the Bathonian Anoual Formation. They produced one of the richest continental biotic assemblages from the Jurassic of Gondwana, including plants, invertebrates and vertebrates. Both the sedimentological facie...

The Rhaetian locality of Saint-Nicolas-de-Port (France) has yielded the most abundant and diverse mammalian assemblage known from the Late Triassic. Most of the material remains undescribed. We review here the morganucodonts from Saint-Nicolas-de-Port. We identify the upper and lower molariforms of the genus Brachyzostrodon. We also identify in the...

Recent fieldwork in the Upper Elliot Formation exposed near the village of Ha Noosi in the the Qacha's Nek District in Lesotho has yielded the sub-complete and articulated skeleton of a new basal sauropodomorph. The only missing elements are the caudal vertebrae, most of the pelvic girdle and the distal part of the right hindlimb. An isolated femur...

Through the systematic excavations conducted by our team since 2010 in the quarry of Angeac-Charente, a large number of vertebrate fossils, including dinosaur, crocodile and turtle remains, have been recovered. To date, the fossiliferous lignitic bone bed has yielded more than 3000 bones or teeth excavated from a surface of 230 m2. Nearly half of t...

Le Lagerstätte de Canjuers est un gisement à conservation exceptionnelle du Jurassique supérieur, représentant un environnement de lagon. La sédimentologie et la stratigraphie du gisement montrent trois périodes de dépôt différentes. Les fossiles sont principalement récoltés dans les niveaux les plus basaux, qui correspondent à la première phase de...

Early Cretaceous ornithomimosaurian theropod dinosaurs have been reported from various localities in Asia, whereas they remain poorly represented and extremely rare in North America, Africa and Europe. So far, the only known European ornithomimosaur is Pelecanimimus from the Barremian of Spain. The recent discovery in southwestern France of the Ang...

The first record of an invertebrate trackway from the lithographic limestones of the Canjuers Lagerstätte is described here. The preserved part of the trackway is approximately 39 cm long and 17 cm wide; it consists of two successive sets of imprints and the beginning of a third one. Two kinds of imprints have been recorded: the first one, well-pre...

a b s t r a c t This paper provides the sedimentological, palaeontological and biostratigraphical characteristics of a newly discovered lignite-bearing sedimentary succession in western France. The lignitic bed, which is reminiscent of some Wealden facies in southern England, is located in Angeac in the Charentes region. The plant remains occur as...

Spinosaurids are among the largest and most specialized carnivorous dinosaurs. The morphology of their crocodile-like skull, stomach contents, and oxygen isotopic composition of the bones suggest they had a predominantly piscivorous diet. Even if close relationships between spinosaurids and Middle Jurassic megalosaurs seem well established, very li...

New tetrapod footprints belonging to the ichnogenus Hyloidichnus have been discovered in Turkey for the first time, in the lower part of the Çakraz Formation (Northwestern Anatolia) and together with macrofloral imprints of Annularia and Stigmaria. These discoveries confirm the Permian age of the fossiliferous red beds in which the coniferophyte Wa...