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Comma shrimp, or cumaceans, are diverse benthic crustaceans, yet they are one of the groups with the poorest fossil record, hindering our understanding of the evolution of the group in deep time. Here, we describe a new species of fossil comma shrimp, Makrokylindrus itoi sp. nov., from the Plio‐Pleistocene of Japan. The singular fossil is exceptionally preserved, including details of the carapace, cuticle, and some appendages, and it represents the first known fossil of the family Diastylidae and only the fourth fossil crown group cumacean known to date. We suggest that the scarce and sparsely known fossil record of cumaceans likely reflects a lack of recognition due to their small size and unfamiliar anatomy, making fossil cumaceans easy to misidentify, be confused with crustacean larvae of unknown affinities, or be interpreted as fragments of other crustaceans (taxonomic bias), rather than a lack of fossilization potential (taphonomic bias). [ABSTRACT FROM AUTHOR]

The Burdigalian/Langhian (B/L) boundary has not yet been designated as a Global Stratotype Section and Point (GSSP), despite various proposed zonal schemes. In the Gulf of Suez region of Egypt, the Burdigalian-Langhian successions are notable for hosting significant hydrocarbon reservoirs within a tectonic rift setting. Therefore, biostatigraphy plays a crucial role in exploration endeavors in this area. The nannofossil biostratigraphy is investigated in two sections, Wadi Baba and Wadi Gharandel, of the lower-middle Miocene from west-central Sinai. Three biozones, NN3 (Sphenolithus belemnos) Zone, NN4 (Helicosphaera ampliaperta) Zone, and NN5 (Sphenolithus heteromorphus) Zone, are identified from the studied interval. The NN4 Zone could be divided into MNN4a/b and MNN4c. Important biovents are discussed, such as the S. heteromorphus paracme interval and the first occurrence and evolution of the Discoaster exilis and Discoaster variabilis groups. Based on the cluster analysis, the recorded taxa can be subdivided into four groups that reflect their palaeoclimatic preferences. The paleoecological interpretation of the studied Rudies Formation indicates prevailing cool and eutrophic nutrient conditions based on the dominance of taxa such as Coccolithus pelagicus, Reticulofenestra minuta, and Cyclicargolithus floridanus. The nannofossil taxa responses to sea level curve are interpreted. Fluctuations in taxa abundance and diversity indicate a slight rise in the sea level at the base of the Burdigalian followed by sudden drop in the sea level at the middle Burdigalian. High sea-level conditions prevailed again until the B/L boundary. During the Langhian period, many small-scale fluctuations in sea-level curve are detected. [ABSTRACT FROM AUTHOR]

Three new fossil species of walnuts, Juglans eoarctica sp. nov., J. nathorstii sp. nov., and J. cordata sp. nov., are described on the basis of nuts recovered from the middle Eocene fossil forests of Axel Heiberg Island in the Canadian Arctic Archipelago. These represent the most northerly occurrence of Juglans and are among the oldest records of Juglans to date. The Axel Heiberg Island walnuts conform to the sections Rhysocaryon and Cardiocaryon and, together with the contemporaneous midlatitude fossil species J. clarnensis Scott, imply the establishment of two distinct Juglans lineages prior to the middle Eocene. Climatic cooling, leading ultimately to Pleistocene glaciation, has transformed high-latitude vegetation and resulted in the American/Eurasian disjunct distribution found in many north temperate families, of which Juglans is typical. With three coexisting species in the Axel Heiberg Island fossil forests, it is clear that Juglans was an important component of this ancient polar landscape and played a significant role in the evolution of northern temperate forest ecosystems. [ABSTRACT FROM AUTHOR]

Based on a single specimen in Eocene Baltic amber, Henoticus groehni sp. nov., the first extinct species of the genus, is described. The new species is studied and illustrated in detail using optical microphotography and X-ray micro-computed tomography. An additional congeneric specimen is discussed but not attributed to the species level. It is shown that exoskeletal depressions on the metaventrite with possible mycangia roles were present in Henoticus already in the Eocene. The possible involvement of the newly described species in dynamic of ecosystems at the early stages of natural pyrogenic succession in Eocene amber forests is hypothesised. [ABSTRACT FROM AUTHOR]

Aim: Modern sharks are a diverse and highly threatened group playing important roles in ecosystems. They have an abundant fossil record spanning at least 250 million years (Myr), consisting primarily of isolated teeth. Throughout their evolutionary history, sharks have faced multiple environmental changes and extinction events. Here, we aim to use dental characters to quantify how shark functional diversity has changed during the last 66 Myr. Location: Global. Time period: Cenozoic era (66–0 million years ago; Ma). Major taxa studied: Sharks (Selachii). Methods: We complied a dataset of over 9000 shark teeth belonging to 537 taxa from museum collections and scientific literature and measured six dental characters strongly linked with functional traits. We then quantified different functional diversity metrics across Cenozoic time bins, compared them against null expectations and identified the most important taxa contributing to maintaining functional diversity. Results: Sharks displayed relatively high functional diversity during the Cenozoic, with 66%–87% of the functional space being occupied for ~60 Myr (Palaeocene to Miocene). High levels of functional redundancy during this time resulted in larger‐than‐expected functional richness; but a large decline (−45%) in redundancy in the Oligocene (~30 Ma) left shark functional diversity highly vulnerable to further loss. Shark functional diversity declined from the late Miocene (~10 Ma) onwards, losing 44% of functional richness by the Recent. Extinct sharks disproportionally contributed to the Cenozoic functional diversity and spanned a wider range of functional space than extant sharks, with the loss of mid‐sized suction feeders and large‐bodied predators driving functional declines. Main conclusions: After maintaining high levels of functional diversity for most of the Cenozoic, sharks lost nearly half of their functional diversity in the last ~10 Myr. Current anthropogenic pressures are therefore likely eroding an already diminished shark functional diversity, leaving future communities ecologically deprived compared with their thriving geological past. [ABSTRACT FROM AUTHOR]

The southeastward extrusion of Indochina along the Ailao Shan-Red River shear zone (ARSZ) is one of two of the most prominent consequences of the India-Asia collision. This plate-scale extrusion has greatly changed Southeast Asian topography and drainage patterns and effected regional climate and biotic evolution. However, little is known about how Indochina was extruded toward the southeast over time. Here, we sampled 42 plant and animal clades (together encompassing 1,721 species) that are distributed across the ARSZ and are not expected to disperse across long distances. We first assess the possible role of climate on driving the phylogenetic separations observed across the ARSZ. We then investigate the temporal dynamics of the extrusion of Indochina through a multitaxon analysis. We show that the lineage divergences across the ARSZ were most likely associated with the Indochinese extrusion rather than climatic events. The lineage divergences began at ~53 Ma and increased sharply ~35 Ma, with two peaks at ~19 Ma and ~7 Ma, and one valley at ~13 Ma. Our results suggest a two-phase model for the extrusion of Indochina, and in each phase, the extrusion was subject to periods of acceleration and decrease, in agreement with the changes of the India-Asia convergence rate and angle from the early Eocene to the late Miocene. This study highlights that a multitaxon analysis can illuminate the timing of subtle historical events that may be difficult for geological data to pinpoint and can be used to explore other tectonic events. [ABSTRACT FROM AUTHOR]

