[Paleontology • 2026] Spinosaurus mirabilis • Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation

Spinosaurus mirabilis

Sereno, Vidal, Myhrvold, Johnson-Ransom, Ciudad Real, Baumgart, Sánchez Fontela, Green, Saitta, Adamou, Bop, Keillor, Fitzgerald, Dutheil,  Laroche, Demers-Potvin, Simarro, Gascó-Lluna,  Lázaro, Gamonal, Beightol, Reneleau, Vautrin, Bertozzo, FGranados, Kinney-Broderick, Mallon, Lindoso, Ramezani & Jahandar, 2026

 

DOI: doi.org/10.1126/science.adx5486

Artwork: Dani Navarro

 Abstract

INTRODUCTION: The fossils of Spinosaurus aegyptiacus, a giant sail-backed, fish-eating theropod dinosaur from northern Africa, have inspired competing lifestyle interpretations, either as a semiaquatic ambush predator stalking shorelines and shallows or a fully aquatic predator in pursuit of prey underwater. Its bones and teeth have been found only in coastal deposits near marine margins, a locale potentially consistent with either lifestyle interpretation.

RATIONALE: In the central Sahara, a new fossiliferous area (Jenguebi) was discovered in beds equivalent in age [Farak Formation; Cenomanian ~95 million years ago (Mya)] to those yielding fossil remains of S. aegyptiacus. We describe from this area a new species, Spinosaurus mirabilis sp. nov., which is very similar to S. aegyptiacus in skeletal form but with a much taller, scimitar-shaped cranial crest. Two new sauropods were found in close association with the new spinosaurid buried in fluvial sediments indicative of an inland riparian habitat.

RESULTS: Spinosaurus mirabilis sp. nov. is distinguished by the low profile of its snout, a hypertrophied nasal-prefrontal crest, greater spacing of posterior maxillary teeth, and other features. Its features highlight the extraordinary specializations of both species of the genus Spinosaurus, including interdigitating upper and lower teeth. Principal component analysis of body proportions places spinosaurids between semiaquatic waders (e.g., herons) and aquatic divers (e.g., darters) distant from all other predatory dinosaurs. A time-calibrated phylogenetic analysis resolves three evolutionary phases: an initial Jurassic radiation when their distinctive elongate fish-snaring skull evolved and split into two distinctive designs, baryonychine and spinosaurine; an Early Cretaceous circum-Tethyan diversification when both reigned as dominant predators; and a final early Late Cretaceous phase when spinosaurines attained maximum body size as shallow water ambush specialists limited geographically to northern Africa and South America.

CONCLUSION: The discovery of the tall-crested S. mirabilis sp. nov. in a riparian setting within an inland basin supports a lifestyle interpretation of a wading, shoreline predator with visual display an important aspect of its biology. At the end of the Cenomanian about 95 million years ago, an abrupt eustatic rise in sea level and the attendant climate change brought the spinosaurid radiation to an end.

Sheathed bony head crests in extinct and living dinosaurs. Spinosaurus mirabilis sp. nov., evolved the tallest head crest of any theropod dinosaur, drawing attention to the midline ornamentation that characterizes the cranium and axial skeleton of all spinosaurids. In life, the crest would have been extended to some degree by a keratinous sheath, as in the living helmeted guinea fowl (Numida meleagris). Visual signaling, as is the case in guinea fowl and other crested avians, was likely the function of spinosaurid cranial crests and trunk and tail sails. Scale bar, 20 cm for S. mirabilis and 3 cm for N. meleagris.

Spinosaurus mirabilis

A single Spinosaurus mirabilis rears over a carcass of the coelacanth Mawsonia on the forested bank of a river some 95 million years ago in what is now the Sahara Desert in Niger. A scimitar-shaped head crest and interdigitating teeth characterize this wading giant, one of the last-surviving species of a spinosaurid radiation some 50 million years in the making.

Artwork: Dani Navarro

Sereno, Paul C.; Vidal, Daniel; Myhrvold, Nathan P.; Johnson-Ransom, Evan; Ciudad Real, María; Baumgart, Stephanie L.; Sánchez Fontela, Noelia; Green, Todd L.; Saitta, Evan T.; Adamou, Boubé; Bop, Lauren L.; Keillor, Tyler M.; Fitzgerald, Erin C.; Dutheil, Didier B.; Laroche, Robert A. S.; Demers-Potvin, Alexandre V.; Simarro, Álvaro; Gascó-Lluna, Francesc; Lázaro, Ana; Gamonal, Arturo; Beightol, Charles V.; Reneleau, Vincent; Vautrin, Rachel; Bertozzo, Filippo; Granados, Alejandro; Kinney-Broderick, Grace; Mallon, Jordan C.; Lindoso, Rafael M.; Ramezani, Jahandar. 2026. Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation. Science. 391 (6787) eadx5486. DOI: doi.org/10.1126/science.adx5486 [19 Feb 2026] 

 

Editor’s summary: Recent descriptions of and debates about the massive, fish-eating dinosaur Spinosaurus have brought this striking predator to the forefront of the dinosaur pantheon. Its huge size and distinctive morphology have stimulated much debate about the degree to which it lived an aquatic lifestyle. Sereno et al. describe a crested fossil Spinosaurus found in northern Africa as a new species. The researchers argue that this group of dinosaurs underwent three phases of evolution with increasing aquatic adaptations and existence in habitats around the Tethys Sea. —Sacha Vignieri

