ABSTRACT The early-middle Miocene deposits of St Bathans, New Zealand, are renowned for their diverse and internationally important avian fossil biota that includes an abundance of fragmentary yet recognisable fossils from the crown bird clade Anseriformes (ducks and geese). We reviewed the taxonomic status of 11 isolated fossil bones previously referred to geese (Anserinae, Anseriformes) from St Bathans. Rigorous reassessment of these specimens using an expanded comparative morphological dataset demonstrated that four specimens can be assigned to the tadornine Miotadorna sanctibathansi and five are probably from a large anatid, potentially the purported anserine Notochen bannockburnensis. A second, slightly smaller, probable anserine is represented by one or possibly two bones, which we name as a new species, Meterchen luti gen. et sp. nov. We did not find any bones that showed a clear affinity with cereopsine anserines, thereby contradicting a previous hypothesis that cereopsines have a long history in Zealandia dating back to at least the early-middle Miocene. Our findings are consistent with current molecular divergence time estimates suggesting that the ancestors of the recently extinct cereopsine Cnemiornis arrived in Zealandia in the late Miocene. https://zoobank.org/urn:lsid:zoobank.org:pub

The upper Miocene Boleo Formation (Baja California Sur, México) provides a record of tectonic controls on mixed evaporite-siliciclastic sedimentation in a transtensional pull-apart basin during continental break-up and onset of seafloor spreading in the central Gulf of California. The thin basal limestone, recently dated at 6.35 ± 0.21 Ma, records abrupt onset of subsidence and rapid marine transgression over a formerly emergent landscape. The siliciclastic member contains coarsening-up mud-sand-gravel parasequences that record progradation of fan deltas into a saline shelf. The laterally equivalent gypsum member consists of shallowing-up parasequences formed by evaporative drawdown in the distal evaporite depocenter. Thin, laterally extensive mudstone and breccia units, which host Cu-Co-Zn stratiform ore deposits, record short-lived pulses of marine transgression, fault activity, hydrothermal activity, and mineralization. Growth strata, internal unconformities, and paleocurrent data record NE tilting on a network of NW-striking syn-depositional normal faults during sediment transport to the northeast. Our results support a model for syn-basinal growth of a large monocline above the tip of a propagating oblique-dextral normal fault at the southwest margin of the Santa Rosalía basin. Large-scale displacement across the monocline was the primary mechanism of subsidence, which likely was enhanced by loading related to mafic intrusions and seafloor spreading in the adjacent Guaymas basin. We propose that marine flooding was geologically instantaneous within existing age uncertainties (± 0.2 m.y.) for >1000 km along the Pacific−North America plate-boundary fault system, consistent with models for rapid acceleration of transtensional strain when the plate boundary became localized in the modern Gulf of California at ca. 7−6 Ma.

The suid assemblages from Europe experienced considerable turnover during the Vallesian (MN9-MN10, early Late Miocene), ultimately leading to a marked decline in diversity during the Turolian. To provide further insight into the timing and paleoecological context of this Vallesian turnover in the suid assemblages, here we revisit the taxonomic composition of the suids from the Late Miocene (9.8 Ma) fossil locality of Can Llobateres 1 (CLL1; Vallès-Penedès Basin, NE Iberian Peninsula), with emphasis on species other than the small tetraconodontine Parachleuastochoerus crusafonti (for which CLL1 is the type locality). Although CLL1 is one of the most thoroughly sampled Vallesian sites from Europe, a recent revision of the faunal list evinced that the occurrence of multiple large mammals is based on fossil remains that were described many decades ago or that have never been published, leading to potentially misleading or, at least, insufficiently substantiated attributions. According to published accounts, three additional suid species are recorded at CLL1, being much scarcer than Pa. crusafonti : the listriodontine Listriodon splendens , the suine Propotamochoerus palaeochoerus , and a large tetraconodontine variously assigned to Versoporcus steinheimensis or ‘ Parachleuastochoerus ’ valentini . Our revision of the available remains, including unpublished material recovered from the 1980s onward, confirms the presence of the two former species and the assignment of the large tetraconodontine to ‘ Pa. ’ valentini . On biochronological grounds, the association of these taxa is characteristic of the early Vallesian, with the record of L. splendens representing the last well-dated occurrence of this species. From a paleoenvironmental viewpoint, the suid assemblage from CLL1 is consistent with previous inferences indicating the presence of a densely forested and humid environment with more open habitats nearby.

