We report on a large and nearly complete elopomorph fish from the Paleogene of Pitt Island, Chatham Islands, New Zealand. The exquisite specimen is three-dimensionally preserved in a volcanic tuff and is the most complete and informative fossil elopomorph reported to date from the Southern Hemisphere. Features indicating elopomorph affinities include the lack of a separate retroarticular ossification on the lower jaw, and a primitively retained median gular. Assignment to the elopiform Family Megalopidae (tarpons) is indicated by the specimen's superior mouth position, large posttemporal fossae, and laterally compressed body covered in large and extensively overlapping cycloid scales. A number of distinctive features, including the elongate body, high and strongly developed coronoid process, enlarged median gular, relatively low-profile head, extra series of anamestic bones in the cheek region, and the continuation of the lateral line scales as a tapering lobe extending onto the base of the caudal fin, indicate that the Pitt Island fish represents a distinctive new taxon within megalopids, herein named Ikawaihere koehleri gen. et sp. nov. The morphology of the specimen as a whole suggests a fish resembling the extant tarpons Megalops atlanticus and M. cyprinoides but with a lower head profile and more attenuated body.

Plant fossils at the southern Zealandia Landslip Hill deposit (early Miocene, Gore Lignite Measures) are preserved in a silcrete matrix and reveal unique three-dimensional structures. Here, we present fossil leaf-based paleoclimate and vegetation reconstructions, as well as a comparison of the diversity at the site to modern New Zealand forests. The early Miocene climate at the site is much warmer than modern (mean annual temperature 17.6 ± 2.3 °C versus ∼10 °C today), but with similar annual precipitation rates (96 +67/-39 cm yr−1 versus ∼100 cm yr−1 today). Temperature seasonality is similar to today, whereas the locality experienced stronger precipitation seasonality, likely due to the southward migration of the moisture-laden westerly wind belt during early Miocene summers. The reconstructed vegetation at Landslip Hill does not tend towards resource retention strategies, like modern dense evergreen climax forest that exists under similar temperature and precipitation combinations in Zealandia today. Instead, the vegetation includes elements of open vegetation, with nearest living relatives of taxa identified at the site being notable post-disturbance taxa, such as Gleicheniaceae and Casuarinaceae. This indicates that the vegetation at Landslip Hill may have been periodically disturbed, potentially by floods, fire or both. Flood disturbance aligns well with the coarse sandstone facies of the deposit, and the lack of planar bedding in which the fossils are found. However, fire disturbance aligns well with the summer-dry conditions at the site. Overall dicot leaf diversity at Landslip Hill is similar to that of modern New Zealand forests, even those at the same depositional latitude (∼45–46°S); however, unlike modern New Zealand forests, there is no clear dominance of a single taxon.

Background The modern chironomid fauna of New Zealand is diverse, highly endemic and reflects a complex biogeographical history. This fauna has been important for developing phylogenetic and biogeographic concepts including Brundin’s writings on transantarctic relationships but until now the fossil record to support these reconstructions has been very limited. Here we describe the first fossil species of Chironomidae, subfamily Orthocladiinae, from New Zealand, based on inclusions in amber from the late Oligocene Pomahaka Formation of the South Island. Methods We examined newly excavated fossil tree resin (amber) from the late Oligocene Pomahaka Formation in southern New Zealand for inclusions. Amber pieces containing chironomids were prepared and morphologically investigated using light-microscopy and µCT-scanning. Specimens were taxonomically evaluated using identification keys for modern adult chironomid midges. Habitus and key morphological features of each specimen were documented photographically and/or by line drawings. Results Thirteen Chironomidae specimens from Pomahaka amber were identified as members of the subfamily Orthocladiinae Kieffer. Bryophaenocladius zealandiae sp. nov. Baranov is the first Southern Hemisphere fossil of the genus. Bryophaenocladius Thienemann, 1934 is absent from the extant fauna of the main islands of New Zealand; however, it may be present on the subantarctic Auckland Islands. Two incompletely preserved specimens are described as Morphotype 1 cf. Bryophaenocladius zealandiae. Based on a male adult, Pterosis extinctus sp. nov. Baranov is described as the first fossil record of the extant genus Pterosis Sublette and Wirth, today represented by a single endemic species on the New Zealand subantarctic Auckland Islands and Campbell Island. Two female adult specimens are described as Morphotype 2 cf. Metriocnemini. The new fossils of the genera Bryophaenocladius and Pterosis belong to chironomid taxa requiring terrestrial or semi-aquatic habitats for larval development, supporting the notion of a humid forest swamp paleoenvironment for the Pomahaka amber source forest.