[Paleontology • 2025] Thikarisuchus xenodentes • A New, diminutive, heterodont Neosuchian from the Vaughn Member of the Blackleaf Formation (Cenomanian), southwest Montana, and Implications for the Paleoecology of heterodont neosuchians

 

Thikarisuchus xenodentes

Allen, Wilberg, Turner & Varricchio, 2025  

 DOI: doi.org/10.1080/02724634.2025.2542185 

Illustration by Dane Johnson/Museum of the Rockies

ABSTRACT

Although crocodyliforms from the Campanian–Maastrichtian of North America have received considerable attention, taxa occurring earlier in the Cretaceous have only recently begun to be more thoroughly studied. Of particular interest amongst these recent discoveries is the heterodont neosuchian Wannchampsus kirpachi Adams 2014 and the similar, undescribed ‘Glen Rose Form’ (USNM 22039). Both hold an unclear phylogenetic position, either forming a clade sister to Atoposauridae, a group of small, heterodont neosuchians from the Jurassic and Cretaceous of Laurasia, or to Paralligatoridae, a clade of larger, platyrostral, homodont neosuchians from the Cretaceous of Asia and North America. Here we describe a new species of diminutive, heterodont neosuchian, Thikarisuchus xenodentes gen. et sp. nov., from the early–middle Cenomanian Vaughn Member of the Blackleaf Formation of southwest Montana. The specimen includes cranial, mandibular, axial, and appendicular elements in articulation and dense concentration. It is recovered in a sister relationship with Wannchampsus and USNM 22039. We propose the name Wannchampsidae (clade nov.) for this group of small, heterodont neosuchians endemic to the Cretaceous of North America. Wannchampsidae is more confidently recovered sister to Atoposauridae due to the recognition of new synapomorphies. The new taxon provides greater clarity on the potential diet and paleoecology of Wannchampsidae and Atoposauridae and displays similar craniomandibular and dental characteristics to the notosuchian group Uruguaysuchidae, strongly suggesting these neosuchian groups were also omnivorous or insectivorous and terrestrially adapted, respectively representing a unique diet and reversion to terrestriality within Neosuchia.

SYSTEMATIC PALEONTOLOGY

CROCODYLOMORPHA Hay, 1930 (sensu Nesbitt, 2011)

CROCODYLIFORMES Hay, 1930 (sensu Clark, 1986)

NEOSUCHIA Clark in Benton and Clark, 1988

WANNCHAMPSIDAE, family nov.

Type Genus—Wannchampsus kirpachi Adams, 2014.

Etymology—'The family of Wannchampsus.’ The stem Wannchamps- is based on the designated type genus Wannchampsus. -idae, is a Latin patronymic suffix.

Under Article 29.2 of the Zoological Code, the suffix -idae denotes a family rank within the family-group.

Phylogenetic Definition—Branch-based clade comprising all taxa more closely related to Wannchampsus kirpachi Adams, 2014 than to Theriosuchus pusillus Owen, 1878 or Shamosuchus djadochtaensis Mook, 1924.

 Skeletal diagram of preserved elements of Thikarisuchus xenodentes (MOR 11969). Preserved ribs and osteoderms are not shown. Silhouette based off Araripesuchus spp., illustrating the convergence in craniodental characteristics and terrestrial affinities between these distantly related crocodyliform taxa.

THIKARISUCHUS XENODENTES, gen. et sp. nov.

Locality, Horizon, and Age—Vaughn Member of the upper portions of the Blackleaf Formation (early–middle Cenomanian). Material originates from The Mound (BL-9) in the Lima Peaks area of southwest Montana, southeast of the town of Lima, MT and was recovered on the surface in float or was surface screened, sifted, and later identified/recovered within the lab.

Diagnosis—A small neosuchian crocodyliform with the following unique combination of characters (autapomorphies denoted by an asterisk): longitudinal groove on posterior dentary laterally adjacent to dentary toothrow for reception of posterior maxillary teeth*; extreme mesiodistal elongation and low apicobasal height of posterior ‘low crowned’ maxillary and dentary teeth*; development of frontoparietal midline ridge into a symmetric, elongate hexagonal boss at frontal-parietal suture*; extension of lateral angular ridge onto lateral surface of posterior dentary*; oreinirostral snout; anteriorly oriented external nares; small, anteroposteriorly aligned sulcus present posterior to triple junction of sutures of the premaxilla, maxilla, and nasals; orbitonasal sulcus (sensu Turner, 2015) on lateral surface of maxilla; occlusal pit on palatal process of maxilla adjacent to 4th and 5th maxillary teeth; ventral surface of posterolateral portion of palatal process of maxilla possesses a shallow groove that accommodates some posterior dentary teeth; internal choana bounded almost entirely by pterygoids, with palatines contributing to anterior margin; procoelous cervical, dorsal, and caudal vertebrae; humeral head convex, with the center of the humeral head positioned proximally above the rest of the surface; humerus proximal to deltopectoral crest strongly deflected medially at ∼45° compared with humeral shaft; highly reduced postacetabular process of ilium; elongate proximal process on fibula.