Low-Mg calcite, precipitating from meteoric fluids, is a common mineral that forms in a variety of near-surface diagenetic environments. However, recent studies, based on a combination of analyses of δ18O and Δ 47 values, have suggested that this mineral might form in disequilibrium and consequently yield kinetic bias in Δ 47 -derived temperatures and fluid δ18O values. Here, we use dual clumped isotope proxies (Δ 47 and Δ 48) to investigate the influence of kinetic isotope effects within different meteoric diagenetic zones of Holocene and Pleistocene carbonates from the southern Florida and the Dominican Republic. In the Miami Oolite, the primary aragonite ooids and secondary low-Mg calcite cements in the bulk sample were separated from each other and their isotopic compositions (δ13C, δ18O, Δ 47 and Δ 48 values) were measured. The Δ 47 and Δ 48 values of the separated aragonite are consistent with the modern ooid sediments and in approximate equilibrium with the surface seawater. In contrast, the low-Mg calcite cement shows the higher Δ 48 and lower Δ 47 values, than expected, with the disequilibrium arising as a result of CO 2 degassing in the vadose zone. Such deviations of Δ 47 and Δ 48 values are also observed in low-Mg calcite vadose cements in the Dominican Republic. While low-Mg calcites formed in the lower freshwater phreatic zone in the Dominican Republic have the Δ 47 - and Δ 48 -derived temperatures close to expected, the same mineral forming near the water-table and upper phreatic zone shows much higher Δ 48 -derived temperatures (up to ∼ 90 °C). The possible origin of such elevated temperatures can be attributed to non-equilibrium processes caused by changes in pH and pCO 2 , mediated by microbial sulfate reduction. Such differential kinetic behavior of Δ 48 values between vadose and phreatic zones could be used as a proxy marker for the presence and the location of a water-table. This study demonstrates the great potential of dual clumped isotopes in the investigation of meteoric diagenesis and will help understand the alteration of ancient sequences and the interpretation of stable C isotope trends that they contain. [ABSTRACT FROM AUTHOR]

A new species Arachnocoris furtivinabis Ma, Du et Yao sp. nov. is described and illustrated, which represents the first fossil record of Arachnocoris, also the first record in the family Nabidae from Cenozoic Dominican amber. Based on the distinctive morphological characters in this new species, including antennomere II much shorter than twice of antennomere I, labial segment III slightly longer than segment II, and parameres round, it is differentiated from other species within Arachnocoris. Compared with the spider-webdwelling taxa of the extant and extinct species in Heteroptera, the evolution of predation strategies for this special group during the Miocene was discussed. [ABSTRACT FROM AUTHOR]

The predation-driven Mesozoic marine revolution (MMR) is believed to have induced a dramatic change in the bathymetric distribution of many shallow marine invertebrates since the late Mesozoic. For instance, stalked crinoids – isocrinids (Isocrinida) have undergone a striking decline in shallow-sea environments and today they are restricted to deep-sea settings (below 100 m depth). However, the timing and synchronicity of this shift are a matter of debate. A delayed onset of MMR and/or shifts to a retrograde, low-predation community structure during the Paleogene in the Southern Ocean were invoked. In particular, recent data from the Southern Hemisphere suggest that the environmental restriction of isocrinids to the deep-sea settings may have occurred at the end of the Eocene around Antarctica and Australia, and later in the early Miocene in New Zealand. Here, we report the anomalous occurrence of the isocrinids in shallow nearshore marine facies from the middle Miocene of Poland (Northern Hemisphere, Central Paratethys). Thus, globally, this is the youngest record of shallow-sea stalked crinoids. This finding suggests that some relict stalked crinoids may have been able to live in the shallow-water environments by the middle Miocene, and further confirms that the depth restriction of isocrinids to offshore environments was not synchronous on a global scale. [ABSTRACT FROM AUTHOR]

The latest geological and geophysical information on the Zeya-Bureya sedimentary basin (Russia, Far East) is summarized. Based on drilling data from corehole and deep wells and 2D and 3D CDPM seismic data, taking into account the integrated interpretation of gravity and magnetic survey data and geological survey materials, a map was compiled for the surface of the pre-Mesozoic basement of the sedimentary basin, as well as structural maps for the top of the Cretaceous formations. The maps reflect a series of rift grabens and uplifts identified by the authors on seismic time sections during their reinterpretation. The method of compiling maps is given. A geological map of sediments overlying the pre-Mesozoic basement of the Zeya-Bureya sedimentary basin and a tectonic map of the sedimentary cover were compiled. During tectonic zoning of the sedimentary cover, the classification of tectonic elements was adopted that is widely used in the tectonic zoning of oil and gas regions, proposed by V.D. Nalivkin and updated at the Trofimuk Institute of Oil and Gas Geology and Geophysics, Siberian Branch, Russian Academy of Sciences (INGG SB RAS). As a result of tectonic zoning in the basin, the Inner Region and the Outer Belt were identified, and the tectonic elements complicating them were characterized. A characteristic feature of the Outer Belt is the presence of large intermediate structures: monoclines and mega- and mesomonoclines. Conversely, the Inner region of the basin is characterized by the presence of a large negative structure, complicated by smaller positive and negative elements. The main stages of the formation and development of the sedimentary cover of the Zeya-Bureya sedimentary basin are identified and described: rifting, early syneclise, late syneclise, and neotectonic. [ABSTRACT FROM AUTHOR]

Combined heavy mineral analysis and detrital zircon geochronology have enabled us to track detritus supplied by the ancestral river systems draining the North American continent into the deep subsurface of the Gulf of Mexico, in both the coastal plain and the offshore deep water areas. During deposition of the Paleocene–Eocene Wilcox Group, sandstones in the western part of the area are interpreted as the products of the Rosita system derived via paleo-Rio Grande material, with a large component of sediment shed from the Western Cordillera. By contrast, samples from wells further east have high proportions of zircons derived from the Yavapai-Mazatzal Province and are attributed to the Rockdale system with sediment fed predominantly by the paleo-Colorado or paleo-Colorado-Brazos. There is evidence that sediment from the Rosita system occasionally extended into the central Gulf of Mexico, and, likewise, data indicate that the Rockdale system sporadically supplied sediment to the western part of the basin. During the Late Eocene of the central Gulf of Mexico (Yegua Formation) there was a distinct shift in provenance. The earlier Yegua sandstones have a large Grenville zircon component and are most likely to have had a paleo-Mississippi origin, whereas the later Yegua sandstones are dominated by zircons of Western Cordilleran origin, similar to Wilcox sandstones fed by the Rosita system via the paleo-Rio Grande. The switch from paleo-Mississippi to paleo-Rio Grande sourcing implies there was a major reorganisation of drainage patterns during the Late Eocene. Miocene sandstones in the deepwater Gulf of Mexico were principally sourced from the paleo-Mississippi, although the paleo-Red River is inferred to have contributed to the more westerly-located wells. [ABSTRACT FROM AUTHOR]

Elongated biconvex Carex fossil fruits are relatively common in fossil assemblages, but they are of much uncertain taxonomic affinity. Three fossil-species have been erected to accommodate the materials from the respective type localities (C. klarae, C. paucifloriformis and C. paucifloroides) and a number of superficially similar-looking fossils were reported from other sites. The formerly proposed affinities mostly pointed to the extant C. pauciflora (subgen. Euthyceras) or Carex sect. Cyperoideae (subgen. Vignea), depending on the authors. But despite the similar superficial resemblance of the fossil remains to these not very closely related sedge taxa, other groups are also possible matches. We used a comparative approach employing stereomicroscope and SEM to analyze the affinities of several Old World "mummified" fossils (ca. 23 to 0.1 Ma) of elongated biconvex fruits. Several samples showed a fair preservation of previously unattested microscopic characters. In particular, one of them allowed us to detect an indirect record of fine silica body morphologies (impressions) on the periclinal walls, which permitted the sound taxonomic placement of the remains from the Miocene of Siberia as a Carex sect. Cyperoideae. In all the other fossils analyzed, the epidermal cell outline and the central position of the main silica body were sufficient to discard assignment to subgen. Euthyceras, despite a purported affinity to C. pauciflora reported in previous literature. In the absence of detailed information on silica bodies, epidermal cell (exocarp) details in fossil specimens do not seem to be determinant for the systematic placement. However, the addition of diagnostic style characters pointed to sect. Cyperoideae as the best match with the available information. Our data support a continued presence of Carex sect. Cyperoideae in the Old World since the Miocene, which candidates Eurasia as a possible place of origin for it, despite DNA-based reconstructions alone proposed North America. This study underlines the importance of detailed taxonomic studies to properly address the identity of fossils and unravel the biogeographic history of plants. [ABSTRACT FROM AUTHOR]

