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In this paper we describe a new lizard from the early Eocene of the Cos locality in the Quercy region (near the Caylus village, Southwest France). The age of the Cos deposit has been proposed as the MP 10-11 interval, close to the transition of the late Ypresian to early Lutetian. The fossil material includes a nearly complete right maxilla and a large section of the right dentary, both elements attributed to Pan-Gekkota. These specimens are morphologically different from crown gekkotans, therefore, we describe them as a new species. Some aspects of the maxilla are very atypical regarding geckos (e.g., the shape of the facial process). The posterior margin of the facial process slopes down gradually dorsoventrally towards the jugal facet, reaching the posterior end of the maxilla, in contrast to gekkotans, where the facial process ends anterior to the posterior end of the maxilla. A similar maxilla is present in the Late Jurassic-Early Cretaceous pan-gekkotan genus Eichstaettisaurus. This suggests that the new fossil taxon represents either a lineage that persisted from the Mesozoic to the early Eocene in Europe, or perhaps a morphology otherwise unrepresented in crown gekkotans. We allocate this taxon provisionally to Pan-Gekkota, and contribute to increase the diversity of this clade in Western Europe during the Paleogene, which now includes the stratigraphically similarly aged Laonogekko lefevrei from France (MP 10), and older Dollogekko from Belgium (MP 7). [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed survey on the rodent fauna from the site of Barranco de los Conejos (Guadix-Baza Basin, southern Spain). Its rodent fauna is composed of three arvicolines (Orcemys giberti, Manchenomys oswaldoreigi, and Tibericola vandermeuleni) and two murids (Castillomys rivas and Apodemus atavus). The three arvicoline species present ever-growing molars. Orcemys giberti and Manchenomys oswaldoreigi can be considered as descendants of local Mimomys species (Mimomys medasensis and Mimomys tornensis, respectively), while Tibericola vandermeuleni is an eastern inmigrant. Loosening of roots in Orcemys giberti and Manchenomys oswaldoreigi is explained as an adaptation to a fossorial way of life, in relation to the Early Pleistocene glacial-interglacial dynamics, which led to cooler and drier conditions. This environmental change would also explain the dispersal of Tibericola from the eastern Mediterranean. [ABSTRACT FROM AUTHOR]

Sarcopterygian remains are relatively common in the so-called "Placoderm Sandstone" (storm-origin bone-bearing breccia) from the Emsian (Lower Devonian) of Podlazie in the Holy Cross Mountains (Poland). Previous studies have mainly referenced the presence of dipnomorphs, chiefly portrayed by porolepiforms and occurrences of dipnoans. Porolepiforms are represented by Porolepis ex gr. P. posnaniensis, based on scales, skull and shoulder-girdle elements, whereas other remains have been attributed to Heimenia sp. The aim of this paper is to present the most detailed description of the porolepiforms and other sarcopterygian fishes from the "Placoderm Sandstone" from the Holy Cross Mountains since 1960s. Here, I present a new study based on more than 200 specimens, using both microtomographic (CT-scan) and silicon casts analyses, which indicate that not two, but at least three different taxa of sarcopterygians occur in the "Placoderm Sandstone" from Podlazie. The new data presented herein depict a more diversified assemblage of sarcopterygians in the marginal-marine environment of the Lower Devonian of the Holy Cross Mountains than previously thought, and shed a new light on sarcopterygian diversity along the shores of the Old-Red continent. [ABSTRACT FROM AUTHOR]

This article is a memorial tribute to Aleksander Nowiński, a prominent paleontologist who passed away in 2023. Nowiński was born in 1935 in Rypin, Poland, and developed a fascination with optics and machines from a young age. He went on to study geology at Warsaw University and became a member of Polish-Mongolian Paleontological expeditions, where he described a new species of sauropod dinosaur. Later in his career, Nowiński focused on tabulate corals, publishing several monographs and papers on their taxonomy and growth patterns. He was known for his meticulous and precise work, as well as his love for classical music. Nowiński retired in 2003 and lived in his hometown until his death in 2023. [Extracted from the article]

Among the great diversity of Oligocene mammals from Quebrada Fiera (Mendoza Province, Argentina), three families of typotherian notoungulates are very abundant. Since the first paper on archaeohyracids in 2010 until the last fieldwork in 2016, numerous unpublished remains were added to the collection. The study of all these remains, together with some revised materials, allows us to provide new anatomical data and some taxonomic decisions on these groups. Within Hegetotheriidae, we present one of the most complete skulls of "Prohegetotherium schiaffinoi" known to date, providing descriptions of certain previously unknown features of the caudal cranium; MCNAM-PV 3984 is discarded as belonging to Hegetotheriopsis sulcatus, as recently suggested, and is considered as Hegetotheriinae indet., like other isolated large specimens and some teeth previously determined as Prohegetotherium sp.; and several well-preserved specimens add to the sample of the pachyrukhine Prosotherium garzoni, including a partial maxilla with erupting P2. Concerning "Archaeohyracidae", Archaeohyrax suniensis is now better represented, recording several ontogenetic stages previously observed in the Bolivian sample of this species. Finally, within Interatheriidae, most new dental material belongs to Argyrohyrax proavus, but an isolated upper molar suggests the presence of a different Interatheriinae at Quebrada Fiera, more similar to the Bolivian Brucemacfaddenia boliviensis than to other Deseadan (late Oligocene) taxa. [ABSTRACT FROM AUTHOR]

Heliolitines are a major tabulate coral group, which experienced their early diversification in the Katian (Late Ordovician). Fossils of this group are well represented in the Kuruktag area of northeastern Tarim Basin, Northwest China, but detailed studies of corals from this area are still lacking. Here, we systematically describe early Katian heliolitines of the Tarim Block based on new material from the lower Katian Yuanbaoshan Formation of southern Kuruktag, which include the plasmoporellids Plasmoporella xinjiangensis and Plasmoporella grandis, the sibiriolitids Mongoliolites obliterans and Mongoliolites sp., the protoheliolitid Wormsipora sp., the proporid Acdalopora sokolovi, the pseudoplasmoporid Navoites irregularis, and the heliolitid Apekinella zeravshanica. A faunal comparison indicates that the biogeographic connections of Tarim Block are closest to Chu-Ili and South Tienshan, but relatively weaker with Qilian and North China. [ABSTRACT FROM AUTHOR]

Re-interpretation of the holotype and only known speci-men of Afrophoca libyca reveals that it represents a me-dium -sized anthracothere, Afromeryx zelteni, a species that is common in the basal Middle Miocene deposits at Gebel Zelten, Libya. This re-identification affects several recently published papers that have accepted it as the earliest known phocid, with repercussions on biogeographic scenarios and phylogeny reconstructions.

