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A new azhdarchid pterosaur from the Late Cretaceous phosphates of Morocco
Abstract
A large azhdarchid pterosaur is described from the Late Maastrichtian phosphatic deposits of the Oulad Abdoun Basin, near Khouribga (central Morocco). The material consists of five closely associated cervical vertebrae of a single individual. The mid-series neck vertebrae closely resemble those of azhdarchids Quetzalcoatlus and Azhdarcho in that they are elongate, with vestigial neural spines, prezygapophysial tubercles, a pair of ventral sulci near the prezygapophyses, and without pneumatic foramina on the lateral surfaces of the centra. The Moroccan pterosaur is referred to a new genus and species of Azhdarchidae: Phosphatodraco mauritanicus gen. et sp.nov. It is mainly characterized by a very long cervical vertebra eight, bearing a prominent neural spine located very posteriorly. Based on comparisons with azhdarchid vertebrae, the estimated wing span of Phosphatodraco is close to 5 m. This discovery provides the first occurrence of Late Cretaceous azhdarchids in northern Africa. Phosphatodraco is one of the few azhdarchids known from a relatively complete neck and one of the latest-known pterosaurs, approximately contemporaneous with Quetzalcoatlus.
... The Moroccan phosphates represents a shallow marine, near shore setting composed of an irregularly alternating facies succession of phosphatic sandstones, marls, limestones and cherts (Fig. 1B). The fossil assemblage is well known for its high abundance and diversity of aquatic and terrestrial vertebrate remains, notably those of large mosasaurs (Bardet et al., 2010;2015;Longrich et al., 2021a, b), sauropterygians (Vincent et al., 2011(Vincent et al., , 2013Lomax and Wahl, 2013), crocodilians (Arambourg, 1952), turtles (De Broin et al., 2014), pterosaurs (Suberbiola et al., 2003;Longrich et al., 2018;Labita and Martill 2020) and various fishes (Arambourg, 1952;Bardet et al., 2017;Vullo et al., 2017Vullo et al., , 2019Brito et al., 2021), but rare terrestrial groups including dinosaurs (Longrich et al., 2017; and mammals (Gheerbrant et al., 2002) are also reported. ...
... Several pterodactyloid pterosaurs are present in the phosphate deposits (Suberbiola et al., 2003;Longrich et al., 2018;Labita and Martill, 2020) but likely would have been incapable of swallowing a large pycnodont due to their slender, edentulous beak morphologies. Furthermore, pycnodonts are generally regarded as bottom feeders (Nursall, 1996a;Kriwet, 2001;Cooper and Martill, 2020;Cawley et al., 2021), theoretically making them inaccessible to aerial pterosaurs fishing the surface waters. ...
Isolated jaw elements (vomers, prearticulars, premaxillae) of pycnodont fishes (Actinopterygii: Pycnodontiformes) occur frequently within the Moroccan Oulad Abdoun phosphate assemblages, although their taphonomy has remained unstudied. Recent collecting has identified two conflicting taphonomies: unetched (unaltered) and etched. Three etched jaw specimens of Phacodus punctatus Dixon, 1850 display severe pitting, corrosive marking and enamel discolouration characteristics on the bone and teeth, strongly inferring them to be regurgitalites. Regurgitalites are fossilised remains of partial or undigested skeletal elements that have been ejected from the mouth of the producer. Taphonomy of these etched specimens is attributed to partial transport through the gut of a larger vertebrate where they were partially digested before being regurgitated orally. Different macropredators in the assemblage are scored on their physiological capabilities of being the producer, with a large mosasaur like Prognathodon being the most plausible culprit. Regurgitalites are previously unreported in the formation, further adding to our understanding of the complex trophic food webs in the latest Cretaceous of Morocco. The elusive form and function of the characteristic dental ‘pits’ in the genus Phacodus are additionally investigated using thin section petrography and scanning electron microscopy (SEM).
... Due to the range of sedimentary environments in which azhdarchid fossils occur ranging from shallow-marine (e.g., Frey and Martill, 1996;Pereda Suberbiola et al. 2003;Longrich et al. 2018) to fluvial and lacustrine settings (e.g., Lawson 1975;Averianov 2010;Ibrahim et al. 2020) it is unlikely that all azhdarchids had the same lifestyle. Similarly, due to the long temporal range (at least 47 my from the Aptian to Maastrichtian) of Azhdarchidae and their morphological disparity, it is unlikely that individual species occupied the same ecological niche through time. ...