Andrena is a species-rich genus of bees with a wide distribution, predominantly in the Holarctic. Here, we describe and illustrate a previously unknown species, Andrena (Labergeia) cenizophila Neff, Bossert & Zabinski n. sp., from southwestern Texas and central Coahuila, Mexico. Phylogenomic analyses recovered the new species as most closely related to Andrena (Labergeia) nahua Neff, a central Mexican species that was hitherto known only from the male sex. The discovery and examination of additional specimens of A. nahua allows us to describe and illustrate the previously unknown female, which shares diagnostic morphological features with the female of A. cenizophila n. sp. Based on these insights, we expand the diagnosis of Labergeia Neff to accommodate both species and discuss morphological affinities with their closest relatives in the subgenus Dactylandrena Viereck. Fossil-informed divergence time estimates indicates that Labergeia originated in the late Miocene, around 8 million years ago (5.37–11.82 mya), and that all known species of the subgenus, as well as its sister lineage Dactylandrena, are distributed in western and/or central North American. Lastly, we discuss the unusual foraging biology of A. cenizophila n. sp., which, based on observations and analyses of scopal pollen loads, is an oligolege of Leucophyllum frutescens (Berl.), I. M. Johnst. (Scrophulariaceae), a shrub commonly known as cenizo, Texas ranger, or Texas purple sage, among others. Interestingly, cenizo has a distinct floral phenology with comparatively short-termed mass blooms of not more than a week in duration, rendering it an unexpected choice for a specialist pollen collector. To our knowledge, A. cenizophila n. sp., is the only New World Andrena species that is oligolectic on plants of the family Scrophulariaceae.

Abstract Over the past 10 million years, coastal-marine settings along the Peruvian Margin have undergone profound geographic and oceanographic transformations, resulting in extensive changes in coastal-marine communities. While mollusk taxonomy research is slowly being integrated into ecosystem-wide analyses, which have historically centered on vertebrates, a long-term chronostratigraphically controlled analysis of molluscan diversity and compositional changes has not been undertaken for this region. We compiled a database covering 152 species, 97 genera, and 51 families of mollusk fossils from the Peruvian Margin (13–16°S) to assess long-term diversification patterns and faunal turnover from the late Miocene to the present. We identified two distinctive molluscan assemblages. The first, dating to the late Miocene (10–6 Ma), underwent a substantial shift during the Mio-Pliocene transition (6–4 Ma), culminating in a second assemblage more akin to modern counterparts. This shift resulted in an increase in diversity, with the younger assemblage (6–0 Ma) exhibiting greater genus richness than the former late Miocene assemblage. The turnover at 6–4 Ma was driven by peaks in bivalve origination (6–5 Ma) along with elevated extinction rates for gastropods (6–5 Ma) and bivalves (5–4 Ma). Ecological analyses revealed that no single ecological trait consistently changed during this interval, indicating that the turnover resulted from a broad reorganization of ecological strategies. We propose that the major molluscan turnover during the late Miocene–early Pliocene is associated with geomorphological changes related to the Andean uplift, the disappearance of semi-embayments, and a sea-level rise.