Clubtail dragonfly Lindenia heeri sp. nov., is described and figured as the first fossil representative of the extant lindeniine genus Lindenia, based on a finely preserved forewing from the mid-Miocene lacustrine maar of Öhningen, Germany. The new species differs from the type and only species of Lindenia tetraphylla in the dark brown pterostigma covering ten cells vs. only five. Otherwise its forewing venation is identical to that of the modern species. The paleoclimatic data fit well with the climatic preferences of extant Lindenia tetraphylla, consistent with the generally warmer climate of that region during that period of time, allowing for more Mediterranean or even subtropical elements of the flora and fauna to persist. [ABSTRACT FROM AUTHOR]

The pterosaur fossil record of Argentina is increasing in recent times, both in the number of localities and their temporal range. The new materials are found in levels that span from the Late Triassic to the Late Cretaceous in age. In this contribution we describe twenty isolated pterosaur teeth from the Cerro de los Leones locality (Picún Leufú, Neuquén Province), where the Lohan Cura Formation (Albian) widely crops out. A new, detailed analysis of these remains allowed us to detect a set of morphological features, such as the enamel texture, cross-section shape, crown curvature, and absence of sharp carinae, which suggests close affinities with Ornithocheiriformes. Moreover, with the large number of tooth specimens, a discrimination of three morphotypes based on the crown curvature, the basal cross-section shape, and the presence of carinae was carried out. We performed extensive morphological comparisons between different members of Ornithocheiriformes with the aim to test the hypothesis that the presence of these different morphotypes reflects distinct anatomical positions of the teeth in the jaws . Thus, considering the heterodont dentition of ornithocheiriforms, the tooth morphological classification proposed here represents a new methodology, not only to identify isolated ornithocheiriform teeth, but also to assign them to the rostral, medial, or the posterior portion of the tooth row. Finally, the evidence of ornithocheiriform pterosaurs in Cerro de los Leones has paleobiogeographical implications, allowing us to correlate it with other Albian faunas from South America, expanding our knowledge of the distribution of Early Cretaceous pterosaurs across southwestern Gondwana. [ABSTRACT FROM AUTHOR]

A new species of bubble-headed trilobite, Staurocephalus oliveae sp. nov., is described from 250 specimens collected from a recently discovered locality in the Sholeshook Limestone Formation (upper Katian, Upper Ordovician; Ashgill, Cautleyan Zone 1 equivalent) in the village of Llanddowror, Carmarthenshire. Although no fully articulated specimens were found, the material is the most abundant and well-preserved of any Ordovician Staurocephalus species known from Britain and Ireland, and enables the complicated 3D structure of its cephalon to be reconstructed. Staurocephalus oliveae sp. nov. is the earliest representative of the genus recorded in Avalonia, following its presumed migration into the area from Laurentia or Baltica. Recognition of this Cautleyan species resurrects the potential usefulness of the long established, widely distributed, Staurocephalus clavifrons as a latest Katian (= Rawtheyan) indicator. [ABSTRACT FROM AUTHOR]

Serially homologous elements pose an identification problem in fragmentary records, particularly those of vertebrate fossils. Examples include individual vertebrae in the vertebral column and teeth in a tooth row. Until an isolated element can be accurately attributed to a specific position within its series, multiple lines of ecological and evolutionary research cannot be conducted. However, varying levels of differentiability between loci, and varying patterns of differentiation across clades, make it impossible to develop a single set of diagnostic traits for any particular set of serial homologues, particularly mammalian molars. Here, we test the utility of a set of classification criteria for distinguishing molar tooth positions of hyraxes (Mammalia, Afrotheria, Hyracoidea), which have been considered indistinguishable in previous taxonomic studies. As part of the test we evaluate the degree to which between-locus variation is conservative in this taxon, which would strengthen the predictive power of proposed traits even in cases where species identity is unknown. Suitable tests for hypotheses of conservatism in categorical traits did not exist, to our knowledge, and we therefore explored the behavior of a previously developed metrics, Borges et al.’s δ, to assess conservatism in contrast to phylogenetic signal produced by Brownian motion. This metric shows some promise but the nature of resulting distributions makes tests difficult to interpret, indicating a line of potential future methods improvement. We used a linear morphometric characterization of shape to validate the candidate traits. In the case of hyracoid molars, relatively simple ratios of linear measurements have strong discriminatory power despite evolutionary variation in between-locus differences. Overall, new or understudied taxa are likely to have lower molar loci differentiable by their relative length and talonid vs. trigonid width. [ABSTRACT FROM AUTHOR]

This study describes an assemblage of Dzieduszyckia brachiopods preserved in sedimentary barite deposits from the Famennian, Upper Devonian of Nevada, USA. The brachiopods lived in a methane-seep environment like those described from Sonora, Mexico, and the Western Meseta, Morocco. Although the original carbonate fabrics are not preserved, pockets of limestone within the brachiopod barite are depleted in with δ13C values ranging from -31.1 to -27.3‰ VPDB. The fossils are preserved as internal and external molds only but record enough detail to demonstrate key internal features of Dzieduszyckia such as a pronounced dorsal septum, septalium, and vertical dental plates. The lack of common bifurcation or trifurcation of the costae as well as larger size of the shells recommends against inclusion within D. sonora as previously published. Based on the number of costae per width of shell, it is possible that there are two distinct species in Nevada, like other localities in Morocco, the Urals, and South China. These new data expand the body of knowledge of these earliest dimerelloids and it is hypothesized that this seep-dwelling macrofauna arose from depauperate-successful lineages between the Famennian biotic crises. As nearly all global Dzieduszyckia deposits are associated with active tectonic margins, it is also suggested that tectonically-driven methane expulsion in low nutrient waters spurred the evolution of dimerelloids. [ABSTRACT FROM AUTHOR]

In this paper we describe a new lizard from the early Eocene of the Cos locality in the Quercy region (near the Caylus village, Southwest France). The age of the Cos deposit has been proposed as the MP 10–11 interval, close to the transition of the late Ypresian to early Lutetian. The fossil material includes a nearly complete right maxilla and a large section of the right dentary, both elements attributed to Pan-Gekkota. These specimens are morphologically different from crown gekkotans, therefore, we describe them as a new species. Some aspects of the maxilla are very atypical regarding geckos (e.g., the shape of the facial process). The posterior margin of the facial process slopes down gradually dorsoventrally towards the jugal facet, reaching the posterior end of the maxilla, in contrast to gekkotans, where the facial process ends anterior to the posterior end of the maxilla. A similar maxilla is present in the Late Jurassic–Early Cretaceous pan-gekkotan genus Eichstaettisaurus. This suggests that the new fossil taxon represents either a lineage that persisted from the Mesozoic to the early Eocene in Europe, or perhaps a morphology otherwise unrepresented in crown gekkotans. We allocate this taxon provisionally to Pan-Gekkota, and contribute to increase the diversity of this clade in Western Europe during the Paleogene, which now includes the stratigraphically similarly aged Laonogekko lefevrei from France (MP 10), and older Dollogekko from Belgium (MP 7).

