Quercy Phosphorites Research Articles

Report of bioerosions and cells in Cainotheriidae (Mammalia, Artiodactyla) from the phosphorites of Quercy (SW France)

The phosphorites of the Quercy from SouthWest France are well known for fossils preserved in 3D with phosphatized soft-tissues. Given that phosphatization is known to favor fine cellular preservation, the present study delves into the histological analysis of white and brown bones of Cainotheriidae (Artiodactyla) recently excavated from the DAM1 site near Caylus. Microscopy revealed that the white bones were completely filled with bacterial erosions, while the brown bones showed a pristine histology and intralacunar content resembling fossilized osteocytes in some areas. After decalcification, a brown bone revealed an abundance of blood vessel-like structures, innumerable osteocyte-like structures with canaliculi and a few chondrocyte-like structures, while a white bone revealed only blood vessel-like structures that looked eaten away. All the data combined suggest the brown bones were shielded from bacterial attacks and were filled with fossilized organic matter and original biological structures. The data taken all together do not support that these structures are casts, but indeed original and endogenous cells. This study encourages further histochemical and mineralogical analyses on Quercy fossils and the unique taphonomy of DAM1 to better understand fossilization processes and their impact on the color of bones, the chemistry of skeletal tissues, soft tissues, and cells.

A 50-million-year-old, three-dimensionally preserved bat skull supports an early origin for modern echolocation

Bats are among the most recognizable, numerous, and widespread of all mammals. But much of their fossil record is missing, and bat origins remain poorly understood, as do the relationships of early to modern bats. Here, we describe a new early Eocene bat that helps bridge the gap between archaic stem bats and the hyperdiverse modern bat radiation of more than 1,460 living species. Recovered from ∼50 million-year-old cave sediments in the Quercy Phosphorites of southwestern France, Vielasia sigei's remains include a near-complete, three-dimensionally preserved skull-the oldest uncrushed bat cranium yet found. Phylogenetic analyses of a 2,665 craniodental character matrix, with and without 36.8 kb of DNA sequence data, place Vielasia outside modern bats, with total evidence tip-dating placing it sister to the crown clade. Vielasia retains the archaic dentition and skeletal features typical of early Eocene bats, but its inner ear shows specializations found in modern echolocating bats. These features, which include a petrosal only loosely attached to the basicranium, an expanded cochlea representing ∼25% basicranial width, and a long basilar membrane, collectively suggest that the kind of laryngeal echolocation used by most modern bats predates the crown radiation. At least 23 individuals of V.sigei are preserved together in a limestone cave deposit, indicating that cave roosting behavior had evolved in bats by the end of the early Eocene; this period saw the beginning of significant global climate cooling that may have been an evolutionary driver for bats to first congregate in caves.

The hindlimb of Amphicynodon leptorhynchus from the lower Oligocene of the Quercy Phosphorites (France): Highlight of new climbing adaptations of this early arctoid

The hindlimb of Amphicynodon leptorhynchus from the lower Oligocene of the Quercy Phosphorites (France): Highlight of new climbing adaptations of this early arctoid

3D models related to the publication: Description of the first cranium and endocranial structures of Stenoplesictis minor (Mammalia, Carnivora), an early aeluroid from the Oligocene of the Quercy Phosphorites (southwestern France)

3D models related to the publication: Description of the first cranium and endocranial structures of Stenoplesictis minor (Mammalia, Carnivora), an early aeluroid from the Oligocene of the Quercy Phosphorites (southwestern France)

Description of the first cranium and endocranial structures of Stenoplesictis minor (Mammalia, Carnivora), an early aeluroid from the Oligocene of the Quercy Phosphorites (southwestern France)

