No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
The first description of Halisaurus (Reptilia Mosasauridae) from Europe, from the Upper Cretaceous of Belgium
Abstract
Presents a description of the skull of species of the genus Halisaurus Marsh 1869. Halisaurus ortliebi (= Phosphorosaurus ortliebi of Dollo, 1889), from the Maastrichtian of Belgium, shows, several character states, including a unique ventral fossa of the parietal. Comparisons are made with the North American H. platyspondylus. H. sternbergi (Wiman, 1920) is no longer considered as belonging to the genus Halisaurus.
... Halisaurinae exhibit a wide geographical range stretching from South and North America to northern Europe, eastern Asia, northern and central Africa and the Middle East (Marsh, 1869;Dollo, 1889;Wiman, 1920;Lingham-Soliar, 1991, 1996, 1998Caldwell and Bell Jr, 1995;Bardet et al., 2000;Holmes and Sues, 2000; Bardet and Suberbiola, 2001; Bardet and Pereda Suberbiola, 2002;Lindgren and Siverson, 2005;Bardet et al., 2005a;P aramo-Fonseca, 2013;Konishi et al., 2016;Longrich, 2016;Longrich et al., 2021a). ...
... The frontal is long and triangular, with a tapered anterior end. At the prefrontal contact, it is wider than in Eonatator sternbergii and Halisaurus ponpetelegans ("Phosphorosaurus" ponpetelegans, see Discussion) and more similar to Halisaurus platyspondylus, H. arambourgi, and Phosphorosaurus ortliebi (Lingham-Soliar, 1996;Holmes and Sues, 2000;Bardet et al., 2005a). The supraorbital process is elongate and broadly convex, similar to Halisaurus platyspondylus and H. arambourgi. ...
... In dorsal view, the parietal table is roughly triangular and smooth, resembling that of H. platyspondylus (Holmes and Sues, 2000); it is very different from that of H. arambourgi whose median surface is elongated, sub-rectangular in shape with convex lateral edges and ornamented by numerous transversal undulated ridges (Bardet et al., 2005a;. The parietal foramen is circular and small relative to the parietal, unlike Halisaurus platyspondylus, H. arambourgi (Holmes and Sues, 2000;Bardet et al., 2005a) and H. ponpetelegans (Konishi et al., 2016)), and much smaller than in Phosphorosaurus ortliebi (Lingham-Soliar, 1996). It lies anteriorly on the parietal table, without crossing the suture with frontal like in P. ortliebi, and is slightly raised relative to the dorsal surface of the parietal table, but without a surrounding ridge like in H. arambourgi. ...
... The frontals are relatively short for halisaurines, the main body (excluding the narial process) being ~140% as long as wide. This contrasts with the very long and slender frontals seen in Eonatator sternbergii (Bardet and Pereda-Suberbiola, 2001) and Phosphorosaurus ortliebi (Lingham-Soliar, 1996), and more closely resembles "Phosphorosaurus" ponpetelegans (Konishi et al., 2016), Halisaurus platyspondylus (Polcyn and Lamb, 2012), and H. arambourgi (Bardet et al., 2005b). ...
... A similar median projection of the frontal is seen in Eonatator sternbergii, and a very small median eminence is found on the frontal in P. ponpetelegans. That of Halisaurus arambourgi forms a broadly convex V-shaped contact with the parietal; the contact is shallowly concave in H. platyspondylus, and the parietal foramen participates in the frontal in Phosphorosaurus ortliebi (Lingham-Soliar, 1996). ...
... Just behind the nares, the dorsal surface of the frontals bears the midline ridge characteristic of mosasaurids (Russell, 1967). It is weakly developed in P. serpentis relative to the condition observed in other halisaurines, where the median ridge forms a thick, tall dorsal keel (Lingham-Soliar, 1996;Bardet et al., 2005b;Polcyn and Lamb, 2012;Konishi et al., 2016). Just behind the nares are a pair of depressions. ...
Mosasaurids (Mosasauridae) were specialized marine lizards that evolved and radiated in the Late Cretaceous. Their diversity peaked in the Maastrichtian, with the most diverse faunas known from Morocco. Here we describe a new species of mosasaurid from this fauna. Pluridens serpentis sp. nov. is described based on two complete skulls and referred jaws. It is referred to Pluridens based on the elongate and robust jaws, small teeth, and specialized tooth implantation. Pluridens is referred to Halisaurinae based on the posteriorly expanded premaxilla, long premaxilla-maxilla suture, broad premaxillary facet on the maxilla, closed otic notch, and small, striated, hooked teeth. The orbits are reduced relative to other halisaurines while the snout is robust and flat with a broad, rounded tip. The jaws bear numerous small, hooked, snake-like teeth. Skulls imply lengths of 5-6 meters; referred material suggests lengths of ≥10 meters. Pluridens’ specialized morphology – especially the contrasting large size and small teeth - suggests a distinct feeding strategy. Small orbits imply that P. serpentis relied on nonvisual cues including touch and chemoreception during foraging, as in modern marine snakes. Numerous neurovascular foramina on the premaxillae are consistent with this idea. The small teeth suggest proportionately small prey. The dentary becomes massive and robust in the largest individuals, suggesting sexual selection and perhaps sexual dimorphism, with the mandibles possibly functioning for combat as in modern beaked whales and lizards. The new mosasaur emphasizes how Maastrichtian mosasaurids were characterized by high species richness, functional diversity of niches occupied, and a certain degree of endemism, i.e. geographic specialization. and continued diversifying until the end of the Cretaceous, just prior to the K-Pg extinction.
... Additional undescribed specimens, similar to but not necessarily conspecific with H. sternbergi, were reported by Bell (1997). Lingham-Soliar (1996) Russell (1967), presumably on the basis of the very large, anteriorly placed parietal foramen. However, the quadrates of this form differ considerably from those of Plioplatecarpus (Lingham-Soliar, 1996, fig. ...