Multiple, small (diameter <20 µm) swellings on the apex of internal moulds of the laterally compressed helcionelloids Eotebenna viviannae and the new species Eotebenna danica from the middle Cambrian (Miaolingian) of Bornholm, Denmark, are interpreted as a muscle attachment scars. The scar pattern is unique amongst currently known helcionelloids both in the abundance of attachment sites and in crossing the median plane of symmetry on the supra-apical (dorsal) surface. Sites of typically two pairs of dorsal muscle scars in other helcionelloids are distributed symmetrically on the dorso-lateral areas. The recognition of four groups of muscle scar patterns in helcionelloids suggests a degree of anatomical diversity within the group that is obscured by the morphological simplicity of the enclosing cap-shaped shells, although evolutionary links to mollusc crown groups are unresolved. In addition to the muscle scars, traces of shell micro-structure are described. [ABSTRACT FROM AUTHOR]

Among non-avian dinosaurs, Heterodontosaurus tucki is unique for possessing complex dental features including both morphological and proportional heterodonty, sub-hypsodonty, tooth occlusion, and extensive low-angled wear facets--a collection of derived traits made additionally noteworthy by their appearance in one of the earliest-branching ornithischian lineages. In many taxa with similar dental characteristics, complex suites of modified dental tissues shape functional occlusal surfaces through wear. It remains unknown if H. tucki possesses similar histological complexity. Here, we investigate the histology and enamel microstructure of H. tucki maxillary cheek teeth from the Early Jurassic upper Elliot Formation of South Africa. Despite possessing a superficially complex dentition, the maxillary teeth exhibit a thin, relatively simple, three-layered enamel schmelzmuster (basal unit, columnar unit, and parallel crystallite) with enamel tubules. On the labial face, the enamel thins out drastically (<6 µm) and is discontinuous with a more simplified enamel microstructure. Surprisingly, a thick band of wear-resistant, histologically distinct dentine arises concurrent with the thinning enamel and appears to form the primary cutting crest of the functional occlusal surface, a role typically filled by enamel. This represents both the phylogenetically and chronologically earliest known acquisition of this form of modified dentine within Ornithischia. [ABSTRACT FROM AUTHOR]

We describe early Tremadocian (Kainella meridionalis Biozone) cephalopods from the Cordillera Oriental, Jujuy, NW Argentina. They consist of numerous small specimens collected at the Quebrada de Arenal, Trancas section, near the town of Tilcara, in the Alfarcito Member of the Santa Rosita Formation. All but three specimens were assigned to a new species of Ellesmeroceras (Family Ellesmeroceratidae), E. humahuacaensis sp. nov., based on its slightly endogastric curvature, the characteristics of the siphuncle and chambers dimensions. Micro CT scanning of one specimen aided in the description of the apex and facilitated the construction of a 3D model of the species. A single, similar specimen was assigned to Ellesmeroceras sp. pending the availability of additional material. Two specimens differ from the rest, being exogastric with a lower angle of expansion. They are tentatively assigned to Bassleroceras sp. This material indicates that Cambrian and early Tremadocian cephalopods are not as different as previously thought. "Diversification" and "extinction" events during the late Cambrian may be attributed to taxonomic "over-splitting" and taphonomic and/or sampling biases, respectively. These specimens are currently the oldest recorded in the Central Andean Basin and of West Gondwana, and probably represent the first migration of cephalopods into the region, when the water column was still poorly colonized. During the middle Tremadocian, subsequent immigrations and originations of several cephalopod orders accounted for a rise in diversity and expansion into new niches during this interval. Some of these taxa persisted into the middle Floian, at which time, a second increase in diversity is recorded. Ellesmeroceras humahuacaensis sp. nov. is interpreted as a sub-vertical nektobenthic organism. [ABSTRACT FROM AUTHOR]

A new gigantic titanosaur Bustingorrytitan shiva gen. et sp. nov. is described. The four specimens upon which this species is erected come from Neuquén Province, Argentina, from levels of the Huincul Formation (Cenomanian). Bustingorrytitan shiva gen. et sp. nov. exhibits some autapomorphic characters such as posterior dorsal vertebrae with spinodiapophyseal laminae bifurcated in two, very well developed anterior and posterior spinodiapophyseal lamina rami, which limit a deep, vertical, socket-like fossa; posterior dorsal neural arches with forked centropostzygapophyseal laminae; hyposphene in anterior caudal vertebrae; humerus with deltopectoral crest strongly expanded distally; and femur with a low longitudinal crest on the lateromedial half of the anterior face, bifurcated in two minor crests, which are directed to their respective condyles. The phylogenetic analysis performed recovers B. shiva gen. et sp. nov. as a lithostrotian, the sister taxon of Saltasauridae. The estimated body mass is 67.297 metric tons (with a standard error of ±17.228), which makes B. shiva gen. et sp. nov. one of the largest sauropods ever recorded. The record of this new sauropod corroborates the idea that gigantism (evolution of forms over the 50 metric tons) would have evolved many times within Eutitanosauria. [ABSTRACT FROM AUTHOR]

Floian, Early Ordovician trilobites are systematically described and revised based on new material from the middle part of the Duoquanshan Formation of the Shihuigou area, northern Qinghai Province, northwest China. The fauna that lived on the shallow-water carbonate platform comprises three species belonging to two families, i.e., Tsaidamaspis diarmatus, Zhiyia tsinghaiensis, and Liexiaspis sp. indeterminate. It exhibits a strong endemicity to the Olongbluk terrane. The new isoteline genus Zhiyia is established on the basis of the material from the Olongbluk terrane and South China palaeoplate, and is characterized by its: (i) almost obsolete cephalic and pygidial axial furrows; (ii) flattened anterior border and narrow (sag., exsag.) occipital ring; (iii) bilobed hypostome with a shallow median notch and a small triangular median projection; (iv) subsemicircular pygidium with wide pygidial axis and border. Faunal evidence indicates that the palaeogeographic position of the Olongbluk terrane may have been situated closer to the South China palaeoplate rather than the North China palaeoplate during the Floian. [ABSTRACT FROM AUTHOR]