Etymology—After “thikari,” the diminutive form of the Greek word “thiki” meaning sheath, referring to the way in which the posterior maxillary teeth ‘sheath’ within the longitudinal groove on the dentary adjacent to the dentary toothrow as well as the diminutive size of the specimen, and “suchus,” from the Latinized form of “soukhos,” Greek for crocodile. After “xeno,” Greek for strange, and “dentes,” Latin for teeth, referring to the strange heterodont dentition and extremely mesiodistally elongate and apicobasally low posterior teeth.

An artistic rendering of Thikarisuchus xenodentes, an extinct crocodyliform from the Cretaceous of Montana.

Illustration by Dane Johnson/Museum of the Rockies

Harrison J. Allen, Eric W. Wilberg, Alan H. Turner and David J. Varricchio. 2025. A New, diminutive, heterodont Neosuchian from the Vaughn Member of the Blackleaf Formation (Cenomanian), southwest Montana, and Implications for the Paleoecology of heterodont neosuchians. Journal of Vertebrate Paleontology. e2542185. DOI: doi.org/10.1080/02724634.2025.2542185 [22 Sep 2025] 

[Paleontology • 2025] Astigmasaura genuflexa • Side by side with Titans: A New rebbachisaurid Dinosaur from the Huincul Formation (upper Cenomanian) of Patagonia, Argentina

  

Astigmasaura genuflexa

Bellardini, Filippi, Carballido, Garrido & Baiano, 2025

  

DOI: doi.org/10.1016/j.cretres.2025.106188

Artwork by Mattia Yuri Messina  facebook.com: MYM PaleoArt 

Abstract

Rebbachisaurids are medium to large-sized, non-selective and ground-level browser diplodocoid sauropods, and they are characterised by highly specialised skulls, widely pneumatized axial elements and gracile appendicular skeletons. Known from the Early Cretaceous to the early Late Cretaceous, the rebbachisaurid fossil record is particularly diversified in Gondwana, with several specimens found in North Africa and South America. Notably, Patagonia has yielded over more than half of all known Rebbachisauridae, including the most basal forms and the youngest rebbachisaurid remains to date. Herein, we describe a new species of Rebbachisauridae from the Huincul Formation (upper Cenomanian) of the Neuquén Basin (Patagonia, Argentina): Astigmasaura genuflexa gen. et sp. nov. New laboratory work provided the complete osteology of the specimen MAU-Pv-EO-629, complementing the previously published hind limb anatomy. Thus, the type material of Astigmasaura comprises the posterior portion of an articulated, postcranial skeleton of a single, morphologically adult individual. Astigmasaura shares different conditions with other Rebbachisauridae, including anterior caudal vertebrae with tall neural spines and tetraradiate neural laminae, asymmetric middle haemal arches, mediolaterally compressed proximal tibiae, and femur with medially inclined distal condyles. Furthermore, Astigmasaura shows a unique combination of diagnostic features that distinguish it from all other sauropods. This new record not only provides new morphological information about the caudal and pelvic girdle anatomy of Rebbachisauridae, which is poorly known to date, and suggests a greater taxonomic diversification within the family during the last stages of its evolutionary history than known before.

Systematic palaeontology

Order Saurischia Seeley, 1887

Suborder Sauropodomorpha von Huene, 1932

Infraorder Sauropoda Marsh, 1878

Superfamily Diplodocoidea Marsh, 1884 (sensu Upchurch, 1995)

Family Rebbachisauridae Bonaparte, 1997

Astigmasaura genuflexa gen. et sp. nov.

 

Etymology. The generic name is derived from El Orejano, a locality in North Patagonia from which the new taxon was found. Orejano is a Spanish word denoting an animal without identification signs or owner, ...

 

Flavio Bellardini, Leonardo S. Filippi, José L. Carballido, Alberto C. Garrido and Mattia A. Baiano. 2025. Side by side with Titans: A New rebbachisaurid Dinosaur from the Huincul Formation (upper Cenomanian) of Patagonia, Argentina. Cretaceous Research. 176, 106188. DOI: doi.org/10.1016/j.cretres.2025.106188 

https://www.conicet.gov.ar/descubren-en-neuquen-una-nueva-especie-de-dinosaurio-sauropodo-que-vivio-hace-95-millones-de-anos/

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[PaleoMammalogy • 2025] Bone Microstructure supports A Mesozoic Origin for a semiaquatic burrowing lifestyle in Monotremes (Mammalia)

Kryoryctes cadburyi  Pridmore, Rich, Vickers-Rich & Gambaryan, 2005

in Hand, Wilson, López-Aguirre, Houssaye, Archer, ... et Beck, 2025. 

DOI: doi.org/10.1073/pnas.2413569122

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Artwork by Peter Schouten.

Significance

The egg-laying monotremes have played a central role in our understanding of mammalian evolution, but their fossil record is poor and their evolutionary history is controversial. Living monotremes are ecologically very distinct from each other: The platypus is well adapted for a semiaquatic lifestyle, whereas echidnas are fully terrestrial. Here, we show that an isolated mammal humerus from the Early Cretaceous of Australia, from a species called Kryoryctes cadburyi, belongs to a monotreme, and that microscopic features of this bone indicate that this monotreme was a semiaquatic burrower. This suggests that the amphibious lifestyle of the modern platypus had its origins at least 100 Mya, during the Age of Dinosaurs, and that echidnas evolved from semiaquatic ancestors.