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One new extinct species of the genus Atomaria Stephens, 1829 is described and illustrated: A. (Anchicera) telnovi sp. nov. from Rovno amber. It is the sixth species of the subgenus Anchicera in Eocene amber; two-thirds of all species and two-thirds of all reported Eocene amber silken fungus beetle specimens belong to this subgenus. The reasons for the relative abundance of Anchicera in the Eocene fossil resins are discussed. A key to extinct Eocene species of Atomaria is provided. [ABSTRACT FROM AUTHOR]

A new species of narrow-waisted bark beetle is described from Eocene Rovno amber (Ukraine): Diagrypnodes villumi sp. nov. (Coleoptera: Salpingidae). This fossil refutes a simplistic view of the genus Diagrypnodes as a typical Gondwanan lineage whose extant species are disjunct between Australia, New Caledonia, and New Zealand. Diagrypnodes villumi is the first definitive fossil species of the subfamily Inopeplinae, the other being Eopeplus stetzenkoi Kirejtshuk and Nel from lowermost Eocene (53 Ma) Oise amber which was placed in this subfamily, albeit tentatively. Extant inopeplines occur in tropical and subtropical areas worldwide. The presence of Diagrypnodes and Eopeplus in Eocene Europe suggest a formerly different and presumably wider distribution of the subfamily. Furthermore, the ant Lasius schiefferdeckeri Mayr (Hymenoptera: Formicidae) preserved in the amber piece as a eusyninclusion with D. villumi is a new example of the simultaneous presence of the temperate and frost intolerant elements in European Eocene amber forests.LSID [ABSTRACT FROM AUTHOR]

Summary: Angiosperm fossil woods of putative Eocene age from Corcovado, Chubut Province are described. They are placed in four taxonomic units: Weinmannioxylon trichospermoides and cf. Caldcluvioxylon of the Cunoniaceae, Myrceugenellites maytenoides of the Myrtaceae, and Nothofagoxylon ruei of the Nothofagaceae. The taxa in the assemblage are in accordance with similar fossil wood assemblages previously described from the Eocene and Oligocene of Patagonia. All the taxa are anatomically similar to trees that live today in Patagonia. Some of the woods show decay patterns by different saproxylic organisms. These include arthropod borings with coprolites and fungal remains in fungi-decayed tissues that are consistent with an active saproxylic community involved in the recycling of wood in the depositional paleoenvironment. [ABSTRACT FROM AUTHOR]

The Cenozoic stratigraphy of the Zagros records the ongoing collision between the Arabian and Eurasian Plates and the closure of NeoTethys. A Paleogene NW‐SE trending foreland basin was inherited from a Late Cretaceous precursor. Widespread progradation into the foredeep was a feature of both margins which, allied to ongoing tectonism, had by the late Eocene led to the narrowing and subsequent division of the foredeep into the Lurestan – Khuzestan and Lengeh Troughs, separated by the northward continuation of the rejuvenated Qatar‐Fars Arch. This sub‐division strongly influenced subsequent deposition and the petroleum geology of the area. In addition, the diachronous nature of the Arabian – Eurasian collision led to strong diachroneity in lithostratigraphic units along the length of the Zagros. Hence its petroleum geology is best understood within a regional sequence stratigraphic framework. This study identifies three tectono‐megasequences (TMS 10, TMS 11a, TMS 11b) and multiple depositional sequences. The Cenozoic contains a world class hydrocarbon province with prolific oil reservoirs in the Oligo‐Miocene Asmari Formation sealed by the evaporite‐dominated Gachsaran Formation, mostly contained within giant NW‐SE trending "whaleback" anticlines concentrated in the Dezful Embayment. Reservoirs in the SW are dominantly siliciclastic or comprise mixed siliciclastics and carbonates, whereas those to the east and NE are dominated by fractured carbonates. There remains untested potential in stratigraphic traps, especially in deeperwater sandstone reservoirs deposited along the SW margin of the foredeep. Late Miocene to Pliocene charge to the Asmari reservoirs was mostly from Aptian – Albian Kazhdumi Formation source rocks. In some fields, an additional component was from organic‐rich late Eocene to earliest Oligocene Pabdeh Formation source rocks confined to the narrowing Lurestan – Khuzestan Trough. Where mature, the latter source rock is also a potential unconventional reservoir target, although the prospective area is limited due to recent uplift and erosion. Deeper Jurassic source rocks contributed to the Cheshmeh Khush field in Dezful North. Silurian source rocks charged gas‐bearing structures in the Bandar Abbas region. [ABSTRACT FROM AUTHOR]

We describe a diverse aquatic insect assemblage from McGraths Flat, a Miocene Lagerstätte in central New South Wales, Australia that includes representatives of Sialidae, Limoniidae, Chironomidae and Chaoboridae. The aquatic insect fossils from this deposit consist predominantly of larvae. These include a new species of phantom midge (Chaoborus, Chaoboridae), three morphotypes of non‐biting midges (Chironomidae), one morphotype of cranefly (Limoniidae) and one morphotype of alderfly (Sialidae). The large number of fossil specimens enabled us to study the ontogeny of the new midge species. We discerned growth rates in fossil larvae, using morphometry of all four instars of Chaoborus. The simultaneous presence of taxa associated with still water and taxa associated with flowing water supports the hypothesis that McGraths Flat was deposited in an isolated water body (oxbow lake/billabong) with influence from a river during high water events. [ABSTRACT FROM AUTHOR]

In the southeastern Tibetan Plateau, region‐scale dextral strike‐slip shear zones, crucial for India‐Asia convergence, were investigated along the Dulongjiang shear zone near the Eastern Himalayan Syntaxis (EHS). Structural, kinematic, and geochronological data from Dulongjiang and Nabang regions in western Yunnan, China, reveal dextral strike‐slip shearing between 30 and 15 Ma. Various rocks were affected by moderate‐temperature shear deformation (∼450–550°C), inferred from microstructures and quartz CPO patterns, during dextral strike‐slip and exhumation of the shear zone. Combined with structures of pre‐, syn‐, and post‐shearing leucogranites, zircon U‐Pb dating indicates that the dextral shear along the shear zone began in the Early Oligocene (30–29 Ma) subsequent to the India‐Asia collision. Micas in mylonitic granites yield 40Ar/39Ar ages, suggesting that the principal dextral shear deformation occurred approximately between 18 and 15 Ma. The Dulongjiang shear zone is linked to the Parlung, Nabang shear zone, and Sagaing Fault, forming a regional Cenozoic dextral shear system around the EHS. The study, combined with tomographic anomalies beneath the India‐Asia collision zone, highlights distinct lithospheric‐scale evolution in southeastern and eastern Tibet. Continuous intracontinental strike‐slip shearing indicates a tectonic shift from Tibetan extension to block rotation around the EHS. From 30 to 15 Ma, slab tear, accompanied by clockwise rotation and dextral strike‐slip shearing, suggests a warmer geodynamic setting influenced by hot mantle flow associated with ongoing subduction of the Indian lithosphere. Oligocene‐Miocene dextral strike‐slip shearing around the EHS, linking southwards with the Sagaing Fault, may correspond to the rotation necessary for slab to bend, stretch, and eventually tear beneath the region. Plain Language Summary: The southeastern Tibetan Plateau undergoes active southeastward extrusion and rotation around the Eastern Himalayan Syntaxis (EHS) due to ongoing Indo‐Eurasian continent collision. N‐S, NW‐SE, and NE‐SW ductile strike‐slip shear zones/faults in Tibet and the Indochina Block reveal this tectonic activity. Understanding their kinematics, linkages, and developmental patterns is crucial for investigating the relationship between Cenozoic surface tectonics and Tibetan Plateau lithospheric evolution. This study focuses on the Jiali‐Dulongjiang‐Nabang dextral (relative rightward movement on both sides of the fault) strike‐slip ductile shear zone/fault system, revealing a curved regional‐scale dextral strike‐slip zone system influenced by continuum rotation deformation, driven by slab tear beneath the EHS region. Contrary to the concept of a conjugated strike‐slip shear/fault system dominating extension tectonics, these findings suggest a significant influence of continuum rotation deformation on the initiation, movement, and linkage of curved dextral strike‐slip shearing around the EHS. Key Points: A network of dextral strike‐slip shear zones formed a regional curved belt around the Eastern Himalayan Syntaxis from ∼30 to ∼15 MaSlab tear beneath the Eastern Himalayan Syntaxis induced unique asthenospheric flow pattern, causing the bending and interconnection of dextral shear zonesThe V‐shaped conjugate shear zones are related to indent‐driven system, marking northward penetration of the Indian plate into Eurasia [ABSTRACT FROM AUTHOR]