The pterosaur assemblage of the mid-Cretaceous Kem Kem Group of Morocco is reviewed. This analysis examines their
taxonomy, palaeoecology and palaeobiology with comments on taphonomy. New material permits the rediagnosis of the
azhdarchoids Alanqa saharica and Afrotapejara zouhrii. Several specimens are reported that do not ft within the paradigms of previously named taxa. They represent three distinct jaw morphotypes, but are not assigned to new taxa here. The
assemblage is highly diverse, including four tooth-bearing taxa assigned to Ornithocheiridae and fve named taxa and three
additional morphotypes assigned to Azhdarchoidea. The Kem Kem Group assemblage is the most diverse for any pterosaurbearing fuvial deposit and one of the most diverse of any pterosaur assemblage. The assemblage is heavily biased in terms of preservation with an as yet unexplained high abundance of jaw fragments. We highlight the importance of fragmentary
material in pterosaur studies.
... This is the case of Quetzalcoatlus northropi from the Maastrichtian of United States (Lawson, 1975;Langston, 1981;Kellner and Langston, 1996;Andres and Langston, 2021), Arambourgiania philadelphiae from the Maastrichtian of Jordan (Arambourg, 1959;Frey and Martill, 1996), Hatzegopteryx thambema from the Maastrichtian of Romania (Buffetaut et al., 2002;Naish and Witton, 2017) and Cryodrakon boreas from the Campanian of Canada (Hone et al., 2019). Moreover, this group also includes relatively large-sized species (wingspan~5e7 m) like Mistralazhdarcho maggii from the Campanian of France (Vullo et al., 2018) and medium-sized species (~3e5 m) like Eurazhdarcho langendorfensis from the Maastrichtian of Romania (Vremir et al., 2013), Azhdarcho lancicollis from the Turonian of Uzbekistan (Nessov, 1984;Averianov, 2010), Aralazhdarcho bostobensis from the SantonianeCampanian of Kazakhstan (Averianov, 2007), Phosphatodraco mauritanicus from the Maastrichtian of Morocco (Pereda-Suberbiola et al., 2003), Quetzalcoatlus lawsoni and Wellnhopterus brevirostris from the Maastrichtian of United States (Andres and Langston, 2021). ...
The largest pterosaur discovered in South America and one of the largest flying vertebrates in the world is described. Thanatosdrakon amaru gen. et sp. nov. is a new azhdarchid found in the upper-most levels of the Plottier Formation (upper Coniacian–lower Santonian, Neuquén Basin), Mendoza, Argentina. Two specimens were identified, the holotype (UNCUYO-LD 307) and the paratype, with an estimated wingspan of ∼ 7 m and ∼ 9 m, respectively. The cladistic analysis, based on 216 characters and 97 taxa, recovered Thanatosdrakon deeply nested within Azhdarchidae. Relationships within this clade are well resolved and the clade Quetzalcoatlinae presents two well-defined sister-groups: (Arambourgiania, Mistralazhdarcho, Aerotitan, Hatzegopteryx, Albadraco) + (Cryodrakon, Thanatosdrakon, Quetzalcoatlus ssp.). Thanatosdrakon is the oldest taxon of the clade Quetzalcoatlinae so far. It is represented by several well-preserved axial and appendicular bones in three dimensions. Some of these elements have never been described in giant azhdarchids (e.g. complete norarium, dorsosacral vertebrae and caudal vertebra) and this allows to expand the knowledge about the anatomy of this diverse group of pterosaurs. Finally, from a paleoecological point of view, Thanatosdrakon was found in floodplain deposits of ephemeral meandering systems indicating that this large flying species inhabited continental environments.
... They are similar in preservation to the eighth cervicals: TMM 42422-7 is nearly complete (Fig. 25) and TMM 41954-40 is missing its neural spine and upper neural arch, further suggesting that these pairs come from the same individuals (e.g., TMM 41954-40/42 and 42422-7/ 8). Ninth cervicals are present in the azhdarchid species Z. linhaiensis (Cai and Wei, 1994), P. mauritanicus (Pereda- Suberbiola et al., 2003), and A. lancicollis (Averianov, 2020), as well as the putative azhdarchid specimens MPC-D 100/116 and 100/ 117 (Tsuihiji et al., 2017). ...