Abstract

The platypus and four echidna species are the only living egg-laying mammals and the sole extant representatives of Order Monotremata. The platypus and echidnas are very disparate both morphologically and ecologically: The platypus is a specialized semiaquatic burrowing form that forages for freshwater invertebrates, whereas echidnas are fully terrestrial and adapted for feeding on social insects and earthworms. It has been proposed that echidnas evolved from a semiaquatic, platypus-like ancestor, but fossil evidence for such a profound evolutionary transformation has been lacking, and this hypothesis remains controversial. Here, we present original data about the Early Cretaceous (108 to 103 Ma) Australian mammal Kryoryctes cadburyi, currently only known from a single humerus, that provides key information relating to this question. Phylogenetic analysis of a 536-character morphological matrix of mammaliaforms places Kryoryctes as a stem-monotreme. Three-dimensional whole bone comparisons show that the overall shape of the humerus is more similar to that of echidnas than the platypus, but analysis of microstructure reveals specializations found in semiaquatic mammals, including a particularly thick cortex and a highly reduced medullary cavity, present in the platypus but absent in echidnas. The evidence suggests Kryoryctes was a semiaquatic burrower, indicating that monotremes first evolved an amphibious lifestyle in the Mesozoic, and providing support for the hypothesis that this is ancestral for living monotremes as a whole. The lineage leading to the modern platypus appears to have been characterized by extremely long term (>100 My) niche conservatism, with echidnas representing a much later reversion to a fully terrestrial lifestyle.

 

An artist’s impression of Kryoryctes cadburyi.

Artwork by Peter Schouten.

 

Suzanne J. Hand, Laura A. B. Wilson, Camilo López-Aguirre , Alexandra Houssaye, Michael Archer, Joseph J. Bevitt, Alistair R. Evans, Amalia Y. Halim, Tzong Hung, Thomas H. Rich, Patricia Vickers-Rich and Robin M. D. Beck. 2025. Bone Microstructure supports A Mesozoic Origin for a semiaquatic burrowing lifestyle in Monotremes (Mammalia). PNAS. 122 (19) e2413569122. DOI: doi.org/10.1073/pnas.2413569122 

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[Paleontology • 2025] Tameryraptor markgrafi • Re-evaluation of the Bahariya Formation carcharodontosaurid (Theropoda: Carcharodontosauridae) and its implications for allosauroid phylogeny

Tameryraptor markgrafi

Kellermann, Cuesta & Rauhut, 2025

 

DOI: doi.org/10.1371/journal.pone.0311096

Life reconstruction by Joschua Knüppe.

Abstract

The first partial skeleton of a carcharodontosaurid theropod was described from the Egyptian Bahariya Oasis by Ernst Stromer in 1931. Stromer referred the specimen to the species Megalosaurus saharicus, originally described on the basis of isolated teeth from slightly older rocks in Algeria, under the new genus name Carcharodontosaurus saharicus. Unfortunately, almost all of the material from the Bahariya Oasis, including the specimen of Carcharodontosaurus was destroyed during World War II. In 1996, a relatively complete carcharodontosaurid cranium was described from similar aged rocks in Morocco and designated the neotype of the species Carcharodontosaurus saharicus in 2007. However, due to the destruction of the original material, comparisons of the neotype to the Egyptian fossils have so far only been done cursorily. A detailed reexamination of the available information on the Egyptian carcharodontosaurid, including a previously undescribed photograph of the exhibited specimen, reveals that it differs from the Moroccan neotype in numerous characters, such as the development of the emargination of the antorbital fossa on the nasals, the presence of a horn-like rugosity on the nasal, the lack of a dorsoventral expansion of the lacrimal contact on the frontals, and the relative enlargement of the cerebrum. The referability of the Egyptian specimen to the Algerian M. saharicus is found to be questionable, and the neotype designation of the Moroccan material for C. saharicus is accepted here under consideration of ICZN Atricle 75, as it both compares more favorably to M. saharicus and originates from a locality closer to the type locality. A new genus and species, Tameryraptor markgrafi gen. et sp. nov., is proposed for the Egyptian taxon. The theropods of the Bahariya Oasis and the Moroccan Kem Kem Group are thus not as closely related as previously thought, and the proposed faunal similarities between these two strata need further examination.

The holotype of Tameryraptor markgrafi (SNSB-BSPG 1922 X46).
Photograph of the mounted specimen at a point prior to April 1944.

Comparison between Tameryraptor markgrafi [SNSB-BSPG 1922 X 46] and SGM-Din 1.
SNSB-BSPG 1922 X 46: (B) nasalia from left lateral, left maxilla from (D) lateral and (F) medial and endocast in (G) dorsal and (H) left lateral view;  
and SGM-Din1: (A) right nasal in lateral view, right maxilla in (C) lateral and (E) medial view and endocast in (I) dorsal and (J) left lateral view;

Sources: (A, C, E, J) [18], (I) modified from [54], (B, D) UAT 678/20/SNSB-BSPG 1922 X 46, (F) [1], (G, H) MB. R. 2056.