Although biostratigraphy and paleoecological studies are central to reconstructing paleodepositional environments and constraining source and reservoir rock distribution during petroleum exploration, detailed applications in offshore Niger Delta wells remain limited. This study analyzes the lithostratigraphy and foraminiferal assemblages of the FT-1 Well, offshore Niger Delta, over the 2,300–2,550 m interval to reconstruct the stratigraphic framework and paleoenvironmental history. Lithostratigraphic analysis reveals predominantly shaly facies, whereas foraminiferal biostratigraphy shows the dominance of benthic species (68.4%) over planktonic species (31.6%), a relationship that is diagnostic of outer–upper bathyal marine settings. The studied interval is assigned to the N18–N19 planktonic foraminiferal zones and to the NNDF 04–NNDF 06 benthic foraminiferal zones of the Neogene Niger Delta. The section is richly fossiliferous, containing abundant and diverse foraminiferal assemblages. The top of the N18–N19 interval is tentatively placed at 2,300 m based on the First Downhole Occurrence (FDO) of Globigerina nepenthes, while the base is constrained by the Last Downhole Occurrences (LDOs) of Neogloboquadrina dutertrei and Globorotalia tumida at 2,490 and 2,540 m, respectively. The NNDF 04 Zone extends from 2,300 to 2,430 m and is marked at its base by the occurrence of Cyclammina cf. minima; NNDF 05 spans 2,430–2,460 m, defined by the FDOs of C. cf. minima and Haplophragmoides narivaensis; NNDF 06 extends from 2,460 m to 2,550 m, the deepest analyzed sample, and is characterized by the continued occurrence of H. narivaensis. Paleoecological interpretation of the foraminiferal assemblages indicates mostly tropical–subtropical conditions with normal marine salinity, but includes cooler-water indicators such as Cyclammina cf. minima, Globocassidulina subglobosa, Uvigerina hispida, and Uvigerina auberiana, which are typical deep-water species. On the basis of the N18–N19 planktonic zonation, the sediments are interpreted to have been deposited during the Late Miocene–Early Pliocene. Collectively, these findings refine the stratigraphic framework and enhance understanding of the paleoenvironmental evolution of the Niger Delta’s offshore deposits, with implications for more accurate prediction of petroleum system elements.

ABSTRACT The Montbrook Fossil Site in Levy County, Florida, is a Late Miocene (6.0–5.6 Ma) fluvial deposit with a diverse turtle assemblage that includes exceptionally well-preserved musk turtles, genus Sternotherus. Sternotherus pugnatus n. sp. is described from eight partial to nearly complete shells, jaws, a maxilla, and hundreds of isolated postcranial bones. It is a small species with a low, narrow, and smooth carapace that is flat dorsomedially and acarinate except for along the posterior midline, lacks a lateral crest along the bridge peripherals, and has highly reduced to absent axillary and inguinal scutes. A cladistic analysis places S. pugnatus and its sister taxon Sternotherus bonevalleyensis within crown group Sternotherus and sister to the extant species Sternotherus peltifer and Sternotherus depressus. Many of the fossil shells exhibit healed injuries from microbial infections and predation attempts, including pockmarks, parallel scrapes, split carapaces, a broken plastral buttress, and punctures with embedded fish tooth tips, documenting previously unknown predator-prey interactions in early Sternotherus. Early Pleistocene fossils of Sternotherus that immediately post-date Pliocene sea level inundation of Peninsular Florida are also discussed and figured, as are Middle to Late Pleistocene musk turtle fossils including Sternotherus odoratus (dwarf and large forms) and Sternotherus minor. ZooBank Nomenclatural Act—https://zoobank.org/urn:lsid:zoobank.org:act:1D0F91CC-716D-4F0C-8994-D32341EED644

The stratigraphic evolution of low-latitude carbonate platforms, highly sensitive to sea-level changes, is often poorly constrained due to limited core data and discontinuous depositional records. This study elucidates the evolution of the Meiji Atoll, a representative low-latitude platform in the southern South China Sea (SCS), since the late Miocene, using the reef-penetrating core (Well NK1) from Nansha Island. By integrating facies analysis, sequence stratigraphy, and geochemical proxies, we identified two third-order sequences (SQ1 and SQ2), each comprising transgressive (TST) and highstand (HST) systems tracts. Geochemical data indicate that TSTs were associated with enhanced upwelling and nutrient availability, fostering algal productivity, while HSTs were marked by subaerial exposure. The overall retrogradational stacking pattern of the atoll reflects a dominant control by long-term sea-level rise, superimposed by eustatic fluctuations. Our findings confirm that eustatic sea-level variations were a primary factor controlling the stratigraphic architecture and development of Cenozoic low-latitude carbonate systems.