A new extinct fossil genus and species of Celastraceae is described, based on numerous well-preserved leaves from the Early Miocene Foulden Maar Lagerstätte , southern New Zealand. The leaves of Palaeochrysa celastroides gen. et sp. nov. are most similar in morphology and anatomy to those of several extant taxa from the proximal Austral-Pacific clade of the family, such as Denhamia , Maytenus and Salaciopsis . This study of leaves with excellent cuticular preservation extends the fossil record of Celastraceae to the Early Miocene of New Zealand, further expanding the past range and biogeography of this largely cosmopolitan plant family.

A new genus and species of fossil whiteflies (Aleyrodidae) and a psyllid (Psyllidae) were discovered in the Hindon Maar Complex, a Fossil-Lagerstätte within the Dunedin Volcanic Group in Otago, South Island of New Zealand. These represent the first fossil records of these sternorrhynchan families (Hemiptera) from New Zealand. Miotetraleurodes novaezelandiae gen. et sp. nov., is described from specimens of puparia attached to angiosperm leaves. It is assigned to the subfamily Aleyrodinae and represents the first fossil whitefly from New Zealand and the third genus known from puparia globally. The forewing of a psyllid (Psyllidae: Hemiptera) was found in the same stratum, and represents the first fossil record of any fossil taxa of the superfamily Psylloidea in New Zealand.

The 47 vertebrate type specimens held in the University of Otago Geology Department are catalogued in detail. A short history of the collection is followed by lists of the type specimens under the Classes Actinopterygii, Reptilia, Aves and Mammalia. A fish trace-fossil is included at the end of the Actinopterygii. Where appropriate, the name changes of the genus or species are given in chronological order. The specimens are briefly described, locality and geological age information is provided.

Previously reported beetle inclusions from New Zealand amber have preserved insufficient morphological details for an identification beyond family-level. Here, we describe the first beetle species from New Zealand amber, Contacyphon pomahakaensis Ruta sp. nov., based on a newly discovered, well-preserved inclusion from the late Oligocene Pomahaka Formation in southern New Zealand. C. pomahakaensis Ruta sp. nov. is the first fossil record of marsh beetles (Scirtidae) described from New Zealand. The worldwide genus Contacyphon is well diversified with exclusively endemic species in New Zealand, suggesting a long presence and independent evolution in the region, which is confirmed by the new Oligocene amber fossil. A coastal swamp forest environment reconstructed for the formation of Pomahaka amber is in agreement with wet forest habitats of extant marsh beetles. Fourier transform infrared (FTIR) analysis of late Oligocene Pomahaka amber indicates that it originates from an Araucariaceae parent plant of Agathis affinity and has undergone comparatively little maturation.