Systematic Paleontology

Theropoda Marsh, 1881

Allosauroidea Marsh, 1878

Carcharodontosauriformes new clade, 

comprising Carcharodontosaurus saharicus, Sinraptor dongi and all descendants of their most recent common ancestor

Carcharodontosauridae Stromer, 1931

Tameryraptor gen nov. 

Etymology: Tameryraptor meaning “thief from the beloved land” is a combination of one of the more informal ancient Egyptian names for Egypt, (ta-mery) meaning beloved land [Silver, 2021]; and the latin word for thief, raptor

 

  Tameryraptor markgrafi sp. nov.

Etymology: markgrafi in reference to Richard Markgraf, the Austrian fossil collector who discovered most of the dinosaur remains described by Stromer.

Holotype: SNSB-BSPG 1922 X 46, now destroyed. The specimen included parts of the left and right maxilla, both nasals, parts of the braincase and endocast of the braincase, three cervical vertebrae, an anterior to anterior mid-caudal vertebra and chevron, the proximal part of a dorsal rib, a left ischium, right and left pubis, both femora and a left fibula. In the absence of the actual specimen, the descriptions and figures of Stromer [1, 25] and the photograph UAT 678/20 stand as representatives for the holotype, in accordance with ICZN article 73.1.4.

Horizon and Locality: SNSB-BSPG 1922 X 46 was found two kilometers from Ain Gedid on the Western foot of the Gebel Harra (Fig 1) in basal layers of hardened, gypsum-free marl (Layer p of Stromer’s 1914 profile) of the Bahariya Formation, Cenomanian.

Diagnosis: Tameryraptor markgrafi gen. nov sp. nov. is a carcharodontosaurid theropod characterized by the following unique character combination (autapomorphies marked with a *): antorbital fossa visible on nasals in lateral view; small nasal horn on the medial rim of the nasals*; maxilla with well-developed antorbital ridge; maxillary teeth highly symmetrical anteroposteriorly; prefrontal facet on frontal not expanded; frontals vaulted dorsally*; femur with spike like accessory trochanter; proximal fibula more anteriorly than posteriorly expanded.

Skeletal reconstruction of SNSB-BSPG 1922 X 46. Preserved elements shown in white. Each square is 1 sq.m.

Life reconstruction of Tameryraptor markgrafi.

By Joschua Knüppe.

Maximilian Kellermann, Elena Cuesta and Oliver W. M. Rauhut. 2025. Re-evaluation of the Bahariya Formation carcharodontosaurid (Dinosauria: Theropoda) and its implications for allosauroid phylogeny. PLoS ONE. 20(1): e0311096. DOI: doi.org/10.1371/journal.pone.0311096

[Paleontology • 2024] Caletodraco cottardi • A New Furileusaurian Abelisaurid (Theropoda: Abelisauridae) from the Cenomanian Chalk of Normandy (North-Western France)

Caletodraco cottardi

Buffetaut, Tong, Girard, Hoyez & Párraga, 2024

 

 www.mdpi.com/2813-6284/2/3/9

Abstract

An articulated group of skeletal elements comprising a sacrum, both ilia and a first caudal vertebra, plus an isolated tooth found in immediate proximity to the bones, from the lower Cenomanian Chalk at Saint-Jouin-Bruneval (Seine-Maritime, Normandy, France) is described and attributed to a new genus and species of abelisaurid theropod, Caletodraco cottardi, on the basis of several characters of the sacrum and pelvis. The peculiar shape of the transverse process of the first caudal vertebra shows that Caletodraco cottardi differs from majungasaurine abelisaurids previously described from Europe, such as Arcovenator escotae, and belongs to the Furileusauria, a group of derived abelisaurids hitherto recognized only from South America. The presence of a furileusaurian abelisaurid in the Cenomanian of Normandy suggests that the biogeographical history of the Abelisauridae in Europe was more complex than hitherto admitted. Several previously described European abelisaurids, such as the Albian Genusaurus sisteronis, may in fact belong to the Furileusauria.

Keywords: Dinosauria; Theropoda; Abelisauridae; Cenomanian; Normandy

  Holotype specimen of Caletodraco cottardi, MHNH 2024.1.1., in dorsal (A,A’), left lateral (B,B’) and ventral (C,C’) views, with explanatory drawings. Front is at left.

Abbreviations: ai: anterior wing of ilium; bf: brevis fossa; cv: centrum of first caudal vertebra; d: depression; dmi: dorsal margin of ilium; li: left ilium; ns: fused neural spines of sacral vertebrae; pdp: posterodorsal process of ilium; s: sacrum; tpc: transverse process of first caudal vertebra; tps: transverse processes of sacral vertebrae.

Dinosauria Owen, 1842

Theropoda Marsh, 1881

Ceratosauria Marsh, 1884

Abelisauridae Bonaparte and Novas, 1985

Brachyrostra Canale et al., 2009

Furileusauria Filippi et al., 2016

Caletodraco cottardi, n.g., n.sp.

