Review of flowers and inflorescences with in situ pollen from the Miocene Foulden and Hindon Konservat-Lagerstätten, southern New Zealand

Abstract

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.