PALEONTOLOGY IN MARCH, 2025

ABSTRACT

Ichthyosaurs were a group of marine Mesozoic reptiles. Their presence in the Portuguese fossil record is scarce and ranges from the Sinemurian to the Toarcian. In this work we describe a new specimen—a nearly complete skull discovered in the Sinemurian of Praia de Água de Madeiros, São Pedro de Moel, Municipality of Marinha Grande (Portugal). This specimen represents the most complete and best preserved cranial remains from the Iberian Peninsula published to date. Phylogenetic analyses performed identified this specimen as a new genus and species, Gadusarus aqualigneus, the first to be identified in the Iberian Peninsula. The species is phylogenetically recovered as a baracromian ichthyosaur, part of the Neoichthyosauria and Parvipelvia clades.

LINK(S)
https://www.app.pan.pl/article/item/app011992024.html

https://www.app.pan.pl/archive/published/app70/app011992024.pdf

ABSTRACT

A virtually complete and articulated plesiosaur skeleton (MH 7) is described from the Lower Jurassic (Toarcian) Posidonienschiefer Formation near Holzmaden in southern Germany. Plesiosaur remains are rare in this rock unit compared to those of other marine reptiles, such as ichthyosaurs and thalattosuchian crocodylomorphs. The new specimen offers an opportunity to assess the biodiversity of Early Jurassic plesiosaurs documented from what is now Central Europe. The osteology of MH 7 is described and compared with other Early Jurassic plesiosaurs based on first-hand observations. Phylogenetic analyses using both equal weighting and weighted parsimony determined phylogenetic placement within Plesiosauria. Plesiopterys wildi is an early-diverging plesiosauroid and a sister taxon to Franconiasaurus brevispinus and Cryptoclidia. MH 7 represents a subadult individual, providing an updated character state diagnosis of Plesiopterys wildi, which has hitherto only been known from the osteologically immature holotype SMNS 16812. The presence of multiple regionally distinct plesiosaur genera and species within the European epicontinental marine basins suggests possible paleobiogeographical segregation during the Toarcian.

LINK(S)
https://peerj.com/articles/18960/

https://peerj.com/articles/18960.pdf

ABSTRACT

Pterosaur fossils in the Mesozoic formation of Southeast Asia are very scarce. A few articles reported isolated teeth and a handful of postcranial elements in northeastern Thailand. Here we report on a pterosaur upper jaw from the Early Cretaceous at Phra Prong locality of eastern Thailand, which is considered the lateral equivalent of the Sao Khua Formation of the Khorat Group. This represents the first pterosaur cranial material in Thailand. It comprises a partial rostrum, preserving eleven tooth positions, and four associated tooth crowns. The anterior tip of the rostrum is dorsoventrally flattened and laterally expanded (spoon-shaped), indicating affinities to the Gnathosaurinae (Ctenochasmatidae). Alveoli borders are conspicuously scalloped and collar-like, and the palatal surface exhibits a pair of sinusoidal grooves. These features bear a strong resemblance to the Late Jurassic gnathosaurines Gnathosaurus subulatus, Tacuadactylus luciae, and Lusognathus almadrava. Our phylogenetic analysis indicates that the Thai pterosaur is closely related to these gnathosaurines. Still, the Thai gnathosaurine is unique in exhibiting a kite-shaped rostrum expansion and is recognized as a new taxon herein named Garudapterus buffetauti gen. et sp. nov. This new specimen provides essential information regarding pterosaurs, including updated data for a better understanding of their diversity and distribution throughout Southeast Asia.