Abstract The predation-driven Mesozoic marine revolution (MMR) is believed to have induced a dramatic change in the bathymetric distribution of many shallow marine invertebrates since the late Mesozoic. For instance, stalked crinoids – isocrinids (Isocrinida) have undergone a striking decline in shallow-sea environments and today they are restricted to deep-sea settings (below 100 m depth). However, the timing and synchronicity of this shift are a matter of debate. A delayed onset of MMR and/or shifts to a retrograde, low-predation community structure during the Paleogene in the Southern Ocean were invoked. In particular, recent data from the Southern Hemisphere suggest that the environmental restriction of isocrinids to the deep-sea settings may have occurred at the end of the Eocene around Antarctica and Australia, and later in the early Miocene in New Zealand. Here, we report the anomalous occurrence of the isocrinids in shallow nearshore marine facies from the middle Miocene of Poland (Northern Hemisphere, Central Paratethys). Thus, globally, this is the youngest record of shallow-sea stalked crinoids. This finding suggests that some relict stalked crinoids may have been able to live in the shallow-water environments by the middle Miocene, and further confirms that the depth restriction of isocrinids to offshore environments was not synchronous on a global scale.

Objective The formation of monsoon climates is attributed to the seasonal reversal of wind direction and precipitation caused by the difference in thermal capacity between land and ocean. Asia is recognized as the most prominent region globally, with monsoon climates, that affect the largest population. The heavy rainfall accompanying monsoons can result in various secondary disasters, substatially jeopardizing human safety and productivity in the region. Consequently, comprehending the formation process of the Asian monsoon holds paramount importance. Methods This study aim to employ geological concepts to establish a connection between the past and present, providing an overview of the components of Asian monsoons, identifying the primary factors influencing their formation and evolution, and summarizing research progress on the South Asian and East Asian monsoons based on sediment records from key Asian locations. Results The findings indicate that during the Cenozoic, the collision between the Indian Plate and the southern margin of the Asian continent altered the distribution of land and sea in Asia. Consequently, the Tibetan Plateau experienced initial uplift, contributing to the emergence of monsoon climates in South Asia and East Asia. However, at this stage, the East Asian region was still primarily influenced by the planetary wind system, and the East Asian monsoon was in its early stages, predominantly restricted to the southern margin of the South China Plate in a localized manner. In contrast, the South Asian Monsoon covered a relatively extensive area. This discrepancy may be attributed to the delayed opening of marginal seas in the East Asian region compared to the relatively earlier occurrence of land and sea distribution in South Asia. However, as the Tibetan Plateau continued to uplift and approach its current altitude during the middle to late Cenozoic, the Asian monsoon entered a strengthening phase, notably impacting regional geological evolution processes. Since the middle to late Cenozoic, the development of the North and South Polar ice caps and the upliftment of the Tibetan Plateau have controlled the Asian monsoon, leading it to undergo multiple stable periods of development. Conclusion The development and evolution of the East Asian and South Asian monsoons are mainly driven by the distribution of sea and land in the Asia, the upliftment of the Tibetan Plateau and the global climate change during the Cenozoic. Significance These findings provide valuable insights into the scientific and rational utilization of the Asian monsoon for conducting systematic Earth science research in Asia.

The article presents a comparative analysis of the Paleozoic and Cenozoic reef formation, mainly in terms of the position of reefs in the basins of continental and oceanic blocks. It is shown that the main formation of reefs took place in the Cenozoic directly in the oceans, including boundaries between oceans and continents, and, to an extremely limited scales, in the basins of the continental segment. In the Paleozoic, reefs were formed not only in oceans, but also in spacious basins of continental block. This is one of the manifestations of the general evolution of carbonate accumulation, when the Paleozoic carbonate sediments were formed in such shallow-water bodies that covered very significant surfaces of continents. [ABSTRACT FROM AUTHOR]

Albatrosses are among the most intensely studied groups of living birds, yet their fossil record remains sparse. Despite modern albatrosses being more abundant and widespread in the Southern Hemisphere, the vast majority of fossil albatrosses identified to date come from Northern Hemisphere localities. Here, we describe Plotornis archaeonautes sp. nov., a new albatross species from the earliest Miocene that represents the earliest record of Procellariiformes in New Zealand and the earliest uncontroversial record of the clade Pan-Diomedeidae from the Southern Hemisphere. Phylogenetic analyses support the placement of Plotornis outside of the clade uniting all extant albatrosses. The new fossil reveals that stem lineage albatrosses were widespread by the onset of the Neogene. Although the humerus of Plotornis archaeonautes exhibits a short processus supracondylaris dorsalis, this early species may have possessed at least one of the unique ossifications associated with the patagial bracing system present in modern albatrosses. [ABSTRACT FROM AUTHOR]

Distinctive, reticulately sculptured ellipsoidal endocarp impressions have been discovered in Middle Miocene lake deposits of Idaho and eastern Oregon in the northwestern USA. We describe a new species based on these endocarp impressions and compare them morphologically with previously described extinct and extant species of Sabia (Sabiaceae) using light microscopy and micro-CT scanning. Sabia megacarpa sp. nov. endocarps are distinguished by their large size but resemble other species of Sabia in their asymmetric elliptical shape, reticulate surface ribs, unilocular morphology and gland-dotted endocarp surface. Although Sabia is now native to Southeast Asia and Malesia, the fossil record indicates this genus was formerly present in Europe and North America. The new species indicates that Sabia survived until at least 16 million years ago in western North America.

Penguin tarsometatarsi are shortened and flattened, and studies devoted to the internal characteristics of these composite bones are very limited. Therefore, we present here a comprehensive, x‐ray‐microscopy‐based analysis based on tarsometatarsi of Eocene stem Sphenisciformes from Seymour Island (Antarctic Peninsula) as well as recent Aptenodytes forsteri, A. patagonicus, and Pygoscelis adeliae penguins. Our study focuses on four aspects: size variability of the medullary cavities, vascularization patterns with emphasis on diaphyseal vessels, cross‐sectional anisotropy, and diaphyseal resistance to bending forces. Small‐sized Eocene penguins (Delphinornis and Marambiornopsis) show well‐developed tarsometatarsal medullary cavities, whereas the cavities of “giant” early Sphenisciformes are either smaller (Palaeeudyptes) or show a conspicuous intermetatarsal size gradient (Anthropornis). Extant penguins exhibit a decrease in cavity dimensions as their body size increases. Distributional tendencies of primary diaphyseal nutrient foramina are quite similar in the smaller Delphinornis, Marambiornopsis, and extant Pygoscelis on one side and in Palaeeudyptes and extant Aptenodytes on the other. Anthropornis shows a unique, plesiomorphic pattern with a prevalence of plantar blood supply to the metatarsals. The diaphyseal nutrient canals diverge in orientation, some obliquely away from the proximal part, others with disparate trajectories. Cross‐sectional anisotropy along the tarsometatarsal shaft generally appears to be rather low. Clustering of coherency curves along certain tarsometatarsal segments may reflect a selection process that exerts a significant influence within biomechanically crucial sections. Diaphyseal resistance to mediolateral bending forces is explicitly more efficient in extant penguins than in Eocene Sphenisciformes. This can be interpreted as an adaptation to the waddling gait of extant penguins. [ABSTRACT FROM AUTHOR]