Pneumatic dorsal ribs are known for many sauropods, but to date costal pneumaticity has received relatively little attention. In particular, the pneumatic ribs of the holotype specimen of Brachiosaurus altithorax have been largely overlooked, although they present a unique configuration of pneumatic features. One rib, with a pneumatic foramen some distance down the shaft, was briefly described and illustrated in the early 20th century by Elmer S. Riggs. A second rib with a pneumatic foramen in the tuberculum of the rib has not previously been described or illustrated. This previously undescribed foramen is similar in location to those in some dorsal ribs of Brontosaurus excelsus and Giraffatitan brancai, but differs from them in both size and shape. The contrasting sites of costal pneumaticity in the holotype individual of Brachiosaurus altithorax emphasize the generally opportunistic mode of postcranial pneumatization, in both sauropods and other ornithodirans, but conform to models of pneumatization following vascularization. [ABSTRACT FROM AUTHOR]

The polychaete borings Caulostrepsis taeniola, Caulostrepsis cretacea, Caulostrepsis avipes, Caulostrepsis penicillus isp. nov., Maeandropolydora elegans, Maeandropolydora sulcans, Sulcichnus sigillum, the bryozoan boring Pinaceocladichnus onubensis and the phoronid boring Talpina cf. hackberryensis occur in coralla of the solitary scleractinian coral Ceratotrochus (Edwardsotrochus) duodecimcostatus in the upper Pliocene middle/lower neritic to upper bathyal fine-grained deposits of NE Tunisia. This very rich assemblage of borings is produced in vivo as suggested by (i) their occurrence close to the surface and mostly in the upper part of coralla (Caulostrepsis ispp., M. elegans), even if they are known to penetrate deeply in the substrate, or (ii) evidence of corallum deformation in response to the boring action (Sulcichnus sulcans). The remaining borings were probably produced post mortem; they penetrate deeply into the corallum (M. sulcans) or always occur shallowly in the substrate (Talpina) and, in addition, cross cut other borings (Pinaceocladichnus). The polychaete borings are dominant. The abundance of the borings is probably caused by ecological pressure from shallower zones in subtropical waters. This resulted in the colonization of hard, small-sized substrates located in relatively deep (offshore) waters. The interpretation of age and palaeoenvironment was elucidated by the analysis of benthic and planktonic foraminifers. [ABSTRACT FROM AUTHOR]

Systematic palaeontological and biometric-statistical analyses (classical clustering and linear discriminant analysis) of statistically significant populations of three early Turonian ammonite species from offshore marls of the Brießnitz Formation (Saxonian Cretaceous Basin, eastern Germany) were used to evaluate a formerly just visually suspected hypothesis of a size dimorphism within the taxa. The studied faunas can in fact be regarded as contemporaneous late early Turonian fossil assemblages derived from a palaeobiogeographic and depositional entity. However, only one of the three species passed the statistical tests. Neither in Lewesiceras peramplum nor in Mammites nodosoides can a dimorphism be proven. In both taxa, no other features than size can be recognised that differ significantly between the overlapping groups. Furthermore, adulthood cannot be proven due to the absence of unequivocal mature modifications. Thus, a combination of large intraspecific variability and commonly incompletely preserved (i.e., small) specimens dissembles dimorphic populations at a first glance. On the other hand, the suspected dimorphism in Spathites (Jeanrogericeras) reveliereanus was confirmed by the statistical analyses of numerous biometric parameters. Not only the maximum diameters but also the distinct apertural cross-sections and ornament show significant differences between the statistically clearly separated two groups. Furthermore, a decline in ornament and widening of the body chamber in fully grown macroconch specimens, regarded as a mature modification of the shell, demonstrate that the antidimorphs really differed in adult morphology. Thus, it can be shown that there are in fact two forms in the fossil assemblage of S. (J.) reveliereanus that, based on their morphological differences and lack of any overlap, represent micro- and macroconchs (inferred males and females) of an evidently dimorphic ammonite species. Finally, we conclude that simple visual inspection is commonly insufficient for the reliable proof of dimorphism in ammonoids. [ABSTRACT FROM AUTHOR]

The growth rings of fossil wood provide valuable data on tree ecology. As many of the parameters controlling width are climatic, it is tempting to use these rings as an indicator of climate. This is what has been done, with great success, by dendrochronological studies of archaeological wood. For wood dating from before the Pleistocene, however, the task is more uncertain. Since around 1980, researchers have relied mainly on a statistical parameter, the mean sensitivity, an average of the difference in width between two consecutive rings. However, there has never been a critical examination of utility and significance of this parameter for fossil wood. I compiled 63 studies that used mean sensitivity for palaeoclimatological inferences. An analysis of this compilation is presented here. Despite its ups and downs since the 1980's, mean sensitivity is increasingly used by palaeobotanists. However, it has been used in very different ways. The values obtained for the same fossil can vary greatly from one researcher to another, but also according to the radii of the woody axis considered. Within fossil wood assemblages, average sensitivity varies widely, but rarely consistently. Overall, mean sensitivity values are continuously, normally and unimodally distributed, and therefore are unsuitable for characterising discrete climate classes. Finally, it seems that the most recent studies are also the least cautious when it comes to interpreting the values obtained. [ABSTRACT FROM AUTHOR]

Echiurans (spoonworms) are a very distinctive group of polychaete annelids that had long been considered to constitute a separate phylum. Their fossil record is extremely limited, although trace fossils that have been suggested to be attributable to them date back as far as the Cambrian Period. The oldest body fossils are from the Carboniferous Mazon Creek Biota, and preserve only limited morphological detail. New material from the Middle Ordovician (Darrivilian, Didymograptus murchisoni Biozone) Castle Bank Biota of Wales shows fine detail of the morphology of a new taxon, Llwygarua suzannae gen. et sp. nov., including several details that indicate an assignment to the derived family Thalassematidae, allied to the speciose genus Ochetostoma. These details include proboscis morphology, anterior setae, and muscle organisation within the trunk. An additional specimen is described in open nomenclature, as it may be either a distinct species, or a juvenile of Llwygarua suzannae gen. et sp. nov. with a relatively elongated proboscis. These worms demonstrate a very early and previously unrecognised diversification of the echiuran grown group, further supporting an early diversification of Annelida as a whole. [ABSTRACT FROM AUTHOR]

