Current models of Philippine Sea (PHS) Plate motion assume a general and large northward shift since the Eocene. In order to constrain better the age and amount of this northward shift, we have conducted a paleomagnetic study on drill and gravity cores, respectively, taken from the seafloor of the northern part of the PHS Plate. The core samples consist of sedimentary rocks or semi-consolidated sediments, and their ages, as estimated from microfossils and strontium isotope ratios, range from the Eocene to late Miocene. The results of stepwise alternating-field and thermal demagnetization experiments revealed that 19 sections at 17 sites out of 58 sections at the 29 sites examined yielded mean paleomagnetic directions with a 95% confidence limit (α 95) of <25 • , and 14 sections at 13 sites have α 95 < 15 •. An estimation of the amount of the northward shift at each site was obtained from the difference between the paleolatitude and the present latitude. This estimation revealed that the northern part of the PHS Plate was located near the equator at 50 Ma and that the majority of the northward shift took place between about 50 and 25 Ma. Very little northward movement occurred after 15 Ma. Based on our data, together with the available paleomagnetic information suggesting clockwise rotation of about 90 • since the Eocene and the requirements from geometry with the surrounding plates, we present a model in which the PHS Plate rotated 90 • clockwise between 50 and 15 Ma on the Euler pole near 23 • N, 162 • E, although it is impossible to specifically determine the Euler pole position.

The Indonesian Throughflow (ITF) controls the oceanic flux of heat and salt between the Pacific and Indian Oceans and therewith plays an important role in modulating the meridional overturning circulation and low latitude hydrological cycle. Here, we report new sea surface temperature and aridity records from the west coast of Australia (IODP Site U1460), which allow us to assess the sensitivity of the eastern Indian Ocean to the major reorganization of Earth’s climate that occurred during the Mid-Pleistocene Transition. Our records indicate glacial coolings at 1.55 and 0.65 million years ago that are best explained by a weakening of the ITF as a consequence of global sea level and tectonic changes. These coincide with the development of pronounced gradients in the carbon isotope composition of the different ocean basins and with substantial changes in regional aridity, suggesting that the restrictions of the ITF influenced both the evolution of global ocean circulation and the development of the modern hydrological cycle in Western Australia.

[1] Lower Aptian carbonates in the Bab Basin at the southern Neo-Tethys margin record significant environmental changes across Oceanic Anoxic Event 1a (OAE1a). A long-lasting negative shift of carbon-isotope ratios (d 13 C) associated with a distinct decrease in oxygen-isotope ratios (d 18 O) in orbitolinid-rich carbonates characterizes the onset of OAE1a (Livello Selli), supporting a hypothesis that a long-lasting volcanic CO 2 emission is the main cause of OAE1a, inducing global warming. A bloom of microencrusters (Lithocodium and Bacinella) across the proto-Bab Basin occurred synchronously at the beginning of the subsequent positive d 13 C excursion, responding to the global carbon-cycle perturbations. The carbonates, formed during the OAE1a, show higher strontium-isotope ratios ( 87 Sr/ 86 Sr) compared with those of global seawater; this was likely caused by a local influx of isotopically heavier strontium, along with nutrients, into the proto-Bab Basin. These biotic proliferations were triggered by an increased nutrient supply induced by intensified continental weathering due to the global warming suggested by the increase in d second-order transgression and lasted until the early stage of the highstand after the OAE1a. The Livello Selli corresponds to the early stage of this transgression.

In eusocial insect colonies, non‐reproductive workers often perform different tasks. Tasks of an individual worker are shifted depending on various factors, e.g., age and colony demography. Although a vitellogenin (Vg) gene play regulatory roles in both reproductive and non‐reproductive division of labours in a honeybee, it has been shown that the insect Vg underwent multiple gene duplications and sub‐functionalisation, especially in apical ant lineages. The regulatory roles of duplicated Vgs were suggested to change evolutionarily among ants, whereas such roles in phylogenetically basal ants remain unclear. Here, we examined the expression patterns of conventional Vg (CVg), Vg‐like A, Vg‐like B and Vg‐like C, as well as Vg receptor, during the task shift in an age‐dependent manner and under experimental manipulation of colony demography in a primitive ant Diacamma sp. Expressions of CVg and Vg‐like A in a brain were associated with a nursing task. It is suggested that associations of brain expressions of these Vgs with worker tasks were acquired in the basal ant lineage, and that such Vg functions could have sub‐functionalised in the derived ant lineage.

Site U1460 ended at 1945 h on 15 August. A total of 133 cores were recovered with the HLAPC system; of the 606.7 m cored, 592.2 m was recovered (recovery = 97%). Hole U1460A After arriving at Hole U1460A (27°22.4948′S, 112°55.4296′E), preparations for coring commenced. As a result of previous difficulty establishing the mudline core at Site U1459 (broken core barrel), the seafloor was tagged with the bit to determine its precise location and whether it was as hard as the previous site. A nonmagnetic HLAPC core barrel was dressed with a core liner, picked up, and run into the hole. Hole U1460A was started at 0115 h on 13 August. Based on the recovery of the mudline core, the seafloor depth was calculated to be 214.5 mbsl. Coring continued with the HLAPC system through Core 356-U1460A-64F to 298.2 m DSF. After the mudline core, each core was advanced 4.7 m despite partial strokes on Cores 2F, 9F, and 64F. Hole U1460A was cored to a final depth of 300.1 m DSF (Core 65F). During coring, a routine slip, cut, and retermination of the coring line was performed. At the conclusion of coring, the drill string was pulled back to 231.6 m DSF and the top drive was set back. The drill string was pulled back to just above the seafloor, clearing the seafloor at 0605 h on 14 August and ending Hole U1460A. Of 300.1 m cored, 291.39 m of material was recovered (recovery = 97.1%). The total time spent on Hole U1460A was 33.25 h. Hole U1460B After offsetting the vessel 20 m north of Hole U1460A, preparations were made to begin Hole U1460B (27°22.4867′S, 112°55.4265′E). A nonmagnetic HLAPC core barrel was dressed with a core liner, picked up, and run into the hole. Hole U1460B was started at 1920 h on 14 August. Based on the recovery of the mudline core, the seafloor depth was calculated to be 214.4 mbsl. Coring continued with the HLAPC system through Core 356-U1460B-68F to 306.6 m DSF. After the mudline core, each core was advanced by recovery in an attempt to cover any gaps from Hole U1460A. Of the 306.6 m cored, 800.81 m was recovered (recovery = 98%). Also in this hole, in situ temperature measurements were made with the APCT-3 before recovering Cores 12F, 20F, 28F, 33F, and 36F. During coring, a routine slip, cut, and retermination of the coring line was performed. At the conclusion of coring, the drill string was pulled back to 260.7 m DSF and the top drive was set back. The drill string was pulled from the hole and the advanced piston corer/extended core barrel bit cleared the rig floor at 1940 h. The thrusters and hydrophones were pulled and secured, and at 1945 h on 15 August, Site U1460 concluded. The total time spent on Hole U1460B was 37.75 h.