Diagnosis: a large abelisaurid theropod showing furileusaurian characteristics, including a straight dorsal margin of the ilium and a distally expanded and crescent-shaped tip of the dorsally orientated transverse process of the first caudal vertebra, with a convex distal margin, differing from previously known furileusaurians by the following autapomorphy: distinctive shape of the transverse process, with a short anterior spine and a rounded and expanded fan-shaped semicircular posterodistal margin.

Locus typicus: cliffs along the English Channel at Saint-Jouin-Bruneval, Seine-Maritime, Normandy (NW France).

 

Derivatio nominis: genus name from the Caleti (or Caletes), a Celtic tribe that inhabited the Pays de Caux [Streiff. 1952]), the part of Normandy on the coast of which the fossil was found, and draco, Latin for dragon. The species is dedicated to Mr Nicolas Cottard, who discovered the specimen in the course of his systematic research on the stratigraphy and paleontology of the Chalk of Normandy and donated it to the Muséum d’histoire naturelle du Havre.

Conclusions: 

The discovery of Caletodraco cottardi shows that dinosaur remains, although exceedingly rare, do occur in the Chalk of the Anglo-Paris basin and that a careful search for fossil vertebrates in these marine formations can yield surprising and important results. The new taxon leads to a reassessment of the fossil record of abelisaurids in Europe, showing that, contrary to what could previously be assumed, majungasaurines were not the only abelisaurid subgroup present in that geographical area, since Caletodraco cottardi apparently belongs to the Furileusauria, a highly derived clade of Abelisauridae. C. cottardi is one of the earliest known Furileusauria and its occurrence in Europe leads to reconsider the biogeographical history of this group of theropods, hitherto known from South America.

 Eric Buffetaut , Haiyan Tong, Jérôme Girard, Bernard Hoyez and Javier Párraga. 2024. Caletodraco cottardi: A New Furileusaurian Abelisaurid (Dinosauria: Theropoda) from the Cenomanian Chalk of Normandy (North-Western France). Foss. Stud. 2(3), 177-195; DOI: 10.3390/fossils2030009

  www.mdpi.com/2813-6284/2/3/9

[Paleontology • 2024] Campananeyen fragilissimus • They all floated in the Cretaceous: New rebbachisaurid (Sauropoda: Diplodocoidea) with a highly pneumatized skeleton from the Upper Cretaceous (lower Cenomanian) of Patagonia, Argentina

 

 Campananeyen fragilissimus

 Lerzo, Fernández-Baldor, Canale, Whitlock, Otero & Gallina, 2024

DOI: 10.1080/08912963.2024.2383708  

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ABSTRACT

Rebbachisaurids are a group of basal diplodocoid sauropods that diversified primarily in Gondwana between the early Lower Cretaceous and the early Upper Cretaceous. Their phylogenetic relationships are still under debate given the fragmentary and incomplete nature of its remains. Here, we provide a detailed description of the postcranial remains of Campananeyen fragilissimus gen. et sp. nov. from the Candeleros Formation (lower Cenomanian) of Neuquén Province, Argentina. Campananeyen presents notable features that allow it to be recognised as a new species by the presence of an underdeveloped crista prootica, paraoccipital process internally hollow and a fuse dorsal alar arm of the ilium. The phylogenetic analysis recovered this taxon as a basal rebbachisaurid closely related to Zapalasaurus, Sidersaura and the specimen from La Amarga Formation MACN-Pv-N 35. The new rebbachisaurid is recovered as the sister taxon of Sidersaura due the presence of procoelous posterior caudal vertebrae and dorsoventrally flattened posterior caudal centra. C. fragilissimus presents an extreme pneumatization of the sacral region with an autapomorphic dorsal alar arm of the sacral transverse processes. Finally, the phylogenetic analysis supports a South American origin for Rebbachisauridae and an early diversification to Africa and Europe by the Barremian-Aptian as previously suggested.

KEYWORDS: Candeleros formation, Dinosauria, Pneumatization, Gondwana, Campananeyen, Rebbachisauridae

Campananeyen fragilissimus gen. et sp. nov. 

 

Lucas N. Lerzo, Fidel Torcida Fernández-Baldor, Juan I. Canale, John A. Whitlock, Alejandro Otero and Pablo A. Gallina. 2024. They all floated in the Cretaceous: New rebbachisaurid (Sauropoda, Diplodocoidea) with a highly pneumatized skeleton from the Upper Cretaceous (lower Cenomanian) of Patagonia, Argentina. Historical Biology: An International Journal of Paleobiology. DOI: doi.org/10.1080/08912963.2024.2383708  

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[Paleontology • 2024] Araripesuchus manzanensis • A New Species of Araripesuchus with durophagous dentition increases the ecological disparity among uruguaysuchid crocodyliforms

Araripesuchus manzanensis

Dumont, Pol, Bona & Apesteguía. 2024. 

