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Cyclical growth marks in cortical bone, deposited before attainment of adult body size, reflect osteogenetic changes caused by annual rhythms and are a general phenomenon in non-avian ectothermic and endothermic tetrapods. However, the growth periods of ornithurines (the theropod group including all modern birds) are usually apomorphically shortened to less than a year, so annual growth marks are almost unknown in this group. Here we show that cortical growth marks are frequent in long bones of New Zealand's moa (Aves: Dinornithiformes), a recently extinct ratite order. Moa showed the exaggerated K-selected life-history strategy formerly common in the New Zealand avifauna, and in some instances took almost a decade to attain skeletal maturity. This indicates that reproductive maturity in moa was extremely delayed relative to all extant birds. The two presently recognized moa families (Dinornithidae and Emeidae) also showed different postnatal growth rates, which were associated with their relative differences in body size. Both species of giant Dinornis moa attained their massive stature (up to 240 kg live mass) by accelerating their juvenile growth rate compared to the smaller emeid moa species, rather than by extending the skeletal growth period. [ABSTRACT FROM AUTHOR]

Prehistoric timescales, volcanic hazard assessment, and understanding of volcanogenic climate events rely on accurate dating of prehistoric eruptions. Most late Quaternary eruptions are dated by 14C measurements on material from close to the volcano that may be contaminated by geologic-sourced infinite-age carbon. Here we show that 14C ages for the Taupo (New Zealand) First Millennium eruption are geographically arrayed, with oldest ages closer to the vent. The current eruption wiggle match date of 232 ± 5 years CE is amongst the oldest. We present evidence that the older, vent-proximal 14C ages were biased by magmatic CO2 degassed from groundwater, and that the Taupo eruption occurred decades to two centuries after 232 CE. Our reinterpretation implies that ages for other proximally-dated, unobserved, eruptions may also be too old. Plateauing or declining tree ring cellulose δ13C and Δ14C values near a volcano indicate magmatic influence and may allow forecasting of super-eruptions. [ABSTRACT FROM AUTHOR]