The island of Taiwan, with its diverse microclimates and key position on the East Asian-Australasian Flyway, attracts numerous bird enthusiasts due to its diverse avian fauna. Nevertheless, due to the scarcity of fossil records, there is a significant knowledge gap between modern and ancient avifaunas in Taiwan. Currently, there is only a single described Pleistocene fossil; it is attributed to Phasianidae. To address this gap, this study describes two new bird fossils, a left humerus and a left tibiotarsus, and discusses them in detail herein. The fossils were collected from the Liuchungchi Formation (Early Pleistocene, 1.95-1.35 Ma) in Niubu, Chiayi, southwestern Taiwan, which represents a neritic environment. The fossils are identified as from species of Gaviidae (loons), with the humerus belonging to an undetermined species of Gavia and the tibiotarsus to Gavia stellata. Loons are seabirds that are primarily distributed in high- and middle latitudes of the Northern Hemisphere. In addition, these birds are extremely rare in modern Taiwan: records are scarce and most are limited to northern and northeastern Taiwan since the 1860s, indicating that the modern Gavia birds only occasionally visit Taiwan. All known Pleistocene fossils of species of Gavia from the northern West Pacific come from Japan. The Taiwan fossils of Gavia provide valuable bird evolutionary and paleobiogeographic information for the subtropical West Pacific and may imply the presence of a distinct avifauna in the region during the Early Pleistocene. [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed survey on the rodent fauna from the site of Barranco de los Conejos (Guadix-Baza Basin, southern Spain). Its rodent fauna is composed of three arvicolines (Orcemys giberti, Manchenomys oswaldoreigi, and Tibericola vandermeuleni) and two murids (Castillomys rivas and Apodemus atavus). The three arvicoline species present ever-growing molars. Orcemys giberti and Manchenomys oswaldoreigi can be considered as descendants of local Mimomys species (Mimomys medasensis and Mimomys tornensis, respectively), while Tibericola vandermeuleni is an eastern inmigrant. Loosening of roots in Orcemys giberti and Manchenomys oswaldoreigi is explained as an adaptation to a fossorial way of life, in relation to the Early Pleistocene glacial–interglacial dynamics, which led to cooler and drier conditions. This environmental change would also explain the dispersal of Tibericola from the eastern Mediterranean.

Sarcopterygian remains are relatively common in the so-called “Placoderm Sandstone” (storm-origin bone-bearing breccia) from the Emsian (Lower Devonian) of Podłazie in the Holy Cross Mountains (Poland). Previous studies have mainly referenced the presence of dipnomorphs, chiefly portrayed by porolepiforms and occurrences of dipnoans. Porolepiforms are represented by Porolepis ex gr. P. posnaniensis, based on scales, skull and shoulder-girdle elements, whereas other remains have been attributed to Heimenia sp. The aim of this paper is to present the most detailed description of the porolepiforms and other sarcopterygian fishes from the “Placoderm Sandstone” from the Holy Cross Mountains since 1960s. Here, I present a new study based on more than 200 specimens, using both microtomographic (CT-scan) and silicon casts analyses, which indicate that not two, but at least three different taxa of sarcopterygians occur in the “Placoderm Sandstone” from Podłazie. The new data presented herein depict a more diversified assemblage of sarcopterygians in the marginal-marine environment of the Lower Devonian of the Holy Cross Mountains than previously thought, and shed a new light on sarcopterygian diversity along the shores of the Old-Red continent.

High-spired Murchisonia-like slit-band gastropods are an important component of late Paleozoic gastropod faunas. Twenty-seven genera of such gastropods have been reported from the Permian, most of which representing the caenogastropod family Goniasmatidae. Only four genera, Trypanocochlea, Wannerispira, Laschmaspira, and Altadema crossed the Permian/Triassic boundary. Based on the study of newly collected specimens and material from natural history collections, we studied the surviving genera as well as the Triassic recovery of this group. Two new species (Laschmaspira lirata sp. nov. and Altadema hausmannae sp. nov.) and one new subfamily (Cheilotomoninae) are introduced. Murchisonia-like caenogastropods, chiefly Goniasmatidae, were diverse and abundant until the Permian, barely survived the end-Permian extinction, regained a certain generic diversity within the Triassic with the evolution of several new genera but failed by far to regain their Permian generic diversity. This once successful and diverse group shares a similar fate (surviving the end-Permian extinction, a reduced Triassic diversity and extinction during Late Triassic crises) as conodonts, orthoceratids, conulariids, and others. This diversity pattern does not qualify for the "Dead Clade Walking" phenomenon, i.e., the extinction shortly after a major mass extinction event (survival without recovery) because they have survived for ca. 30 Ma (at least until the Norian) and even produced a number of new genera. The exact time of their extinction is unknown but there are no safe Rhaetian occurrences. Their extinction is part of a long-term selective trend against the character "shell-slit". [ABSTRACT FROM AUTHOR]

The vast majority of cephalopods of the order Tarphyceratida are known from regions that were located at mid- or low palaeolatitudes during the Ordovician (mainly Baltica, Laurentia, and Chinese palaeoblocks). Only a handful of tarphyceratid specimens are known from high palaeolatitude regions of peri-Gondwana and Gondwana. Here, we describe the two best-preserved trocholitid cephalopods known to date from the Ordovician of the Prague Basin. The first is from the late Darriwilian/early Sandbian Dobrotivá Formation and is assigned to Trocholites fugax, a species previously recorded from roughly coeval strata of Iberia, France, and Bohemia. The specimen thus strengthens previous hypotheses regarding the interchange of non-benthic faunas between Baltica and different regions of peri-Gondwana during the Middle/Late Ordovician boundary interval. The second specimen, assigned to a new species of Trocholites chaloupkai sp. nov., is from the late Sandbian-early Katian Zahořany Formation and thus represents one of the stratigraphically youngest Trocholites in the Ordovician of peri-Gondwana. Internal structures of the shell of the holotype of the new species were studied using micro-CT tomography. This revealed that T. chaloupkai sp. nov. closely resembles the stratigraphically older (Darriwilian) species Trocholites depressus from Estonia. [ABSTRACT FROM AUTHOR]

Ornithosuchids are a Late Triassic pseudosuchian archosaur group, consisting of four species (three from South America, and one from Scotland). All of them have triangular skulls with a protruding premaxilla, large nostrils, an extensive diastema in their narrow snout, a short jaw that does not reach the anterior end of the skull, and serrated posteriorly curved teeth. For this clade, carnivorous and scavenger habits have been previously proposed. Within the Ornithosuchidae, Riojasuchus tenuisceps (from Argentina) has the most morphologically extreme characteristics. Based on CT scans of the preserved skulls we generated a 3D model, and over this, we estimated the volumes of the adductors and abductor muscles and the force exerted by each. From these data we built the finite element model and measured the bite force (1.8-2.3 kN). Lateral, tractive, and torsional forces were applied to the end of the snout to evaluate the structural response of the skull during feeding. The results show that R. tenuisceps could resist tractive and torsional stresses better than lateral stress. Additionally, we analysed the peculiar morphological characteristics of the skull and their functional implications. We observed that the upper and lower dental rows were laterally separated from each other, preventing the generation of a cutting line during occlusion, and therefore, R. tenuisceps would have fed on small-sized prey that it could swallow whole. The curved premaxilla and the short mandible would not allow it to bite with the tip of the snout (ruling out the scavenging hypothesis), but were instead more adequate to capturing prey suspended in a fluid. This set of results allows us to propose that R. tenuisceps could have had a zoophagous diet and a wading habit, being able to feed on fish, amphibians, or any small animals that they could catch from the shoreline. [ABSTRACT FROM AUTHOR]