Quetzalcoatlus is the largest flying organism ever known and one of the most familiar pterosaurs to the public. Despite a half century of interest, it remains very incompletely described. This shortfall is addressed here through a full morphological description of Quetzalcoatlus and the other pterosaur material of Big Bend National Park, Texas. The first reported material was described and named Quetzalcoatlus northropi by Douglas Lawson in 1975, but in two separate publications. A ruling by the International Commission of Zoological Nomenclature was required for the name to be made available. Review of the pterosaur fauna of the Park recovers three valid species of azhdarchid pterosaurs in the latest Cretaceous Period Javelina and Black Peaks formations. The size and occurrence of these species are correlated with depositional environment. The holotype of the giant Quetzalcoatlus northropi and six other giant specimens referred to it occur in stream-channel deposits, including the youngest reported pterosaur. The vast majority of specimens (200+) are from large pterosaurs found in the abandoned channel-lake deposits at Pterodactyl Ridge; they form a diagnosable natural group erected as the new species Quetzalcoatlus lawsoni. A moderate-sized partial skull and cervical series also found in the abandoned channel-lake deposits at Pterodactyl Ridge, but lower in the section, is distinct from both species and is erected as Wellnhopterus brevirostris, gen. et sp. nov. Overbank flood-plain facies preserve another eleven specimens of extreme size variation, including small azhdarchids. The Big Bend pterosaur fauna provides the greatest known sample of azhdarchid pterosaurs and three-dimensional pterosaur morphology.
A fragmentary and the largest single bone element from the Lower Cretaceous Kanmon Group in Kyushu Island, southwestern Japan reported yet to date is described. This specimen has a fossa and lenticular foramen on its lateral surface and internal chambers of both large and small sizes. It was identified as the cervical vertebra of a titanosauriform sauropod dinosaur mainly based on such pneumatic structure. This specimen represents the first titanosauriform to be described from the Kanmon Group.
Here, we describe the first pterosaur remains from Angola, an assemblage of fourteen bones from the Lower Maastrichtian marine deposits of Bentiaba, Namibe Province. One new species is introduced, Epapatelo otyikokolo, gen. et sp. nov., which comprises an articulated partial left humerus and ulna as well as an articulated left ulna and radius (from a second individual). Phylogenetic analysis confirms a non-nyctosaurid pteranodontian attribution for this new taxon and supports a new apomorphy-based clade, Aponyctosauria, which is here defined. Late Cretaceous pteranodontians are rare in Sub-Saharan Africa and throughout the Southern Hemisphere. Preliminary histological analysis also reveals a likely sub-adult age for one of the specimens. This fossil assemblage provides a first glimpse of Angolan pterosaur paleobiodiversity providing further insight into the Gondwanan ecosystems of the Upper Cretaceous.
A B S T R A C T
The Cretaceous-Paleogene (K-Pg) transition saw mass extinctions in terrestrial and marine ecosystems. Terrestrial vertebrate diversity patterns across the K-Pg boundary have seen extensive study, but less is known about marine vertebrates. We describe a new mosasaurid from the latest Maastrichtian phosphatic beds of Morocco, showing how mosasaurids evolved to become apex predators in the latest Cretaceous. Thalassotitan atrox n. gen. et sp., from the Oulad Abdoun Basin of Khouribga Province, Morocco is characterized by large size, a broad skull, massive jaws, and reduced cranial kinesis, suggesting it was highly adapted for carnivory. Teeth resemble those of killer whales in their robust, conical shape, and show heavy wear and damage. Phylogenetic analysis recovers Thalassotitan as a close relative of Prognathodon currii and P. saturator within the Prognathodontini. Among the associated fauna, three genera of mosasaurids, elasmosaurid plesiosaur, chelonioid turtle, and enchodontid fish show acid damage, and could be prey ingested by mosasaurids, likely Thalassotitan. Thalassotitan shows mosasaurids evolved to fill the marine apex predator niche, a niche occupied by orcas and white sharks today. Mosasaurs continued to diversify and fill new niches until their extinction at the end of the Cretaceous.
The Maastrichtian Javelina Formation of southwestern Texas comprises a thick sequence of stream channel and floodplain deposits accumulated in a broad southeast-trending valley, several hundred kilometers inland from the Late Cretaceous shoreline. Three pterosaur species are found here. Remains of Quetzalcoatlus lawsoni, sp. nov., are concentrated in deposits of shallow alkaline lakes that developed in abandoned reaches of stream channels. Areas surrounding the lakes were vegetated with fan palms, and the higher floodplain supported a subtropical forest dominated by the dicot tree Javelinoxylon and araucariacean conifers. The shallow lakes were inhabited by a diverse invertebrate fauna of arthropods, gastropods, and bivalves, a likely food source for the slender-beaked Quetzalcoatlus lawsoni, sp. nov., which may have had a lifestyle similar to modern large gregarious wading birds. In contrast, remains of the giant Q. northropi are rare and found instead only in stream channel facies. It may have had a more solitary lifestyle and preferred riparian habitats. The warm, dry, subtropical but nonseasonal conditions of the region may represent a preferred climatic regime for azhdarchid pterosaurs generally.
