Topic
Microcachrys
About: Microcachrys is a research topic. Over the lifetime, 21 publications have been published within this topic receiving 389 citations.
Papers
TL;DR: Patterns of extinctions in Tasmania suggest that Pleistocene climatic change at middle-high latitudes presented an environmental stress not previously experienced during the Cenozoic, perhaps through widespread periglacial conditions, but also provided ecological and evolutionary opportunities for rainforest species tolerant of a wide range of conditions experiencedduring the late Pleistsocene.
Abstract: The relatively simple flora and structure of Nothofagus cunnirzghantii cool temperate rainforest in Tasmania is widely accepted to be the result of repeated glaciation during the Pleistocene. Plant macrofossils, spores and pollen preserved at Regatta Point, western Tasmania, indicate that several gymnosperms and subcanopy angiosperms with warm temperate affinities had survived one to several episodes of cold, possibly glacial climates, before becoming extinct in the early to middle Pleistocene: Callitris/Actirzostrobus, Dacrycarpus, Austromyrtus, Eucalyptus spathulata-type, Haloragodendron-type, Loranthaceae, Quintinia and Symplocos. These co-existed in Nothofagus-Lagarostrobos franklinii rainforest with a number of taxa that are now restricted to upper subalpine-alpine habitats in Tasmania, such as Astelia, Gunnera and Microcachrys. The community is difficult to interpret in terms of modem species and we propose that either extinct taxa are being concealed by essentially modem pollen morphologies, that ecological preferences have altered since the early-middle Pleistocene, or both. Patterns of extinctions in Tasmania (and New Zealand) suggest that Pleistocene climatic change at middle-high latitudes presented an environmental stress not previously experienced during the Cenozoic, perhaps through widespread periglacial conditions, but also provided ecological and evolutionary opportunities for rainforest species tolerant of a wide range of conditions experienced during the late Pleistocene.
64 citations
TL;DR: Squamastrobus tigrensis nov. gen. has been found in early Cretaceous strata (Baquero Formation), Santa Cruz Province, Argentina as discussed by the authors.
53 citations
TL;DR: Fossils from the late Oligocene or early Miocene Newvale site, South Island, New Zealand, 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.
Abstract: 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.
41 citations
TL;DR: In this paper, the authors compared the morphology, cuticle, and paleoecology of Microcachrys tetragona from the Oligo-Miocene of New Zealand and M. novae-zelandiae from Tasmania.
Abstract: Premise of the study: Microcachrys tetragona (Podocarpaceae), endemic to the mountains of Tasmania, represents the only remaining taxon of one of the world ’ s most ancient and widely distributed conifer lineages. Remarkably, however, despite its ~150 Myr heritage, our understanding of the fossil history of this lineage is based almost entirely on the pollen record. Fossils of Microcachrys are especially important in light of recent molecular phylogenetic and dating evidence. This evidence dates the Microcachrys lineage to the Mesozoic and does not support the traditional placement of Microcachrys as sister to the southeastern Australian genus Pherosphaera. Methods: We undertook comparative studies of the foliage architecture, cuticle, and paleoecology of newly discovered fossils from the Oligo-Miocene of New Zealand and M. tetragona and discussed the importance of Microcachrys in the context of Podocarpaceae phylogeny. Key results: The fossils represent the oldest and fi rst extra-Australian macrofossils of Microcachrys and are described as the new foliage species M. novae-zelandiae . These fossils confi rm that the distinctive opposite decussate phyllotaxy of the genus is at least as old as the Oligo-Miocene and contribute to evidence that Microcachrys plants were sometimes important components of oligotrophic swampy habitats. Conclusions: Leaf fossils of Microcachrys closely comparable with the only extant species confi rm that this lineage had a much wider past distribution. The fossil record and recent molecular phylogenetic studies, including that of Microcachrys , also serve to emphasize the important status of Tasmania as a refugium for seed plant lineages.
31 citations
TL;DR: The elongate cones of Scarburgia and Harrisiocarpus compared to those of extant podocarps suggest that the size of the female cone in the Podocarpaceae became reduced during evolution subsequent to the Jurassic.
18 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 1 |
| 2014 | 2 |
| 2011 | 2 |
| 2007 | 1 |
| 2004 | 1 |