Deep-time (=pre-Quaternary) maar lakes and certain other, hydrologically deep volcanogenic lakes, are often excellent Konservat-Lagerstätten representing unique windows into past biota and ecosystems. Many deposits from such lakes contain animal and plant remains in extraordinary preservation, often with soft tissues or fine morphological and anatomical details preserved. Such Lagerstätten have the potential to provide in-depth information on a variety of organisms, which is important for understanding their biology and ecology, their evolution and palaeobiogeography, but also for elucidating entire ecosystems with their numerous biotic and abiotic interactions. The formation of such Lagerstätten is intimately linked to volcanic processes, amongst which phreatomagmatic explosions that formed maar-diatreme volcanoes are probably the most important, but also other volcanic processes can lead to the formation of deep volcanogenic lakes (e.g. in certain calderas). Maar lakes and other volcanogenic Konservat-Lagerstätten occur in a large number of volcanically active regions worldwide, although older deposits are often difficult to access as they are more likely to be eroded or covered by younger deposits. The accessibility of many of the better-known localities is often connected to the mining of natural resources, ranging from diamonds, to volcanic rocks such as basalts to the lacustrine sediments that may have filled volcanic craters, including diatomites and ‘oil-shales’. Most or even all of the maar and other volcanogenic lakes presented here in greater detail, can be considered as important geoheritage sites. Although currently some of these deposits have at least some kind of legal protection as monuments of natural heritage, others remain in danger of being exploited commercially for natural resources and hence, ultimately destroyed. Moreover, many scientific questions related to these ancient lakes and their biota covered here in more detail, as well as those related to lakes only briefly mentioned in passing, have not been posed, let alone answered. This makes maar lakes and other volcanogenic lakes important resources for present-day and future research. The present contribution should be seen as a global call to scientists to find further localities that represent similar volcanogenic lacustrine settings, as they may be the source of vital and surprising new information about the plants, animals, and environments of the past. Examples of pre-Quaternary maar and other volcanogenic lakes that are presented here in greater detail include the following localities: Paleocene: Menat (France); Eocene: Messel, Eckfeld (Germany), Mahenge (Tanzania); Oligocene: Enspel, Rott, Hammerunterwiesenthal, Baruth, Kleinsaubernitz (Germany); Miocene: Foulden Maar, Hindon Maar Complex (New Zealand), Randeck Maar, Hirnkopf-Maar, Höwenegg, Öhningen (Germany); Pliocene: Ruppach-Goldhausen (Germany), Camp dels Ninots (Spain).

Chiton (Class Polyplacophora) fossils are rare globally, mostly because they are restricted to hard habitats such as rocky shores that are taphonomically under-represented in the geological record. New Zealand is rich in Cenozoic marine molluscan fossils, but chitons are very uncommon. The earliest New Zealand records of fossil chiton species are all from the Late Oligocene (Duntroonian) Chatton Formation in Southland. They include Callochiton chattonensis Ashby 1929 [New Zealand fossil Polyplacophora (Chitons). Transactions and Proceedings of the Royal Society of New Zealand. 60:366-369], Acanthochitona (Notoplax) ashbyi (Laws 1932 [New Tertiary Mollusca from New Zealand. No. 2. Transactions and Proceedings of the New Zealand Institute. 62:183-199]) and Rhyssoplax allanthomsoni Mestayer 1929 [Notes on New Zealand Mollusca. Transactions and Proceedings of the Royal Society of New Zealand. 60(4):247-150]. At Cosy Dell farm, Waimumu, New Zealand, the Chatton Formation contains a diverse chiton fauna representing seven families and seven genera, including Callochiton cf. chattonensis, Acanthochitona cf. ashbyi, Ischnochiton sp., Leptochiton cf. inquinatus, Lorica sp., Plaxiphora sp., and Rhyssoplax sp., the highest recorded fossil chiton diversity in New Zealand. All genera described in the fossil assemblage are associated with extant taxa around modern New Zealand rocky intertidal and shallow near shore environments. The study extends the New Zealand stratigraphic range of four genera (Ischnochiton, Plaxiphora, Lorica and Leptochiton) back to the Duntroonian (Late Oligocene), provides the first taxonomic descriptions of each chiton taxon from the site and discusses the paleoecological and biostratigraphic significance of these rarely preserved components of a rocky shore ecosystem.