Strontium isotopes (87Sr/86Sr) are commonly used to assess the age of Cenozoic dolostones found on many isolated oceanic islands. The possible influence of Rubidium (Rb) content on the 87Sr/86Sr ratios, however, has generally been ignored. This critical issue is assessed by examining the 87Sr/86Sr ratios and elements (Rb, Sr, Al, Ti and K) of seventy‐one samples that came from a ca 339 m thick cored interval of Cenozoic dolomite on the Xisha Islands, South China Sea. For the dolomite from the upper Pliocene Yinggehai Formation (180.5 to 308.5 m; average 23% dolomite) there is a positive correlation between the 87Sr/86Sr ratios and Rb concentrations, whereas for the dolomite from the lower late Miocene Huangliu Formation (308.5 to 519 m; average >98% dolomite) such a correlation is not evident. Combined with high‐temperature experiments, correlation between Al, Ti, K, Rb and 87Sr/86Sr indicates that Rb containing old 87Rb from terrestrial materials modified the 87Sr/86Sr ratios of the Yinggehai dolomite, but not those from the Huangliu dolomite. This is mainly attributed to the different sources of terrestrial dust carried by different East Asian monsoon systems between the late Miocene and Pliocene, and probably also influenced by the dolomitization process to some extent. To test for 87Rb contamination, extrapolation of results from the Yinggehai dolomite and Huangliu dolomite indicate that concentrations of Rb < 1 ppm, Al < 1000 ppm, Ti < 15 ppm and K < 250 ppm in the dolomite indicates that terrestrial inputs are minimal and that the measured 87Sr/86Sr ratios can be used for determining the dolomitization age. Potentially, these concentration thresholds may serve as a screening criterion for assessing the reliability of Sr isotope chronostratigraphy of other island dolostones throughout the world. [ABSTRACT FROM AUTHOR]

The Carbonate Compensation Depth (CCD) refers to the depth within the ocean where the production and dissolution rates of carbonates reach equilibrium, widely likened to the oceanic calcareous 'snowline'. The reconstruction of deep-time CCD has significant implications for understanding ocean circulation, seawater chemical conditions, sediment distribution, and the surface carbon cycle. This paper critically reviews the methods for CCD reconstruction, summarizes the driving mechanisms of the Cenozoic CCD evolution and its association with the carbon cycle, and offers insights into future directions for CCD research. CCD reconstruction has evolved over the past half century from early qualitative to quantitative methods. These methodological improvements have markedly improved the accuracy and resolution of CCD. Existing studies have indicated a general trend of the CCD deepening across major ocean basins since the Cenozoic, interspersed with a minor shallowing phase during the mid-Miocene. The variations in the CCD are primarily influenced by factors such as ocean productivity, weathering, and shelf-basin partitioning. During climate events such as the Paleocene-Eocene Thermal Maximum, the CCD exhibits pulselike fluctuations. Future research should focus on precision and quantification while integrating model simulations to further explore the correlations and response mechanisms between the CCD and the paleoclimate as well as the carbon cycle. [ABSTRACT FROM AUTHOR]

The Late Miocene natural traps of Cerro de los Batallones (Madrid, Spain) have yielded thousands of fossils of vertebrates, mostly carnivoran mammals such as hyaenids, amphicyonids, ailurids, mustelids, ursids, and felids, especially Batallones-1 and Batallones-3. Among these carnivorans, the tiger-sized saber-toothed felid Machairodus aphanistus was the top predator of the association, and one of the most abundant taxa, represented by thousands of fossils, including several examples of bone pathologies that have never been studied. In this work, we carry out a paleopathological analysis of some of these pathologies from the Batallones sample of this large early machairodontine, with a description of the pathological changes that occurred in the affected bones, a possible diagnosis, and the ethological and ecological consequences of the presence of these diseases in the living animal. The pathological sample of M. aphanistus studied here included a calcaneus and a Mc III from Batallones-1, and a mandible from Batallones-3. The fossils were X-rayed, and their pathologies were described and compared to non-pathological bones. The calcaneus showed a bone callus indicative of osteitis/osteomyelitis or a tumor; the mandible had evidence of the development of an abscess located in the left mandibular body; and the Mc III shows a marked osteosclerosis. These injuries affected the hunting ability of these individuals and gradually weakened them, very likely contributing to their final entrapment in the Batallones cavities, where they were attracted by the presence of previously trapped animals. [ABSTRACT FROM AUTHOR]

[Display omitted] Fossil plants in sub-basaltic and fluvial silcretes differ in their geological setting, silica source, taphonomy, preservation and the plants and communities represented: these factors collectively indicate distinct silicification pathways. This review shows that the floras in sub-basaltic silcretes are mostly autochthonous, being derived from the local vegetation, whereas the floras in inland fluvial silcretes are transported and allochthonous. The floras in both are three-dimensionally preserved. The plants in sub-basaltic silcretes are usually permineralised, preserving internal anatomy and cellular morphology, whereas the plants in inland fluvial silcretes occur as moulds/impressions that may preserve epidermal and surface features. Both types of silcrete floras offer insights into past environments and ecological drivers. Terrestrial (ground-dwelling) ferns are frequently preserved in situ in sub-basaltic silcretes whilst in the inland fluvial silcretes they are represented only by pinnule fragments or abscised pinnules. The extraordinary anatomical preservation of soft tissues in sub-basaltic silcretes, e.g., exocarps of fruits, bark on wood, actively growing vegetative shoots (fern croziers) and root nodules, is evidence of rapid burial by volcanogenic sediments and subsequent silicification by silica-rich groundwaters. The source of silica was hydrothermal fluids released at the time of eruption and/or the weathering of overlying volcanics, and the acidic (humic) conditions resulting from buried plant material provided ideal geochemical conditions for silica precipitation and plant permineralisation. The sub-basaltic silcrete floras formed contemporaneously with Eocene–Miocene volcanism in eastern Australia, whereas the formation of inland pedogenic and fluvial silcretes was probably initiated during the Paleocene–Eocene Thermal Maximum (PETM). The fine surface preservation of plants in inland fluvial silcrete floras indicates rapid burial but no organic material is preserved, probably because oxidising groundwaters stripped out the organics before silicification occurred. The comparatively less silica-rich groundwaters associated with fluvial silcretes and the sandy substrates would have further contributed to the loss of plant material. [ABSTRACT FROM AUTHOR]

Scratch circles, previously defined as 'bedding plane parallel sedimentary structures formed by the passive rotation of a tethered organism into the surrounding sediment', have hitherto been identified in the geological record from the Ediacaran to the Paleocene, as well as in modern settings. They have not met the definition of trace fossils, being passively registered by a part of a plant. Several variations of scratch circle morphology have been identified in or on Pliocene and Pleistocene deposits on the Cape south coast of South Africa, allowing for an expansion of the scratch circle temporal range. Furthermore, these novel forms require a redefinition of the term 'scratch circle'. Anthropogenic origins need to be considered for occurrences in the Pleistocene; guidelines to assist in distinguishing such causes from typical scratch circles are presented. Scratch circles may conceivably have inspired the creation of circular patterns (palaeo-art) in sand by Middle Stone Age hominins. Evaluation of scratch circles in snow allows for subtle features to be determined. A re-evaluation of what the term 'trace fossil' constitutes could be considered, in order to include the term palaeo-ichnobotany. [ABSTRACT FROM AUTHOR]