ABSTRACT We describe a well-preserved cranium of one of the earliest aeluroid carnivorans from the Quercy Phosphorites, southwestern France. The structure of the auditory region (auditory bulla with two chambers separated by a true septum, prominent ventral process of promontorium with facet for the posterior wall of the ectotympanic) reveals that it belongs to a primitive viverrid-like group called ‘stenoplesictoids’, and more precisely to the genus Stenoplesictis. Using high-resolution X-ray micro-tomography, we reconstructed for the first time virtual endocranial structures (brain endocast, stapes, and bony labyrinths) of a ‘stenoplesictoid’. The brain endocast has a well-developed neocortex and simple coronolateral and suprasylvian sulci, more evolved than older Carnivoramorpha and indicates a primitive step towards the extant genera. Based on the characters of the dentition and of the auditory region, we conclude that this cranium belongs to Stenoplesictis minor. While we still cannot suggest phylogenetic relationships between ‘stenoplesictoids’ and other aeluroids, our study constitutes a first attempt to unravel new morphological data to better characterise the enigmatic ‘stenoplesictoids’, a step forward in the understanding of the evolution of early aeluroids.

Climbing Adaptations of an Enigmatic Early Arctoid Carnivoran: the Functional Anatomy of the Forelimb of Amphicynodon leptorhynchus From the Lower Oligocene of the Quercy Phosphorites (France)

This paper provides a detailed description and the functional anatomy of the forelimb of an early Oligocene genet-sized arctoid carnivoran, Amphicynodon leptorhynchus, to infer its probable lifestyle. This work represents the first insights into the functional anatomy of the postcranial skeleton and palaeoecology of an emblematic member of the first radiation of arctoid carnivorans, the poorly known Amphicynodontidae, a group very likely related to bears. So far, the Amphicynodontidae have only been studied on the basis of their cranial and dental remains. The fossil site of Itardies (MP23, lower Oligocene), in the Quercy Phosphorites (France), have yielded hundreds of postcranial remains attributed to Am. leptorhynchus, allowing a complete analysis of its locomotor behaviour in comparison to a large sample of extant carnivorans showing diverse lifestyles. The anatomy of the forelimb of Am. leptorhynchus indicates well-developed climbing skills and grasping abilities. Thus, this early arctoid was probably living mostly in trees, moving on the ground basically for foraging as observed in small modern climbing carnivorans such as the red panda or the kinkajou, although some other climbing carnivorans can also live in rocky areas.

From toad to frog, a CT-based reconsideration of Bufo servatus, an Eocene anuran mummy from Quercy (France)

ABSTRACT In the 19th century, natural mummies of amphibians were discovered in the Quercy Phosphorites. The specific collection site was never formally reported, which hampers precise dating of these specimens. Still, the name Bufo servatus was erected based on the external morphology of one of the mummified specimens. A tomography of a similarly preserved specimen revealed a preserved skeleton, soft tissues and gut contents. We analyze here the holotype of Bufo servatus using CT-scanning in order to investigate its potentially preserved internal features. Like the previous specimen, a subcomplete articulated skeleton was identified in the B. servatus holotype. Surprisingly, this skeleton is almost identical to that of Thaumastosaurus gezei, an Eocene anuran from Western Europe to which other specimens from this mummy series were previously assigned. The few differences between the specimen skeletons highlight ontogenetic and intraspecific variations, making T. gezei a junior synonym of B. servatus and creating the new combination Thaumastosaurus servatus. Given its association with previously described Quercy specimens, this redescribed anuran is probably from the same time interval as T. gezei. Previous phylogenetic analyses assigned T. servatus to Ranoides, with natatanuran affinities. Using data from this newly described specimen, we tested here further its taxonomic affinities. Our analyses confirm this position, and formally identify T. servatus as a Natatanuran member of Pyxicephalidae (currently endemic of equatorial Africa) and more precisely, a stem-Pyxicephalinae. This result confirms the origin of Thaumastosaurus, a member of the African herpetofauna occupying Western Europe before the Grande Coupure at the Eocene/Oligocene transition.