... 5). Lingham-Soliar (1996) reassigned Phosphorosaurus to Halisaurus based on the structure of the frontal, which closely resembles that of Halisaurus sternbergi (e.g., Russell, 1970, fig. 165). ...
... The complete left quadrate (Fig. 4) closely resembles that of Halisaurus sternbergi (Wiman, 1920, fig. 5) and is similar to that of Phosphorosaurus ortliebi (Dollo, 1889;Lingham-Soliar, 1996), although neither quadrate is complete in the holotype of the latter. In contrast with other mosasaurs, where the circular or oval tympanic rim is uniformly curved in lateral view, the rim in USNM 442450 is slightly concave anteriorly, but abruptly turns posteriorly in a tight arc to join the nearly straight dorsal margin. ...
A new specimen of the basal mosasaur Halisaurus platyspondylus from the Severn Formation of Prince Georges County, Maryland (Upper Cretaceous: middle Maastrichtian) represents the most complete partial skeleton of this uncommon taxon to be described to date. The characteristic dorsoventral compression of the vertebral centrum is most pronounced in the anterior trunk vertebrae, and the centra of the posterior trunk vertebrae exhibit proportions more similar to those in other mosasaurs such as Plioplatecarpus. The postorbitofrontal forms its primary contact with the frontal rather than the parietal, and the supraoccipital is firmly attached to the ventral side of the parietal. The plane of articulation between the parietals and supratemporal is neither vertical (as in Varanidae) nor horizontal (as in Mosasauridae), but forms an angle of about 55 degrees with the horizontal. The quadrate bears a long, ventrally-flared suprastapedial process but appears to lack an infrastapedial process. Close similarities in the structure of the frontal and parietal with “Clidastes” sternbergii support referral of the latter to Halisaurus , but reference of Phosphorosaurus ortliebi to Halisaurus is questionable. Halisaurus has been recorded from the Santonian to the late Maastrichtian.
... Our intent is to augment the original anatomical description and phylogenetic analysis of this taxon, provide comparisons with other halisaurines, and identify new characters for use in a forthcoming phylogenetic analysis of mosasauroid relationships. Until quite recently, halisaurine mosasaurs were poorly known and most reported specimens [e.g., Marsh, 1869; Dollo, 1889; Russell, 1970; Baird and Case, 1966; Baird, 1986] are isolated and poorly preserved elements with the exception of a relatively complete skeleton from the late Santonian – earliest Campanian of western Kansas [Wiman, 1920; Russell, 1970; Bardet and Pereda Suberbiola, 2001], a partial skull from the Maastrichtian of Belgium [Dollo, 1889; Lingham-Soliar, 1996] , and a partial skull and vertebral column from Maryland [Holmes and Sues, 2000]. In recent years, discovery and collections of new specimens and reexamination of museum collections has fueled a flurry of publications documenting the morphology of these forms and refining phylogenetic hypotheses [Bell, 1997; Lingham-Soliar, 1988; Lingham-Soliar, 1996; 1998; Lindgren and Siverson, 2005; Lindgren, 2007; Bardet and Pereda Suberbiola, 2001; Bardet et al., 2005; Polcyn and Bell, 2005; Polcyn et al., 2007]. ...
... Until quite recently, halisaurine mosasaurs were poorly known and most reported specimens [e.g., Marsh, 1869; Dollo, 1889; Russell, 1970; Baird and Case, 1966; Baird, 1986] are isolated and poorly preserved elements with the exception of a relatively complete skeleton from the late Santonian – earliest Campanian of western Kansas [Wiman, 1920; Russell, 1970; Bardet and Pereda Suberbiola, 2001], a partial skull from the Maastrichtian of Belgium [Dollo, 1889; Lingham-Soliar, 1996] , and a partial skull and vertebral column from Maryland [Holmes and Sues, 2000]. In recent years, discovery and collections of new specimens and reexamination of museum collections has fueled a flurry of publications documenting the morphology of these forms and refining phylogenetic hypotheses [Bell, 1997; Lingham-Soliar, 1988; Lingham-Soliar, 1996; 1998; Lindgren and Siverson, 2005; Lindgren, 2007; Bardet and Pereda Suberbiola, 2001; Bardet et al., 2005; Polcyn and Bell, 2005; Polcyn et al., 2007]. Halisaurus was erected by Marsh in 1869 to replace the original name Macrosaurus orally proposed by him the same year. ...
... Distinct facets are visible on the anterolateral portion of the median ridge in H. arambourgi (WDC specimen) and completely preserved in P. ortliebi, but that portion of the frontal is not preserved in either specimen of H. platyspondylus. In P. ortliebi, the narrower median ridge runs the entire length of the frontal, diverging posteriorly forming a triangular raised area, the posterior portion of which borders the pineal foramen [Lingham-Soliar, 1996]. In Eonatator (e.g., RMM 6890 and FMNH PR 195) the frontal is also relatively narrow but bears a broad, low median ridge separating well-defined paramedian depressions, and converging anterolateral margins [Russell, 1970:Fig. ...
... Until quite recently, halisaurine mosasaurs were poorly known and most reported specimens [e.g., Marsh, 1869;Dollo, 1889;Russell, 1970;Baird and Case, 1966;Baird, 1986] are isolated and poorly preserved elements with the exception of a relatively complete skeleton from the late Santonian -earliest Campanian of western Kansas [Wiman, 1920;Russell, 1970;Bardet and Pereda Suberbiola, 2001], a partial skull from the Maastrichtian of Belgium [Dollo, 1889;Lingham-Soliar, 1996], and a partial skull and verte- bral column from Maryland [Holmes and Sues, 2000]. In recent years, discovery and collections of new specimens and reexamination of museum collections has fueled a flurry of publications documenting the morphology of these forms and refining phylogenetic hypotheses [Bell, 1997;Lingham-Soliar, 1988;Lingham-Soliar, 1996;1998;Lindgren and Siverson, 2005;Lindgren, 2007;Bardet and Pereda Suberbiola, 2001;Bardet et al., 2005;Polcyn and Bell, 2005;Polcyn et al., 2007]. ...