The boron isotope ratio of seawater (δ11Bsw) is a parameter which must be known to reconstruct palaeo pH and CO2 from boron isotope measurements of marine carbonates. Beyond a few million years ago, δ11Bsw is likely to have been different to modern. Palaeo δ11Bsw can be estimated by simultaneously constraining the vertical gradients in foraminiferal δ11B (Δδ11B) and pH (ΔpH). A number of subtly different techniques have been used to estimate ΔpH in the past, all broadly based on assumptions about vertical gradients in oxygen, and/or carbon, or other carbonate system constraints. In this work we pull together existing data from previous studies, alongside a constraint on the rate of change of δ11Bsw from modeling. We combine this information in an overarching statistical framework called a Gaussian Process. The Gaussian Process technique allows us to bring together data and constraints on the rate of change in δ11Bsw to generate random plausible evolutions of δ11Bsw. We reconstruct δ11Bsw, and by extension palaeo pH, across the last 65Myr using this novel methodology. Reconstructed δ11Bsw is compared to other seawater isotope ratios, namely Sr87/86 ${}^{87/86}\mathrm{S}\mathrm{r}$, Os187/188 ${}^{187/188}\mathrm{O}\mathrm{s}$, and δ7Li, which we also reconstruct with Gaussian Processes. Our method provides a template for incorporation of future δ11Bsw constraints, and a mechanism for propagation of uncertainty in δ11Bsw into future studies. Plain Language Summary: Boron naturally exists in two forms—11B and 10B. Measuring the ratio of these two forms of boron within marine shells allows us to estimate how alkaline the ocean was in the past, which is related to how much carbon dioxide is in the atmosphere. Before we can do this calculation though, we need to know some other parameters, one of which is the relative abundance of the two forms of boron in the ocean at the time (which we call δ11Bsw). Preexisting studies have estimated δ11Bsw at particular times, and here we combine them to generate a full reconstruction across the last 65 million years, accounting for uncertainties. Our reconstruction is informed by limiting the rate at which δ11Bsw can change, based on model simulations. We provide a set of plausible evolutions of δ11Bsw which can be used in future work when calculating past ocean pH. Key Points: We reconstruct the temporal evolution of seawater isotope ratios of boron, strontium, lithium, and osmium over the last 65 million yearsThe evolution of seawater boron isotope ratio shows similarity to the evolution of strontium, lithium and osmium isotope ratiosRandomly drawn, smooth time series are provided for use in uncertainty propagation in calculation of palaeo pH [ABSTRACT FROM AUTHOR]

The present‐day deformation style of the Eastern Cordillera in NW Argentina is strongly influenced by the inversion of pre‐existing Paleozoic and Mesozoic structures. In particular, the extensional faults and lithological contrasts resulting from the Cretaceous–Paleogene Salta Rift phase form heterogeneities that were preferentially reactivated during the Andean orogeny. Constraining the timing and characteristics of reactivation is a key to understanding the interplay between tectonics and inherited crustal anisotropies. In this study, we combine structural and sedimentological field data with a low‐temperature thermochronology data set from the area surrounding the fault‐bounded Cianzo basin. The southeastern boundary is formed by the inverted Hornocal fault, which was the basin‐bounding normal fault of the Lomas de Olmedo sub‐basin (Salta Rift basin). Lacustrine deposits of the Yacoraite Formation overspill on the footwall of this fault and mark tectonic quiescence during the post‐rift phase of the Salta Rift. Apatite (U‐Th‐Sm)/He and fission track ages in the Hornocal fault hanging wall show an onset of rapid cooling interpreted to be concomitant with fault inversion between the latest Oligocene and middle Miocene (∼24–15 Ma). Low‐temperature thermochronology data also constrain the timing of major folding in the eastern limb of the Cianzo syncline to pre‐10 Ma, whereas the western limb started tilting post‐10 Ma. Characterization of exhumation patterns related to fault activity surrounding the Cianzo basin emphasizes the influence of the pre‐existing structural framework on deformation in fold‐and‐thrust belts. Key Points: Pre‐existing structures in fold‐and‐thrust belts influence deformation and exhumation patternsLow‐temperature thermochronology data show that inversion of the Hornocal normal fault began in the latest Oligocene–middle MioceneOut‐of‐sequence activity along the Cianzo thrust, as well as eastward propagation of exhumation began in the middle Miocene–Pliocene [ABSTRACT FROM AUTHOR]

[Display omitted] The Indo-Pacific warm pool (IPWP) is crucial for regional and global climates. However, the development of the IPWP and its effect on the regional climate during the Cenozoic remain unclear. Here, using a compilation of sea surface temperature (SST) records (mainly since the middle Miocene) and multimodel paleoclimate simulations, our results indicated that the extent, intensity and warmest temperature position of the IPWP changed markedly during the Cenozoic. Specifically, its extent decreased, its intensity weakened, and its warmest temperature position shifted from the Indian to western Pacific Ocean over time. The atmospheric CO 2 dominated its extent and intensity, while paleogeography, by restricting the distribution of the Indian Ocean and the width of the tropical seaways, controlled the shift in its warmest temperature position. In particular, the eastward shift to the western Pacific Ocean from the middle to late Miocene inferred from compiled SST records likely resulted from the constriction of tropical seaways. Furthermore, by changing the atmospheric thermal structure and atmospheric circulation, the reduced extent and intensity of the IPWP decreased the annual precipitation in the western Indian Ocean, eastern Asia and Australia, while the shift in the warmest temperature position from the Indian to western Pacific Ocean promoted aridification in Australia. Qualitative model-data agreements are obtained for both the IPWP SST and regional climate. From the perspective of past warm climates with high concentrations of atmospheric CO 2 , the expansion and strengthening of the IPWP will occur in a warmer future and favor excessive precipitation in eastern Asia and Australia. [ABSTRACT FROM AUTHOR]

Dryland calcicolous plants are drought-tolerant species that are adapted to survive on alkaline low-nutrient bare substrates derived from limestone around the world. Outcrops of the Otekaike Limestone of North Otago host some rare low-growing (<10 cm) endemic calcicoles, and conservation reserves have been created at some localities. The calcicoles occupy microhabitats in solution cavities in limestone outcrops, growing in thin (<10 cm) limestone debris accumulations, including detrital sand and silt. Calcicoles also grow in coarse and fine disaggregated limestone talus deposits at tops and bottoms of outcrops, commonly with the low-growing exotic hawkweed but the calcicoles are displaced by taller species, especially grasses. Calcicole substrates have pH 8 to 9, with a balance between calcite dissolution and calcite re-precipitation. Electrical conductivity is typically <500 µS/cm, but can be as high as 7 mS/cm with evaporative salts and salt weathering enhancing porosity. The limestone contains variably oxidised authigenic glaucony and pyrite, which provide some plant nutrients (K, Mg, Fe, S, N) as roots penetrate porous limestone, with apatite providing phosphate. Persistence of these rare calcicolous communities in soil-free settings is strongly affected by the underlying mineralogy and geochemistry, and some similar microhabitats may occur on other rock types. [ABSTRACT FROM AUTHOR]

The Qaidam Basin is the largest Cenozoic sedimentary basin on the northern part of Qinghai-Xizang Plateau, with a stratum thickness exceeding 10 km. By revealing the magnetic fabric information preserved in Cenozoic within the basin, it is possible to reconstruct the regional tectonic stress orientation, which is of great significance for exploring the tectonic deformation and dynamic mechanism in the northern part of Qinghai-Xizang Plateau. The anisotropy of magnetic susceptibility in various directions of Cenozoic strata samples from Lulehe section in the northern Qaidam Basin was measured. Subsequently, magnetic fabric information was obtained from 1 070 samples, and an analysis was conducted on the morphology of the magnetic fabric and its related parameters. The results show that the magnetic fabric of strata during 23.7-9.9 Ma in Lulehe section shows an initial deformation magnetic fabric, with its magnetic lineation indicating the direction of compression stress. The magnetic fabric of strata during 9.9-5.2 Ma is characterized by sedimentary fabric, and no obvious tectonic stress direction is recorded. After removing the effects of structural rotation using magnetic declination, variations are observed in the orientation of the compressive stress recorded by the magnetic fabric in Lulehe section over different periods, respectively. During 23.7-18.1 Ma, it gathers at ～25°, revealing that the northern Qaidam Basin suffers from near SN compression stress in the Early Miocene. During 18.1-15.2 Ma, the direction of compressive stress rotates counterclockwise from ～25° to ～-20°. During 15.2-9.9 Ma, the direction of compressive stress rotates clockwise from ～-20° to ～20°. These results reveal that the compression stress direction of the northern Qaidam Basin first rotates counterclockwise (18.1-15.2 Ma) and then rotates clockwise (15.2-9.9 Ma) in the Middle Miocene. Based on the surrounding tectonic framework and the previous analysis of tectonic deformation, it is considered that the rotation of tectonic stress on the northern margin of Qaidam Basin since the Middle Miocene may be closely related to the superposition of bidirectional compression stress from East Kunlun and Qilian Mountains [ABSTRACT FROM AUTHOR]

