A new ornithomimid dinosaur from the Upper Cretaceous Packard Shale formation (Cabullona Group) Sonora,México

New ornithomimid material discovered from the Upper Cretaceous Packard Shale Formation, (Cabullona Group) of Sonora, Mexico is described. The material includes a partial skeleton, which is assigned to a new genus and species, Tototlmimus packardensis. This new taxon differs from other ornithomimids in having five unique characteristics that separate it from other Northamerican ornithomimids: (1) a distinctively articulation between metatarsals, where the distal ends of metatarsals II and IV contact directly with the distal facet of metatarsal III; (2) a metatarsal III with a weakly ginglymoid distal articular face; (3) the medial and lateral sides of metatarsal III are shaped into the form of metatarsals II and IV, so all distal ends fit together when they articulate; (4) an asymmetrical and narrow pedal ungual with shallow grooves in both medial and lateral sides; and finally, (5) the presence of a deep sulcus on the ventromedial edge, close to the articular end. Phylogenetic analysis suggests that Tototlmimus packardensis corresponds to a derived ornithomimid included in the Northamerican clade, forming a monophyly with Ornithomimus. Tototlmimus packardensis is the first definitive ornithomimid described for Mexico, and represents one of the southernmost occurrences in the Western Interior Basin of North America.     

Geochemistry of Lower Cretaceous limestones of the Alisitos Formation,Baja California,México: Implications for REE source and paleo-redox conditions

Measurement of the major and trace elements were carried out on the Lower Cretaceous limestones interbedded in the volcano-sedimentary Alisitos Formation, northwestern México to understand the source of rare earth elements (REEs) and paleo-redox conditions. The five limestone beds (from the base up, Unit 5 to Unit 9) of the Alisitos Formation show large variations in SiO₂ content (0.9–27.9%). A low concentration of CaO is observed in Unit 6 and Unit 8, and high content of CaO is observed in Unit 5, Unit 7 and Unit 9. The limestones are depleted in many trace elements with respect to Post-Archaean Australian Shale (PAAS), whereas Sr shows slight enrichment when compared to PAAS. The concentrations of ΣREE are higher in Unit 6 and Unit 8 (37.4 ± 7.5; 46.6 ± 19.4; respectively) than Unit5, Unit7, and Unit 9 (9.1 ± 3.2; 11.3 ± 9.4; 4.2 ± 2.5; respectively). The limestones of the Alisitos Formation show a non-seawater-like REE + Y pattern with positive Eu anomalies relative to PAAS (0.95–2.47). Variations in ΣREE, Al₂O₃, Zr, Sc, REE + Y patterns, and Y/Ho ratios are influenced mainly by the amount of terrigenous materials. The variations in the Eu/Eu*, La/Sc and La/Co suggest that the terrigenous materials included in the lower four limestone beds (from Unit 5, Unit 6, Unit 7 and Unit 8) were likely contributed by intermediate to felsic rocks whereas terrigenous materials from Unit 9 were derived from mafic to intermediate source rocks. The slightly negative to slightly positive Ce anomalies in the studied limestones resulted from variations in the bottom water oxygenation. This was also corroborated by V/Cr and Ni/Co ratios suggesting that the depositional environments experienced large fluctuations in oxygenation conditions ranging from oxic to anoxic conditions during the deposition of limestones of the Alisitos Formation.     

A New Lizard (Lepidosauria: Squamata) from the Upper Cretaceous of Henan, China

Funiusaurus luanchuanensis gen. et sp. nov. was described on the basis of an incomplete skull from the Upper Cretaceous Qiupa Formation of the Tantou Basin in Luanehuan County, Henan Province. It is the second representative of lizards known from Luanchuan and adds a new member to the Luanchuan Fauna. F. luanchuanensis is a small-sized lizard and systematically assigned to the Polyglyphanodontidae of the Teiioidea because of the presence of a caniniform tooth and an elongate posterior process of the postorbital. It is distinctive in that the heterodont dentition bears 19 teeth in both the upper and lower jaws, the 3^rd maxillary tooth is large and caniniform, the post-caniniform teeth in maxilla and those posterior to the 3^rd dentary tooth are chisel-like in lateral view, the prefrontal possesses a fossa on its lateral surface, the postorbital with an extremely elongate posterior process and the well-developed retroarticular process has a deep fossa on its dorsal surface. In phylogeny, our analysis suggests a close relationship of Funiusaurus to the large-sized Tianyusaurus from the same basin within the Tuberocephalosaurinae. The discovery of Funiusaurus is significant in confirming the status of the Tuberocephalosaurinae, which includes a group of the Asian members of the Polyglyphanodontidae only.     