We combine published and new mineralogical data on most major taxa of brachiopods from all over the world, to investigate patterns and controls on brachiopod carbonate mineralogy. Measurements of 1726 specimens in 162 species (including 56 fossil species) ranged from 79°N to 74°S and from intertidal to almost 4000 m deep. Calcareous brachiopods mostly create strong resilient valves of very low-Mg calcite (χ¯ = 1.3 wt% MgCO3). The substrate-cemented Craniida (χ¯ = 8.9 wt% MgCO3) and Thecideida (χ¯ = 6.5 wt% MgCO3) are unusual in precipitating calcite with higher Mg content. This is the first study to find bimineralic brachiopods; a few species show a combination of low-Mg (χ¯ = 0.8 wt% MgCO3) and intermediate-Mg calcite (χ¯ = 7.2 wt% MgCO3) (sensu Smith AM, Key MM Jr, Gordon DP. 2006. Skeletal mineralogy of bryozoans: taxonomic and temporal patterns. Earth-Science Reviews. 78:287–306.). While Mg in calcite varies systematically among valve layers and sometimes along the growth axis, we found no consistent difference between valves of the same individual. A weak latitudinal signal indicates some overall temperature control of Mg, but in general, brachiopods are active calcifiers, precipitating low-Mg calcite even when Mg:Ca ratio in seawater is high. The drivers on brachiopod mineralogy are individual, environmental, and phylogenetic – resulting in complex variability.

Summary The mid-Cretaceous is an important time for the diversification of forests globally, including the rise to dominance of the angiosperms and the beginning of the isolation of Zealandia. In New Zealand, little information is available on the mid-Cretaceous xyloflora. New specimens of fossil wood from the mid-Cretaceous Tupuangi Formation were collected from Waihere Bay, Pitt Island, Chatham Islands, of which 16 well-preserved samples were identified, representing Araucariaceae ( Agathoxylon , 5 samples), Cupressaceae ( Taxodioxylon and Cupressinoxylon , one sample each), Podocarpaceae ( Protophyllocladoxylon , one sample), and the ‘Group B’ and ‘Group C’ Mesozoic conifers (four samples each) defined in Bamford & Philippe (2008). Of these, only Taxodioxylon had been identified previously from the Tupuangi Formation. Two new species are erected, Cupressoxylon dianneae sp. nov. and Protophyllocladoxylon jacobusii sp. nov. These records are important for understanding the mid-Cretaceous flora of New Zealand and the history of the unique modern flora of New Zealand.

Well-preserved flowers of Miocene age containing anthers and in situ pollen are exceptionally rare in the fossil record of the Southern Hemisphere. A review of the 70 or so flowers/inflorescences from the 23 Ma Foulden Maar diatomite and the 15 Ma carbonaceous mudstones of the Hindon Maar Complex reveals a wide range of morphological features including petals, stamens and anthers with in situ pollen. The flowers range in size from 2 to 23 mm and vary in shape from generalist dish-bowl, to tubular or bell-shaped. The association of these flowers with previously described dispersed pollen provides crucial new data on source plants. The range of taxa represented by flowers include Alstroemeriaceae (Luzuriaga), a palm (Arecaceae), Akaniaceae (Akania), Araliaceae (Pseudopanax), cf. Cunoniaceae, Elaeocarpaceae, Euphorbiaceae, Loranthaceae, Meliaceae ('Dysoxylum'), Monimiaceae (Hedycarya), Onagraceae and Rutaceae and other, as yet unidentified taxa. Some, such as Fuchsia and Hedycarya, represent the only definite fossil flowers for their respective families. Although all these fossil species are extinct, about half of the families have living relatives in New Zealand, while relatives of other locally extinct taxa now occur in eastern Australia and New Caledonia. Some genera also provide links to South America (e.g., Fuchsia). Consistent with evidence from leaves, the flowers indicate a mesothermal rainforest flora that occupied the fertile basaltic soils surrounding the small maar lakes. Overall, the flowers are remarkably similar to their modern-day relatives suggesting that floral size, structure and pollination syndromes have changed little since the Miocene.(c) 2022 Elsevier B.V. All rights reserved.

