Daphne E. Lee

New Zealand Eocene, Oligocene and Miocene Macrofossil and Pollen Records and Modern Plant Distributions in the Southern Hemisphere

The modern New Zealand flora has a relatively low number of families and genera in relation to land area, but well-preserved macrofossils and pollen from three sites in southern New Zealand suggest that the floras in Eocene, Oligocene and Miocene times were much more diverse at the generic level. At Pikopiko, Southland, a late Eocene in situ forest with fern understory was dominated by conifers, Casuarinaceae, Lauraceae, Nothofagus, Proteaceae, and mesothermal angiosperms including palms (aff. Calamus), Sapindaceae: Cupaniae and Picrodendraceae. At Newvale Mine, Southland, a leaf bed within a thick lignite seam represents leaf fossils preserved in a late Oligocene oligotrophic bog. This site demonstrates that Agathis, Dacrycarpus, Dacrydium, Halocarpus, Microcachrys, Podocarpus and Phyllocladus coexisted with diverse angiosperms including Nothofagus, Gymnostoma, Cunoniaceae, Ericaceae, Sapindaceae and several Proteaceae. Pollen data add Meliaceae, Myrtaceae, Onagraceae and Rubiaceae to the flora. At Foulden Maar, Otago, mummified leaves and flowers, including several with in situ pollen, demonstrate the existence of a diverse flora surrounding an Early Miocene lake. This site contains numerous monocot macrofossils including Astelia, Cordyline, Ripogonum and Typha, as well as the oldest fossils known for Orchidaceae and Luzuriagaceae. This flora was dominated by Lauraceae with affinities to Cryptocarya and Litsea, but other families include Araliaceae, Cunoniaceae, Elaeocarpaceae, Euphorbiaceae sensu lato, Menispermaceae, Myrsinaceae, Myrtaceae, Onagraceae, Proteaceae and Sterculiaceae. Many ferns, conifers, and Nothofagus are from lineages with Gondwanan ancestors, whereas other taxa show links to Australia (e.g., Gyrostemonaceae), New Caledonia (e.g., Beauprea) and South America (e.g., Luzuriaga, Fuchsia). Many of these taxa are now extinct in New Zealand, and therefore indicate much wider biogeographic ranges for many families and genera in the past.

High conifer diversity in Oligo-Miocene New Zealand

Eight species of Podocarpaceae foliage are recognised from the late Oligocene or early Miocene Newvale site, South Island, New Zealand, and the following five new species are described: two of Dacrydium Lamb. and one each of Dacrycarpus (Endl.) de Laub., Phyllocladus Rich. ex Mirb. and Halocarpus Quinn. The latter is the first macrofossil record of this New Zealand endemic genus. All these conifers, plus Agathis Salisb., Microcachrys Hook.f. and Podocarpus Pers., co-occurred in the local vegetation at Newvale. In conjunction with prior records of macrofossils and pollen, these fossils indicate that the late Paleogene to early Neogene conifer flora of New Zealand was very diverse, with all but one of the extant genera present, together with several regionally or globally extinct genera, and multiple species of many of these genera. This fossil diversity is similar to the Paleogene fossil conifer diversity observed in south-eastern Australia (and particularly Tasmania) and in parts of North America.

Subtropical rainforest vegetation from Cosy Dell, Southland: plant fossil evidence for Late Oligocene terrestrial ecosystems

A fossil flora from the basal Chatton Formation at Cosy Dell farm near Waimumu, Southland, New Zealand comprises wood, seeds, pollen and spores. A Late Oligocene age (25.4–24.4 Ma) determined from macro- and nannofossils constrains the beginning of marine transgression in this area. The palynoflora comprises more than 100 taxa, in addition to a few spores recycled from underlying Jurassic Murihiku basement. At least 16 ferns are present. Conifers include Araucariaceae and Podocarpaceae (Dacrydium, Dacrycarpus, Lagarostrobos, Microcachrys, Phyllocladus and Podocarpus). The angiosperm palynoflora comprises monocots including Arecaceae, Asparagaceae, Asteliaceae, Pandanaceae and Typhaceae and numerous dicots including Casuarinaceae, Cunoniaceae, Euphorbiaceae, Loranthaceae, Malvaceae, Myrtaceae, Nothofagaceae, Proteaceae and Strasburgeriaceae. The drift flora includes wood and seeds including the tropical legume Entada. Elongate limpets and mangrove snails provide indirect evidence for seagrasses and mangroves. The predominance of rainforest tree pollen and fern spores suggests a regional subtropical coastal forest and high rainfall.