... Until quite recently, halisaurine mosasaurs were poorly known and most reported specimens [e.g., Marsh, 1869;Dollo, 1889;Russell, 1970;Baird and Case, 1966;Baird, 1986] are isolated and poorly preserved elements with the exception of a relatively complete skeleton from the late Santonian -earliest Campanian of western Kansas [Wiman, 1920;Russell, 1970;Bardet and Pereda Suberbiola, 2001], a partial skull from the Maastrichtian of Belgium [Dollo, 1889;Lingham-Soliar, 1996], and a partial skull and verte- bral column from Maryland [Holmes and Sues, 2000]. In recent years, discovery and collections of new specimens and reexamination of museum collections has fueled a flurry of publications documenting the morphology of these forms and refining phylogenetic hypotheses [Bell, 1997;Lingham-Soliar, 1988;Lingham-Soliar, 1996;1998;Lindgren and Siverson, 2005;Lindgren, 2007;Bardet and Pereda Suberbiola, 2001;Bardet et al., 2005;Polcyn and Bell, 2005;Polcyn et al., 2007]. ...
... Dis- tinct facets are visible on the anterolateral portion of the median ridge in H. arambourgi (WDC specimen) and com- pletely preserved in P. ortliebi, but that portion of the fron- tal is not preserved in either specimen of H. platyspondylus. In P. ortliebi, the narrower median ridge runs the entire length of the frontal, diverging posteriorly forming a trian- gular raised area, the posterior portion of which borders the pineal foramen [Lingham-Soliar, 1996]. In Eonatator (e.g., RMM 6890 and FMNH PR 195) the frontal is also relatively narrow but bears a broad, low median ridge separating well-defined paramedian depressions, and converging anterolateral margins [Russell, 1970: Fig. 165]. ...
Halisaurine mosasaurs are poorly known, represented by a small number of specimens from the Santonian-Maastrichtian (~86 Ma
– ~66 Ma), but enjoyed broad palaeobiogeographic distribution during that time. They are important for understanding mosasaur
evolution because certain aspects of their morphology retain the relatively plesiomorphic or minimally modified squamate conditions;
however, existing material is limited and certain anatomical details are lacking. We report here two new specimens of Halisaurus arambourgi including a well-preserved, nearly complete skull and postcranial skeleton, and a partial skull that preserves details of
the braincase and quadrate. We focus our description on morphology that augments the original description of this species
and provides comparisons with other halisaurines. Braincase and temporal arcade characters confirm the plesiomorphic nature
of Halisaurus, supporting a relatively basal position of Halisaurinae within Mosasauridae. Comparisons of cranial morphology support reconstruction
of relationships within Halisaurinae, indicating that H. arambourgi is most closely related to H. platyspondylus, Phosphorosaurus (= H. ortliebi) is the sister taxon to those taxa, and Eonatator is the most basal described halisaurine. The proportions of the epipodials and the caudal vertebral centrum morphometrics
indicate H. arambourgi is more derived than the Santonian to early Campanian Eonatator sternbergii but less derived than a Halisaurus sp. specimen from the mid-Maastrichtian of the Moreno Formation of California, USA. Moreover, vertebral morphometrics reveals
that H. arambourgi possessed a downturned tail that likely supported a crescent-like fluke.
... On the basis of the rather similar form of the frontal in the type, and only known, specimen (IRScNB R34) of Phosphorosaurus ortliebi Dollo, 1889 Baird and Case, 1966)], Lingham-Soliar (1996) interpreted P. ortliebi as a member of Halisaurus. However, in accordance with Holmes and Sues (2000), we consider Phosphorosaurus Dollo, 1889 a valid taxon generically distinct from Halisaurus on the basis of the following features: 1) a prominent median ridge runs the full length of the frontal in Phosphorosaurus (see Lingham-Soliar, 1996, fig. ...
... On the basis of the rather similar form of the frontal in the type, and only known, specimen (IRScNB R34) of Phosphorosaurus ortliebi Dollo, 1889 Baird and Case, 1966)], Lingham-Soliar (1996) interpreted P. ortliebi as a member of Halisaurus. However, in accordance with Holmes and Sues (2000), we consider Phosphorosaurus Dollo, 1889 a valid taxon generically distinct from Halisaurus on the basis of the following features: 1) a prominent median ridge runs the full length of the frontal in Phosphorosaurus (see Lingham-Soliar, 1996, fig. 2; personal observation of IRScNB R34). ...
... In Halisaurus the median keel is visible only on the anterior two-thirds of the element (see e.g., Bardet and Pereda Suberbiola, 2001, fig. 1b; personal observation of PMU R163); and 2) the very large parietal foramen is bordered anteriorly by the frontal in Phosphorosaurus (see Lingham-Soliar, 1996, fig. 2), whereas it is of more moderate size and located well behind the fronto-parietal suture in Halisaurus (see e.g., Wiman, 1920, fig. ...
Remains of Halisaurus sternbergi (Wiman, 1920) from the latest Early Campanian (sensu germanico) of the Kristianstad Basin, southern Sweden, represent the first record of this species outside of the USA. The material comprises numerous marginal tooth-crowns, a premaxilla, an incomplete pterygoid, and vertebrae. The Kristianstad Basin population of H. sternbergi was probably derived from individuals that migrated from the Mississippi Embayment in North America sometime during the Early Campanian. Even though H. sternbergi thrived in great numbers in the coastal waters of the southern part of the Baltic Shield during the latest Early Campanian, the population appears to have been short-lived. Available data indicate that H. sternbergi, along with several other species of mosasaurs, vanished from the region following an intercontinental mosasaur extinction event, or a series of events, near the Early/Late Campanian boundary.