LINK(S)
https://www.sciencedirect.com/science/article/abs/pii/S0195667125000588

ABSTRACT

Despite some exceptional cases, the Lower Cretaceous theropod record from Iberia mainly comprises isolated teeth and fragmentary skeletons. In the Cameros Basin, theropods have been mostly documented in the Eastern Cameros sub-basin with baryonychine spinosaurids dominating this sector. Instead, theropods are rarer in the Western Cameros sub-basin. Here, we describe material from the Western Cameros sub-basin, recovered in the upper Hauterivian–lower Barremian Golmayo Formation of Soria (Los Caños and Zorralbo I sites), which allowed us to identify three early-branching tetanuran and three baryonychine dental morphotypes, and a large-sized spinosaurid from Zorralbo I. The latter is represented by cranial, axial, and appendicular bones, and identified as a large-sized baryonychine based on anatomical and phylogenetic studies. Our results demonstrate that the theropod assemblages are consistent within the entire Cameros Basin, exhibiting a dominance of baryonychines. Western Cameros theropods are not only limited to Baryonychinae but they would also coexist with other early-branching tetanurans and coelurosaurians. The Lower Cretaceous Iberian record is represented by taxa from all major clades within Theropoda (i.e., Tetanurae, Allosauroidea, Carcharodontosauria, Coelurosauria, Ornithomimosauria, Paraves and Dromaeosauridae), being Spinosauridae the most prevalent group, with five described genera and species and a large number of tooth morphotypes. Indeed, three spinosaurine and ten baryonychine tooth morphotypes have been identified in the Iberian record so far. This study demonstrates that the entire Cameros Basin has a great representation of the theropod record of the Iberian Peninsula, and it underscores the potential of this basin to understand the Iberian palaeobiodiversity, especially in spinosaurids.

LINK(S)
https://www.sciencedirect.com/science/article/abs/pii/S0195667125000576

ABSTRACT

Herrerasauridae were among the first large carnivorous dinosaurs. Although their anatomy and phylogenetic relationships have been previously studied, little is known about their paleobiology. Bone pathologies provide clues about the behaviour of ancient organisms, and this study evaluates presumed craniofacial pathologies in herrerasaurid specimens to infer their etiology and implications. Our analysis reveals that the craniofacial marks analysed are most likely pathological in nature and possibly result from intraspecific agonistic interactions, rather than post-mortem alterations. The relatively high frequency of lesions identified supports this claim. In the sample of herrerasaurids with preserved skulls analysed, nearly half presented craniofacial lesions. The bone traumas identified here are the oldest evidence of pathology in dinosaurs. Identification and analysis of pathologies in early dinosaurs can provide insights into their paleobiology and evolution of behavioural characteristics.

LINK(S)
https://link.springer.com/article/10.1007/s00114-025-01978-0

ABSTRACT

Therizinosaurs were a group of herbivorous/omnivorous theropod dinosaurs that lived in Asia and North America during the Cretaceous Period. These theropods are notable for their three-fingered hands sporting large claw-like unguals. Here, we describe a new and unusual species of the therizinosaurid Duonychus tsogtbaatari, recovered from the lower Upper Cretaceous Bayanshiree Formation of the Gobi Desert of Mongolia. This species is different from other therizinosaurs in that the hand possesses only two fingers, rather than three fingers, the typical condition for Avetheropoda, providing further insight into forelimb/hand reduction among theropods. Phylogenetically, Duonychus reveals a broader but still limited appearance of didactyly among avetheropodans. The manual ungual of Duonychus tsogtbaatari also preserves a nearly complete three-dimensional structure covering the ungual of the left manual digit I, which represents a keratinous manual claw. The strong curvature of this large claw and high ungual flexion indicate that Duonychus was likely amplectorial (grasping) and an effective grasper of vegetation, despite having only two functional fingers.

LINK(S)
https://www.cell.com/iscience/fulltext/S2589-0042(25)00401-8

https://www.cell.com/action/showPdf?pii=S2589004225004018

ABSTRACT

The phylogenetic position of the Dodo (Raphus cucullatus (Linnaeus 1758)) and Solitaire (Pezophaps solitaria (Gmelin 1789)), the large extinct pigeons of the Mascarene Islands, has been determined by analysis of molecular and morphological data. However, robust and concordant phylogenetic relationships of these taxa have not been satisfactorily determined using morphological data. Furthermore, several other large extinct terrestrial columbids have not been included in any previous analyses – either morphological or molecular – precluding robust knowledge of their relationships. A new parsimony analysis was undertaken, utilising 32 columbid taxa (including the extinct taxa Bountyphaps Worthy & Wragg 2008, Microgoura Rothschild 1904, Natunaornis Worthy 2001, Gallicolumba nui Steadman, 1992 and G. longitarsus Balouet & Olson 1989) and 140 osteological, soft-part and behavioural characters. The results of the present analysis support the findings of Janoo and Shapiro et al. in the placement of the Dodo and Solitaire close to Goura Stephens 1819, and of the latter authors’ analysis in recovering similar clades. Differences in the results may be due to the effects of homoplasy (convergence towards terrestriality and large size) and heterochrony (paedomorphism and peramorphism), which played an important part in the evolution of the Dodo and Solitaire.