Leaf fossils of Proteaceae tribe Persoonieae from the Late Oligocene–Early Miocene of New Zealand

Fossils from the Newvale lignite mine, Southland, are the first substantiated foliar records of Proteaceae nsubfamily Persoonioideae. The fossils possess very large stomata, a probable synapomorphy for Persoonioideae, and within nProteaceae the combination of this feature and more or less parallel-aligned, brachyparacytic stomatal complexes and nundulate anticlinal epidermal cell walls is uniquely found in this subfamily. The new genus Persoonieaephyllum is described nto recognise affinity of the fossil leaves and cuticles with tribe Persoonieae of Persoonioideae and their distinction from its nonly other extant representative, Placospermum. Two new species are described. P. ornatum is represented by linear leaves nless than 20mm wide and possessing more or less parallel-aligned major veins. These leaves closely match those of extant nhypostomatic, broad-leaved species of tribe Persoonieae and are distinct from Placospermum in venation and several ncuticular details. P. villosum has so far been recovered only as cuticular material in disaggregated lignite. It is distinct from nP. ornatum in having abundant trichome bases, an absence of surface tubercules, and even larger stomata (guard cells often n>70 mm long). The fossils extend the known record of Persoonioideae in the New Zealand–New Caledonia region by n~20 million years.

The early Miocene paleolake Manuherikia: vegetation heterogeneity and warm-temperate to subtropical climate in southern New Zealand

The Manuherikia Group in southern New Zealand represents terrestrial sediments associated with a large paleolake, Lake Manuherikia, formed during a period of basin subsidence in the early Miocene, ca. 18.7–15.1xa0Ma. Micro- and macrofloral assemblages collected throughout the Manuherikia Group were studied to derive terrestrial climate proxies, relying on leaf physiognomy (CLAMP) and taxonomic affinity (bioclimatic analysis). The assemblages were also analyzed for the component loading of the relative abundances of different leaf morphotypes and the results were interpreted in light of stratigraphic and lateral ecological variation. Independent paleoclimate proxies from a variety of depositional environments consistently indicate warm-temperate to marginally subtropical mean annual temperatures (16.5–20xa0°C) and high annual precipitation (1,500–2,500xa0mm) during the Burdigalian–Langhian of mid-latitude New Zealand. Leaf physiognomy reveals an amplified seasonal contrast in both precipitation and temperature, possibly caused by seasonal shifts in the position of the subtropical high-pressure cells and westerly wind belts, causing overcast wet winters and dry summers. Regional and local vegetation variation was most likely caused by fluctuations in lake levels, which in turn may have been affected by enhanced seasonality from short-term climate oscillations.

Proteaceae leaf fossils from the Oligo–Miocene of New Zealand: new species and evidence of biome and trait conservatism

Abstract. At least seven foliar taxa of Proteaceae occur in Oligo–Miocene lignite from the Newvale site. These taxa include two new species of the fossil genus Euproteaciphyllum, and previously described species of tribe Persoonieae and Banksia. Other specimens from Newvale are not assigned to new species, but some conform to leaves of the New Caledonian genus Beauprea, which is also represented in the lignite by common pollen. Two other Euproteaciphyllum species are described from the early Miocene Foulden Maar diatomite site. One of these species may belong to Alloxylon (tribe Embothrieae) and the other to tribe Macadamieae, subtribe Gevuininae. Ecologically, the species from Newvale represented important components of wet, oligotrophic, open vegetation containing scleromorphic angiosperms and very diverse conifers. In contrast, Proteaceae were large-leaved and rare in Lauraceae-dominated rainforest at the volcanic Foulden Maar site. Overall, the Oligo–Miocene fossils confirm that Proteaceae was formerly much more diverse and dominant in the New Zealand vegetation, and provide fossil evidence for biome conservatism in both leaf traits and lineage representation.

Long‐term evolution of an Oligocene/Miocene maar lake from Otago, New Zealand

Foulden Maar is a highly resolved maar lake deposit from the South Island of New Zealand comprising laminated diatomite punctuated by numerous diatomaceous turbidites. Basaltic clasts found in debris flow deposits near the base of the cored sedimentary sequence yielded two new 40Ar/39Ar dates of 24.51u2009±u20090.24 and 23.38u2009±u20090.24 Ma (2σ). The younger date agrees within error with a previously published 40Ar/39Ar date of 23.17u2009±u20090.19 Ma from a basaltic dyke adjacent to the maar crater. The diatomite is inferred to have been deposited over several tens of thousands of years in the latest Oligocene/earliest Miocene, and may have been coeval with the period of rapid glaciation and subsequent deglaciation of Antarctica known as the Mi-1 event. Sediment magnetic properties and SEM measurements indicate that the magnetic signal is dominated by pseudo-single domain pyrrhotite. The most likely source of detrital pyrrhotite is schist country rock fragments from the inferred tephra ring created by the phreatomagmatic eruption that formed the maar. Variations in magnetic mineral concentration indicate a decrease in erosional input throughout the depositional period, suggesting long-term (tens of thousands of years) environmental change in New Zealand in the latest Oligocene/earliest Miocene.