DOI: 10.1080/14772019.2024.2373987 

 

Abstract

Notosuchia is a group of crocodyliforms with mostly terrestrial habits that lived during the Mesozoic and up to the Miocene. Within this group Uruguaysuchidae is so far represented by eight species, six of them clustered in the genus Araripesuchus. Two species of this genus, A. patagonicus and A. buitreraensis, come from different localities in Patagonia (Argentina) from the Candeleros Formation (Cenomanian age). Here we present a third species of Araripesuchus from this formation. The new species comes from the same locality as Araripesuchus buitreraensis, but differs in numerous features including the presence of different molariform teeth. The new species was included in a phylogenetic analysis and, in agreement with previous analyses, Uruguaysuchidae is recovered as monophyletic and placed within Notosuchia as the sister clade of Peirosauridae. Uruguaysuchidae includes all species of Araripesuchus as well as Anatosuchus minor and Uruguaysuchus aznarezi. The new species adds new information to the ecological diversity of the group its bulbous molariforms with a quadrangular occlusal surface bounded by mamelons is interpreted as indicative of a durophagous diet, suggesting the presence of niche partitioning between the two sympatric species A. manzanensis and A. buitreraensis.  

Keywords: Notosuchia, Araripesuchus, Patagonia, La Buitrera, durophagous diet, niche partitioning

 

María Lucila Fernández Dumont, Diego Pol, Paula Bona and Sebastián Apesteguía. 2024. A New Species of Araripesuchus with durophagous dentition increases the ecological disparity among uruguaysuchid crocodyliforms. Journal of Systematic Palaeontology. 22(1);  2373987. DOI: doi.org/10.1080/14772019.2024.2373987 

[Paleontology • 2024] Fona herzogae • A New semi-fossorial thescelosaurine Dinosaur (Neornithischia: Thescelosauridae) from the Cenomanian-age Mussentuchit Member of the Cedar Mountain Formation, Utah

Fona herzogae

Avrahami, Makovicky, Tucker & Zanno, 2024

 

DOI: 10.1002/ar.25505

Abstract

Thescelosaurines are a group of early diverging, ornithischian dinosaurs notable for their conservative bauplans and mosaic of primitive features. Although abundant within the latest Cretaceous ecosystems of North America, their record is poor to absent in earlier assemblages, leaving a large gap in our understanding of their evolution, origins, and ecological roles. Here we report a new small bodied thescelosaurine—Fona herzogae gen. et sp. nov.—from the Mussentuchit Member of the Cedar Mountain Formation, Utah, USA. Fona herzogae is represented by multiple individuals, representing one of the most comprehensive skeletal assemblages of a small bodied, early diverging ornithischian described from North America to date. Phylogenetic analysis recovers Fona as the earliest member of Thescelosaurinae, minimally containing Oryctodromeus, and all three species of Thescelosaurus, revealing the clade was well-established in North America by as early as the Cenomanian, and distinct from, yet continental cohabitants with, their sister clade, Orodrominae. To date, orodromines and thescelosaurines have not been found together within a single North American ecosystem, suggesting different habitat preferences or competitive exclusion. Osteological observations reveal extensive intraspecific variation across cranial and postcranial elements, and a number of anatomical similarities with Oryctodromeus, suggesting a shared semi-fossorial lifestyle.

SYSTEMATIC PALEONTOLOGY

DINOSAURIA Owen (1842).

ORNITHISCHIA Seeley (1887).

NEORNITHISCHIA Cooper, 1985 (sensu Butler et al., 2008).

ORNITHOPODA Marsh, 1881 (sensu Butler et al., 2008).

THESCELOSAURIDAE (Sternberg, 1937). 

THESCELOSAURINAE (Sternberg, 1940).

THESCELOSAURINAE indet.

Fona herzogae sp. nov.

  Holotype: NCSM 33548, a single partially articulated, nearly complete skeleton. 

 Occurrence: NCSM 33548 was recovered from the Karmic Orodromine locality (UT-16-07-22-Z1), lower Mussentuchit Member, upper Cedar Mountain Formation, Emery County, Utah, USA (Figure 1). Stratigraphic occurrence is between MAZ1 and Last Chance Sandstone (99.466 + 0.046/−0.053 Ma; Tucker et al., 2023) making it the only locality definitively preserving F. herzogae from the lower Mussentuchit unit to date. Mini Troll (NCPALEOUT16) is the geologically youngest locality, emplaced below MAZ3, with an age of 99.231 + 0.090/−0.052 Ma. FMNH PR 4581 was preserved at the Manolo site (UT130831), (99.411 + 0.056/−0.061 Ma) above MAZ2 in the upper Mussentuchit (Figure 1).

Age data is based on a Bayesian age stratigraphic model (Trayler et al., 2020) of the member originally detailed in Tucker et al. (2023). Materials referable to Fona span the lower to upper Mussentuchit Member of the Cedar Mountain Formation, a range of, at minimum, 235,000 kyr. UT-16-07-22-Z1 and NCPALEOUT16 are located on land administered by the US Bureau of Land Management, respectively; exact locality information is restricted by federal statute and is available to qualified researchers via the NCSM.