LINK(S)
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2473546

ABSTRACT

Oxygen isotope compositions in tooth dentine of Spinosaurus aegyptiacus were investigated as a potential proxy for high-resolution reconstructions of palaeoenvironments in Cenomanian Cretaceous Morocco. The dentine was sampled sequentially along the tooth growth direction, and the successive δ18O values exhibited cycles which likely tracked the oxygen isotope compositions of ingested water and inferred changes in additional palaeoenvironmental properties. A conceptual model of catchment palaeohydrology was reconstructed to explain the mechanisms of isotopic variation. Seasonally variable water balance in the catchment or changes in water sources throughout the extensive deltaic environments are the most likely explanations for the seasonal profiles. With analysis of isotopic change in the conceptual model and comparison with data of modern tropical and subtropical deltas, we found similarities between palaeoclimates and modern data, and effectively identified the wet and dry seasons represented by troughs and peaks in the δ18O curves. These preliminary results demonstrated that palaeoenvironmental information at sub-seasonal resolution can be well preserved in theropod tooth dentine. The methodology developed in this study can be applied to the existing abundant reserves of theropod teeth to construct a Mesozoic palaeoclimatic database.

LINK(S)
https://www.sciencedirect.com/science/article/pii/S0031018225001932

https://www.sciencedirect.com/science/article/pii/S0031018225001932/pdfft?md5=4361974a5ec27756375de062d84df71b&pid=1-s2.0-S0031018225001932-main.pdf

ABSTRACT

We report here the discovery of subfossil subterranean bird burrows in the Tibesti, the Sahara’s highest mountains (Chad). In the Enneri Gonoa area, thousands of these burrows were found in cliffs of ignimbrite rock. Their morphology was studied in detail during a field survey in May 2024, one year after their discovery. Their distribution in the areas of western Tibesti, where the volcanic rock ignimbrite crops out in Enneris, also became clear. Several bird species construct subterranean nesting structures. We suggest burrow-digging bee-eaters, hirundines or kingfisher species are the probable producers. These species do not longer breed in the Tibesti Mountains but may have thrived here during the African Holocene Humid Period (~ 9500 to ~ 6500 cal yr BP) only to vanish from the region with progressing aridification. Our findings represent not only the first subfossil subterranean avian breeding structures but also provide evidence of the former bird populations in the Tibesti region during the more humid climate of the early to mid-Holocene.

LINK(S)
https://link.springer.com/article/10.1007/s10336-025-02268-2

ABSTRACT

Epidermal scales in sauropsids perform a wide array of biological functions, which can relate to their shape and size. Accordingly, growth-related changes in scale morphology may reflect distinct functions between juvenile and adult individuals, such as use in mating interactions. Such patterns are poorly explored in both extant reptiles and non-avian dinosaurs, limiting functional interpretations. Here, we investigate scale growth in the ornithischian ceratopsid Chasmosaurus belli and hadrosaurid Prosaurolophus maximus by comparing scale morphologies between juveniles and adults of each taxon. Scale shape is generally consistent across growth stages in both taxa, and changes in C. belli feature scale length cannot reject isometry. However, there is a greater increase in C. belli feature scale width. In practical terms, the magnitude of these size differences rejects the hypothesis that feature scale morphology played a role in mating interactions, suggesting instead that their size was largely non-adaptive. To contextualise the patterns in the sampled dinosaurs, we assessed scale growth and allometry using an ecologically diverse sample of eight extant reptile species belonging to Crocodylidae, Scincidae, Elapidae and Pythonidae. While isometry is the overall most frequent pattern of scale growth in our sample of extant reptiles, most species demonstrate positive scale allometry in at least one area of their bodies, which is likely a response to changing body proportions. Scale shapes in the studied extant species, as in both dinosaurs, are largely retained through growth. This study provides the first detailed assessment of skin growth in non-avian dinosaurs, supporting morphological stasis in the growth of most of their scales.