The upper Eocene-Oligocene carnivorous mammals from the Quercy Phosphorites (France) housed in Belgian collections

The Quercy Phosphorites Formation in France is world famous for its Eocene to Miocene faunas, especially those from the upper Eocene to lower Oligocene, the richest of all. The latter particularly helped to understand the ‘Grande Coupure’, a dramatic faunal turnover event that occurred in Europe during the Eocene-Oligocene transition. Fossils from the Quercy Phosphorites were excavated from the middle 19th century until the early 20th century in a series of sites and became subsequently dispersed over several research institutions, while often losing the temporal and geographical information in the process. In this contribution, we provide an overview and reassess the taxonomy of these barely known collections housed in three Belgian institutions: the Université de Liège, KU Leuven, and the Royal Belgian Institute of Natural Sciences. We focus our efforts on the carnivorous mammals (Hyaenodonta and Carnivoramorpha) and assess the stratigraphic intervals covered by each collection. These fossils are derived from upper Eocene (Priabonian), lower Oligocene (Rupelian), and upper Oligocene (Chattian) deposits in the Quercy area. The richness of the three collections (e.g., the presence of numerous postcranial elements in the Liège collection), the presence of types and figured specimens in the Leuven collection, and some identified localities in the RBINS collection make these collections of great interest for further studies on systematics and the evolution of mammals around the ‘Grande Coupure’.

Description of a new species of Cynodictis Bravard & Pomel, 1850 (Carnivora, Mammalia) from the Quercy Phosphorites with comments on the use of skull morphology for phylogenetics

Amphicyonidae Trouessart, 1885 are among the oldest known carnivoran groups, with the oldest representatives in Europe belonging to the genus CynodictisBravard & Pomel, 1850. This genus, discovered in the middle of the 19th century, presents a particularly confusing taxonomic history. Early on it was subject to taxonomic inflation, but now its diversity is reduced to six species. It is therefore interesting to question the relevance of dental characteristics, knowing that these structures have, very often, been the only anatomical elements used for the description of extinct mammalian taxa. Thanks to the several deposits of the Quercy Phosphorites, many crania of Cynodictis are available, allowing us to address this issue. In this comparative study, several skulls belonging to this genus are compared. Finally, we describe a new species, Cynodictis peignei n. sp., and discuss the relevance of cranial characters in comparison with dental characters and the ecological information from these structures.

New genus of amphicyonid carnivoran (Mammalia, Carnivora, Amphicyonidae) from the phosphorites of Quercy (France)

An isolated mandible of Carnivora (Mammalia) from the phosphorites of Quercy (France) is described as a new genus. It is compared with the amphicyonid genus Cynodictis, some primitive North American amphicyonids, and with European and North American Eocene carnivoraforms. I conclude that it is a primitive amphicyonid which may be dated to the middle or late Eocene.

Carnivora from the early Oligocene of the ‘Phosphorites du Quercy’ in southwestern France

The early Oligocene carnivorans from the Quercy phosphorites (southwestern France) studied herein come from three localities: Mas de Got, La Plante2 and Valbro, all in MP 22 of the European Paleogene Mammal stratigraphy scheme. These localities contain a rich carnivoran fauna with weasel-sized to tiger-sized species in diverse families, especially Amphicynodontidae (with four species of Pachycynodon and two of Amphicynodon) and Nimravidae. New taxa are described (Wangictis n. gen., Peignictis pseudamphictis n. gen., n. sp.). We note the absence of taxa often present in the sites of the Quercy phosphorites, such as the family Amphicyonidae and, in the Feloidea, the genera StenoplesictisFilhol, 1880 and PalaeoprionodonFilhol, 1880. The fauna of the three localities is typical of the early Oligocene prior to a faunal turnover in the middle Oligocene. Future research in the Quercy will give more precision to the timing and mode of this faunal event.

Necrosaurus or Palaeovaranus? Appropriate nomenclature and taxonomic content of an enigmatic fossil lizard clade (Squamata)

Necrosaurus cayluxi is an enigmatic lizard from the Paleogene of the Phosphorites of Quercy, France that was first mentioned in the 19th century. Although it is generally believed that Filhol was the author who established this taxon, I am herein demonstrating that authorship should in fact be attributed to Zittel, a fact that also influences not only its generic nomenclature, but also its appropriate type material. As such, the valid name for this taxon should be Palaeovaranus cayluxi and its holotype is a left maxilla. Additionally, Ophisauriscus eucarinatus from the middle Eocene of Geiseltal, Germany, another taxon that was previously assigned to Necrosaurus, is herein shown to be a nomen dubium, whereas Melanosauroides giganteus from the same locality, is considered a valid species and is recombined as Palaeovaranus giganteus comb. nov. The suggested changes in nomenclature also affect “Necrosauridae”, a poorly defined clade of lizards from the Cretaceous–Paleogene of Europe, North America, and Asia. In order to maintain nomenclatural stability and define a monophyletic lineage, I am here establishing the new family Palaeovaranidae fam. nov., which includes solely the genus Palaeovaranus. The known occurrences of Palaeovaranus across the Paleogene of Western Europe are discussed.