  DIAGNOSIS: Fona herzogae is a small-bodied, early diverging ornithischian with the following unique combination of characters (autapomorphies are denoted with an asterisk) (Figure 5) *(1) a rostral maxillary fossa located caudal to the first tooth position (unknown in Oryctodromeus and possibly shared by Isaberrysaura and Haya); *(2) an otoccipital that bears a dorsoventrally elongate fossa on the medial surface of the occipital condyle located directly caudal to the medial opening of CN XII; *(3) a rostrocaudally oriented ventral canal on the prootic; *(4) The dorsal margin of the axis neural spine is parallel with the dorsal suture of the centrum, forming an angle of essentially ~0°. *(5) Ischial shaft has bulbous thickening along the dorsal margin directly distal to the obturator process (prominent on both ischia of at least two individuals and weakly present on only the right of another.) (6) base of the prepubic process bears a prominent lateral swelling (possibly present but significantly reduced in Oryctodromeus and Th. neglectus). (7) the caudoventral prong of the jugal's caudal process underlaps a groove along the ventral margin of the quadratojugal (shared by Th. neglectus, likely Changmiania, and possibly at least one specimen of Jeholosaurus [STMN 23–17]). (8) dentary teeth with vertical wear facets on the labial surface that terminate abruptly near the crown base to form a mesiodistally inclined shelf (shared by Oryctodromeus). (9) A low, round tuberosity on the medial side of the scapula located directly opposite to the glenoid ridge (shared with Oryctodromeus and possibly Iani smithi). Standard skeletal measurements of NCSM 33548 are provided in Table 1. Characters 7–9 serve as important synapomorphies that help place Fona within Thescelosaurinae.

Fona n. gen.

  Etymology: Fona (/Foat'NAH/) from the Austronesian language Finoʼ CHamoru. The ancestral maga'håga of the CHamoru people is Fo'na whose name can be translated as ‘the origin’. With her brother Pontan, whose name can be translated as ‘a ripe coconut’, they became the first paramount female and male chiefs (the ancestral maga'låhi of the CHamoru people), ancestrally venerated according to CHamoru tradition (Borja-Quichocho-Calvo, 2021; Cruz, 2022). According to oral history and legend, when Pontan's spirit began to perish and die, Fo'na discovers her powers and uses them to craft parts of Pontan's body into the pieces of the universe. His eyes were turned into the sun and moon, his eyebrows became the rainbows, his back the earth, his chest the sky, his blood the ocean, and from his stomach and penis the mountains and the sacred Creation Point stone pillar were born (Duhaylonsod & Cepeda, 2022). Fo'na had such sorrow from the loss of her brother that her tears flowed down his body to form the currents of the sea, and in reverence to her brother's dream, she decided to bring life to the universe, throwing herself into the earth where her body turned to stone. From her fossilized body sprang forth the first people at Fuha Rock, imbued with her good spirit (Cepeda, 2021; Cunningham, 1992; Perez, 2019; Perez, 2021). This ancestral story of the CHamoru people mirrors the life and death of the thescelosaurine dinosaurs at the Mini Troll locality, as there were at least two subadult individuals that may have been male and female, or perhaps siblings. Additionally, their bodies fell into the earth where they too fossilized. This naming, rooted in the story of Pontan's sacrifice and Fo'na's love for her brother, highlights the CHamoru values of inafa'måolek (to make good for all), geftåo (the need for compassion, selflessness, and familial bonds) (Duhaylonsod & Cepeda, 2022), the importance of the equality shared between women and men (Naholowa'a, 2018), and ongoing efforts to decolonize paleontology (Monarrez et al., 2021). 

Fona herzogae sp. nov.

  Etymology: The specific epithet honors Lisa Herzog (discoverer of the Mini Troll locality) for her unparalleled dedication to the paleontology program at the NCSM and the collection, care, and conservation of fossil specimens worldwide.

CONCLUSION: 

Fona herzogae adds to the cryptic diversity of the Mussentuchit Member dinosaur fauna, serving as an important component of this exceptional mid-Cretaceous ecosystem. It would have lived alongside the hadrosauromorph Eolambia caroljonesa (McDonald et al., 2017), the Rhabdadontomorph Iani smithi (Zanno, Gates, et al., 2023), the small-bodied tyrannosaur Moros intrepidus (Zanno, Tucker, et al., 2019), the large-bodied allosaurian Siats meekerorum (Zanno & Makovicky, 2013), an unnamed oviraptorosaur (Zanno, Avrahami, et al., 2019) and neoceratopsian (Zanno, Tucker, et al., 2023), and a collection of other terrestrial vertebrates (Avrahami et al., 2018).

The presence of a distinct thescelosaurine taxon in the Mussentuchit member supports the hypothesis that the ancestors of Thescelosaurus were present in North America as early as the Cenomanian, co-inhabiting the continent with their sister-taxon Orodrominae. To date, members of these clades have not been found together, suggesting different habitat preferences. Shared ecomorphology with, and a close phylogenetic affinity with Oryctodromeus demonstrated here, supports a shared semi-fossorial lifestyle. Some of the extensive intraspecific variation among specimens of Fona is likely attributable to ontogenetic transformations, whereas others may suggest a broad phenotypic range for the taxon or may point to sexual dimorphism.

 

Haviv M. Avrahami, Peter J. Makovicky, Ryan T. Tucker, Lindsay E. Zanno. 2024. A New semi-fossorial thescelosaurine Dinosaur from the Cenomanian-age Mussentuchit Member of the Cedar Mountain Formation, Utah. The Anatomical Record

DOI: doi.org/10.1002/ar.25505

https://sciences.ncsu.edu/news/life-underground-suited-new-dinosaur-fine