Myhrvold et al. 1 suggest that our inference of subaqueous foraging among spinosaurids 2 is under... more Myhrvold et al. 1 suggest that our inference of subaqueous foraging among spinosaurids 2 is undermined by selective bone sampling, inadequate statistical procedures, and use of inaccurate ecological categorizations. Myhrvold et al. 1 ignore major details of our analyses and results, and instead choose to portray our inferences as if they were based on qualitative interpretations of our plots, without providing additional analyses to support their claims. In this manuscript, we thoroughly discuss all the concerns exposed by Myhrvold et al. 1. Additional analyses based on our original datasets 2 and novel data presented by Myhrvold et al. 1 do not change our original interpretations: while the spinosaurid dinosaurs Spinosaurus and Baryonyx are recovered as subaqueous foragers, Suchomimus is inferred as a non-diving animal.
Pterodactyloid pterosaurs underwent a diversification in the Late Jurassic and Early Cretaceous, ... more Pterodactyloid pterosaurs underwent a diversification in the Late Jurassic and Early Cretaceous, followed by a major turnover event in the mid-Cretaceous, when ornithocheirids and basal azhdarchoids were replaced by pteranodontids, nyctosaurids and azhdarchids in the latest Cretaceous. However, precise patterns of turnover are obscured by the incompleteness of the pterosaur fossil record. Fossils from the middle Cretaceous Kem Kem beds of Morocco (?Albian –Cenomanian) have helped shed light on the diversity of pterosaurs from this time and provide a window into the diversity of a continental pterosaur assemblage from this critical transitional period. Two toothed pterosaurs, the ornithocheirids Siroccopteryx moroccensis and Coloborhynchus fluviferox, have been reported from the Kem Kem beds. Here, we report a partial mandible and two premaxillae representing three additional taxa of toothed pterosaurs. The mandibular symphysis closely resembles that of Anhanguera piscator from the Romualdo Member of the Santana Formation of Brazil in the arrangement and spacing of the alveoli, the weak anterior upturn of the jaw, and the ventral crest. One premaxilla closely resembles that of the ornithocheirid Ornithocheirus simus from the Cambridge Greensand Formation of eastern England. A second premaxilla is referred to Coloborhynchus, bearing similarities to C. clavirostris from the Hastings Group of southern England, and C. fluviferox from the Kem Kem beds of Morocco. In total, the Kem Kem pterosaur fauna includes at least nine species, of which five are ornithocheirids. The Kem Kem assemblage supports the hypothesis that toothed pterosaurs remained diverse during the mid Cretaceous before disappearing from post-Cenomanian strata.
The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, C... more The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the “Kem Kem beds”, are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward large-bodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms. No comparable modern terrestrial ecosystem exists with similar bias t...
Myhrvold et al. 1 suggest that our inference of subaqueous foraging among spinosaurids 2 is under... more Myhrvold et al. 1 suggest that our inference of subaqueous foraging among spinosaurids 2 is undermined by selective bone sampling, inadequate statistical procedures, and use of inaccurate ecological categorizations. Myhrvold et al. 1 ignore major details of our analyses and results, and instead choose to portray our inferences as if they were based on qualitative interpretations of our plots, without providing additional analyses to support their claims. In this manuscript, we thoroughly discuss all the concerns exposed by Myhrvold et al. 1. Additional analyses based on our original datasets 2 and novel data presented by Myhrvold et al. 1 do not change our original interpretations: while the spinosaurid dinosaurs Spinosaurus and Baryonyx are recovered as subaqueous foragers, Suchomimus is inferred as a non-diving animal.
Pterodactyloid pterosaurs underwent a diversification in the Late Jurassic and Early Cretaceous, ... more Pterodactyloid pterosaurs underwent a diversification in the Late Jurassic and Early Cretaceous, followed by a major turnover event in the mid-Cretaceous, when ornithocheirids and basal azhdarchoids were replaced by pteranodontids, nyctosaurids and azhdarchids in the latest Cretaceous. However, precise patterns of turnover are obscured by the incompleteness of the pterosaur fossil record. Fossils from the middle Cretaceous Kem Kem beds of Morocco (?Albian –Cenomanian) have helped shed light on the diversity of pterosaurs from this time and provide a window into the diversity of a continental pterosaur assemblage from this critical transitional period. Two toothed pterosaurs, the ornithocheirids Siroccopteryx moroccensis and Coloborhynchus fluviferox, have been reported from the Kem Kem beds. Here, we report a partial mandible and two premaxillae representing three additional taxa of toothed pterosaurs. The mandibular symphysis closely resembles that of Anhanguera piscator from the Romualdo Member of the Santana Formation of Brazil in the arrangement and spacing of the alveoli, the weak anterior upturn of the jaw, and the ventral crest. One premaxilla closely resembles that of the ornithocheirid Ornithocheirus simus from the Cambridge Greensand Formation of eastern England. A second premaxilla is referred to Coloborhynchus, bearing similarities to C. clavirostris from the Hastings Group of southern England, and C. fluviferox from the Kem Kem beds of Morocco. In total, the Kem Kem pterosaur fauna includes at least nine species, of which five are ornithocheirids. The Kem Kem assemblage supports the hypothesis that toothed pterosaurs remained diverse during the mid Cretaceous before disappearing from post-Cenomanian strata.
The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, C... more The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the “Kem Kem beds”, are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward large-bodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms. No comparable modern terrestrial ecosystem exists with similar bias t...
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