A re-interpretation of the Eocene anuran Thaumastosaurus based on microCT examination of a 'mummified' specimen.

What originally appeared to be only an external cast of an anuran ‘mummy’ from the Quercy Phosphorites (southwestern France) was described as Rana plicata during the 19th century. Its geographical provenance is only vaguely known; therefore its precise age within the Paleogene was uncertain. The taxon was erected on the basis of the external morphology of the specimen, which includes few diagnostic characters. As a further complication, the name Rana plicata was recently shown to be unavailable at the time of the description, and the name Rana cadurcorum was proposed as a replacement. In order to see whether internal features were fossilized, the fossil was CT scanned. This showed that a large part of the skeleton is preserved. Unexpectedly, the scans revealed that the skull of the mummy is almost identical to that of Thaumastosaurus gezei, another anuran from the late middle or late Eocene of the Quercy Phosphorites. The few observed differences are attributable to intraspecific and ontogenetic variation, and R. cadurcorum is a junior subjective synonym of T. gezei. The mummy is therefore probably from the same time interval as T. gezei. The latter was previously known only by its skull, but the mummy provides important information on the postcranial skeleton. Earlier assessments, based only on the skull, placed Thaumastosaurus close to South American hyloid anurans, but a new phylogenetic analysis including postcranial characters reveals ranoid affinities. This study exemplifies the usefulness of modern imaging technologies that allow non-destructive study of previously inaccessible internal anatomical features.

A new late Early Oligocene vertebrate fauna from Moissac, South-West France

The new vertebrate locality Moissac-IV, in SW France, yields the alligatoroid Diplocynodon sp., the turtle Trionyx sp., and a diversified mammal fauna. The mammal assemblage includes the rodent Protechimys cf. lebratierensis, the artiodactyls Caenomeryx sp., Lophiomeryx chalaniati, Gelocus sp., Metriotherium aff. mirabile, Entelodon sp., and Anthracotherium sp., the perissodactyls Protaceratherium albigense and Eggysodon gaudryi, the carnivore Nimravus intermedius, and the creodonts Hyaenodon dubius and Hyaenodon? leptorhynchus. The Moissac-IV fauna, referred to the MP24 reference level, is both totally distinct from those of Moissac-I (MN1, Earliest Miocene) and Moissac-II (MP29, Late Oligocene) and older than Moissac-III (MP26). It provides original data in a stratified context just prior the Early-Late Oligocene transition, i.e. a stratigraphical interval, which for SW France, was essentially documented by karstic fillings of the Phosphorites of Quercy so far.

New data on the Cainotheriidae (Mammalia, Artiodactyla) from the early Oligocene of south-western France

The Cainotheriidae are small artiodactyls that suddenly appeared in the late Eocene of western Europe. A revision of early Oligocene cainotheriid lineages is proposed on the basis of newly dated material from the Quercy Phosphorites (south-western France). A significant diversification of the group occurred at the end of the Eocene. Few species seem to have persisted through the Eocene/Oligocene boundary, but the Cainotheriidae subsequently diversified rapidly during the early Oligocene. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 144, 145−166.

Des chambres de pupation de Dermestidae (Insecta : Coleoptera) sur un os de mammifère tertiaire (phosphorites du Quercy) : implications taphonomiques et paléoenvironnementales

The larvae of some species of Dermestidae (Coleoptera) are able to bore the bones of a carrion for pupation. Several pupal chambers have been observed on an unciform belonging to a fossil rhinocerotid ( Mesaceratherium sp.) from the late Oligocene/earliest Miocene of the phosphorites of Quercy (SW France). Such an unusual observation demonstrates the occurrence of dermestids in the entomofauna of the phosphorites of Quercy, and suggests at least the existence of paleoclimatic episodes with dry seasons, during a period usually considered as a relatively humid one. This is the earliest occurrence of such ichnofossils on a fossil mammal bone.