LINK(S)
https://onlinelibrary.wiley.com/doi/10.1111/joa.14247

https://onlinelibrary.wiley.com/doi/pdf/10.1111/joa.14247

ABSTRACT

The uppermost Cretaceous continental deposits of Transylvania (western Romania) represent one of the most iconic sources for fossil vertebrates from the Late Cretaceous European Archipelago. Among the numerous uppermost Cretaceous sites known from the Transylvanian Basin, Petreşti-Arini is one of the most important, due to its geological age and preservation of an unusual transitional near-shore environment. Current knowledge of the local vertebrate assemblage included many of the groups typically present in the Upper Cretaceous of Romania but not the hadrosauroids or titanosaurs. In this report, we describe a right humerus of a hadrosauroid discovered at Petreşti-Arini in the lower part of the Sebeş Formation. The humerus can be confidently assigned to a basal hadrosauroid based on its long and robust deltopectoral crest (45% of the humeral length) that is nevertheless shorter than in derived members of the clade (in which the deltopectoral crest is > 55% of humeral length). The specimen represents the first record of hadrosauroids from Petreşti-Arini, dated to around the latest Campanian, making it not only the stratigraphically oldest record of hadrosauroids in the Transylvanian Basin but also one of their earliest well-constrained occurrences across Haţeg Island overall. The specimen refines previous scenarios and gives a better age constraint on the arrival of hadrosauroids to Haţeg Island, documenting their introduction to this area before the end of the Campanian. Additionally, it might imply some sort of paleoenvironmental control over hadrosauroid distribution on Haţeg Island.

LINK(S)
https://www.sciencedirect.com/science/article/pii/S1871174X25000307?via%3Dihub

ABSTRACT

Prototaxites was the first giant organism to live on the terrestrial surface, reaching sizes of 8 metres in the Early Devonian. However, its taxonomic assignment has been debated for over 165 years1-7. Tentative assignments to groups of multicellular algae or land plants1,2,8-11 have been repeatedly ruled out based on anatomy and chemistry5,7,11-16 resulting in two major alternatives: Prototaxites was either a fungus5,6,17-22 or a now entirely extinct lineage 7,16,23. Recent studies have converged on a fungal affinity5-7,17-20,22. Here we test this by contrasting the anatomy and molecular composition of Prototaxites with contemporary fungi from the 407-million-year-old Rhynie chert. We report that Prototaxites taiti was the largest organism in the Rhynie ecosystem and its anatomy was fundamentally distinct from all known extant or extinct fungi. Furthermore, our molecular composition analysis indicates that cell walls of P. taiti include aliphatic, aromatic, and phenolic components most similar to fossilisation products of lignin, but no fossilisation products characteristic of chitin or chitosan, which are diagnostic of all groups of extant and extinct fungi, including those preserved in the Rhynie chert. We therefore conclude that Prototaxites was not a fungus, and instead propose it is best assigned to a now entirely extinct terrestrial lineage.

LINK(S)
https://www.biorxiv.org/content/10.1101/2025.03.14.643340v1

https://www.biorxiv.org/content/biorxiv/early/2025/03/17/2025.03.14.643340.full.pdf