... Additional undescribed specimens, similar to but not necessarily conspecific with H. sternbergi, were reported by Bell (1997). Lingham-Soliar (1996) Russell (1967), presumably on the basis of the very large, anteriorly placed parietal foramen. However, the quadrates of this form differ considerably from those of Plioplatecarpus (Lingham-Soliar, 1996, fig. ...
... 5). Lingham-Soliar (1996) reassigned Phosphorosaurus to Halisaurus based on the structure of the frontal, which closely resembles that of Halisaurus sternbergi (e.g., Russell, 1970, fig. 165). ...
... The complete left quadrate (Fig. 4) closely resembles that of Halisaurus sternbergi (Wiman, 1920, fig. 5) and is similar to that of Phosphorosaurus ortliebi (Dollo, 1889;Lingham-Soliar, 1996), although neither quadrate is complete in the holotype of the latter. In contrast with other mosasaurs, where the circular or oval tympanic rim is uniformly curved in lateral view, the rim in USNM 442450 is slightly concave anteriorly, but abruptly turns posteriorly in a tight arc to join the nearly straight dorsal margin. ...
A new specimen of the basal mosasaur Halisaurus platyspondylus from the Severn Formation of Prince Georges County, Maryland (Upper Cretaceous: middle Maastrichtian) represents the most complete partial skeleton of this uncommon taxon to be described to date. The characteristic dorsoventral compression of the vertebral centrum is most pronounced in the anterior trunk vertebrae, and the centra of the posterior trunk vertebrae exhibit proportions more similar to those in other mosasaurs such as Plioplatecarpus. The postorbitofrontal forms its primary contact with the frontal rather than the parietal, and the supraoccipital is firmly attached to the ventral side of the parietal. The plane of articulation between the parietals and supratemporal is neither vertical (as in Varanidae) nor horizontal (as in Mosasauridae), but forms an angle of about 55 degrees with the horizontal. The quadrate bears a long, ventrally-flared suprastapedial process but appears to lack an infrastapedial process. Close similarities in the structure of the frontal and parietal with “Clidastes” sternbergii support referral of the latter to Halisaurus, but reference of Phosphorosaurus ortliebi to Halisaurus is questionable. Halisaurus has been recorded from the Santonian to the late Maastrichtian.
... 11). Con H. ortliebi comparte la prolongación posterior de la cresta frontal y la posición anterior del foramen parietal (Dollo, 1889;Lingham-Soliar, 1996); con H. platyspondylus comparte la amplia participación de los prefrontales en el borde posterior de las narinas externas y la geometría general del frontal (Holmes y Sues, 2000); con H. arambourgi comparte las proporciones relativas entre las longitudes del frontal, de las narinas externas y de la porción rostral anterior a las narinas y la presencia de una pequeña cresta del prefrontal sobre la parte anterior de la órbita (Bardet et al., 2005), además de la ancha barra posterior del premaxilar, rasgo sugerido también para H. platyspondylus por Polcyn y Lamb (2012). Finalmente, con E. sternbergii comparte la forma alargada del cráneo, las proporciones generales de la región parietal, los márgenes cóncavos del frontal y la presencia de grandes nasales (Wiman, 1920;Bell, 1997 El halisaurino colombiano difiere de Eonatator sternbergii por mostrar la terminación posterior de la sutura premaxilarmaxilar a la altura del séptimo diente maxilar. ...
... Tomado y modificado deBardet et al., 2005. A, Halisaurus platyspondylus (tomadode Holmes & Sues, 2000);B, Halisaurus ortliebi (tomado deLingham-Soliar, 1996); C, Halisaurus arambourgi (tomado de ...
In this study a new mosasaur found in Colombia is given out. The fossil was extracted from Campanian rocks, North of the town of Coello, Tolima Department. It is a nearly complete articulated skeleton with soft tissue remains preserved in its cavities. It was determined as a new species of the genus Eonatator, E. coellensis, based on the systematics proposed in 2005 by Bardet and others. The anatomy of the anterior part of the skull, as well as the morphology and the inter-relationships of the bones of the pelvic girdle and limbs, constitute a new contribution to the genus definition. The Colombian specimen represents the most complete halisaurine mosasaur known so far in the world, and provides new evidences of ovoviviparity in mosasaurs.
... 11). Con H. ortliebi comparte la prolongación posterior de la cresta frontal y la posición anterior del foramen parietal (Dollo, 1889;Lingham-Soliar, 1996); con H. platyspondylus comparte la amplia participación de los prefrontales en el borde posterior de las narinas externas y la geometría general del frontal (Holmes y Sues, 2000); con H. arambourgi comparte las proporciones relativas entre las longitudes del frontal, de las narinas externas y de la porción rostral anterior a las narinas y la presencia de una pequeña cresta del prefrontal sobre la parte anterior de la órbita (Bardet et al., 2005), además de la ancha barra posterior del premaxilar, rasgo sugerido también para H. platyspondylus por Polcyn y Lamb (2012). Finalmente, con E. sternbergii comparte la forma alargada del cráneo, las proporciones generales de la región parietal, los márgenes cóncavos del frontal y la presencia de grandes nasales (Wiman, 1920;Bell, 1997 El halisaurino colombiano difiere de Eonatator sternbergii por mostrar la terminación posterior de la sutura premaxilarmaxilar a la altura del séptimo diente maxilar. ...
... Tomado y modificado deBardet et al., 2005. A, Halisaurus platyspondylus (tomadode Holmes & Sues, 2000);B, Halisaurus ortliebi (tomado deLingham-Soliar, 1996); C, Halisaurus arambourgi (tomado de ...
In this study a new mosasaur found in Colombia is given out. The fossil was extracted from Campanian rocks, North of the town of Coello, Tolima Department. It is a nearly complete articulated skeleton with soft tissue remains preserved in its cavities. It was determined as a new species of the genus Eonatator, E. coellensis, based on the systematics proposed in 2005 by Bardet and others. The anatomy of the anterior part of the skull, as well as the morphology and the inter-relationships of the bones of the pelvic girdle and limbs, constitute a new contribution to the genus definition. The Colombian specimen represents the most complete halisaurine mosasaur known so far in the world, and provides new evidences of ovoviviparity in mosasaurs.