Prolacerta broomi is one of the most important of fossil reptiles. First considered as one of the earliest members of squamates, this basal archosauromorph has been used as a model for diapsid morphological evolution ever since its discovery, playing a pivotal role in hypotheses on the origin of diapsid reptiles. The holotype of Prolacerta broomi (UCMZ 2003.41R) is known from a mostly complete skull, but the original description is limited to the superficial features of the skull roof and palate. Since then, many other specimens of Prolacerta broomi have been recovered that potentially account for this limited access to anatomical information, but it remains unclear whether these aspects correspond well to the known material of the holotype. Here, the skull morphology of the holotype of Prolacerta broomi is revisited through the use of µCT scans. The identifications of some cranial elements have been corrected, such as the left prefrontal and lacrimal, and several new elements are revealed, including the epi- and ectopterygoids, prearticular, coronoid, and braincase bones. The orbitonasal region is described in detail and significantly shows a contribution of the lacrimal to the dorsal alveolar canal. Finally, the addition of the holotype as an independent OTU in recently published analyses indicate conflicts with the current knowledge on Prolacerta broomi phylogenetic affinity and taxonomy. First, it points to potential taxonomic inconsistency since the holotype does not form a monophyletic group with other Prolacerta broomi OTUs in any of the analyses and, second, it suggests a more basal position for the holotype than that recovered in some studies, more basal than rhynchosaurs and close to the origin of Crocopoda. Together, these findings indicate areas of future research interest in the study of early evolving archosauromorphs. [ABSTRACT FROM AUTHOR]

Numerous dromaeosaurid taxa recovered from the Upper Cretaceous strata of the Gobi Desert raise questions over niche partitioning among closely related species. Here, I describe a dromaeosaurid specimen from the Baruungoyot strata of the Khulsan locality, containing a partial skull in close association with the left hind limb. The material can be referred to the velociraptorine Shri devi, until now known only from a single specimen lacking a skull, collected from the same site. The referral is based on the apomorphic morphology of the pes, including the highly hypertrophic ungual of the second digit and details of the metatarsus. The skull of S. devi confirms its close affinities with Velociraptor mongoliensis, but shows distinctive features among Velociraptorinae, including a short antorbital fenestra, a Z-shaped maxillo-jugular suture, a distinct labial ridge above the supralabial foramina row of the maxilla, and the posterior position of the last maxillary tooth. The skull of S. devi is slender, but relatively short when compared to other velociraptorines, suggesting convergence to the North American eudromaeosaurians. The Baruungoyot strata with S. devi represent less arid conditions than the aeolian Djadokhta strata yielding V. mongoliensis, supporting earlier observations linking the elongation of the dromaeosaurid snout with the environment. [ABSTRACT FROM AUTHOR]

The new "libelluloid" family Cordulibellulidae is described to accommodate a new genus and species Cordulibellula inopinata from the Eocene Green River Formation, Utah, USA. Even if its affinities remain somewhat uncertain because of the lack of information on structures others than those of the hind wing, ts putative closest relatives are known from the Late Jurassic and Early Cretaceous. Therefore, this new fossil is interpreted as a "relict" taxon surviving until the Paleogene. This new addition to the odonatan paleoentomofauna of the Green River Formation confirms the high diversity of this clade during the Paleogene and in this formation. [ABSTRACT FROM AUTHOR]

New discoveries of Cenozoic deep-water hydrocarbon seep deposits and continued collecting at previously documented sites in the North Pacific region have resulted in additional fossils of vesicomyid bivalves and necessitate a systematic review. We report five new vesicomyid species, including four species from western Washington State, USA: Isorropodon humptulipsense sp. nov. from middle to upper Eocene strata of the Humptulips Formation and the "Siltstone of unit B", the oldest record for Isorropodon, Pleurophopsis thieli sp. nov. from upper Eocene to lowermost Oligocene strata of the Lincoln Creek, Makah, and Pysht formations, and Pliocardia? guthrieorum sp. nov. and Squiresica plana sp. nov. from Oligocene strata of the Lincoln Creek and Pysht formations. The new species Squiresica yooni sp. nov. is from the Middle Miocene Duho Formation in South Korea. We report possibly the as-yet oldest Vesicomya from a lower Oligocene seep deposit in the Lincoln Creek Formation in western Washington. Pliocardia kawadai was previously only known from Lower to Middle Miocene strata in Japan; with our new record from the Lower to Middle Miocene Astoria Formation in western Washington, this species represents the first fossil vesicomyid species with a trans-Pacific distribution. The large and elongated Pleurophopsis chinookensis is restricted to upper Eocene strata; previous Oligocene records are shown to belong to other species. [ABSTRACT FROM AUTHOR]

We describe two new genera of phymaraphiniid lithistid sponges Twertupia gen. nov. and Pickettispongia gen. nov. from the upper Eocene Pallinup Formation of South Western (SW) Australia based on new, rich and very well preserved material. Type material of these two genera, earlier described from poorly preserved material, were originally attributed to Thamnospongia subglabra and Stachyspongia neoclavatela (in case of species of Twertupia), and to Discoderma tabelliformis (case of species of Pickettispongia). This is the first record of bodily preserved phymaraphiniid sponges from Eocene rocks, as well as from the southern hemisphere. We discuss extant and fossil representatives of Phymaraphiniidae and their geographical distribution, concluding that the present day occurrences of these sponges are the result of a much larger Mesozoic Tethyan distribution. [ABSTRACT FROM AUTHOR]

Solutans were among the most enigmatic pre-radial and asymmetric echinoderms. A new species Dehmicystis ariasi sp. nov. is described from the upper part of the Llagarinos Formation, lower Ludlow (Silurian) of Northwest Spain. This is the first solutan formally described from Iberia and the first from the Silurian worldwide. Dehmicystis was previously known based on a small number of poorly preserved specimens from the Emsian, Lower Devonian Hunsrück Slate of Germany. New observations based on the newly studied material suggest that Dehmicystis displayed a feeding appendage facing towards the substrate, and the periproct on the opposite face of the theca. Comparisons with other solutans and new data suggest that Dehmicystis was a detritus feeder that moved over the substrate capturing organic particles from the sediment with a single feeding arm. [ABSTRACT FROM AUTHOR]