ABSTRACT

Mosasaur taxa recovered from the Bearpaw Formation, Alberta, Canada, generally show exceptional preservation after rapid burial. Since the mosasaur community consisted of two dominant taxa, Mosasaurus missourensis Prognathodon overtoni, and three less prevalent taxa Tylosaurus proriger, Mosasaurus conodon, and Plioplatecarpus primaevus, some form of habitat or dietary niche partitioning is to be expected. To test this, several approaches are tried. Two-dimensional microwear analysis is used as an exploratory method to quantify tooth abrasion by food items. The good preservation of skull material reveals complete tooth rows of the upper and lower jaws for Mosasaurus missouriensis and Prognathodon overtoni, as well as isolated teeth for all taxa. The teeth are also measured for tooth bending strength to test stress regarding usage of teeth per taxon. Energy-dispersive X-ray spectroscopy (EDX) measurements show trace elements which may be a preliminary test for relative trophic level positioning. Some mosasaurs have their stomach contents preserved, providing direct and unambiguous evidence of diet. The results show a relatively clear separation of two-dimensional microwear counts between Mosasaurus, Prognathodon, and Plioplatecarpus, which, to some extent, is reflected in the EDX analyses, too. Tooth bending strength measurements show a clear difference between the latter three mosasaurs but no difference between the lower and upper jaws in Mosasaurus or Prognathodon. The combination of these three techniques maps a clear dietary niche differentiation of Bearpaw mosasaurs, which lays the groundwork for future analytical or chemical palaeoecological studies.

LINK(S)
https://www.mdpi.com/1424-2818/17/3/205

ABSTRACT

Since the discovery of the holotype of Polycotylus sopozkoi in the Southern Urals, several skeletons referable to Polycotylus were collected from the upper Santonian – lower Campanian bone bed at its type locality (Izhberda quarry, Orenburg Region, Russia). Here we describe these new specimens, which together with the holotype constitute an ontogenetic series from small juveniles with the propodial length of 27 cm to a large adult individual with the propodial length exceeding 47 cm and traces of senile pathologies of limb elements. The new specimens significantly expand the knowledge of the morphology and variation of the postcranial skeleton in Polycotylus. They also reveal additional diagnostic features of Polycotylus sopozkoi (28 cervical vertebrae, one of the highest counts for polycotylines, and strongly tapered anterodistal processes of cervical ribs), and shared traits with P. latipinnis (divergent anteromedial processes and pronounced anterior shelf of the coracoid), which were previously unnoticed in the known specimens and supplement the generic diagnosis. The observed individual variation in Polycotylus sopozkoi has implications for phylogenetic and ontogenetic studies of plesiosaurs, and for assessment of the taxonomic value of some characters in polycotylids.

LINK(S)
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2472161

ABSTRACT

A new specimen of pterosaurian mandible from the Late Jurassic (Tithonian) Portland Limestone Group of southern England is described. Morphological considerations permit assignment to Pterodactyloidea. The elongate slender mandible and numerous closely spaced alveoli suggest it is a member of the Ctenochasmatidae. A faint median ridge on the occlusal surface between two grooves, converging into a median groove anteriorly, and the lack of a distinct premaxilla suggest the specimen is part of the symphysis of the mandible. This is the first documented record of a pterodactyloid from the Portland Group of England.

LINK(S)
https://www.sciencedirect.com/science/article/pii/S0016787825000094?via%3Dihub

ABSTRACT

Mixodectids are poorly understood placental mammals from the Paleocene of western North America that have variably been considered close relatives of euarchontan mammals (primates, dermopterans, and scandentians) with hypothesized relationships to colugos, extinct plagiomenids, and/or microsyopid plesiadapiforms. Here we describe the most complete dentally associated skeleton yet recovered for a mixodectid, specifically Mixodectes pungens from the early Paleocene of the San Juan Basin, New Mexico. A partial skull with all the teeth erupted and associated axial skeleton, forelimbs, and hind limbs, with epiphyses fused, indicate that it was a mature adult. Results from cladistic analyses incorporating new data robustly support primatomorphan (Primates + Dermoptera) affinities of Mixodectidae, but relationships within Euarchonta are less clear, with Mixodectes recovered as a stem primatomorphan, stem dermopteran, or stem primate. Analyses of postcrania suggest that M. pungens was a relatively large (~ 1.3 kg), claw-climbing arborealist capable of frequent clinging on large diameter vertical supports. With teeth suggesting an omnivorous diet that included leaves, M. pungens occupied a unique ecological niche in the early Paleocene of North America that differed from contemporary, arboreal plesiadapiforms that were smaller and more frugivorous. Euarchontans were thus a more diverse radiation in the early Cenozoic than previously appreciated.