... A previous record (Lingham-Soliar, 1996) of halisaurine mosasaurs from the Maastrichtian type area has now been shown to be based exclusively on Plioplatecarpus marshi (Mulder, 2003b), a common species in the area (see previous). ...
... It seems this possibility has not yet been considered(Fig. 2); if so, it may link the type to a recent record of P. giganteus from the upper Campanian of Champagne (France) byBardet et al. (1997); -Halisaurus ortliebi (holotype: IRScNB R34; seeDollo, 1889c;Lingham-Soliar, 1996), from near Mesvin; and -Mosasaurus lemonnieri (holotype: IRScNB R28 (ex 1470); seeDollo, 1889cDollo, , 1892Lingham-Soliar, 2000), from Mesvin.Mulder et al. (2004) have recently suggested that this 'species' might in fact be nothing more than the juveniles of M. hoffmanni. In addition,Caldwell et al. (2004) observed that one of the specimens referred to M. lemonnieri (IRScNB 3211) showed close similarities to members of the New Zealand genus Moanasaurus. ...
Mosasaur taxa currently known from Campanian-Maastrichtian strata in the Liège-Limburg (SE Netherlands, NE Belgium) and Mons (southern Belgium) basins are listed and briefly discussed and their stratigraphic ranges indicated. Recently published and/or ongoing work on coleoid and ammonoid cephalopods in these areas allows tie points between NW Europe and the United States (Western Interior, Gulf Coast, Atlantic Seaboard) to be established. Future studies need to refine the resultant, rather crude, scheme. The ultimate aim is a more robust picture of mosasaur taxonomy, biostratigraphy and palaeobiogeography, and a detailed evaluation of migratory patterns across the Atlantic.
... The fossil record of large sized squamates in the Cretaceous is dominated by mosasauriforms (mosasaurs and related taxa, see Fig. 1). This aquatic radiation (Bardet et al., 2003;Haber and Polcyn, 2005;Evans et al., 2006) culminated in the successful mosasaurs, which greatly expanded during the Late Cretaceous (Fig. 1A, C) (Lingham-Soliar, 1996;Bardet et al., 1999Bardet et al., , 2000Bardet et al., , 2003Bardet et al., , 2006Bardet et al., , 2013aMachalski et al., 2003;Pierce and Caldwell, 2004;Rage and N eraudeau, 2004;Bell and Polcyn, 2005;Smith and Buchy, 2008;Vullo et al., 2009;P aramo-Fonseca, 2011;Mak adi et al., 2012;Pereda-Suberbiola et al., 2015;Paparella et al., 2018;Smith et al., 2019). Among terrestrial squamates, large taxa include borioteiioids (e.g. ...
Appendicular remains of squamate reptiles are barely described in the fossil record due to their low preservational potential and generally poor diagnostic information. Not many squamate fossil individuals preserve appendicular bony elements, these being mainly restricted to the rare articulated specimens found in a limited number of localities with specific conditions that favor exceptional preservation. Detailed descriptions of these bones, especially tarsals and metatarsals, are thus scarce in the literature due to the lesser relevance given to these elements in most anatomical descriptions. In this study we analyze an unpublished fossil specimen from the Maastrichtian of Basturs-1 (Lleida, Catalonia, Spain) corresponding to several articulated appendicular pes bones of a possible member of Varaniformes. We also provide detailed insights on the anatomy of the tarsalia and metatarsalia, particularly in angui- morphs. The fossil specimen here described, with an estimated snout-vent length (SVL) of ~581 mm, reveals the putative varaniform from Basturs-1 as one of the largest Mesozoic terrestrial lizards, and possibly the largest from the European fossil record. Previous observations of an association between large lizards and dinosaur nesting sites are further supported by the find of this giant form in a locality known for the presence of numerous dinosaur eggs.
... Still, some of the clades are substantially underrepresented even though detailed descriptions of their members have been published and some of those taxa have been scored for characters in older versions of the same data set. For example, the current version of the data set includes only two halisaurine OTUs (Halisaurus platyspondylus and Eonatator sternbergii; with the latter being labeled as 'Halisaurus sternbergi') even though detailed studies have also been published, for example, for Halisaurus arambourgi (Bardet et al., 2005;Polcyn et al., 2012) or Phosphorosaurus ortliebi (Lingham-Soliar, 1996;Holmes & Sues, 2000;Bardet et al., 2005). Likewise, the data set could be supplemented by recently described Eonatator coellensis (Páramo-Fonseca, 2013) and Phosphorosaurus ponpetelegans (Konishi et al., 2016). ...
Mosasauroid squamates represented the apex predators within the Late Cretaceous marine and occasionally also freshwater ecosystems. Proper understanding of the origin of their ecological adaptations or paleobiogeographic dispersals requires adequate knowledge of their phylogeny. The studies assessing the position of mosasauroids on the squamate evolutionary tree and their origins have long given conflicting results. The phylogenetic relationships within Mosasauroidea, however, have experienced only little changes throughout the last decades. Considering the substantial improvements in the development of phylogenetic methodology that have undergone in recent years, resulting, among others, in numerous alterations in the phylogenetic hypotheses of other fossil amniotes, we test the robustness in our understanding of mosasauroid beginnings and their evolutionary history. We reexamined a data set that results from modifications assembled in the course of the last 20 years and performed multiple parsimony analyses and Bayesian tip-dating analysis. Following the inferred topologies and the 'weak spots' in the phylogeny of mosasauroids, we revise the nomenclature of the 'traditionally' recognized mosasauroid clades, to acknowledge the overall weakness among branches and the alternative topologies suggested previously, and discuss several factors that might have an impact on the differing phylogenetic hypotheses and their statistical support.