The calcareous nannofossil genus Reticulofenestra and its related taxa are called "reticulofenestrids," and they were one of themajor nannofossil groups during the Cenozoic. The reticulofenestrid specimens are composed of two shields, proximal and distal, which are circular or subcircular in shape and consist of tiny calcite plates. Cyclic changes in the size and shape of reticulofenestrid coccoliths have been used to characterize their evolution. The major taxonomic turnover in this group was related to environmental changes during the Cenozoic. From the Oligocene to the Miocene, there were several different types of reticulofenestrids. The primary taxon of reticulofenestrids disappeared during the Oligocene-Miocene boundary, and elliptical species emerged during the early Miocene. However, it is uncertain exactly when and how the change in reticulofenestrids occurred. To understand the evolutionary trends of reticulofenestrids, we conducted biometric analyses from the Oligocene to the Miocene. Detailed observation and measurement of reticulofenestrid coccoliths under a scanning electron microscope revealed a significant size reduction in the group near the Oligocene--Miocene, which corresponds to a period of rapid global cooling. Furthermore, regarding the reticulofenestrid taxa in this study, central structures characterize the Oligocene genus Dictyococcites, and the long axis length of the coccolith outline and central areas can be effective characteristics for distinguishing between theMiocene Cyclicargolithus and Reticulofenestra. These results suggest that morphological differences of reticulofenestrids are expressed not only in the shape and size of the coccolith but also in the size and shape of its central area [ABSTRACT FROM AUTHOR]

The northeastern periphery of the Qaidam Basin is a crucial region for comprehending the northeastward growth of the Tibetan Plateau, as it documents Late Cenozoic crustal deformation that elucidates the plateau's growth process. In this study, we reconstruct three stages of crustal deformation in the northeastern periphery of the Qaidam Basin during the Late Cenozoic based on interpretation of growth strata from five seismic profiles, structural mapping of the typical superimposed folds and detailed detrital zircon analysis within the study area. (1) During the Early Miocene to Late Miocene period (23–8.6 Ma), there was NW–SE extensional deformation in the northeast margin of the Qaidam Basin, which exerted control over the deposition of the Youshashan Formation. (2) The NW–SE shortening occurred during the Late Miocene period (8.6–8.1 Ma), subsequent to the deposition of the Youshashan Formation and preceding the deposition of the Shizigou Formation, resulting in a parallel unconformity between these two geological units. (3) The intense shortening of the NE–SW direction occurred during the Late Miocene and Pliocene epochs (8.1–2.5 Ma). The timing of this deformation aligns with the sedimentary age of the Shizigou Formation, suggesting that the initial deformation age may represent the onset of NE extrusion from the Tibetan Plateau towards the northeast margin of the Qaidam Basin. The present study not only delineates a Late Cenozoic structural dome resulting from two‐stage crustal shortening in the northeastern periphery of the Tibetan Plateau, but also provides a crucial evidence for reconstructing the Late Cenozoic intracontinental deformation process in this region. [ABSTRACT FROM AUTHOR]

A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation. Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions, the geometry, kinematics, and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang (Pearl) River Mouth basin were investigated. Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation. The intense rifting of the main faults of the transfer zone controlled the development of source rocks and fault-controlled slope break paleogeomorphology. The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap, and the secondary faults in the transfer zone contribute to the hydrocarbon transportation. The conjugate intersection area of the NE- and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation. [ABSTRACT FROM AUTHOR]

Diplura are an ancient group of basal (apterygote) hexapods that thrive in various cryptic terrestrial habitats. Despite an ancient origin that extends at least to the Devonian period, the dipluran fossil record is exceedingly sparse. Here, we document five very rare fossil specimens of the family Campodeidae in amber from the Miocene of the Dominican Republic and the Eocene of the Baltic region. Microscopic preservation in amber provides unique detail for taxonomic placement of small, delicate, soil- and leaf litter-dwelling organisms like these. New taxa include the following: in Lepidocampinae, Lepidocampa glaesi sp. nov. (in Dominican amber); and in Campodeinae, Litocampa eobaltica sp. nov. (in Baltic amber) and Rostricampa engeli gen. et sp. nov. (in Dominican amber). Rostricampa has an extraordinary rostrum formed by sclerotized extensions of the clypeus and, probably, the labium, unique among diplurans. These new taxa provide rare additional data on the fossil record of the earliest diverging lineages of the hexapods and shed light on their evolution and ecology. [ABSTRACT FROM AUTHOR]

Reconstructing global mean surface temperature (GMST) is one of the key contributions that paleoclimate science can make in addressing societally relevant questions and is required to determine equilibrium climate sensitivity (ECS). GMST has been derived from the temperature of the deep ocean (Td), with previous work suggesting a simple Td‐GMST scaling factor of 1 prior to the Pliocene. However, this factor lacks a robust mechanistic basis, and indeed, is intuitively difficult to envisage given that polar amplification is a ubiquitous feature of past warm climate states and deep water overwhelmingly forms at high latitudes. Here, we interrogate whether and crucially, why, this relationship exists using a suite of curated data compilations and two sets of paleoclimate model simulations. We show that models and data are in full agreement that a 1:1 relationship is a good approximation. Taken together, the two sets of climate models suggest that (a) a lower sensitivity of SST in the season of deep water formation than high latitude mean annual SST in response to climate forcing, and moreover (b) a greater degree of land versus ocean surface warming are the two processes that act to counterbalance a possible polar amplification‐derived bias on Td‐derived GMST. Using this knowledge, we provide a new Cenozoic record of GMST. Our estimates are substantially warmer than similar previous efforts for much of the Paleogene and are thus consistent with a substantially higher‐than‐modern ECS during deep‐time high CO2 climate states. Key Points: Deep ocean temperature changes are used to constrain global mean surface temperature yet the underlying assumptions lack detailed scrutinyBoth curated data compilations and climate model simulations demonstrate that deep ocean‐derived global mean surface temperature (GMST) estimates are robustWe update the transformation equations and provide a revised estimate of GMST through the Cenozoic [ABSTRACT FROM AUTHOR]

Phylogenetic studies of fossil bivalves are crucial for understanding evolution in both extinct and extant species, and the family Carditidae has received limited research attention in this regard. The endemic genus Malarossia comes from the Eocene deposits of Ukraine and the diversity of carditids during this time have been broadly described from North America and Western Europe, although little is known beyond these regions. The aim of this study is to explore the phylogenetic position of the genus Malarossia and discuss trends in shell size among carditids. To accomplish this, a phylogenetic analysis was conducted using 51 species and 153 morphological characters. Our findings indicate that Malarossia represents an early diverging genus within the subfamily Scalaricarditinae, supported by morphological characters related to development and number of radial ribs, placement of pallial line, and umbones, among others. A wide range in shell size can be seen among carditids, with average values ranging from 3 to 100 mm. Notably, the larger sizes were predominantly observed during the Paleocene–Eocene, in the Venericorini. The Miodomeridinae and Scalaricarditinae had the smallest shell sizes, spanning from the Eocene to the present. Paedomorphic heterochronic processes are suggested for the origin of the small size observed in the Scalaricarditinae subfamily. [ABSTRACT FROM AUTHOR]