The index-species of calcareous nannoplankton in two cored wells, penetrating the Miocene rocks of the Alba Guyot, have been used to identify time intervals for deposition of the young (Pleistocene-to-modern, <1.8–0.2 Ma) Fe-Mn crust from Unit III in the complete section of the Magellan Seamounts Fe-Mn crusts, Late Miocene (>7–13 Ma) basanite tuff, tuffite sublayer (<5.6–7.0 Ma), as well as the ancient crust and buried nodules formed prior to the Early Miocene – Late Oligocene (>18–24 Ma). There have been discovered young Fe-Mn crust sublayers of contrasting composition and growth rate: early, enriched in Mn, Ni, Cu, Nb, and late, substantially ferruginous, with high REE, Y, Be, Sc, V, Zn, Rb, Cs, Sr, Zr, Hf, Mo, Sb, Pb, Th and U contents. Disregarding the duration of a probable break in the deposition of ore matter (Fe-Mn oxyhydroxides), the young crust with a Co-chronometry-based thickness of ~4 mm was formed over a period of ~2.3 Ma with an average growth rate from 1.6 mm/Ma in the early sublayer to 2.2 mm/Ma in the late sublayer. A young Fe-Mn crust 4–8 mm thick began to form on Miocene rocks 4.5 to 2.3 Myr, when the guyot surface was at depths below the oxygen minimum zone in the ocean water column (>600–700 m). A contrasting change in the composition of the late sublayer (a significant increase in Fe, REE, Y, V, Zn, Sr, Zr, Hf, Mo, Sb, Pb, Th and U contents) could have been caused by a 500000-year-old rapid subsidence of the guyot to depths similar to present-day (1250–1500 m at the plateau level). The average Co concentration (0.8–1.0 wt. %) in the young Fe-Mn crust on Miocene rocks is almost twice that of the bulk composition of thick (multilayered) crusts in other parts of the guyot. Relatively small-scale distribution of the young Fe-Mn crust, anomalously enriched in Co, will apparently have an insignificant impact on the increase in inferred ore reserves on the Alba Guyot for this strategically important metal.

Abstract Since the end of the Laramide Orogeny (~50 Ma), southwest Montana has experienced complex tectonic, climatic, volcanic, and mantle dynamic processes that have left an imprint on the landscape. Here, we examine the impact of post-orogenic and recent hotspot-related processes on the landscape by quantifying the Cenozoic exhumation history of the Madison and Gallatin Ranges, located on the northern flank of the Yellowstone hotspot (YSH) in southwest Montana. We apply the apatite (U-Th-Sm)/He (AHe) thermochronometer to Cretaceous and Paleogene intrusions from three transects to constrain the Cenozoic cooling history. We also present three new zircon U-Pb crystallization ages. AHe dates from 16 samples produced dates ranging from 67 ± 8.3 Ma to 6.2 ± 0.76 Ma. Most dates are between 45 and 20 Ma and younger than their crystallization age. Samples from the elevation transect with the largest relief display a positive relationship between AHe date and elevation, and thermal history modeling shows a phase of exhumation from ~30–23 Ma. AHe dates in the Madison Range young as they approach the Madison Fault, the range-bounding normal fault, and we ascribe most of the exhumation in the Madison Range to extension and tectonic exhumation due to footwall uplift. We interpret the ~30–23 Ma cooling to represent fault initiation and a phase of Oligocene extension that shows that post-orogenic extensional faulting and collapse propagated into the Laramide domain at that time. Late Miocene AHe dates near the fault represent a renewed phase of motion in the Miocene to recent, though our data lack the resolution to constrain the specific timing. Erosional exhumation due to YSH-driven regional uplift appears to be minimal.