Quantitative leaf mass per area reconstructions and prevalence of plicate vernation in broad-leaved Nothofagaceae fossils reveal that deciduousness was common in the middle to late Miocene of New Zealand. This functional type was subsequently lost, as modern-day New Zealand Nothofagaceae have small leaves that live for at least a year. Moreover, fully deciduous trees across all plant families are rare in the current New Zealand flora. Based on modern-day distribution in the Southern Hemisphere, broad-leaved deciduous Nothofagaceae occupy regions with consistently large seasonal differences in precipitation and cloud cover, relative to other functional types in the family (evergreen, small-leaved). Specifically, broad-leaved deciduous Nothofagaceae are in leaf in summer when cloud cover and precipitation are low, but are leafless in winter when cloud cover and precipitation is high. Notably, the seasonal difference in precipitation and cloud cover are more important in explaining deciduousness in Nothofagaceae than winter temperatures. Therefore, potential summer photosynthetic gains likely determine deciduousness in Nothofagaceae. Miocene palaeoclimate reconstructions reveal that New Zealand broad-leaved deciduous Nothofagaceae also thrived in a climate with larger seasonal precipitation differences than today, in an overall warmer climate. We suggest that deciduous Nothofagaceae in the New Zealand flora went extinct as the global climate cooled and summer photosynthetic gains diminished, as summers became progressively rainier and cloudier, favoring an evergreen habit.

The Galaxiidae is a Southern Hemisphere family of freshwater fish, considered to be of Gondwanan origin based on the current distribution of species in New Zealand, Australia (including Tasmania), New Caledonia, Africa, South America, and on some associated and subantarctic islands. The fossil record of galaxiids is extremely sparse and geographically restricted. The only galaxiid fossils currently known come from several Miocene lakes in southern New Zealand. They include more than 100 articulated fishes, some remarkably preserving soft parts such as eyes and skin, skulls and jaw components, and more than 200 isolated otoliths. Common coprolites and in situ preserved gut content at one site (Foulden Maar) indicate the different diets of larvae and adult fish. These discoveries reveal a diverse Galaxias fauna, the presence of lake-locked populations, ontogenetic diet shifts, and representatives of several non-migratory Galaxias lineages associated with inland streams and lakes. There are at least six Galaxias species based on macrofossils and six separate otolith-based species from varied volcanic and regional lacustrine environments. This diversity points to southern New Zealand as a centre of biodiversity and speciation in Galaxiidae in the early to late Miocene.

Rising atmospheric CO2 is expected to increase global temperatures, plant water-use efficiency, and carbon storage in the terrestrial biosphere. A CO2 fertilization effect on terrestrial vegetation is predicted to cause global greening as the potential ecospace for forests expands. However, leaf-level fertilization effects, such as increased productivity and water-use efficiency, have not been documented from fossil leaves in periods of heightened atmospheric CO2. Here, we use leaf gas-exchange modeling on a well-preserved fossil flora from early Miocene New Zealand, as well as two previously published tropical floras from the same time period, to reconstruct atmospheric CO2, leaf-level productivity, and intrinsic water-use efficiency. Leaf gas-exchange rates reconstructed from early Miocene fossils, which grew at southern temperate and tropical latitudes when global average temperatures were 5–6 ∘C higher than today, reveal that atmospheric CO2 was ∼450–550 ppm. Early Miocene CO2 was similar to projected values for 2040 CE and is consistent with an Earth system sensitivity of 3–7 ∘C to a doubling of CO2. The Southern Hemisphere temperate leaves had higher reconstructed productivity than modern analogs, likely due to a longer growing season. This higher productivity was presumably mirrored at northern temperate latitudes as well, where a greater availability of landmass would have led to increased carbon storage in forest biomass relative to today. Intrinsic water-use efficiency of both temperate and tropical forest trees was high, toward the upper limit of the range for modern trees, which likely expanded the habitable range in regions that could not support forests with high moisture demands under lower atmospheric CO2. Overall, early Miocene elevated atmospheric CO2 sustained globally higher temperatures, and our results provide the first empirical evidence of concomitant enhanced intrinsic water-use efficiency, indicating a forest fertilization effect.

