Résumé/Abstract Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of th... more Résumé/Abstract Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of the Mahajanga Basin, NW Madagascar, are hère described. They consist of a large tooth crown and a pedal ungual. The tooth is similar to the teeth of some basai ...
The fossil record of ornithischian dinosaurs from Africa is particularly scarce and limited to a ... more The fossil record of ornithischian dinosaurs from Africa is particularly scarce and limited to a few historic localities. In this study we describe new ornithischian remains from the Albian deposits of southern Tunisia (Tataouine Governorate), represented by isolated teeth of large-bodied iguanodontians. Teeth display a wide, diamond-shaped crown with a primary ridge dividing the occlusal surface in two unequal parts and two or more secondary ridges. Hook-like denticles are present on both mesial and distal crown margins and do not display mammillae. In overall morphology, specimens are comparable to those of many Early Cretaceous basal hadrosauriforms, including isolated ornithopodan teeth from comparably-aged levels of Niger. Transversal sections of the crowns permitted identification of dental tissues, which include a thick enamel, and well developed longitudinal and transverse giant tubules. Their relative extents appear to be related to the size, thus developmental age, of the tooth. Teeth are representative of the Oum ed Diab Member, a unit characterized by coastal deposits accumulated under arid to xeric climatic conditions and dominated by fish, crocodilians, and hydraulically transported rebbachisaurid and spinosaurid remains. Sedimentological data and preservation bias strongly support selective taph-onomic causes for the fossil distribution of ornithischians in southern Tunisia questioning the purported geographic and paleoecologic distribution of isolated Saharan dinosaurs.
A serrated tooth from the lower Senonian (Upper Cretaceous) Polazzo fossil site (Karst, NE Italy)... more A serrated tooth from the lower Senonian (Upper Cretaceous) Polazzo fossil site (Karst, NE Italy) is the first record of a notosuchian crocodyliform from Italy. Although it shares synapomorphies with teeth referred to the European Doratodon and with the Gondwanan Araripesuchus, it is distinct in the unusual combination of features, suggesting the presence of a yet unreported species of notosuchian in the Adriatic-Dinaric Carbonate Platform occurring in the Tethys between the Afroarabian continent and the North European land during Late Cretaceous times. Notosuchians were tipically terrestrial crocodyliforms, supporting the presence of emergent areas on the carbonate platform.
The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod kn... more The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod known to date from the Upper Cretaceous of Europe. Previous studies of this remarkable taxon have included its phylogenetic interpretation as an aberrant dromaeosaurid with velociraptorine affinities. However, Balaur displays a combination of both apparently plesiomorphic and derived bird-like characters. Here, we analyse those features in a phylogenetic revision and show how they challenge its referral to Dromaeosauridae. Our reanalysis of two distinct phylogenetic datasets focusing on basal paravian taxa supports the reinterpretation of Balaur as an avialan more crownward than Archaeopteryx but outside of Pygostylia, and as a flightless taxon within a paraphyletic assemblage of long-tailed birds. Our placement of Balaur within Avialae is not biased by character weighting. The placement among dromaeosaurids resulted in a suboptimal alternative that cannot be rejected based on the data to hand. Interpreted as a dromaeosaurid, Balaur has been assumed to be hypercarnivorous and predatory, exhibiting a peculiar morphology influenced by island endemism. However, a dromaeosaurid-like ecology is contradicted by several details of Balaur's morphology, including the loss of a third functional manual digit, the non-ginglymoid distal end of metatarsal II, and a non-falciform ungual on the second pedal digit that lacks a prominent flexor tubercle. Conversely, an omnivorous ecology is better supported by Balaur's morphology and is consistent with its phylogenetic placement within Avialae. Our reinterpretation of Balaur implies that a superficially dromaeosaurid-like taxon represents the enlarged, terrestrialised descendant of smaller and probably volant ancestors.
