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Papers by Ronan Allain

Research paper thumbnail of Le marécage fossile d’Angeac-Charente

Paléontologie d'aujourd'hui

Research paper thumbnail of Un musée de dinosaures à Tazouda

Paléontologie d'aujourd'hui

Research paper thumbnail of Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary

Geodiversitas

This contribution describes the continental micro-and macrovertebrate fauna of Angeac-Charente (B... more 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 Cretaceous mixed continental bonebed and Lagerstätte known to date in the World, and it provides a good picture of a Purbeckian paleocommunity. It includes remarkable taxa such as a new ornithomimosaur, a large turiasaur, an helochelydrid turtle and numerous mammals. The vertebrate fauna of Angeac has beyond all a Purberckian character. Many exclusively European genera and species belong to families with an essentially Laurasian paleogeographic distribution. Some taxa nevertheless suggest dispersal events between Africa and Europe at the Jurassic/Cretaceous transition. The successive Charente faunas of Chassiron (Tithonian), Cherves-de-Cognac (Berriasian) and Angeac-Charente improve our poor knowledge of the evolution of continental vertebrate faunas at the Jurassic/Cretaceous transition. Rather than reflecting an important faunal turnover between the Tithonian and the Berriasian, they record environmental changes related to the sealevel regression that characterizes the end of the Jurassic.

Research paper thumbnail of Le Supercontinent

Research paper thumbnail of Paléobiodiversité des vertébrés du Lagerstätte du Crétacé inférieur d'Angeac–Charente (sud–ouest de la France), implications pour le renouvellement faunique continental à la limite J/K

This contribution describes the continental micro-and macrovertebrate fauna of Angeac-Charente (B... more 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 Cretaceous mixed continental bonebed and Lagerstätte known to date in the World, and it provides a good picture of a Purbeckian paleocommunity. It includes remarkable taxa such as a new ornithomimosaur, a large turiasaur, an helochelydrid turtle and numerous mammals. The vertebrate fauna of Angeac has beyond all a Purberckian character. Many exclusively European genera and species belong to families with an essentially Laurasian paleogeographic distribution. Some taxa nevertheless suggest dispersal events between Africa and Europe at the Jurassic/Cretaceous transition. The successive Charente faunas of Chassiron (Tithonian), Cherves-de-Cognac (Berriasian) and Angeac-Charente improve our poor knowledge of the evolution of continental vertebrate faunas at the Jurassic/Cretaceous transition. Rather than reflecting an important faunal turnover between the Tithonian and the Berriasian, they record environmental changes related to the sealevel regression that characterizes the end of the Jurassic.

Research paper thumbnail of Volume 29 Numéro 1

Research paper thumbnail of Figure 6 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 6. Ventral view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felix... more Figure 6. Ventral view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin) comb. nov.: A, photograph; B, illustrative sketch. Abbreviations: d, dentary; sp, splenial.

Research paper thumbnail of Figure 10. Partial lower jaw MNHN.F INA 22 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 10. Partial lower jaw MNHN.F INA 22 of Fortignathus felixi (de Lapparent de Broin) comb. n... more Figure 10. Partial lower jaw MNHN.F INA 22 of Fortignathus felixi (de Lapparent de Broin) comb. nov.: A, B, photograph and illustrative sketch in left lateral view; C, D, photograph and illustrative sketch in right lateral view. Abbreviations: d1–d6, dentary alveoli from positions 1 to 6.

Research paper thumbnail of Figure 5. Partial lower jaw MNHN.F INA 25 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 5. Partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de B... more Figure 5. Partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov.: A, B, photograph and illustrative sketch in left lateral view; C, D, photograph and illustrative sketch in medial view. Abbreviations: d1–d19, dentary alveoli from positions 1 to 19; m?, maxillary tooth enamel; sp, splenial.

Research paper thumbnail of Figure 11 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 11. Measurements of jaw width and height across the symphyseal sections of dyrosaurid croc... more Figure 11. Measurements of jaw width and height across the symphyseal sections of dyrosaurid crocodyliforms, including Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov., specimens MNHN.F INA 21 and MNHN.F INA 22.

Research paper thumbnail of Figure 2 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 2. Osteoderms assigned to Crocodyliformes indeterminate (formerly Elosuchus felixi de Lapp... more Figure 2. Osteoderms assigned to Crocodyliformes indeterminate (formerly Elosuchus felixi de Lapparent de Broin, 2002): A, MNHN.F INA 38 in dorsal view; B, MNHN.F INA 38 in ventral view; C, MNHN.F INA 40 in dorsal view; D, MNHN.F INA 41 in dorsal view.