The Azhdarchidae have come to be known as the most diverse clade of Late Cretaceous pterosaurs and the largest flying creatures in existence. Since the erection of the taxon nearly four decades ago, many partial specimens have been referred to it from the Early Cretaceous and Late Jurassic, but none of these identifications can be confirmed. The most comprehensive phylogenetic analysis and taxonomy of Pterosauria is presented, and the evolutionary history of the Azhdarchidae is reviewed. As currently known, azhdarchids are restricted to the Late Cretaceous (Turonian–Maastrichtian). Fourteen species are currently included in the Azhdarchidae: Quetzalcoatlus northropi and Q. lawsoni are recovered as sister taxa in a monophyletic Quetzalcoatlus, with Arambourgiania philadelphiae, Hatzegopteryx thambema, a trichotomy with Cryodrakon boreas and Wellnhopterus brevirostris, Zhejiangopterus linhaiensis, Eurazhdarcho langendorfensis, a Phosphatodraco mauritanicus + Aralazhdarcho bostobensis sister group, as well as an Azhdarcho lancicollis + Albadraco tharmisensis + Aerotitan sudamericanus + Mistralazhdarcho maggii clade are recovered as successive outgroups to Quetzalcoatlus in the Azhdarchidae. The previous azhdarchid species Montanazhdarcho minor and Radiodactylus langstoni are recovered as non-azhdarchid azhdarchiforms; Alanqa saharica and Argentinadraco barrealensis are thalassodromines; Cretornis hlavaci and Volgadraco bogolubovi are pteranodontians; and Bakonydraco galaczi is a tapejarine. Up to a dozen pterosaur lineages persist into the latest Cretaceous (Maastrichtian Age) including azhdarchids, pteranodontids, and nyctosauromorphs. In the Late Cretaceous, an ornithocheirid, cimoliopterids, a lonchodrachonid, a lonchodectid, pteranodontians, tapejarines, thalassodromines, a chaoyangopterine, and azhdarchiforms are present. The pterosaurs did not have a terminal decline in diversity and were increasing in species number at the end of the Cretaceous Period.
New specimens of pterosaurs from the Solnhofen Lithographic Limestone (Upper Jurassic, Bavaria, Germany) and the Crato-Formation (Lower Cretaceous, Ceará, north east Brazil) with spectacular soft-part preservation are described. The feet of a Pterodactylus preserve scaly heel pads, webbing between the toes and extremely long claw sheaths. An azhdarchid from the Lower Cretaceous from Brazil shows identical structures. For the first time the detailed structure of the webbing in a Pterodactylus is reported. Fibres in the dorsal skull area of the Pterodactylus and an undescribed tapejarid from Brasil hint on the presence of cranial crests which consist completely (Pterodactylus) or mainly (Tapejaridae indet.) of soft tissue.
A life-sized model skeleton of the giant pterosaur Arambourgiania philadelphiae, with an 11.5 metre wingspan, was designed and constructed in just 11 weeks. Arambourgiania was reconstructed on the basis of better-known but related pterosaurs. The postcranial skeleton was modelled in clay, moulded in silicone rubber and cast in epoxy resin. The skull was modelled from plastic sheeting, epoxy putty and polyurethane foam. The finished model appeared on the BBC's children's programme "Blue Peter", before being displayed at Portsmouth City Museum and Records Office as part of an exhibition entitled "Giant Wings over Dinosaur World" from 28th September to 10th November 1996. The exhibition has since appeared in Leicester and Germany.
Pterosaurs are rare components of Texas Cretaceous faunas. The best known is Quetzalcoatlus northropi , from the Javelina Formation (Maastrichtian) of Big Bend National Park, with a wingspan of some 11-12 m (Lawson, 1975; Langston, 1986; Busbey and Lehmann, 1989). Texas pterosaur specimens of less spectacular proportions include a pteranodontid partial humerus (USNM 13804) from the Eagle Ford Formation (late Cenomanian-late Turonian) of Austin (Gilmore, 1935; Bennett, 1989) and a first wing phalanx of a pterodactyloid from the Buda Formation (Cenomanian) of Hays County (Langston, 1974; Lawson, 1975). Pterosaur bones were also recorded at localities near Forestburg, Montague County (Zangerl and Denison, 1950), in the Antlers Formation (Winkler et al., 1990), although these specimens are undiagnostic hollow bone fragments.