ABSTRACT Two small bones from the Upper Triassic of Cromhall Quarry (Gloucestershire, England), w... more ABSTRACT Two small bones from the Upper Triassic of Cromhall Quarry (Gloucestershire, England), which are referred in the literature to pterosaurian wing metacarpals, are compared with wing metacarpals of unequivocal pterosaur specimens from the Upper Triassic of Italy and Greenland as well as those of the Liassic Dimorphodon macronyx from England. The two are morphologically distinct from the unequivocal wing metacarpals. Comparison with the phalanges of drepanosauromorphs suggests that they are probably penultimate phalanges of those bizarre diapsids. Drepanosauromorphs are now known from Cromhall Quarry, but they were not in 1990 when the two presumed wing metacarpals were described. There is no definitive evidence of the presence of pterosaurs in the Triassic of the UK.
The taxonomy and phylomorphogenesis of conodont pectiniform elements around the Carnian/Norian bo... more The taxonomy and phylomorphogenesis of conodont pectiniform elements around the Carnian/Norian boundary is rather problematic for the apparent provincialism that affects many conodont species (Kozur, 2003; Mazza & Rigo, 2008a) and for the large number of ...
Résumé/Abstract Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of th... more Résumé/Abstract Two large theropod remains from the Middle Jurassic (Isalo IIIb, Bathonian) of the Mahajanga Basin, NW Madagascar, are hère described. They consist of a large tooth crown and a pedal ungual. The tooth is similar to the teeth of some basai ...
The fossil record of ornithischian dinosaurs from Africa is particularly scarce and limited to a ... more The fossil record of ornithischian dinosaurs from Africa is particularly scarce and limited to a few historic localities. In this study we describe new ornithischian remains from the Albian deposits of southern Tunisia (Tataouine Governorate), represented by isolated teeth of large-bodied iguanodontians. Teeth display a wide, diamond-shaped crown with a primary ridge dividing the occlusal surface in two unequal parts and two or more secondary ridges. Hook-like denticles are present on both mesial and distal crown margins and do not display mammillae. In overall morphology, specimens are comparable to those of many Early Cretaceous basal hadrosauriforms, including isolated ornithopodan teeth from comparably-aged levels of Niger. Transversal sections of the crowns permitted identification of dental tissues, which include a thick enamel, and well developed longitudinal and transverse giant tubules. Their relative extents appear to be related to the size, thus developmental age, of the tooth. Teeth are representative of the Oum ed Diab Member, a unit characterized by coastal deposits accumulated under arid to xeric climatic conditions and dominated by fish, crocodilians, and hydraulically transported rebbachisaurid and spinosaurid remains. Sedimentological data and preservation bias strongly support selective taph-onomic causes for the fossil distribution of ornithischians in southern Tunisia questioning the purported geographic and paleoecologic distribution of isolated Saharan dinosaurs.
A serrated tooth from the lower Senonian (Upper Cretaceous) Polazzo fossil site (Karst, NE Italy)... more A serrated tooth from the lower Senonian (Upper Cretaceous) Polazzo fossil site (Karst, NE Italy) is the first record of a notosuchian crocodyliform from Italy. Although it shares synapomorphies with teeth referred to the European Doratodon and with the Gondwanan Araripesuchus, it is distinct in the unusual combination of features, suggesting the presence of a yet unreported species of notosuchian in the Adriatic-Dinaric Carbonate Platform occurring in the Tethys between the Afroarabian continent and the North European land during Late Cretaceous times. Notosuchians were tipically terrestrial crocodyliforms, supporting the presence of emergent areas on the carbonate platform.