... Holmes and Sues, 2000, Fig. 4), H. arambourgi (cf. Polcyn et al., 2012, Fig. 2) and P. ortliebi (Lingham-Soliar, 1996, Fig. 5; MSF personal observations). Specimen MML 1234 differs from P. ortliebi by the shape and extension of the tympanic meatus and the shape of the suprastapedial process. ...
tHalisaurinae is a subfamily of enigmatic, small- to medium-sized mosasauroids, whichretain a mosaic of primitive and derived features. The first record of a South American Hal-isaurus with precise stratigraphic information includes a quadrate carrying a tympanic disctogether with twelve vertebrae, collected in the Late Maastrichtian of Jagüel Formationin northern Patagonia (Argentina). The preservation of a tympanic disc allows exploringand discussing the mechanisms of sound transmission in these mosasauroids. The loca-tion of the tympanic disc resembles that one formed by the extracolumella of aquaticturtles and at least one extant lizard. Based on morphological comparison of the middleear we discuss previous hypotheses on the modification of the tympanic middle ear systemof mosasauroids for underwater hearing, in a manner similar to that observed in aquaticturtles.
... The prefrontal articulation is only weakly developed antorbitally, slightly incising the lateral surface of the descending processes and forming a simple, fibrous lap-joint with ventral surface of the frontal but with no corresponding excavation. Phosphorosaurus ortliebi was described and named by Dollo (1889) and subsequently redescribed and referred to the genus Halisaurus by Lingham-Soliar (1996). Some characters do unite Phosphorosaurus with Halisaurus, including the configuration of the quadrate but significant differences also exist, warranting retention of Dollo's (1889) genus (Polcyn et al., in press). ...
... 1. The lower Maastrichtian 'Craie phosphatée de Mons' (Belemnella obtusa Zone) in the Mons Basin, southern Belgium (LINGHAM-SOLIAR & NOLF, 1990;LINGHAM-SOLIAR, 1992, 1994CALD-WELL et al., 2004;MULDER et al., 2004;JAGT, 2005) -SOLIAR, 1993-SOLIAR, , 1994-SOLIAR, , 1995-SOLIAR, , 1996-SOLIAR, , 1999DOR-TANGS et al., 2002;JAGT et al., 2002;MULDER, 2003a, b;SCHULP et al., 2004;JAGT, 2005;SCHULP, 2006;see also MULDER & MAI, 1999 (LINDGREN, 2005a, b;LINDGREN & SIVER-SON, 2002. ...
Preliminary descriptions are given of selected specimens from an assemblage of >65 isolated vertebrate remains, collected in 1985 at the Labirinta cave situated between the villages of Drashan and Breste, east of Cherven Briag (Vratsa district, northwest Bulgaria), from strata of late Maastrichtian age (Kajlâka Formation). Recorded are a fragmentary lower jaw of a mosasaurine squamate, Mosasaurus cf. hoffmanni (MANTELL, 1829), with two teeth preserved in situ, as well as two isolated teeth of lamniform sharks, assigned to Squalicorax pristodontus (AGASSIZ, 1843) and Anomotodon sp. Other vertebrate remains in this assemblage include rather poorly preserved fragments of skull and appendicular skeleton of mosasaurs, but it cannot be ruled out that other vertebrate groups (elasmosaurid plesiosaurs) are represented as well. To establish this, the additional material needs to be studied in detail and compared with existing collections; it will be described in full at a later date. A partial phragmocone of a scaphitid ammonite, found associated, is here assigned to Hoploscaphites constrictus (J. SOWERBY, 1817) and briefly described as well. This record dates the Labirinta cave sequence as Maastrichtian, as does the echinoid Hemipneustes striatoradiatus (LESKE 1778); tooth morphology of Squalicorax pristodontus and a find of the pachydiscid ammonite Anapachydiscus (Menuites) cf. terminus WARD and KENNEDY 1993 from correlative strata nearby narrow this down to late, or even latest Maastrichtian. Finally, some remarks on mosasaur and plesiosaur distribution during the Campanian-Maastrichtian across Europe are added.
... The prefrontal articulation is only weakly developed antorbitally, slightly incising the lateral surface of the descending processes and forming a simple, fibrous lap-joint with ventral surface of the frontal but with no corresponding excavation. Phosphorosaurus ortliebi was described and named by Dollo (1889) and subsequently redescribed and referred to the genus Halisaurus by Lingham-Soliar (1996). Some characters do unite Phosphorosaurus with Halisaurus, including the configuration of the quadrate but significant differences also exist, warranting retention of Dollo s (1889) genus (Polcyn et al., in press). ...
The first detailed morphological description of Mosasaunis lemonnieri is presented. Comparisons are made with other mosasaurs and a number of extant reptiles, principally among the "lizard" families. A number of intraspecific variable characters, including an unusually high number of pygal vertebrae, are noted. The study shows that there are considerable similarities between M. lemonnieri and Mosasaunis hoffmanni, which supports an earlier cladistic analysis indicating sister taxa status between the two forms. However, the latter is a considerably more robust and gigantic taxon. Previous assignment to M. conodon is rejected here. M. lemonnieri was less widespread than A/, hoffmanni with main occurrences in Belgium and to a lesser extent The Netherlands. M. lemonnieri was clearly a dominant mosasaur in the Belgian locality judging by the large quantity of its remains discovered there.