The oldest theropods from the Neuquén Basin: Predatory dinosaur diversity from the Bajada Colorada Formation (Lower Cretaceous: Berriasian–Valanginian), Neuquén,Argentina

Here, we describe new theropod materials (several isolated teeth, an axis, two caudal centra and a proximal left tibia) from the type locality of the Bajada Colorada Formation (Lower Cretaceous, Berriasian–Valanginian). Although fragmentary, the recovered material shows a diverse association of meat-eating dinosaurs for this poorly understood period of time. Three techniques were used to assess the phylogenetic position of the isolated teeth: multivariate (PCA), discriminant and phylogenetic analyses. The morphotypes 1, 2 and 3 (small non-recurved isolated crowns) were regarded as Theropoda indet., as our analyses failed to support a more precise classification. Two large almost complete ziphodont crowns, considered morphotype 4, were identified as belonging to megalosaurid tetanurans by phylogenetic, discriminant and multivariate analyses, thus likely representing the first record of this ancient family in South America, and the youngest worldwide. We refer the axis to a small abelisauroid ceratosaurian based on the following suite of characters; long and pointed epipophyses, a pneumatic foramen in the centrum, the invaginated spinopostzygapophyseal lamina, and the anteroposteriorly long, dorsally convex, and dorsally/posteriorly unexpanded neural spine. The caudal centra can be referred to a theropod, and tentatively to Abelisauroidea, suggesting that they may belong to the same taxon than that represented by the axis. The tibia lacks the incisura tibialis, presents a low, sharp and proximally positioned fibular crest, and has a deep lateral fossa, which is limited dorsally by a coarse, rounded in section and anteriorly directed crest. This combination of features allows to refer it to a large abelisaurid. The Bajada Colorada dinosaur record includes so far a small abelisauroid, a large abelisaurid, a probably medium to large megalosaurid tetanuran, diplodocid and dicraeosaurid sauropods. It shows some similarities with Middle and Upper Jurassic units in central Patagonia, Africa and Portugal, suggesting that no significant dinosaur faunal turnover took place through the Jurassic-Cretaceous event in the southern part of South America.     

Pygostyle-like Structure from Beipiaosaurus (Theropoda, Therizinosauroidea) from the Lower Cretaceous Yixian Formation of Liaoning, China

Pygostyle was previously considered as a unique structure of ornithothoracine birds, used to maneuver tail feathers. A similar structure from an oviraptorosaurian dinosaur was considered functionally associated with the rectrices as in birds. We report a pygostyle-like structure from a therizinosauroid dinosaur. The presence of filamentous integuments, but absence of rectrices, on the tail of this therizinosauroid, combined with other lines of evidence, suggests that the initial function of the pygostyle was not related to the rectrices.     

The First Stegosaur （Dinosauria, Ornithischia） from the Upper Jurassic Shishugou Formation of Xinjiang, China

A new stegosaur species, Jiangjunosaurus junggarensis, gen. et sp. nov., is erected based on a specimen collected from the Upper Jurassic upper section of the Shishugou Formation in the Junggar Basin, Xinjiang, China. It represents the first stegosaur from the Jurassic of Xinjiang and increases the diversity of the dinosaur fauna in the Shishugou Formation. The new genus is characterized by symmetrical and proportionally wide tooth crowns, a sub-rectangular axial neural spine seen in lateral view, and large openings on the lateral surfaces of the cervical centra. A preliminary character analysis suggests that this new taxon is more derived than the Middle Jurassic stegosaur Huayangosaurus but more primitive than most other known stegosaur species.     