Research paper thumbnail of Figure 4 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 4. Dorsal view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi... more Figure 4. Dorsal view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov.: A, photograph; B, illustrative sketch. Abbreviations: d1–d19, dentary alveoli from positions 1 to 19; m?, maxillary tooth enamel; sp, splenial.

Research paper thumbnail of Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from the analysis using all 104 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early ori...

Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from t... more Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from the analysis using all 104 operational taxonomic units (OTUs). B, subset of results from the analysis excluding Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov., showing the only differences with the 104 OUT analyses (i.e. in the resolution of Dyrosauridae, Pholidosauridae and Crocodylia). Bootstrap values are shown above the relevant nodes. C, subset of results from the analysis excluding F. felixi comb. nov. and Pholidosaurus schaumbergensis von Meyer, 1841, showing the differences with the 104 OUT analysis alone (i.e. in the resolution of Dyrosauridae and Pholidosauridae). Abbreviations: CI, ensemble consistency index; RI, ensemble retention index; RC, rescaled consistency index; HI, ensemble homoplasy index.

Research paper thumbnail of New data on the theropod diversity from the Middle to Late Jurassic of the Vaches Noires cliffs (Normandy, France)

Geodiversitas, 2022

Dinosaur remains found at the Vaches Noires cliffs (Calvados, Normandy) have usually been discove... more 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. Consequently, many of these bones were never described. Thus, and for the first time, private and public collections are gathered to obtain a global vision of theropod remains from the Vaches Noires cliffs. Most of the dinosaur remains from this locality belong to theropods. Some bones are from the same individual but have been isolated as a result of cliff erosion and tidal action which also mixed specimens from different stratigraphic levels. This over-representation of theropod remains is enigmatic because it is not found in other similar deposits. A specific way of life is likely to explain that fact, but it could also be a simple statistical effect due to a limited sample. At least 3 taxa are tentatively identified: Streptospondylus altdorfensis Meyer, 1832, another megalosauroid and an allosauroid.

Research paper thumbnail of A Lower Cretaceous Lagerstätte from France: a taphonomic overview of the Angeac‐Charente vertebrate assemblage

Lethaia, 2021

Terrestrial ecosystems from the Lower Cretaceous of Europe and bonebeds formed in swampy environm... more 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 numerous trample and crocodile bite marks; 22 taxa from the abundant vertebrate microremains; >10 vertebrate coprolite morphotypes with plant and vertebrate inclusions; abundant sauropod and stegosaur tracks including some preserved in '4-D'; termite coprolites; mollusc moulds; ostracods and plants, including coniferous wood, cones, leaves and cuticle fragments, charophytes and pollen. The richness, diversity and preservation of the fossils qualify the site as a fossil-Lagerstätte. The site represents a 'snapshot' into a Lower Cretaceous ecosystem. This is supported by REE analyses of biogenic apatite and sediment samples, the fossils being found in a single stratigraphical interval and the record of sedimentological and taphonomic 'frozen scenes'. The Angeac-Charente bonebed is highly diverse, dominated by an ornithomimosaur taxon, and contains both macro-and microfossils. This indicates a complex formation, likely primarily influenced by ecological and biologic processes, but also significant physical processes. These include crocodyliform predation and/or scavenging on turtles, ornithomimosaurs and fishes; probable mass mortality occurrence of an ornithomimosaur herd; possible social behaviour of stegosaurs; limited hydraulic transport of most sauropod bones and intense dinoturbation. □ Bonebed, Early Cretaceous, ecosystem, Lagerstätte, swamp, taphonomy.

Research paper thumbnail of Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvier, du Jurassique de Normandie

Allain, R. (2001): Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvi... more Allain, R. (2001): Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvier, du Jurassique de Normandie. Geodiversitas 23 (3): 349-367

Research paper thumbnail of FIG. 18 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 18. — Tazoudasaurus naimi, caudal vertebrae: A, B, posterior mid-caudal vertebra (To1-88) in... more FIG. 18. — Tazoudasaurus naimi, caudal vertebrae: A, B, posterior mid-caudal vertebra (To1-88) in right lateral view; C, D, mid-caudal vertebra (To1-288) in left lateral view; E, F, distal caudal vertebra (To1-317) in right lateral view; G, H, distal caudal vertebra (To1-357) in right lateral view. Abbreviations: cf, chevron facet; ns, neural spine; poz, postzygapophysis; prz, prezygapophysis. Scale bar: 5 cm.