LINK(S)
https://www.nature.com/articles/s41598-025-90203-z

https://www.nature.com/articles/s41598-025-90203-z.pdf

ABSTRACT

Poposauroids (Pseudosuchia; Paracrocodylomorpha) are one of several lineages of ecologically unique archosauriform reptiles that diversified throughout the Triassic Period. Fossils of the poposauroid lineages Shuvosauridae and Poposaurus are well known from Late Triassic deposits across western Pangaea, represented by abundant materials in the southwestern United States in the Chinle Formation and the Dockum Group and rarer occurrences in the Ischigualasto Formation of Argentina. However, Late Triassic records of these lineages are currently unknown in other parts of Pangaea. Here, we extend the geographic range of Late Triassic poposauroids by reporting two incomplete femora from the Newark Supergroup of the eastern United States. Both specimens are from the Chatham Group of North Carolina, the first (NCSM 27054) from a quarry near Wadesboro in Anson County (Cumnock Formation), and the second (AMNH FR 24431) from a quarry near Gulf in Chatham County (Pekin Formation). Both possess diagnostic character states of Poposauroidea and the more complete specimen, NCSM 27054, lacks character states of shuvosaurids. We conclude that these femora represent poposauroids similar (if not identical) to Poposaurus gracilis among known taxa in the clade. Our findings expand the Late Triassic range of Poposauroidea into the central/eastern Pangaean Atlantic rift zone. NCSM 27054 and AMNH FR 24431 may represent some of the oldest Late Triassic poposauroid fossils and help fill a gap in the stratigraphic range of Poposauroidea.

LINK(S)
https://bioone.org/journals/Palaeodiversity/volume-18/issue-1/pale.v18.a1/First-occurrences-of-Poposauroidea-Archosauria--Paracrocodylomorpha-from-North-Carolina/10.18476/pale.v18.a1.full

ABSTRACT

The diversity of the fauna of the late Permian K6 Formation of the Metangula graben of northern Mozambique is coming to light thanks to recent discoveries made by the PaleoMoz Project. Here we describe the first diagnosable gorgonopsian remains from the K6a2 Member of the Metangula graben, specimen PPM2018-7Z. This specimen is a large-bodied gorgonopsian, and shows several features similar to the latest late Permian species Inostrancevia africana. PPM2018-7Z shares various autapomorphies with Inostrancevia africana including the extremely narrowed jugal ventral to the orbit, the pineal foramen being positioned far posteriorly, the anteroposteriorly expanded ventral portion of postorbital bar, the orbit being larger than the temporal fenestra and by having prefrontal rugosities and foramina. The tooth morphology of Inostrancevia africana is here accessed based on the left canine of PPM2018-7Z, which is characterised by low labial ridges, a short mesial carina and thick basal denticles of the mesial carina. PPM2018-7Z is phylogenetically recovered close to Inostrancevia africana within the “Russian clade gorgonopsians”. PPM2018-7Z and Inostrancevia africana do not possess an interorbital ridge that is present in some rubidgeines such as Clelandina and Dinogorgon. Furthermore, PPM2018-7Z and inostranceviines retain a postfrontal with a posterior process that extends posteriorly invading the parietal border, unlike in rubidgeines in which the posterior process of the postfrontal is absent. The presence of Inostrancevia africana in the K6a2 Member of the Metangula graben helps correlating this member to the Daptocephalus Assemblage Zone in the Karoo Basin of South Africa.

LINK(S)
https://sjpp.springeropen.com/articles/10.1186/s13358-025-00348-7

https://sjpp.springeropen.com/counter/pdf/10.1186/s13358-025-00348-7.pdf

ABSTRACT

The fossil record of dinosaurs in Scotland mostly comprises isolated highly fragmentary bones from the Great Estuarine Group in the Inner Hebrides (Bajocian–Bathonian). Here we report the first definite dinosaur body fossil ever found in Scotland (historically), having been discovered in 1973, but not collected until 45 years later. It is the first and most complete partial dinosaur skeleton currently known from Scotland. NMS G.2023.19.1 was recovered from a challenging foreshore location in the Isle of Skye, and transported to harbour in a semi-rigid inflatable boat towed by a motor boat. After manual preparation, micro-CT scanning was carried out, but this did not aid in identification. Among many unidentifiable elements, a neural arch, two ribs and part of the ilium are described herein, and their features indicate that this was a cerapodan or ornithopod dinosaur. Histological thin sections of one of the ribs support this identification, indicating an individual at least eight years of age, growing slowly at the time of death. If ornithopodan, as our data suggest, it could represent the world's oldest body fossil of this clade.