A specimen of a halisaurine mosasaur is reported from Japan for the first time, closing the pre-existing biogeographical gap between the Middle East and the eastern Pacific. Phosphorosaurus ponpetelegans sp. nov., from the lowermost Maastrichtian of Hokkaido, has been assigned to the genus Phosphorosaurus for sharing the following suite of major cranial characters with P. ortliebi, the type species from Belgium: apex of posterodorsal triangular plateau on frontal reaching level of interorbital constriction; frontal lateral border forming a step-like junction between interorbital and preorbital segments of frontal; preorbital segment of frontal sloping anteroventrally; and stapedial meatus parallel-sided in latero-medial view. Potential autapomorphies that distinguish P. ponpetelegans from other members of Halisaurinae include: postorbitofrontal jugal process elongate and stalk-like, projecting laterally; this process distally bearing a ventrally facing depression for jugal articulation; and lateral surangular-articular suture angular rather than round. The long and laterally projecting jugal processes, when combined with a depressed as well as narrow snout, provide compelling evidence for well-developed binocular vision for the new mosasaur, with an estimated binocular field of view (BFoV) of 35o. This value is unusually high for non-ophidian squamates that typically exhibit a BFoV of 10‒20o, and is higher than those of other measured mosasaur taxa by at least 5o. Among colubrid snakes, nocturnal species exhibit greater BFoV than diurnal ones in both arboreal and terrestrial taxa. Known also from the Maastrichtian of Hokkaido are fossils of lantern fish (myctophids) and 10-armed cephalopods (coleoids), both of which are typically bioluminescent today. It is hence proposed that the exceptionally large, forward-facing eyes of P. ponpetelegans may well have been a special adaptation for a nocturnal lifestyle, where they hunted small, bioluminescent prey items at night while avoiding direct competition with larger, more piscine mosasaurine taxa such as Mosasaurus hobetsuensis that co-existed with P. ponpetelegans.
Halisaurinae is a subfamily of enigmatic, small- to medium-sized mosasauroids, which retain a mosaic of primitive and derived features. The first record of a South American Halisaurus with precise stratigraphic information includes a quadrate carrying a tympanic disc together with twelve vertebrae, collected in the Late Maastrichtian of Jagüel Formation in northern Patagonia (Argentina). The preservation of a tympanic disc allows exploring and discussing the mechanisms of sound transmission in these mosasauroids. The location of the tympanic disc resembles that one formed by the extracolumella of aquatic turtles and at least one extant lizard. Based on morphological comparison of the middle ear we discuss previous hypotheses on the modification of the tympanic middle ear system of mosasauroids for underwater hearing, in a manner similar to that observed in aquatic turtles.
A global comparison of coeval Maastrichtian marine reptiles (squamates, plesiosaurs, chelonians ana crocodyliformes) of Europe, New Jersey, northwestern Africa and Middle-East has been performed. More than twenty outcrops and fifty species (half of them being mosasaurids) have been recorded. PEA and Cluster Analysis have been performed using part of this database and have revealed that marine reptile faunas (especially the mosasaurid ones) from the Mediterranean Tethys are clearly segregated into two different palaeobiogeographical provinces: 1) The northern Tethys margin province (New Jersey and Europe), located around palaeolatitudes 30-40°N and developping into warm-temperate environments, is dominated by mosasaurid squamates and chelonioid chelonians; it is characterized by the mosasaurid association of Mosasaurus hoffmanni and Prognathodon sectorius. 2) The southern Tethys margin province ( Brazil and the Arabo-African domain), located between palaeolatitudes 20°N-20°S and developping into intertropical environments, is dominated by mosasaurid squamates and bothremydid chelonians; it is characterized by the mosasaurid association of Globidens phosphaticus as well as by Halisaurus arambourgi and Platecarpus (?) ptychodon (Arabo-African domain). These faunal differences are interpreted as revealing palaeoecological preferences probably linked to differences in palaeolatitudinal gradients and/or to palaeocurrents. On a palaeoecological point on view and concerning mosasaurids, the mosasaurines (Prognathodon, Mosasaurus, Globidens and Carinodens) prevail on both margins but with different species. The ichthyophageous plioplatecarpines Plioplatecarpus (Northern margin) and Platecarpus (?) ptychodon (Southern margin) characterise respectively each margin. The halisaurine Halisaurus is present on both margins but with different species. Of importance, the tylosaurines remain currently unknown on the southern Tethys margin and are restricted to higher palaeolatitudes. Chelonians (bothremydids and chelonioids) are respective of each margin, which probably indicates lower dispersal capabilities compared to mosasaurids. The relative scarcity of plesiosaurs and crocodyliformes could be linked to different ecological preferences. The noteworthy crocodyliforme diversity increase in the Palaeogene is probably linked to mosasaurid extinction during the biological crisis of the K/Pg boundary.
A mosasaurid skull, 6 cervicals, the anterior two dorsals and a single posterior dorsal vertebra were found in Oron, Negev Desert, Israel, in latest Campanian deposits. The skull is dorsoventrally compressed and somewhat distorted, but otherwise in good condition, although sutures are often indistinct, in part due to weathering and in part due to the great size and presumable old age of the specimen. At an overall length of 1,422 mm it is one of the largest skulls ever discovered. The skull bears resemblance to those of advanced mosasaurines, in particular the type species of Prognathodon, P. solvayi, but differs from all previously known mosasaurids in having a frontal distinctly wider than long. Cladistic analysis on cranial and mandibular characters of 33 ingroup taxa were performed. A Nelsen consensus tree (1:225, ci:44 ri:76) based on 3 equally parsimonious trees placed this new specimen as the sister taxon to P. solvayi, with the American species of Prognathodon forming successive outgroups to these two. The present specimen extends the size range of known globidensine mosasaurines by around a factor two.
A new mosasaur from the Iullemmeden Basin in S.W. Niger, Pluridens walken gen. et sp. nov., has a highly anteriorly elongated dentary with at least one and a half times the number of teeth of any other recorded mosasaur. Referred material of P. walkeri is also recorded from southern Nigeria, providing vertebrate evidence that a seaway connected the Iullemmeden Basin to the Gulf of Guinea in the south and to the Tethys in the north, i.e., that the seaway was apparently open-ended. The ecology and evolution of mosasaurs from west and southwest Africa are discussed in relation to a Trans-Saharan Seaway and faunal migrations. Mosasaurs in the Iullemmeden Basin appear to have been adapted to a shallow sea and lagoonal environment. A new feeding strategy is proposed for mosasaurs i.e., it is possible that Pluridens walkeri occupied the vacated feeding niches of the early ichthyosaurs.