Research paper thumbnail of FIG. 15 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 15. — Tazoudasaurus naimi, anterior caudal vertebra (To1- 100): A, B, anterior view; C, D, p... more FIG. 15. — Tazoudasaurus naimi, anterior caudal vertebra (To1- 100): A, B, anterior view; C, D, posterior view. Abbreviations: cprl, centroprezygapophyseal lamina; di, diapophysis; nc, neural canal; ns, neural spine; poz, postzygapophysis; prdl, prezygodiapophyseal lamina; prz, prezygapophysis; psf, postspinal fossa; spol, spinopostzygapophyseal lamina. Scale bar: 5 cm.

Research paper thumbnail of FIG. 40 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 40. — Tazoudasaurus naimi, left ulna of a juvenile individual (To1-374): A, anterior view; B... more FIG. 40. — Tazoudasaurus naimi, left ulna of a juvenile individual (To1-374): A, anterior view; B, posterior view; C, lateral view; D, medial view; E, proximal view; F, distal view. Abbreviations: alp, anterolateral process of the ulna; amp, anteromedial process of the ulna; ol, olecranon area; raf, radial fossa; ras, radial articular surface. Arrow indicates the anterior direction. Scale bar: 5 cm.

Research paper thumbnail of FIG. 43 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 43. — Tazoudasaurus naimi, left tibia of a juvenile individual (To1-76): A, B, lateral view;... more FIG. 43. — Tazoudasaurus naimi, left tibia of a juvenile individual (To1-76): A, B, lateral view; C, D, medial view; E, F, anterior view; G, H, posterior view; I, J, proximal view; K, L, distal view. Abbreviations: aspa, articular surface for the ascending process; cc, cnemial crest; pvp, posteroventral process. Scale bars: 5 cm.

Research paper thumbnail of Le marécage fossile d’Angeac-Charente

Paléontologie d'aujourd'hui

Research paper thumbnail of Un musée de dinosaures à Tazouda

Paléontologie d'aujourd'hui

Research paper thumbnail of Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary

Geodiversitas

This contribution describes the continental micro-and macrovertebrate fauna of Angeac-Charente (B... more 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 Cretaceous mixed continental bonebed and Lagerstätte known to date in the World, and it provides a good picture of a Purbeckian paleocommunity. It includes remarkable taxa such as a new ornithomimosaur, a large turiasaur, an helochelydrid turtle and numerous mammals. The vertebrate fauna of Angeac has beyond all a Purberckian character. Many exclusively European genera and species belong to families with an essentially Laurasian paleogeographic distribution. Some taxa nevertheless suggest dispersal events between Africa and Europe at the Jurassic/Cretaceous transition. The successive Charente faunas of Chassiron (Tithonian), Cherves-de-Cognac (Berriasian) and Angeac-Charente improve our poor knowledge of the evolution of continental vertebrate faunas at the Jurassic/Cretaceous transition. Rather than reflecting an important faunal turnover between the Tithonian and the Berriasian, they record environmental changes related to the sealevel regression that characterizes the end of the Jurassic.

Research paper thumbnail of Le Supercontinent

Research paper thumbnail of Paléobiodiversité des vertébrés du Lagerstätte du Crétacé inférieur d'Angeac–Charente (sud–ouest de la France), implications pour le renouvellement faunique continental à la limite J/K

This contribution describes the continental micro-and macrovertebrate fauna of Angeac-Charente (B... more 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 Cretaceous mixed continental bonebed and Lagerstätte known to date in the World, and it provides a good picture of a Purbeckian paleocommunity. It includes remarkable taxa such as a new ornithomimosaur, a large turiasaur, an helochelydrid turtle and numerous mammals. The vertebrate fauna of Angeac has beyond all a Purberckian character. Many exclusively European genera and species belong to families with an essentially Laurasian paleogeographic distribution. Some taxa nevertheless suggest dispersal events between Africa and Europe at the Jurassic/Cretaceous transition. The successive Charente faunas of Chassiron (Tithonian), Cherves-de-Cognac (Berriasian) and Angeac-Charente improve our poor knowledge of the evolution of continental vertebrate faunas at the Jurassic/Cretaceous transition. Rather than reflecting an important faunal turnover between the Tithonian and the Berriasian, they record environmental changes related to the sealevel regression that characterizes the end of the Jurassic.