First Findings of Trace Fossils from the Tavda Formation (Middle–Upper Eocene) in the Southwestern Part of Western Siberia

Trace fossils have been found for the first time in the Tavda Formation shallow marine facies, and their possible indicative value has been evaluated. The results of the ichnofossil study suggest that the Tavda Basin had low hydrodynamics. Under these conditions boreal and thetic waters of different characteristics were blended, which caused periodic formation of thermohaline water stratification and anoxic conditions in bottom water levels. Such periodic events conditioned mass extinctions of a wide variety of the Eocene marine biota thus preconditioning the development of freshwater fauna in the upper levels of the Tavda Sea along with saturation of the index beds of the Tavda Formation with micro- and macrofossils.     

Large-Sized Ankylosaur (Dinosauria) from the Lower Cretaceous Jiufotang Formation of Western Liaoning, China

Two incomplete bones referred to ankylosaur scapulocoracoid and humerus are described, which were discovered from the Early Cretaceous Jiufotang Formation of Dachengzi Town, Kazuo County, Liaoning Province. Ankylosaur dinosaurs have ever been found in the Lower Cretaceous Yixian, Fuxin and Sunjiawan Formations of western Liaoning. The occurrence of ankylosaurs within Jiufotang Formation improves our knowledge on the ankylosaur stratigraphic distribution. Based on the length of scapulocoracoid, the new dinosaur is estimated to exceed 6.0 meters long, representing the largest ankylosaur in western Liaoning.     

Cretornis hlavaci Frič, 1881 from the Upper Cretaceous of Czech Republic (Pterosauria,Azhdarchoidea)

Cretornis hlavaci Frič, 1881 from the Upper Cretaceous (Turonian) of Czech Republic is a valid taxon referred to Azhdarchoidea based on having a saddle-shaped humeral head, pneumatic foramen on proximal humerus present on anterior side and absent on posterior side, elongate deltopectoral crest with subparallel proximal and distal margins, pneumatic foramen absent on distal side of humerus, metacarpals I–III not articulated with carpus and displaced on anterodorsal side of wing metacarpal, and wing metacarpal much longer than humerus. Absence of a pneumatic foramen on posterior side of proximal humerus suggests attribution of Cretornis hlavaci to Neoazhdarchia. It has a unique construction of the distal ulna with a dorsal articulation surface placed distinctly proximal to the tuberculum shared only with the non-azhdarchid azhdarchoid Montanazhdarcho minor from the Campanian of North America. Cretornis hlavaci differs from the latter taxon by the structure of its humerus and distinctly longer wing metacarpal. It is more derived than “Tapejaridae” but shares with Azhdarchidae the deltopectoral crest of the humerus displaced distally from humeral head. Cretornis cannot be assigned to Azhdarchidae because of the oval cross section of the second wing phalanx. A unique rhombic outline of the distal humerus of Cretornis hlavaci is a possible autapomorphy for this taxon. Its wing span estimated as 1.5–1.6 m. This is the first taxon of non-azhdarchid pterosaurs known from the Upper Cretaceous of the Eastern Hemisphere.     

The bivalve Anopaea (Inoceramidae) from the Upper Jurassic–lowermost Cretaceous of Mexico

In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian–lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic–earliest Cretaceous, between Mexico and the Antarctic Realm.     

New Material of Zhenyuanopterus (Pterosauria) from the Early Cretaceous Yixian Formation of Western Liaoning

A new partial specimen of Zhenyuanopterus from the Lower Cretaceous Yixian Formation of Beipiao city, Liaoning Province is described. This specimen is slightly larger than half the size of the holotype. Although it is not complete, it provides new information on Zhenyuanopterus both in taxonomy and ontogeny： the total number of the caudal vertebrae is 15; the forelimb is more robust than the hindlimb; the growth rate of the humerus and femur is constant, and their ratio is about 1. Compared with the holotype, the scapula and coracoid grow faster than the humerus and the femur. The scapula and coracoid may slow their growth rate after a certain ontogenetic stage. The pectoral girdle, robust forelimb and weak hindlimb of the new material（XHPM1088） together with data from the holotype of Zhenyuanopterus indicate that this taxon spent less time on land than in the sky or other ecological niches such as forests and cliffs.     