The genus Conioselinum Fisch. ex Hoffm. (Apiaceae) presents long-standing taxonomic challenges due to poorly resolved infrageneric relationships and significant morphological convergence with related genera such as Ligusticum s.l. Although integrating plastomes and nrDNA data has been effective in resolving complex phylogenies, a comprehensive phylogenetic framework and a critical reevaluation of key diagnostic traits for Conioselinum remain insufficient. Our nrDNA phylogeny established a robust framework supporting the monophyly of Conioselinum as nested within the Hymenidium clade, delineating three distinct subclades (A, B, and C). This phylogenetic framework is further corroborated by corresponding morphological traits. We reaffirmed that the terminal localization of vascular bundles in fruit ribs is a stable synapomorphy for Conioselinum, when integrated with a consistent suite of diagnostic markers—specifically deciduous basal leaves, linear bracteoles, and absent or obsolete calyx teeth—it effectively distinguishes the genus from closely related allies. Divergence time estimation traced a rapid radiation from the Late Miocene to the Pleistocene, coinciding with the Qinghai-Tibet Plateau uplift. Furthermore, selective pressure analyses identified positive or relaxed selection in six genes (ycf1, matK, rpoA, ycf2, rps7, and ccsA), suggesting their role in adapting to alpine environmental stresses. Evident cytonuclear conflicts in some taxa underscore a complex history likely involving reticulate evolution. This study highlights the utility of integrating phylogenomics with morphology to resolve complex taxonomies. Based on congruent evidence from both sources, we propose a revised circumscription for Conioselinum. Together, these molecular and morphological insights establish a solid foundation for future taxonomic revisions and enhance our understanding of adaptive diversification in Apiaceae.

ABSTRACT This study aims to unravel the petroleum system(s) of the Geisum area within Egypt's prolific Gulf of Suez rift basin through investigating the hydrocarbon potential of source rocks and genetic origin of petroleum plays. A total of 135 cutting samples were analyzed using organic geochemical procedures, including Rock‐Eval pyrolysis and vitrinite reflectance (%Ro), whereas 1D basin models were applied to simulate the basin's burial and thermal histories. Gas chromatography‐flame ionization detector (GC–FID), GC–mass spectrometry (GC–MS), and GC‐combustion–isotope ratio mass spectrometry (GC–C–IRMS) were conducted on 12 crude oils and six source rock extracts to assess bulk geochemical characteristics, biomarkers, and isotopic compositions of parent source rocks. The 1D‐modeling results along the NW–SW profile suggest that the Geisum area is a productive province, including Brown Limestone as the primary source (TR = 85%–95%), whereas Matulla/Wata contributed moderately (TR = 25%–44%), and Rudeis only expelled hydrocarbons in the southern compartment. Furthermore, heat flow (HF) rather than erosion predominantly controls thermal maturity, with peak generation occurring during the Late Miocene (7–5 Ma) in the northern and southern sectors. Structurally, the area is divided into three compartments due to Oligocene rifting, which influenced hydrocarbon migration pathways. The multivariate chemometric analysis reveals three genetically distinct oil families distributed across different oilfields in the Gulf of Suez. Family I, in the Geisum oilfield, likely derives from carbonate‐rich Sudr/Brown Limestone (high gammacerane, C 29 sterane dominance, depleted δ 1 3 C). Family II, from the same oilfield, is attributed to marine Matulla shales (moderate gammacerane, C 27 steranes, similar δ 1 3 C). Family III, from the Tawila oilfield, appears sourced from mixed marine/lacustrine Rudeis sediments (low gammacerane, C 28 steranes, enriched δ 1 3 C).