The type specimen of Clidastes sternbergii Wiman, 1920, a basal mosasaurid from the Santonian of Kansas (USA), is reviewed. Its attribution to Halisaurus is confirmed. H. sternbergii is mainly defined on the basis of cranial characters: frontal with a smooth dorsal surface bearing a prominent median ridge; parietal with a triangular table extending far posteriorly and bearing a medium sized circular foramen, which is located at a distance equal to twice its diameter from the frontal-parietal suture. The vertebral column and appendicular skeleton retain many plesiomorphies. H. sternbergii is the oldest species of the genus, also known in the Maastrichtian.
A new species of the basal mosasaurid Halisaurus from the Late Cretaceous (Late Maastrichtian) of the Oulad Abdoun Phosphate Basin of Morocco is described on the basis of both cranial and postcranial remains. H. arambourgi sp. nov. is characterized by unique features of the nares, frontal, parietal, girdle and limb bones. A phylogenetical analysis supports the monophyletic status of Halisaurus; H. platyspondylus (Maastrichtian, New Jersey), H. ortliebi (Maastrichtian, Belgium) and H. arambourgi form an unresolved polytomy. This study does not support the attribution of ‘Halisaurus’sternbergii (Santonian, Kansas) to Halisaurus nor to any known genus. A new genus, Eonatator, is proposed for the reception of this species, Eonatator sternbergii comb. nov. The new taxon Halisaurinae (Halisaurus + Eonatator) is the sister-group of more advanced mosasaurids (Natantia). Halisaurines are defined by the shape of the lateral premaxilla–maxilla suture; an oblique contact plane between the parietal and the supratemporal; a preaxial ridge present on the distal two-thirds of the radius length; and tibia and fibula long and slender with slightly expanded extremities. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 143, 447–472.
mosasaurid reptiles from central Poland. Acta Palaeontologica Polonica 48 (3): 397–408. Isolated marginal teeth and tooth crowns of Late Campanian and Late Maastrichtian mosasaurid reptiles (Squamata, Platynota) from the Wisła River valley area, central Poland, are described and illustrated. These comprise two Late Campanian taxa from Piotrawin quarry: Prognathodon sp. and Plioplatecarpinae sp. A., and four late Late Maastrichtian taxa from Nasiłów quarry: Mosasaurus cf. hoffmanni Mantell, 1829, M. cf. lemonnieri Dollo, 1889c, "Mosasaurus (Leiodon) cfr. anceps" sensu Arambourg (1952), and Plioplatecarpinae sp. B. In addition, the previously described frag− mentary jaw with associated teeth of the Late Campanian age from Maruszów quarry (west of the Wisła River area), is re− assigned to Mosasaurus cf. hoffmanni. This specimen suggests that M. hoffmanni or a closely related (ancestral?) species already appeared in Europe during the Late Campanian (well−documented European occurrences of M. hoffmanni are Late Maastrichtian in age). At least part of the described mosasaur material is likely to stem from periodic feeding in the area (broken−off or shed tooth crowns) or from floating carcasses (complete teeth and jaw fragments). Marcin Machalski [mach@twarda.pan.pl], Instytut Paleobiologii PAN, ul. Twarda 51/55, PL 00−818 Warszawa, Poland; John W.M. Jagt [john.jagt@nhmmaastricht.nl], Natuurhistorisch Museum Maastricht, de Bosquetplein 6−7, P.O. Box 882, NL−6200 AW Maastricht, the Netherlands; Rudi W. Dortangs, Hoofdstraat 36, NL−6436 CG Amstenrade, the Netherlands; Eric W.A. Mulder [eric292@gmx.net], Museum Natura Docet, Oldenzaalsestraat 39, NL−7591 GL Denekamp, the Netherlands; Andrzej Radwański, Instytut Geologii Podstawowej, Wydział Geologii UW, Al. Żwirki i Wigury 93, PL 02−089 Warszawa, Poland.
Squamata (amphisbaenians, “lizards”, mosasaurs, and snakes) is an extremely diverse clade with a rich fossil record. There is little consensus about the interrelationships of the major squamate clades (i.e., Iguania, Gekkota, Scincomorpha, Anguimorpha, Amphisbaenia, and Serpentes), or even the membership of some of these clades. Morphology-based cladistic analyses typically agree only that the major dichotomy in extant squamates is between Iguania and all other taxa. The phylogenetic placement of Amphisbaenia and Serpentes is particularly problematic. Incomplete taxon sampling is likely a major contributing factor to the absence of a consensus about squamate interrelationships. This study examines squamate relationships using 222 ingroup taxa scored for 363 morphological characters. Analysis of these data recovered 2,213 equally short trees with a length of 3,273 steps and a retention index of 0.7164. The results confirm the monophyly of the clades Scleroglossa (extant squamates exclusive of Iguania), Gekkota, Scincomorpha, Lacertoidea, Scincoidea, Anguimorpha, Carusioidea, Platynota, and Varanoidea. Novel results include the identification of a clade containing Scincidae sensu lato, Dibamidae, Amphisbaenia, and Serpentes; identification of a Mesozoic clade containing Bainguis, Eoxanta lacertifrons, Globaura venusta, and Myrmecodaptria; and identification of Dalinghosaurus as a basal shinisaur. A new taxonomic scheme is outlined. The names Iguanomorpha, Scincogekkonomorpha, Evansauria, and Mosasauriformes are applied to the stem-based groups including Iguania, Scleroglossa, Autarchoglossa, and Mosasauria, respectively. The importance of strict rigidity within taxonomy is questioned; taxonomy is most useful as a tool for communication about organisms or groups of organisms.
The presence of
Halisaurus
(Squamata, Mosasauridae) in the uppermost Cretaceous of the Maastrichtian type area, suggested by Lingham-Soliar (1996) on the strength of two partial vertebrae, is questioned. The anatomy of these elements suggests that they pertain not to
Halisaurus
, but more probably to
Plioplatecarpus marshi
Dollo, 1882.
ResearchGate has not been able to resolve any references for this publication.