Mössbauer characteristics,mineralogy and isotopic age (Rb-Sr,K-Ar) of Upper Riphean glauconites from the UK Formation,the southern Urals

Comprehensive mineralogical analysis, Mössbauer spectroscopy and isotopic-geochronological study have been carried out for globular phyllosilicates (GPS) of glauconite group from the Uk Formation, the second one below the top of the Upper Riphean stratotype in the southern Urals. Glauconites have been sampled in the Kurtaza and Kulmas sections remote from each other in the Alatau anticlinorium that corresponds to western facies zone of the Bashkirian meganticlinorium. As is shown, size and density monomineral fractions of globules are represented by Al-glauconite according to established structural formula. The isotopic (Rb-Sr and K-Ar) dating of glauconites from the Uk Formation is performed for the first time along with computer simulation of cation arrangements in their crystal lattice and comparison of the results obtained with data of Mössbauer spectroscopy. It has been assumed by simulation that origin and transformation of the Rb-Sr and K-Ar systems in glauconite are concurrent to stages in structural evolution of this mineral, which have been controlled by geological and geochemical events in the history of sedimentary successions. The approach has been aimed at recognition of stratigraphically meaningful isotopic dates corresponding to the glauconite formation at the stage of the early diagenesis close to sedimentation time and the “rejuvenated” dates characterizing ages of subsequent geological events. The comparison of simulated cation arrangements with data of Mössbauer spectroscopy shows that the Rb-Sr (663 ± 9 Ma) and K-Ar (669 ± 16 Ma) dates established for glauconites correspond to the time of early diagenesis in their host sediments, being suitable for age assessment of the Uk Formation. The dates obtained are of interregional and wider significance, as they must be taken into consideration when constructing the general curve of Sr isotope variations in the Late Riphean oceans.     

A new “slime star” (Echinodermata,Asteroidea, Velatida) from the Upper Cretaceous Chalk of the United Kingdom

New material of pterasterid asteroids from the UK chalk is described on the basis of ossicles recovered from washed residues. A new species, Pteraster lyddenensis sp. nov., is erected for oral and adambulacral ossicles and a primary radial ossicle from the Cenomanian Grey Chalk Subgroup of Dover (Kent), and the first UK record of Pteraster kutscheri Gale, 2022 is described from the upper Campanian Chalk of Norwich (Norfolk); both taxa belong to extant groups of Pteraster. Pteraster lyddenensis sp. nov. is the oldest known representative of the genus. The benthic invertebrate fauna of the Cretaceous chalk facies includes a number of extant genera which at the present day dwell in the deep sea. However, their presence was probably due to the low-productivity oceanic palaeoenvironment of the Chalk Sea, simulating deep-ocean conditions, rather than its depth.     

Sporopollen Assemblages from the Cretaceous Yimin Formation of the Hailar Basin, Inner Mongolia, China

Three sporopollen assemblages are recognized for the first time from the Cretaceous Yimin Formation in the Hailar Basin of eastern Inner Mongolia. They are （in ascending order）： the lmpardecispora-Aequitriradites- Clawttipollenites assemblage; the Triporoletes-Pilosisporites-Asteropollis assemblage; and the Appendicisporites- Asteropollis-Tricolpites assemblage, distributed in Members 1, 2 and 3 of the Yimin Formation respectively. Recognition of this biostratigraphic sequence is very important for the division and correlation of the Yimin Formation in the basin. Meanwhile, the age of the Yimin Formation is considered to be Barremian to Early Albian based on the palynological data.     

Effect of climatic oscillations on flood occurrence on Papaloapan River,México,during the 1550–2000 period

This study presents a chronology of historical and measured flood events in the Papaloapan River basin of Mexico during 450 years. Twenty-eight historical floods were recorded during the period 1550–1948 on this river and one flood event (1969) in the instrumental era (1949–2000), of which 14 were extraordinary floods and only 15 were catastrophic ones. There were several flood-rich decades during 1860–1870, 1880–1890, 1920–1930 and 1940–1950. Wavelet analysis found a significant flooding periodicity of 58 years. The wavelet coherence analysis found that flooding had an in-phase relationship with the Atlantic Multidecadal Oscillation and also with the Pacific Decadal Oscillation. Logistic regression corroborated that there exists a positive relationship between floods events and these two natural climatic oscillations. The logistic regression model predicted correctly 92% of flood events.     