The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod kn... more The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod known to date from the Upper Cretaceous of Europe. Previous studies of this remarkable taxon have included its phylogenetic interpretation as an aberrant dromaeosaurid with velociraptorine affinities. However, Balaur displays a combination of both apparently plesiomorphic and derived bird-like characters. Here, we analyse those features in a phylogenetic revision and show how they challenge its referral to Dromaeosauridae. Our reanalysis of two distinct phylogenetic datasets focusing on basal paravian taxa supports the reinterpretation of Balaur as an avialan more crownward than Archaeopteryx but outside of Pygostylia, and as a flightless taxon within a paraphyletic assemblage of long-tailed birds. Our placement of Balaur within Avialae is not biased by character weighting. The placement among dromaeosaurids resulted in a suboptimal alternative that cannot be rejected based on the data to hand. Interpreted as a dromaeosaurid, Balaur has been assumed to be hypercarnivorous and predatory, exhibiting a peculiar morphology influenced by island endemism. However, a dromaeosaurid-like ecology is contradicted by several details of Balaur's morphology, including the loss of a third functional manual digit, the non-ginglymoid distal end of metatarsal II, and a non-falciform ungual on the second pedal digit that lacks a prominent flexor tubercle. Conversely, an omnivorous ecology is better supported by Balaur's morphology and is consistent with its phylogenetic placement within Avialae. Our reinterpretation of Balaur implies that a superficially dromaeosaurid-like taxon represents the enlarged, terrestrialised descendant of smaller and probably volant ancestors.
ABSTRACT Two small bones from the Upper Triassic of Cromhall Quarry (Gloucestershire, England), w... more ABSTRACT Two small bones from the Upper Triassic of Cromhall Quarry (Gloucestershire, England), which are referred in the literature to pterosaurian wing metacarpals, are compared with wing metacarpals of unequivocal pterosaur specimens from the Upper Triassic of Italy and Greenland as well as those of the Liassic Dimorphodon macronyx from England. The two are morphologically distinct from the unequivocal wing metacarpals. Comparison with the phalanges of drepanosauromorphs suggests that they are probably penultimate phalanges of those bizarre diapsids. Drepanosauromorphs are now known from Cromhall Quarry, but they were not in 1990 when the two presumed wing metacarpals were described. There is no definitive evidence of the presence of pterosaurs in the Triassic of the UK.
The taxonomy and phylomorphogenesis of conodont pectiniform elements around the Carnian/Norian bo... more The taxonomy and phylomorphogenesis of conodont pectiniform elements around the Carnian/Norian boundary is rather problematic for the apparent provincialism that affects many conodont species (Kozur, 2003; Mazza & Rigo, 2008a) and for the large number of ...
Brachauchenine pliosaurids were marine macropredatory reptiles that might have been the only evol... more Brachauchenine pliosaurids were marine macropredatory reptiles that might have been the only evolutionary lineage of pliosaurid plesiosaurians that crossed the Jurassic-Cretaceous boundary. Yet progress in understanding their origins and phylogenetic relationships has been hindered by limited knowledge of Early Cretaceous brachauchenine pliosaurid diversity and disparity relative to Late Cretaceous members of the clade. Late Cretaceous brachauchenines currently include only three valid taxa: Brachauchenius lucasi and Megacephalosaurus eulerti, initially described from the Turonian of Kansas, as well as ʽPolyptychodonʼ hudsoni from the Turonian of Texas. In Europe, the clade has long been represented by the widely distributed taxon Polyptychodon interruptus. However, recent reappraisal of the original type material of Polyptychodon from the mid-Cretaceous of England has shown that P. interruptus lacks diagnostic features, prompting a revision of all available specimens attributed to this classic taxon. Arguably the most complete is a partial cranium from the Cenomanian–middle Turonian of Dorking, England. This has been dubbed the ʽDorking specimen’, and was first described in 1860 by Sir Richard Owen, who referred it to Polyptychodon interruptus. Its historical association has also subsequently prompted suggestions that the specimen be designated the neotype of P. interruptus. Though incomplete, its morphology allows for comparisons with other brachauchenines, suggesting its potentially distinct nature. The phylogenetic placement of the specimen further supports the affinity with other Late Cretaceous brachauchenine pliosaurids, which clearly occupied apex-predator niches in marine ecosystems (including those of Europe) up until the end of the Turonian.
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