A primitive nimravine skull from the Quercy fissures, France: implications for the origin and evolution of Nimravidae (Carnivora)

A carnivore skull from the Phosphorites of Quercy, France, is described herein. Its well-preserved basicranial structure, cat-like morphology, and dental reduction support the assignment of this specimen to the Nimravidae. This is the most primitive nimravid described and its overall morphology is the closest yet to the hypothetical ancestor of the Nimravinae as previously conceived. In addition, the monophyly of the Nimravinae is reinforced by the similar basicranium of the specimen described here compared to other nimravid genera. It suggests that this typical basicranial structure appeared well ahead the sabretooth features in this group. The early evolution and diversification of the Nimravinae occurred during the Late Eocene in the northern hemisphere but the precise geographic area is still unknown. A rapid evolution during the initial radiation of the group or an incomplete fossil record in Eurasia could both equally explain the rapid and worldwide distribution of the Nimravinae.

A primitive nimravine skull from the Quercy fissures, France: implications for the origin and evolution of Nimravidae (Carnivora)

A carnivore skull from the Phosphorites of Quercy, France, is described herein. Its well-preserved basicranial structure, cat-like morphology, and dental reduction support the assignment of this specimen to the Nimravidae. This is the most primitive nimravid described and its overall morphology is the closest yet to the hypothetical ancestor of the Nimravinae as previously conceived. In addition, the monophyly of the Nimravinae is reinforced by the similar basicranium of the specimen described here compared to other nimravid genera. It suggests that this typical basicranial structure appeared well ahead the sabretooth features in this group. The early evolution and diversification of the Nimravinae occurred during the Late Eocene in the northern hemisphere but the precise geographic area is still unknown. A rapid evolution during the initial radiation of the group or an incomplete fossil record in Eurasia could both equally explain the rapid and worldwide distribution of the Nimravinae.

Un assemblage d'os grignoté par les rongeurs au Paléogène (Oligocène supérieur, phosphorites du Quercy)

Abstract Bone gnawing modifications by rodents at a large scale is a taphonomical feature usually found in Plio-Pleistocene assemblages. We report for the first time such a case within the 26-Myr-old karstic fissure filling assemblage of Pech-Desse (phosphorites of Quercy, Upper Oligocene, MP 28). A selection is observed on small ungulate long bones and other elements with a similar size. As predation evidences are also numerous on these taxa, and because some similar gnawed bones have been observed within the contemporaneous locality of Pech-du-Fraysse, we propose a secondary intervention of theridomyid rodents (maybe Archaeomys) on a carnivore laird.

The Eocene–Oligocene ungulates from Western Europe and their environment

A survey of Paleogene ungulates from Western Europe is drawn up from the results of previous work on the ungulate lineages of this period and from new data on two groups particularly representative of the Oligocene ungulate fauna: the ruminants and the Cainotheriidae based on new material collected in localities of the Quercy Phosphorites. The history of ungulates from Western Europe at the Eocene–Oligocene transition is marked by different phases of extinction and origination related to environmental changes. In this perspective, the relative diversity of groups and the modifications of their tooth morphology, which reflect a diet change, resulting from vegetation modifications are analysed from the Early Eocene to the Late Oligocene. In Western Europe, the Late Eocene and the Early Oligocene was a period of transition with an important change in faunal and floral composition. The diversity analysis of ungulates suggests that the Grande Coupure is the result of gradual climatic and geographic events that occurred from the Middle Eocene (Mammalian Paleogene (MP)13/14 reference levels) to the Early Oligocene (MP 21/22 reference levels). During this period, it has been demonstrated that important adaptive changes occurred in the ungulate dental pattern (selenodonty in artiodactyls, semihypsodonty in perissodactyls), and appendicular skeleton (fusion of the cuboid and navicular bones of the tarsus in artiodactyls). These morphological modifications coincided with environmental changes that were less extreme than in North America.