First occurrence of the Salvador Formation in the Jatobá Basin (Pernambuco,Northeast Brazil): Facies characterization and depositional systems

Fan deltas, constituting proximal depositional systems adjacent to boundary faults, are common features associated with rift basins. The Cretaceous fan delta systems of the Salvador Formation, deposited during the rift phase of the Recôncavo-Tucano-Jatobá Basin, were first reported in the Recôncavo Basin and later discovered in the Tucano Basin. Because of the absence of any outcrops in the Jatobá Basin until now, these alluvial fans were interpreted solely through seismic analysis. We report the first revealed outcrops of the Salvador Formation in that basin and characterize their depositional systems as interlayered with the lacustrine Candeias Formation. Based on facies and architecture, the alluvial system can be subdivided into three associations: (1) proximal fan delta, characterized by meter-scale conglomerate bodies with a predominance of boulders and cobbles with thin sandstone layers; (2) distal fan delta, characterized by sheet-like pebble conglomerate and sandstone layers with flame and load structures; and (3) lacustrine, further subdivided into shallow lake facies reddish shales and mudstones with oolitic limestones and deep lake facies grey to green shales with pyrite. Paleocurrent measurements for the proximal fan association show paleoflow direction varying from SW to SE, which is expected for the rift phase alluvial system. The Recôncavo-Tucano-Jatobá rift system has two conglomeratic units, namely the Salvador and Marizal Formations, the former a syn-rift and the latter a post-rift unit. The absence of sedimentary clasts in the conglomerates, very low maturity, the presence of giant clasts, and a visible relationship between boundary faults in the outcrop, define the syn-rift Salvador Formation characteristics. Based on the facies and paleocurrent analyses, the Salvador Formation deposits in Jatobá Basin were interpreted as a deposition of a debris flow-dominated fan delta, indicating the lacustrine setting represented by the Candeias Formation.     

Multicusped crocodyliform teeth from the Upper Cretaceous (São José do Rio Preto Formation,Bauru Group) of São Paulo,Brazil

The six peculiar multicusped teeth described here were collected from sediments of the Upper Cretaceous of São José do Rio Preto Formation, near Ibirá (northeastern São Paulo, Brazil). Their bulbous crowns are slightly labio-lingual compressed, and bear a main plus two accessory cusps, which conceal a well developed cingulum. Wear facets are seen on the main and distal accessory cusps. Comparison to the known Crocodyliformes with multicusped teeth show that the new material is not referable to “protosuchians” or eusuchians, nor related to two unnamed forms from Morocco and “notosuchians” such as Uruguaysuchus, Chiamaerasuchus, and Simosuchus. On the other hand, possible affinities with Candidodon and Malawisuchus were maintained based on shared traits. This includes teeth with the main cusp and some accessory cusps arranged in more than one axis, a previously defined unambiguous apomorphy of the putative clade composed of Candidodon plus Malawisuchus. The term Candidodontidae can be applied to this group, and defined as all taxa closer to Candidodon itapecuruensis than to Notosuchus terrestris, Uruguaysuchus aznarezi, Comahuesuchus brachybuccalis, Sphagesaurus huenei, Baurusuchus pachecoi, and Crocodylus niloticus.     

First representative of the genus Helius Lepeletier and Serville, 1828 (Diptera,Limoniidae) from the Lower Cretaceous Álava amber (Spain)

Helius alavensis sp. nov., one of the oldest representative of the genus Helius Lepeletier and Serville, 1828 (Diptera: Limoniidae), is described from the Álava amber (Lower Cretaceous, upper Albian), northern Spain. This is the first representative of the subfamily Limoniinae and of the genus Helius described from this fossil resin.     

New Material of Feilongus (Reptilia: Pterosauria) from the Lower Cretaceous Jiufotang Formation of Western Liaoning

Based on a new nearly naturally preserved skull and four cervical vertebrae of the pterosaur Feilongus sp. from the lower Cretaceous Jiufotang Formation of Beipiao, western Liaoning province, northeastern China, the diagnosis of Feilongus is amended. The revised diagnosis notes long, curved, needle-shaped teeth that are confined to the jaw far anterior to the nasoantorbital fenestra; posterior teeth that are slightly smaller than the anterior teeth; cervical vertebrae elongated with a ratio of length to width greater than 5; tooth number of about 78; and two cranial sagittal crests.