Research paper thumbnail of Volume 29 Numéro 1

Research paper thumbnail of Figure 6 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 6. Ventral view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felix... more Figure 6. Ventral view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin) comb. nov.: A, photograph; B, illustrative sketch. Abbreviations: d, dentary; sp, splenial.

Research paper thumbnail of Figure 10. Partial lower jaw MNHN.F INA 22 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 10. Partial lower jaw MNHN.F INA 22 of Fortignathus felixi (de Lapparent de Broin) comb. n... more Figure 10. Partial lower jaw MNHN.F INA 22 of Fortignathus felixi (de Lapparent de Broin) comb. nov.: A, B, photograph and illustrative sketch in left lateral view; C, D, photograph and illustrative sketch in right lateral view. Abbreviations: d1–d6, dentary alveoli from positions 1 to 6.

Research paper thumbnail of Figure 5. Partial lower jaw MNHN.F INA 25 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 5. Partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de B... more Figure 5. Partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov.: A, B, photograph and illustrative sketch in left lateral view; C, D, photograph and illustrative sketch in medial view. Abbreviations: d1–d19, dentary alveoli from positions 1 to 19; m?, maxillary tooth enamel; sp, splenial.

Research paper thumbnail of Figure 11 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 11. Measurements of jaw width and height across the symphyseal sections of dyrosaurid croc... more Figure 11. Measurements of jaw width and height across the symphyseal sections of dyrosaurid crocodyliforms, including Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov., specimens MNHN.F INA 21 and MNHN.F INA 22.

Research paper thumbnail of Figure 2 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 2. Osteoderms assigned to Crocodyliformes indeterminate (formerly Elosuchus felixi de Lapp... more Figure 2. Osteoderms assigned to Crocodyliformes indeterminate (formerly Elosuchus felixi de Lapparent de Broin, 2002): A, MNHN.F INA 38 in dorsal view; B, MNHN.F INA 38 in ventral view; C, MNHN.F INA 40 in dorsal view; D, MNHN.F INA 41 in dorsal view.

Research paper thumbnail of Figure 4 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early origin of the clade Dyrosauridae

Figure 4. Dorsal view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi... more Figure 4. Dorsal view of the partial lower jaw MNHN.F INA 25, the holotype of Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov.: A, photograph; B, illustrative sketch. Abbreviations: d1–d19, dentary alveoli from positions 1 to 19; m?, maxillary tooth enamel; sp, splenial.

Research paper thumbnail of Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from the analysis using all 104 in Revision of the enigmatic crocodyliform Elosuchus felixi de Lapparent de Broin, 2002 from the Lower-Upper Cretaceous boundary of Niger: potential evidence for an early ori...

Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from t... more Figure 13. Strict consensus cladograms from the modified Young matrix analyses. A, results from the analysis using all 104 operational taxonomic units (OTUs). B, subset of results from the analysis excluding Fortignathus felixi (de Lapparent de Broin, 2002) comb. nov., showing the only differences with the 104 OUT analyses (i.e. in the resolution of Dyrosauridae, Pholidosauridae and Crocodylia). Bootstrap values are shown above the relevant nodes. C, subset of results from the analysis excluding F. felixi comb. nov. and Pholidosaurus schaumbergensis von Meyer, 1841, showing the differences with the 104 OUT analysis alone (i.e. in the resolution of Dyrosauridae and Pholidosauridae). Abbreviations: CI, ensemble consistency index; RI, ensemble retention index; RC, rescaled consistency index; HI, ensemble homoplasy index.

Research paper thumbnail of New data on the theropod diversity from the Middle to Late Jurassic of the Vaches Noires cliffs (Normandy, France)

Geodiversitas, 2022

Dinosaur remains found at the Vaches Noires cliffs (Calvados, Normandy) have usually been discove... more 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. Consequently, many of these bones were never described. Thus, and for the first time, private and public collections are gathered to obtain a global vision of theropod remains from the Vaches Noires cliffs. Most of the dinosaur remains from this locality belong to theropods. Some bones are from the same individual but have been isolated as a result of cliff erosion and tidal action which also mixed specimens from different stratigraphic levels. This over-representation of theropod remains is enigmatic because it is not found in other similar deposits. A specific way of life is likely to explain that fact, but it could also be a simple statistical effect due to a limited sample. At least 3 taxa are tentatively identified: Streptospondylus altdorfensis Meyer, 1832, another megalosauroid and an allosauroid.