ABSTRACT Orbital forcing is a key driver of Central Asian hydroclimate variability, yet the expression and mechanisms of the half‐precession cycle remain poorly understood in mid‐latitude terrestrial records. Here we present high‐resolution (millennial‐scale) late Miocene (~8230–8155 ka) magnetic records from lacustrine sediments in the Qaidam Basin. Integrated analysis demonstrates that magnetic parameters (χ lf , χ fd , χ fd /HIRM) provide robust proxies for chemical weathering and precipitation variability, evidenced by strong covariation between χ lf and χ fd and between χ fd /HIRM and Rb/Sr. Spectral analysis reveals a significant ~10 kyr periodicity, indicating half‐precession forcing on the basin's hydroclimate during the late Miocene. We attribute this cyclicity to alternating precipitation regimes: East Asian summer monsoon dominance during Northern Hemisphere summer perihelion and winter precipitation dominance 10 kyr later during Southern Hemisphere summer perihelion or Northern Hemisphere winter perihelion. These findings provide robust terrestrial evidence for half‐precession cyclicity in mid‐latitude Asia, advancing understanding of suborbital‐scale continental climate dynamics.

Tabanus bifarius Loew, 1858 is a horsefly species distributed throughout the Mediterranean region and in the areas of central and southeastern Europe and partly in Asia. In this study, we conducted the first comprehensive phylogeographic and population genetic analysis of T. bifarius collected from 13 localities across Türkiye and Iran, through utilizing mitochondrial (COI) and nuclear DNA (ITS1–5.8S–ITS2) markers. A total of 81 haplotypes and 59 nuclear alleles were identified among 187 sequenced individuals. Both mitochondrial and nuclear DNA patterns and diversity observed in T. bifarius are indicative of complex historical and demographic processes. Among all the populations studied, Eskişehir and Hatay exhibited the highest genetic diversity, which may be due to the region’s topography and transitional zones. Phylogenetic analyses suggested that T. bifarius split from the outgroup species approximately 5.53 million years ago (MYA) during the Late Miocene–Early Pliocene, likely driven by tectonic and climatic events. Subsequent diversification events that occurred during times of climatic and environmental fluctuations in the Late Pliocene and Early Pleistocene also seemed to have significantly affected the species and gave rise to the formation of some important genetic lineages. Our analyses results indicate that T. bifarius exhibits a structured genetic landscape shaped by multiple refugial routes, geographic barriers, and Quaternary climatic oscillations. Further, our findings suggest that the species likely entered Anatolia through three distinct routes: (1) from the Levant region into southern Anatolia via Hatay; (2) from the Caucasus into northeastern Anatolia through Ardahan; and (3) from the Iranian Plateau into eastern Anatolia via Van.

Molecular insights into spined loaches (Cobitidae: <i>Cobitis</i> ) reveal the complex evolutionary history of freshwater fishes in the Iberian Peninsula and North Africa

BackgroundThe steppe rat snake, Elaphe dione, has one of the broadest terrestrial distributions among snakes. Its distribution spans from the Azov Sea and the Caucasus to the Pacific coast of Far East Asia. The steppe rat snake is one of the few reptile species with an extensive distribution in both the Western and Eastern Palearctic, making its evolutionary history of particular interest in understanding biogeographical patterns and connections between these regions. However, knowledge of its genetic variability and phylogeography remains limited. In this study, we examined the phylogeographic structure of E. dione to shed light on its genetic diversity and diversification history in the Western and Eastern Palearctic.MethodsWe reconstructed phylogenies and analyzed the genetic structure of E. dione populations originating from most of its geographic range using three mitochondrial DNA gene fragments (12S rRNA, COI, ND4+tRNAs). In total, we analyzed sequences from 130 E. dione specimens from 100 locations. We used maximum likelihood and Bayesian inference methods to reconstruct phylogenetic trees, supplemented by an analysis of haplotype networks, molecular clocks, and a neutrality test for historical demography.ResultsWe identified 11 phylogeographic lineages grouped into three broader clades that diverged during the Late Miocene-Pliocene. The average uncorrected genetic distance between these 11 lineages ranged from 0.7% to 6.7% based on sequences of the COI fragment. Most of the contemporary range of E. dione is occupied by a single clade, with lineages distributed west and east of the Central Asian mountains. This west-east split in the clade occurred approximately 1.7 million years ago (Mya), followed by vicariant radiation in the Western and Eastern Palearctic during the Mid-Pleistocene era. Spatial patterns of mtDNA variation identified areas of post-last glacial maximum (LGM) dispersal and secondary contact zones of several lineages in the Altai and the Changbai Mountains.DiscussionOur study is the most comprehensive phylogeographic analysis of E. dione to date. The territory of central China most probably served as an ancestral area of this species, where E. dione diverged from its most recent common ancestor with E. bimaculata during the Late Miocene. The most active period of diversification in E. dione was estimated to have occurred later (∼1.3 Mya) than other widespread Palearctic species. Furthermore, this period is correlated across the species’ range and coincides with the beginning of the Mid-Pleistocene climatic transition. Climatic and environmental transitions during this period may have triggered the allopatric divergence of E. dione in multiple glacial refugia. Notably, diversification in the Western Palearctic resulted in a greater number of phylogeographic lineages, which could be linked to a greater number of suitable refugia. However, further evidence is needed to confirm these scenarios.