LINK(S)
https://www.cambridge.org/core/journals/earth-and-environmental-science-transactions-of-royal-society-of-edinburgh/article/first-and-most-complete-dinosaur-skeleton-from-the-middle-jurassic-of-scotland/A738B17F5A78106E6B8C75D211153333

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/A738B17F5A78106E6B8C75D211153333/S1755691024000148a.pdf/div-class-title-the-first-and-most-complete-dinosaur-skeleton-from-the-middle-jurassic-of-scotland-div.pdf

ABSTRACT

Here we describe a new fossil invertebrate and vertebrate assemblage from a previously unknown locality of the Anacleto Formation (Campanian, Upper Cretaceous), near General Roca city, Río Negro Province, Argentina. The specimens were found in a single fossiliferous layer, which yielded bivalves and gastropods, including the first fossil record of the terrestrial clade Megalomastomatidae and the first undoubted record for the terrestrial subulinid Leptinaria. Vertebrates are represented by fishes (lepisosteids, percomorphs, and the dipnoan Metaceratodus kaopen), chelid turtles, a single crocodyliform scute, an indeterminate pterosaur, an incomplete meridiolestidan mammalian jaw, and abelisaurid and rinconsaurian titanosaur dinosaurs. The latter is represented by several individuals of a small and gracile-limbed form. The phylogenetic analysis recovers a monophyletic Rinconsauria including the new taxon, plus Rinconsaurus, Pitekunsaurus, Overosaurus, and Muyelensaurus. The new titanosaur indicates that rinconsaurians were characterized by a body shape that was different from other titanosaurs, with brachiosaur-like posture, gracile limbs, and protonic tail. The faunistic assemblage is characterized by the abundance, but low diversity, of chelid turtles and a very low number of crocodyliforms. This taxonomic composition is reminiscent of other faunal assemblages of the latest Cretaceous of northern Patagonia, but differs markedly from Campanian assemblages known from North America and Europe.

LINK(S)
[OFFICIAL PUBLICATION LINK UNAVAILABLE]

https://novataxa.blogspot.com/2025/03/chadititan.html

ABSTRACT

The Wukongopteridae is an important pterosaur clade from the Yanliao Biota, combining features of basal and derived pterosaurs. So far, the Wukongopteridae consists of five species divided into three genera: Wukongopterus lii, Darwinopterus modularis, Darwinopterus linglongtaensis, Darwinopterus robustodens, and Kunpengopterus sinensis. Here we report a new species, Darwinopterus camposi sp. nov., based on an almost complete skeleton (IVPP V 17957). The new species is referred to Darwinopterus due to the presence of an elongated posterior region of the skull and the bony premaxillary crest that starts about the anterior margin of the nasoantorbital fenestra. It differs from all other wukongopterids by having the dorsal margin of the premaxillary crest straight, without an extensive dorsal projection and presenting a smooth lateral surface. Furthermore, D. camposi sp. nov. has eighteen and fourteen teeth on each side of the upper and lower jaws, respectively, and the fourth phalanx of the wing finger shorter than the first. IVPP V 17957 shows some fused postcranial bones, like the extensor tendon process to the first wing finger phalanx, but also has unfused premaxilla and frontal, which provides further information about wukongopterid ontogeny.

LINK(S)

https://www.scielo.br/j/aabc/a/fbbdmLJJcwNKwxdPrtHDpVc/?lang=en

https://www.scielo.br/j/aabc/a/fbbdmLJJcwNKwxdPrtHDpVc/?lang=en&format=pdf