Campanellula capuensis was described as belonging to the Trochamminacea (trochospiral tests) and later transferred to the genus Orbitolinopsis of the Orbitolinidae (uniserial tests). Challenging its identity as a species of Orbitolinopsis, the most widely accepted classifications of agglutinated foraminifera reinstate Campanellula but retain its inclusion within the Orbitolinidae, subfamily Dictyoconinae. New material from the type locality and the San Lorenzello section (Matese Mountains, southern Apennines, Italy) as well as the construction of a 3D model allow to reinstate the original description as a low- to high-trochospirally (conical) coiled foraminifer with numerous chambers per whorl and to display an overall conical test morphology. An orbitolinid test construction including uniserial chambers (throughout the test or in its adult part) is absent. The conflicting opinions on taxonomic status of Campanellula are discussed leading to the removal from the order Loftusiina and the suborder Orbitolinina. Instead, Campanellula should be included into the order Lituolida and the suborder Verneuilinina. Campanellula capuensis represents a biostratigraphic and palaeobiogeographic marker taxon, restricted to upper Hauterivian-lower Barremian inner platform carbonates of the southern Neotethyan margin. [ABSTRACT FROM AUTHOR]

One of the main "databases", on which palaeontologists carry on their studies, is constituted by palaeontological collections. These collections are the final result of fieldwork and surveys, sampling activities, preparation and curatorial processes, and analyses. However, the content of a palaeontological collection can also be strongly biased, leading researchers to post-collection skewed results. Post-collection biases (e.g., breakage, loss of fragments, etc.) are directly linked to human activities, occurring during excavation, transport, preparation, and storage. Here, we present the case of the vertebrate remains from the Brazilian lower Carnian Santacruzodon Assemblage Zone (Santa Cruz Sequence, Santa Maria Supersequence, Paraná Basin). The studied specimens came from the Schoenstatt Sanctuary fossil site, a key outcrop for both the sequence and Santacruzodon AZ. We evaluated vertebrate remains from three Brazilian scientific collections, compiled through more than 25 years of fieldwork. The specimens housed in the three collections present high degrees of post-collection fragmentation, as well as significant differences in the bone elements present, when comparing cranial vs. post-cranial elements. Moreover, some differences in curatorial attitude have also been noticed, especially in restoration choices, leading to "discrimination" in post-collection fossil quality and highlighting the existence of the "craniocentrism" problem. [ABSTRACT FROM AUTHOR]

The rare Middle Jurassic ammonite Oecoptychius refractus is revisited based on material collected in southern Poland (Ogrodzieniec quarry) and France (St.-Laon near Loudun, western France). Based on available data and an evalua- tion of the literature, O. refractus ranges from the middle Callovian Kosmoceras jason Zone to the upper Callovian Quenstedtoceras lamberti Zone. Additionally, two specimens from Kachchh (western India) were re-evaluated and are now assigned to the lower part of the upper Callovian Peltoceras athleta Zone, similar to specimens from southern Germany. In the present study, O. refractus displays large morphological variation in the shape of the body-chamber, with a gradation from V- to U-shape. Additionally, the smaller upper Callovian specimens from Poland are morphologically closer to the lectotype (more evolute and compressed) and form a separate grouping as compared to the much larger middle Callovian specimens from France. Based on available data, the authors tentatively propose Phlycticeras polygonium var. waageni [M] as the dimorphic partner of O. refractus [m]; both dimorphs have similar morphology (ribbing pattern and striations), suture line and co-occur from middle to upper Callovian. Oecoptychius refractus maintains its morphological variability throughout the middle and upper Callovian, before its final dissapearance in the Q. lamberti Zone. Oecoptychius refractus is better documented from western Tethyan localities (Poland, Germany and France) as compared to those from the eastern Tethys (Madagascar and India). Recurrent sea level rises in the Middle Jurassic might be one of the plausible factors for its extensive palaeobiogeographic range. [ABSTRACT FROM AUTHOR]

Fossils of Devonian ammonoids are abundant and well-preserved in the Anti-Atlas of Morocco; as such they provide an invaluable record of regional morphological disparity changes (diversity of shapes) that characterise the first steps of ammonoid evolution. However, they were rarely analysed quantitatively with respect to their morphological spectrum. Here, we investigated the morphological disparity of the Early-Middle Devonian ammonoids of the Moroccan AntiAtlas by analysing the shape of their whorl profile. A geometric morphometric approach based on the acquisition of outline semilandmark coordinates was used to analyse the whorl profiles. For comparison, morphometric ratios based on classical conch measurements were also analysed to investigate the overall conch geometry. Several standard disparity estimators were computed to measure different aspects of morphological disparity fluctuations through time. It appears that a major increase in disparity occurred throughout the Early Devonian, followed by fluctuating disparity during the Middle Devonian constituting a general decreasing trend. Only the end-Eifelian Kačák Event shows a significant decrease in disparity. Thus, the ammonoids explored the range of possible shapes fairly quickly during their initial radiation; however, we found no evidence for an early burst of shape diversity (i.e., the rise does not exceed the expectations given diversity). Nevertheless, correlation tests between diversity and disparity time series support that they are partially decoupled. The highly resolved biozone record highlights that the increase in disparity began earlier than the increase in diversity that characterises the late Emsian. [ABSTRACT FROM AUTHOR]

The North Pacific rim was home to an extinct group of semi-aquatic marine mammals, the order Desmostylia, which superficially resembled hippos. Desmostylians are an uncommon fossil vertebrate in most localities where they occur, and Oligocene taxa particularly so. Beyond the type dentition and two femora of Cornwallius sookensis, and the skull and postcrania of Behemotops proteus, both previously described from the region of Muir Creek locality of the upper Oligocene Sooke Formation of southern coast of Vancouver Island, British Columbia, Canada, no other records from this site have been reported. Additional specimens of teeth have now been found in the Royal British Columbia Museum and Canadian Museum of Nature, including a long-forgotten and unreported paratype. In total, three additional teeth, one of B. proteus and two possibly belonging to C. sookensis, are reported here from its type locality. More importantly, the upper molar reported here, as well as UCMP 36078 from Baja California and USNM 181740 from Oregon, all resemble each other but should be considered as belonging to Cornwallius only with caution. [ABSTRACT FROM AUTHOR]