Research paper thumbnail of A Lower Cretaceous Lagerstätte from France: a taphonomic overview of the Angeac‐Charente vertebrate assemblage

Lethaia, 2021

Terrestrial ecosystems from the Lower Cretaceous of Europe and bonebeds formed in swampy environm... more 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 numerous trample and crocodile bite marks; 22 taxa from the abundant vertebrate microremains; >10 vertebrate coprolite morphotypes with plant and vertebrate inclusions; abundant sauropod and stegosaur tracks including some preserved in '4-D'; termite coprolites; mollusc moulds; ostracods and plants, including coniferous wood, cones, leaves and cuticle fragments, charophytes and pollen. The richness, diversity and preservation of the fossils qualify the site as a fossil-Lagerstätte. The site represents a 'snapshot' into a Lower Cretaceous ecosystem. This is supported by REE analyses of biogenic apatite and sediment samples, the fossils being found in a single stratigraphical interval and the record of sedimentological and taphonomic 'frozen scenes'. The Angeac-Charente bonebed is highly diverse, dominated by an ornithomimosaur taxon, and contains both macro-and microfossils. This indicates a complex formation, likely primarily influenced by ecological and biologic processes, but also significant physical processes. These include crocodyliform predation and/or scavenging on turtles, ornithomimosaurs and fishes; probable mass mortality occurrence of an ornithomimosaur herd; possible social behaviour of stegosaurs; limited hydraulic transport of most sauropod bones and intense dinoturbation. □ Bonebed, Early Cretaceous, ecosystem, Lagerstätte, swamp, taphonomy.

Research paper thumbnail of Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvier, du Jurassique de Normandie

Allain, R. (2001): Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvi... more Allain, R. (2001): Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvier, du Jurassique de Normandie. Geodiversitas 23 (3): 349-367

Research paper thumbnail of FIG. 18 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 18. — Tazoudasaurus naimi, caudal vertebrae: A, B, posterior mid-caudal vertebra (To1-88) in... more FIG. 18. — Tazoudasaurus naimi, caudal vertebrae: A, B, posterior mid-caudal vertebra (To1-88) in right lateral view; C, D, mid-caudal vertebra (To1-288) in left lateral view; E, F, distal caudal vertebra (To1-317) in right lateral view; G, H, distal caudal vertebra (To1-357) in right lateral view. Abbreviations: cf, chevron facet; ns, neural spine; poz, postzygapophysis; prz, prezygapophysis. Scale bar: 5 cm.

Research paper thumbnail of FIG. 15 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 15. — Tazoudasaurus naimi, anterior caudal vertebra (To1- 100): A, B, anterior view; C, D, p... more FIG. 15. — Tazoudasaurus naimi, anterior caudal vertebra (To1- 100): A, B, anterior view; C, D, posterior view. Abbreviations: cprl, centroprezygapophyseal lamina; di, diapophysis; nc, neural canal; ns, neural spine; poz, postzygapophysis; prdl, prezygodiapophyseal lamina; prz, prezygapophysis; psf, postspinal fossa; spol, spinopostzygapophyseal lamina. Scale bar: 5 cm.

Research paper thumbnail of FIG. 40 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 40. — Tazoudasaurus naimi, left ulna of a juvenile individual (To1-374): A, anterior view; B... more FIG. 40. — Tazoudasaurus naimi, left ulna of a juvenile individual (To1-374): A, anterior view; B, posterior view; C, lateral view; D, medial view; E, proximal view; F, distal view. Abbreviations: alp, anterolateral process of the ulna; amp, anteromedial process of the ulna; ol, olecranon area; raf, radial fossa; ras, radial articular surface. Arrow indicates the anterior direction. Scale bar: 5 cm.

Research paper thumbnail of FIG. 43 in Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco

FIG. 43. — Tazoudasaurus naimi, left tibia of a juvenile individual (To1-76): A, B, lateral view;... more FIG. 43. — Tazoudasaurus naimi, left tibia of a juvenile individual (To1-76): A, B, lateral view; C, D, medial view; E, F, anterior view; G, H, posterior view; I, J, proximal view; K, L, distal view. Abbreviations: aspa, articular surface for the ascending process; cc, cnemial crest; pvp, posteroventral process. Scale bars: 5 cm.