New Zealand climate during the early to middle Miocene was subtropical to warm-temperate, in contrast to the predominance of cool-temperate climates in New Zealand today. Both modern and Miocene environmental settings of New Zealand are strongly moderated by the surrounding ocean. Seasonal moisture deficits occur today in rain shadow regions in New Zealand, but the potential and nature of seasonal moisture deficits under globally warmer conditions is uncertain. Here, we reconstruct seasonal moisture balance (precipitation - potential evapotranspiration) using seasonal temperature and mean annual precipitation estimates derived from early to middle Miocene (23-11 Ma) fossil leaf assemblages, combined with a Penman-Monteith model for potential evapotranspiration. The model incorporates uncertainty in temperature, precipitation, vapor pressure deficit, radiation and wind speed. Our results suggest that three out of nine sites investigated have a very high potential for summer moisture deficits (lowest monthly moisture balance < -90 +/- 40 mm month(-1)), without considering potential differences in infra-annual rainfall. These three sites all have the potential of an annual negative moisture balance (< -230 +/- 460 mm year(-1)). The highest negative moisture balance in New Zealand today is similar to -400 mm year(-1). Additionally, the three sites with the highest potential for moisture deficits all are from the Manuherikia Group, of which the depositional period may partially overlap with the Middle Miocene Climatic Optimum. Other sites had moderate (lowest monthly moisture balance < -40 +/- 50 mm month(-1)) to low (lowest monthly moisture balance < 45 +/- 60 mm month(-1)) potential for moisture deficits. Moisture deficit potential appeared to be highly dependent on the reconstructed mean annual precipitation. The trend from the early/middle Miocene to middle/late Miocene boundary of decreasing potential for moisture deficits agrees with a global cooling trend and regional increase in precipitation. Our study highlights the importance of potential evapotranspiration in globally warmer conditions, as seasonal moisture deficits may occur even in environments that are considered strongly ocean-moderated, such as New Zealand.

In order to provide quantitative data concerning patterns of shell breakage and repair in rhynchonelliform brachiopods, we studied undisturbed death assemblages from a New Zealand fiord complex where three species of terebratulide and one rhynchonellide occur in dense mixed patches on the near vertical walls. Proportions of damaged (both repaired and non-repaired) individuals varied between both taxa and sampling site. However, the general observation was that few individuals show signs of having been able to repair damage but the proportion of individuals showing unrepaired, and hence presumably fatal, breakages was higher (up to 76% in Magasella sanguinea from one sample from Tricky Cove in Doubtful Sound). Damage was mostly concentrated around the anterior margins and affected both valves and is consistent with having been clamped between a set of either jaws or claws. Potential culprits include fish (wrasse), rock lobsters and echinoids. As yet it is unclear whether the damage results from deliberate feeding activity or as collateral damage from grazers feeding on other organisms on the fiord walls which may allow secondary predation by asteroids. The net effect is, however, the same, in that the damage appears to have been fatal. More structured sampling is now required to understand the spatial variation in this damage and mortality, and also to establish the culprits with more certainty.

A fossil cycad pinna fragment with dichotomising and anastomosing venation and cuticular preservation from the middle Miocene Hindon Maar deposits, Otago, New Zealand, is assigned to the extinct genus Pterostoma (Cycadales: cf. Zamiaceae) as a new species: P. neehoffii. The leaf features of the Hindon Maar fossil differ from previously reported Pterostoma-like macrofossils and dispersed cuticles from New Zealand and Australia in having the combination of narrow guard cell flanges, poorly developed epidermal cuticular ridges and apparently lacking trichomes, suggesting that there were at least three cycad species present in the Neogene of New Zealand. The fossil is also placed into a broader overview of the macrofossil and pollen record for cycads in New Zealand and their possible paleoenvironments.