Snakeheads of the genus Channa display remarkable diversity in body size and ecology, yet evolutionary relationships within several species complexes remain unresolved. Channa pyrophthalmus, a recently described dwarf species endemic to Myanmar, represents a key lineage for investigating allopatric diversification in freshwater fishes. Here, we report the first complete mitochondrial genome of C. pyrophthalmus and perform comparative mitogenomic analyses across 18 Channa species. Phylogenetic analyses based on mitochondrial protein-coding genes robustly place C. pyrophthalmus as the sister lineage to C. gachua sensu stricto, supporting recent taxonomic revisions. While mitochondrial coding regions are highly conserved across the genus, the control region exhibits pronounced lineage-specific structural variation driven by tandem repeats. Divergence-time estimation dates the split between C. pyrophthalmus and C. gachua to ∼7.1 Ma (Late Miocene), a timeline congruent with the Late Miocene accelerated uplift of the Indo-Burman Ranges. Selection analyses reveal contrasting evolutionary regimes: pervasive purifying selection characterizes the dwarf lineage, whereas episodic positive selection on ND5 marks the ancestral lineage of giant snakeheads, indicating adaptive shifts in mitochondrial bioenergetics. Additionally, accelerated evolution in ATP8 was detected in rheophilic lineages. Together, these findings link geological vicariance and mitochondrial metabolic evolution to body size diversification in Channa.

Abstract International Ocean Discovery Program (IODP) Site U1417, located in the Surveyor Fan (Gulf of Alaska), preserves hemipelagic sediments influenced by glacial and fluvial depositional processes from the Cordilleran Ice Sheet in the Chugach–St. Elias Mountains and Coastal Mountains. The biogenic opal content was measured for a total of 441 samples from the late Miocene to early Pleistocene intervals and its flux for hemipelagic sediments was calculated to trace the history of biogenic opal deposition. On the whole, the biogenic opal content confirms the division of the lithostratigraphic units and subunits: diatom‐bearing clay‐rich intervals versus clast‐rich terrigenous intervals. The high biogenic opal content results from the better preservation of diatom ooze, whereas the low biogenic opal content is due to diatom‐poor terrigenous sediments including diamict deposited from sedimentary gravity flows during the late Miocene. On the other hand, the biogenic opal deposition from the late Miocene to early Pleistocene might have been attributed to the degree of diatom production controlled by global climate change. The variation of biogenic opal flux at Site U1417, compared with other regions in the North Pacific, represents the global climate events such as Late Miocene Biogenic Bloom, mid‐Pliocene Warmth, and Northern Hemisphere Glaciation. Despite regional differences in oceanographic conditions, surface water productivity in the Gulf of Alaska has been attributed to the basin‐to‐basin redistribution of nutrients by global thermohaline circulation and the related Pacific Ocean ventilation. This study underlines that biogenic opal deposition at IODP Site U1417 has recorded global climate evolution since the late Miocene.