The evolution and reforming history of the Cenozoic basins in the northeastern Tibetan Plateau (NETP) are significant for understanding the northeastward growth of the Tibetan Plateau. The sediments in these basins archived the spatial‐temporal patterns of the surface uplift and deformation processes in response to remote effects of growth of the NETP. Here, we present an integrated provenance analysis of the Ningnan basin in the NETP to provide direct insights into the basin evolution and further constraints of the Tibetan Plateau's northeastward growth. In this study, the Cenozoic strata (the Sikouzi, Qingshuiying, Zhang'enpu and Ganhegou formations) in the Ningnan basin yield complex detrital zircon age distributions featured by predominant age populations at 200–360 Ma and 360–540 Ma with minor Precambrian ages. Detrital zircon U‐Pb ages indicate that the southwestern Ordos Block, the western Qinling orogenic belt, and the eastern Qilian orogenic belt are primary source areas. Additionally, adjacent local paleo‐uplifts (e.g., Xi‐nanhuashan, Xiangshan, Liupan mountains.) also provided minor volumes of sediment. In addition, conglomerates and paleocurrent directions of the Sikouzi–Ganhegou formations exhibit an apparent change since the late Mocene, revealing an obvious provenance shift. The quantitatively determined mixing proportions of the surrounding source areas also reveals that the early source‐to‐sink system was replaced during the deposition of the Ganhegou Formation. Combined with previous studies, we suggest that the formation of the Ningnan basin was controlled by normal faults in extension setting and experienced continued sediment accumulation during the Qingshuiying–Zhang'enpu period; since the late Miocene, the significant provenance shift reflects the obvious northeastward growth of the NETP and led to the extinction of the Ningnan basin. [ABSTRACT FROM AUTHOR]

The aridification of the Australian continent led to the diversification of mygalomorph spiders in the Miocene, but a depauperate fossil record has made it difficult to investigate evolution across this epoch. Here, we describe the first fossil barychelid spider (Araneae: Barychelidae) in the world and the second fossil mygalomorph spider from Australia. It is placed as a new genus and species (Megamonodontium mccluskyi gen. et sp. nov.). Megamonodontium resembles Monodontium Kulczyński, 1908, a genus that persists in rainforests through Singapore, Indonesia and Papua New Guinea. The new specimen is the second largest spider fossil in the world and is approximately five times larger than extant Monodontium. The fossil shows that this lineage once occupied mesic rainforest habitats in Australia but has since been replaced by other spiders. [ABSTRACT FROM AUTHOR]

Taking the Paleogene Shahejie Formation in Nanpu sag of Bohai Bay Basin as an example, this study comprehensively utilizes seismic, mud logging, well logging, physical property analysis and core thin section data to investigate the metamorphic reservoir formed by contact metamorphism after igneous rock intrusion. (1) A geological model of the igneous intrusion contact metamorphic system is proposed, which can be divided into five structural layers vertically: the intrusion, upper metamorphic aureole, lower metamorphic aureole, normal sedimentary layers on the roof and floor. (2) The intrusion is characterized by xenoliths indicating intrusive facies at the top, regular changes in rock texture and mineral crystallization from the center to the edge on a microscopic scale, and low-angle oblique penetrations of the intrusion through sedimentary strata on a macroscopic scale. The metamorphic aureole has characteristics such as sedimentary rocks as the host rock, typical palimpsest textures developed, various low-temperature thermal metamorphic minerals developed, and medium-low grade thermal metamorphic rocks as the lithology. (3) The reservoir in contact metamorphic aureole has two types of reservoir spaces: matrix pores and fractures. The matrix pores are secondary "intergranular pores" distributed around metamorphic minerals after thermal metamorphic transformation in metasandstones. The fractures are mainly structural fractures and intrusive compressive fractures in metamudstones. The reservoirs generally have three spatial distribution characteristics: layered, porphyritic and hydrocarbon impregnation along fracture. (4) The distribution of reservoirs in the metamorphic aureole is mainly controlled by the intensity of thermal baking. Furthermore, the distribution of favorable reservoirs is controlled by the coupling of favorable lithofacies and thermal contact metamorphism, intrusive compression and hydrothermal dissolution. The proposal and application of the geological model of the intrusion contact metamorphic system are expected to promote the discovery of exploration targets of contact metamorphic rock in Nanpu sag, and provide a reference for the study and exploration of deep contact metamorphic rock reservoirs in the Bohai Bay Basin. [ABSTRACT FROM AUTHOR]

Shape analysis of a large sample of the thecideid brachiopod Thecidellina from the Pliocene and Pleistocene rocks on the Caribbean island of Curaçao highlights asymmetry within the population. However, the 30 analysed specimens display a lack of a consistent asymmetry. The brachiopods were cemented to substrates by a cicatrix, accommodated by a change in shell structure. The plastic morphology of Thecidellina may have been due to overcrowding and competition for resources on limited substrates.

Abstract The Curitiba Sedimentary Basin (CSB) is a small and shallow sedimentary basin, which is part of the Continental Rift of Southeastern Brazil. New exposures allowed for the identification of a subaqueous facies association, named Guatupê Unit, within the Guabirotuba Formation. For the first time in the CSB, sedimentary facies clearly deposited within a subaqueous environment, probably a swamp, are described and consists of wavy heterolithic and massive mud with linsen. In addition, mudflow deposits entering the water body are also identified and documented by massive sand facies with organic matter and load structures at their base. The latter indicates that the underlying sediments were plastic and contemporary. These sedimentary features, associated with palynoflora and a fossil trunk tree, indicate that the climate was humid enough to maintain permanent water bodies, like swamps, and vegetation, including trees. Other facies of the Guatupê Unit document mudflows and channelized tractive fluxes, whose association indicates that they were probably deposited in an alluvial fan environment. The facies, facies association, depositional processes, environment, and Miocene age of the Guatupê deposit are quite different from the previous sedimentary units reported for CSB sedimentary infill and the original definition of the formations.

Abstract The difficulty of correlating continental deposits hinders predicting lacustrine and palustrine carbonate facies variations in time and space. This study aims to understand better the factors governing these facies heterogeneities by measuring carbonate isotopes and conducting facies, petrographic and sequence stratigraphic analyses of the Lutetian–Aquitanian deposits of the Paris Basin, that record the transition from marine to lacustrine environments. Large‐scale correlations enabled the definition of two lacustrine–palustrine carbonate facies models. (1) The coastal lacustrine system (Bartonian to Rupelian), consists of fine‐grained brackish carbonate exhibiting episodic marine inputs during short‐term relative sea‐level maxima and evaporite sedimentation during relative sea‐level minima. Lacustrine sediments differ notably from marine ones with more negative δ13C and δ18O compositions that co‐vary and a biota adapted to low salinity conditions. In the associated palustrine environment, depositional sequences evolve upwards from micritic lacustrine deposits to nodular and then laminar calcretes. Microbial‐coated grains and rhizoliths indicate biological processes during repeated subaerial exposure phases in sub‐tropical to arid climates. (2) The inland lacustrine system (Rupelian and Aquitanian) was disconnected from the marine domain and showed evidence of microbial activity with microbial crusts and oncoidal rudstones. Facies rich in micritic intraclasts composed of palustrine and lacustrine facies indicate the reworking of already lithified sediments along the margins. In the palustrine domain, the calcrete facies are less abundant than breccias formed in‐situ by desiccation, limestones with root traces, or organic‐rich wackestones and marls. This system reflects a more temperate climate with more developed microbial structures and less exposed carbonates than the coastal lacustrine system. The southward migration of the depocentre and the transition from marine environments to (1) coastal and then (2) inland systems are controlled by uplift phases induced by Pyrenean and Alpine orogenesis. Third‐order relative sea‐level variations appear to control only short‐term cycles in coastal systems.