Among the great diversity of Oligocene mammals from Quebrada Fiera (Mendoza Province, Argentina), three families of typotherian notoungulates are very abundant. Since the first paper on archaeohyracids in 2010 until the last fieldwork in 2016, numerous unpublished remains were added to the collection. The study of all these remains, together with some revised materials, allows us to provide new anatomical data and some taxonomic decisions on these groups. Within Hegetotheriidae, we present one of the most complete skulls of “Prohegetotherium schiaffinoi” known to date, providing descriptions of certain previously unknown features of the caudal cranium; MCNAM-PV 3984 is discarded as belonging to Hegetotheriopsis sulcatus, as recently suggested, and is considered as Hegetotheriinae indet., like other isolated large specimens and some teeth previously determined as Prohegetotherium sp.; and several well-preserved specimens add to the sample of the pachyrukhine Prosotherium garzoni, including a partial maxilla with erupting P2. Concerning “Archaeohyracidae”, Archaeohyrax suniensis is now better represented, recording several ontogenetic stages previously observed in the Bolivian sample of this species. Finally, within Interatheriidae, most new dental material belongs to Argyrohyrax proavus, but an isolated upper molar suggests the presence of a different Interatheriinae at Quebrada Fiera, more similar to the Bolivian Brucemacfaddenia boliviensis than to other Deseadan (late Oligocene) taxa.

A new fossil occurrence of freshwater sponges (Porifera: Demospongiae) is reported from the Deccan volcanic associated Naskal intertrappean locality, deposited in an interval of <100 kyr across the Cretaceous/Paleogene (K/Pg) boundary. This is the oldest record of siliceous fossil birotule spicules (gemmuloscleres) belonging to asexual resting stages typical of the order Spongillida. The analysis supports the ascription of these fossils to the family Palaeospongillidae. The diagnosis and description of Longibirotula Pronzato and Manconi gen. nov. and its type species Longibirotula antiqua Manconi and Samant sp. nov. from the Naskal intertrappean is based on skeletal and gemmular spicular morphotraits. The findings have provided evidence of the presence of diversified groups of freshwater sponges during the Late Cretaceous on the Indian subcontinent and Gondwanaland. From the biogeographic context, the findings track the evolutionary trends of the oldest continental sponges in the Asian and Australasian/Insular Pacific regions. [ABSTRACT FROM AUTHOR]

Afropereboria magnifica gen. et sp. nov., is the oldest African representative of the Permian "cicada-like" family Pereboriidae. The family diagnosis is discussed and emended. Synapomorphic characters of the Pereboriidae are proposed. The two genera Jifara and Scytophara are excluded from this family, confirming that Pereboriidae are strictly Permian. The relationships between the two Permian families Pereboriidae and Ignotalidae and the Triassic Curvicubitidae are still not clear and will need a phylogenetic analysis. We propose new putatively apomorphic diagnostic characters for the Pereboriidae. We also discuss some characters supposed to discriminate the Pereboriidae from the Ignotalidae. The Permian Pereboriidae had a disjunctive distribution between the northern and southern parts of Pangea, under cool temperate climates, separated by the intertropical zones. [ABSTRACT FROM AUTHOR]

Pseudoplankton are organisms that are adapted for a mode of life attached to floating objects. In modern oceans common examples are lepadid barnacles, which attach themselves to man-made and natural objects, especially wood logs. In the fossil record, pseudoplankton examples are commonly found in black shales, such as the lower Toarcian Posidonia Shale Formation of Germany. Here there are occasional large logs of fossil wood covered in specimens of the inoceramid bivalve Pseudomytiloides dubius, with or without specimens of the pentacrinitid crinoid Seirocrinus subangularis. Some Posidonia Shale logs show evidence of for intra-species succession with younger S. subangularis specimens attached onto the stems of older ones. Another example of pseudoplankton from the Posidonia Shale is the occurrence of the numerous disarticulated specimens of the phosphatic-shelled eolepadid barnacle Toarcolepas mutans associated with a piece of fossil wood, which constitutes the oldest example of pseudoplanktonic barnacles in the fossil record. Here we report a limestone concretion from the lower Toarcian Strawberry Bank Lagerstätte (Ilminster, Somerset, UK) that preserves a piece of fossil wood with a pseudoplanktonic colony comprising at least a hundred specimens of T. mutans that attached onto a layer of P. dubius bivalves, that had already attached onto the wood. This is one of very few examples of temporal succession for pseudoplankton in the Toarcian and is also unusual in being preserved in a mixed carbonate-siliciclastic facies, rather than a black shale. The occurrence of T. mutans in the Strawberry Bank Lagerstätte concretion represents the second record of the species and also the equal oldest example of pseudoplanktonic barnacles in the fossil record. [ABSTRACT FROM AUTHOR]

New material of disarticulated paleoscolecid remains have been found in "Small Shelly/Skeletal Fossils" assemblages from Cambrian Stage 3 extracted from a section in the Khubsugul Lake region of northern Mongolia. The current material is composed of isolated phosphatic plates, rendering the whole-body reconstruction and comparisons difficult. However, the morphology of the plates is unique enough to warrant description of a new genus and species Floraconformis egiinensis. The new taxon is characterised by a stellate depression network spreading from the middle that separates numerous elevations. Floraconformis egiinensis gen. et sp. nov. represents one of the oldest records of isolated palaeoscolecid plates. [ABSTRACT FROM AUTHOR]

Articulated fossil ophiuroids from South America were reported for the Devonian, Cretaceous, Eocene, and Miocene. Here we report the first Jurassic record of an articulated ophiuroid from the Sierra Chacaicó Formation (early Pliensbachian-Sinemurian) in Neuquén Basin, Argentina, and discuss the taphonomic processes that allowed its preservation. The Sierra Chacaicó Formation represents the onset of the Early Jurassic extensive marine transgression in the basin. The basal section comprises shoreface and offshore Gilbert-type delta system, which was affected by hyperpycnal discharges. The middle and upper sections are represented by offshore deposits, affected by storms and eroded by hyperpycnal channel-levee systems. The ophiuroid specimen was found in levels of massive, fine, tuffaceous sandstone beds and covered by coarse sandstone containing a large amount of plant debris and organic matter. It was preserved articulated, with a complete disc and almost complete arms. Based on the microstructure of the spine-bearing lateral arm plates, the ophiuroid is assigned to Sinosura, an extinct genus of the family Ophioleucidae, widespread in the Lower Jurassic deposits of Europe but previously unknown from other parts of the world. The posture of the ophiuroid, with one arm curved distally and extended in one direction and the other four arms symmetrically oriented in the opposite direction, suggests a walking or escape movement frozen in time. This implies that the ophiuroid was buried alive by sediment thick enough to prevent successful escape. The taphonomic and sedimentologic evidence indicates that the fossil material was found in hyperpycnal deposits accumulated in offshore positions, which carried a high concentration of sediment in suspension. [ABSTRACT FROM AUTHOR]