Abstract The Indo‐Pacific Gateway is a narrow tropical passage connecting the Pacific and Indian Oceans, and alterations in its topographic configuration can significantly influence the volume of water exchanged between the two oceans through the Indonesian Throughflow (ITF). In the modern ocean, the ITF extends from the surface to a depth of 500 m, with its strongest flow occurring in the upper thermocline (100–300 m). Here, we present radiolarian assemblage data from Ocean Drilling Program Site 710 in the western tropical Indian Ocean to reconstruct the history of ITF variability since the Late Miocene. The radiolarian assemblages associated with the ITF can be categorized into two groups: (a) surface ITF taxa, linked to shallow waters, and (b) thermocline ITF taxa, which correspond to subsurface waters. A significant decrease in the relative abundance of surface ITF taxa occurred at 7.5 Ma. Additionally, a faunal turnover from high‐salinity thermocline taxa to low‐salinity thermocline ITF taxa was observed at 3.5 Ma, suggesting a paleoceanographic transition from higher to lower salinity conditions in the thermocline. We propose that these changes reflect modifications in the topographic configuration of the Indo‐Pacific Gateway, which likely occurred in a stepwise manner over these periods. Radiolarian‐based SST data indicate stepwise cooling from 9.0 to 6.5 Ma, followed by a reversal to a warming trend from 4.5 to 2.0 Ma, with a slight decrease in SST after 2.0 Ma. These SST variations are likely influenced by regional topographic changes such as ITF dynamics, in addition to global climate trends.

ABSTRACT Aim The species‐rich flora of southern Africa results from Neogene species accumulation involving multiple geographically distinct radiations. This diversity was enhanced by lineage cross‐seeding amongst several broadly defined regional floras. We examine the relative ages and the role of shifts between southern African habitats in the Desert and Fynbos floras in a single lineage of Cape daisies, the resin daisy genus Pteronia . Using these xeric‐adapted shrublets, we more finely dissect the radiations to explore the relative ages of occupation and diversification in the different winter‐rainfall floras of South Africa (fynbos, renosterveld, and succulent karoo vegetation), as well as the adjacent arid and semi‐arid Desert, Nama Karoo and Kalahari Savanna floras. Location Southern Africa, focusing on the winter‐rainfall floras and adjacent arid/semi‐arid regions in the south‐western corner of the subcontinent. Methods A dated species‐level molecular phylogenetic hypothesis for Pteronia and outgroups is presented. Eight floristic and biogeographic areas of distribution are identified. Ancestral areas and the timing, frequency, and direction of range change events amongst these areas are inferred using the statistical DEC model on a sample of dated posterior trees. Results Pteronia is strongly supported as monophyletic and began diversifying in the late Miocene, consistent with other Cape radiations, particularly those associated with arid regions. From the ancestral range of the genus in the northern parts of the Succulent Karoo and/or fynbos vegetation, the first novel vegetation type to be colonised was Nama Karoo at the end of the Miocene, followed by south‐eastern Succulent Karoo, renosterveld in the early Pliocene, and Kalahari Savanna in the Late Pliocene. The subtropical thicket and Bushmanland bioregions were colonised more recently in the Pleistocene. Early diversification in Pteronia gave rise to two lineages. The first lineage diversified in and remains strongly confined to the northern Succulent Karoo. The second lineage diversified in both fynbos and a range of adjacent arid/semi‐arid vegetation types, experiencing more frequent shifts between habitat types. Main Conclusions Speciation in Pteronia is associated with two geographic patterns: firstly, diversification within single habitat types, which applies to the northern succulent karoo and to a lesser extent, the fynbos vegetation, and secondly, diversification associated with shifts between habitat types. Habitat shifts appear to be strongly influenced by habitat adjacency and ecological similarity. Understanding the nature and timing of historical habitat shifts in Pteronia may contribute to the knowledge of interactions between different floras within South Africa, both winter and summer rainfall, as well as the timing of colonisation of these areas, particularly the Succulent and Nama Karoo.