Reproductive niche conservatism in the isolated New Zealand flora over 23 million years

The temporal stability of plant reproductive features on islands has rarely been tested. Using flowers, fruits/cones and seeds from a well-dated (23 Ma) Miocene Lagerstätte in New Zealand, we show that across 23 families and 30 genera of forest angiosperms and conifers, reproductive features have remained constant for more than 20 Myr. Insect-, wind- and bird-pollinated flowers and wind- and bird-dispersed diaspores all indicate remarkable reproductive niche conservatism, despite widespread environmental and biotic change. In the past 10 Myr, declining temperatures and the absence of low-latitude refugia caused regional extinction of thermophiles, while orogenic processes steepened temperature, precipitation and nutrient gradients, limiting forest niches. Despite these changes, the palaeontological record provides empirical support for evidence from phylogeographical studies of strong niche conservatism within lineages and biomes.

An early Miocene ant (subfam. Amblyoponinae) from Foulden Maar: the first fossil Hymenoptera from New Zealand

Kaulfuss, U., Harris, A.C., Conran J.G. & Lee, D.E., 2014. An early Miocene ant (subfam. Amblyoponinae) from Foulden Maar: the first fossil Hymenoptera from New Zealand. Alcheringa 38, 568–574. ISSN 0311-5518. The ant subfamily Amblyoponinae is presently represented in New Zealand by one endemic species in the cosmopolitan genus Stigmatomma and an introduced Australian species of Amblyopone. The fossil record of the group is restricted to two species of Stigmatomma from late Eocene Baltic Amber. Here, we describe the third fossil record, an Amblyopone-like specimen from the early Miocene of Otago, southern New Zealand, based on a winged male that resembles the extant A. australis Erichson in size, general habitus and characters of wing venation, but also shares features with the African amblyoponine genus Zymmer. This represents the first fossil record of Amblyoponinae from the Southern Hemisphere and the first example of Hymenoptera among the few pre-Quaternary insect fossils known from New Zealand. It suggests a long history of Amblyoponinae in New Zealand and Australia. Uwe Kaulfuss [uwe.kaulfuss@otago.ac.nz] and Daphne E. Lee [daphne.lee@otago.ac.nz], Department of Geology, University of Otago, PO Box 56, Dunedin 9016, New Zealand; Anthony C. Harris [anthony.harris@otagomuseum.govt.nz], Otago Museum, PO Box 6202, Dunedin 9059, New Zealand; John G. Conran [john.conran@adelaide.edu.au], ACEBB & SGC, School of Earth and Environmental Sciences, The University of Adelaide, Benham Bldg, DX 650 312, Adelaide SA 5005, Australia. Received 18.3.2014; revised 15.5.2014; accepted 23.5.2014.

Diverse and abundant insect herbivory on Miocene Nothofagaceae of the Dunedin Volcano, Otago, New Zealand

Terrigenous sediments occurring within the mid/upper Miocene Dunedin Volcanic Group in southern New Zealand contain well-preserved leaf-beds, commonly dominated by Nothofagaceae leaf fossils. Abundant insect herbivory traces occur on Nothofagaceae leaf fossils from the Double Hill and Kaikorai Valley localities, including 28 types of external foliage feeding traces, 8 types of galling and a possible fungal trace, several not described previously. Relatively high diversity of insect herbivory traces on broad-leaved Nothofagaceae suggests a high diversity of insect herbivores. The high abundance and diversity of trace fossils in combination with evidence for plicate vernation suggests that Nothofagaceae growing on the mid/late Miocene Dunedin Volcano had shorter leaf retention times than modern New Zealand Nothofagaceae. The loss of Nothofagaceae diversity from New Zealand due to cooling climate in the late Neogene could also have meant the demise of an arthropod community adapted to living on broad-leaved Nothofagaceae. Insect damage diversity and amount at Double Hill was significantly higher than at Kaikorai Valley, as well as the occurrence of plicate vernation and leaves with stunted growth forms. This suggests that there may have been some difference in the insect diversity of the two sites, relating to local palaeoenvironment, such as higher temperatures at Double Hill during the warm season and/or differences in forest density.