Evolution of New Zealand's terrestrial fauna: a review of molecular evidence

New Zealand biogeography has been dominated by the knowledge that its geophysical history is continental in nature. The continental crust (Zealandia) from which New Zealand is formed broke from Gondwanaland ca 80 Ma, and there has existed a pervading view that the native biota is primarily a product of this long isolation. However, molecular studies of terrestrial animals and plants in New Zealand indicate that many taxa arrived since isolation of the land, and that diversification in most groups is relatively recent. This is consistent with evidence for species turnover from the fossil record, taxonomic affinity, tectonic evidence and observations of biological composition and interactions. Extinction, colonization and speciation have yielded a biota in New Zealand which is, in most respects, more like that of an oceanic archipelago than a continent.     

The age and origin of the Pacific islands: a geological overview

The Pacific Ocean evolved from the Panthalassic Ocean that was first formed ca 750 Ma with the rifting apart of Rodinia. By 160 Ma, the first ocean floor ascribed to the current Pacific plate was produced to the west of a spreading centre in the central Pacific, ultimately growing to become the largest oceanic plate on the Earth. The current Nazca, Cocos and Juan de Fuca (Gorda) plates were initially one plate, produced to the east of the original spreading centre before becoming split into three. The islands of the Pacific have originated as: linear chains of volcanic islands on the above plates either by mantle plume or propagating fracture origin, atolls, uplifted coralline reefs, fragments of continental crust, obducted portions of adjoining lithospheric plates and islands resulting from subduction along convergent plate margins. Out of the 11 linear volcanic chains identified, each is briefly described and its history summarized. The geology of 10 exemplar archipelagos (Japan, Izu-Bonin, Palau, Solomons, Fiji, New Caledonia, New Zealand, Society, Galápagos and Hawaii) is then discussed in detail.     

Process and pattern in the biogeography of New Zealand – a global microcosm?

Aim  To describe New Zealand's historical terrestrial biogeography and place this history in a wider Southern Hemisphere context.
Location  New Zealand.
Methods  The analysis is based primarily on literature on the distributions and relationships of New Zealand's terrestrial flora and fauna.
Results  New Zealand is shown to have a biota that has broad relationships, primarily around the cool Southern Hemisphere, as well as with New Caledonia to the north. There are hints of ancient Gondwanan taxa, although the long-argued predominance of taxa derived by vicariant processes, driven by plate tectonics and the fragmentation of Gondwana, is no longer accepted as a principal explanation of the biota's origins and relationships.
Main conclusions  Most of the terrestrial New Zealand flora and fauna has clearly arrived in New Zealand much more recently than the postulated separation of New Zealand from Gondwana, dated at c. 80 Ma. There is a view that New Zealand may have disappeared completely beneath the sea in the early Cenozoic, and acceptance of this would mean derivation of the entire biota by transoceanic dispersal. However, there are elements in the biota that seem to have broad distributions that date back to Gondwanan times, and also some that are thought unlikely to have been able to disperse to New Zealand across ocean gaps, especially freshwater organisms. Very strong connections to the biota of Australia, rather than to South America, are inconsistent with the timing of New Zealand's ancient and early separation from Gondwana and seem likely to have resulted from dispersal.     

Pseudofoenus caledonicus, a new species of hyptiogastrine wasp (Hymenoptera: Gasteruptiidae) from New Caledonia

Abstract  Pseudofoenus caledonicus sp. nov. is described from New Caledonia, and is the second member of the Hyptiogastrinae recorded from these islands. This discovery points to a more diverse fauna of Hyptiogastrinae in the south-west Pacific, which also includes P. ritae (Cheesman), from New Caledonia and Vanuatu, P. extraneus (Turner) from Fiji, and a number of species from New Guinea and New Zealand. Although a revised phylogenetic analysis does not resolve the relationships of P. caledonicus , neither the two New Caledonian species nor the south-west Pacific fauna in general are likely to be monophyletic. This fauna is discussed in terms of its relationships with Pseudofoenus spp. from mainland Australia, and possible mechanisms that have given rise to the current distribution of species.     

A diverse fossil terrestrial arthropod fauna from New Zealand: evidence from the early Miocene Foulden Maar fossil lagerstätte

Fossil evidence for the evolutionary history of terrestrial arthropods in New Zealand is extremely limited; only six pre‐Quaternary insects (Triassic to Eocene) have been recorded previously, none of Miocene age. The Foulden Maar fossil lagerstätte in Otago has now yielded a diverse arthropod assemblage, including members of the Araneae, Plecoptera, Isoptera, Hemiptera, Coleoptera, Hymenoptera, Trichoptera and Diptera. The fauna significantly emends the fossil record for the Southern Hemisphere, provides an unparalleled insight into a 23‐million‐year‐old New Zealand lake/forest palaeoecosystem and allows a first evaluation of arthropod diversity at a time coeval with or shortly after the maximum marine transgression of Zealandia in the late Oligocene. The well‐preserved arthropods chiefly represent ground‐dwelling taxa of forest floor and leaf litter habitats, mostly from sub‐families and genera that are still present in the modern fauna. They provide precisely dated fossil evidence for the antiquity of some of New Zealand's terrestrial arthropods and the first potential time calibrations for phylogenetic studies. The high arthropod diversity at Foulden Maar, together with a subtropical rainforest flora and fossil evidence for complex arthropod–plant interactions, suggests that terrestrial arthropods persisted during the Oligocene marine transgression of Zealandia.     

Heteroblasty on Chatham Island: A comparison with New Zealand and New Caledonia

We used a comparative approach to investigate heteroblasty in the Chatham Islands. Heteroblasty refers to abrupt changes in the morphology of leaves and shoots with plant height. Common on isolated islands such as New Caledonia and New Zealand, which once had flightless, browsing birds, heteroblasty is hypothesised to be an adaptation to deter bird browsing. The Chatham Islands are a small archipelago located 800 km off the east coast of New Zealand, which has clear floristic links to New Zealand. However, unlike New Caledonia and New Zealand, the Chathams never had flightless, browsing birds. We investigated heteroblasty on the Chatham Islands by: (1) comparing height-related changes in leaf morphology and branching architecture in several plant taxa with heteroblastic relatives on the New Zealand mainland; (2) characterising changes in leaf morphology in heteroblastic tree species endemic to the Chathams; and (3) comparing overall trends in leaf heteroblasty on the Chathams with New Caledonia and New Zealand. Reversions to homoblasty were observed in the three Chatham Island taxa with heteroblastic relatives on the New Zealand mainland. However, two endemic tree species were clearly heteroblastic; both produced dramatically larger leaves as juveniles than as adults. Inter-archipelago comparisons showed that this trend in leaf morphology is rare among heteroblastic species in New Caledonia and New Zealand. Therefore, while some of our results were consistent with the hypothesis that heteroblasty is an adaptation to avoid bird browsing, other processes also appear to have shaped the expression of heteroblasty on Chatham Island.     

Conservation and restoration of New Zealand Island ecosystems

An ecological collapse has precipitated pioneering conservation initiatives in New Zealand. Many terrestrial communities in t he New Zealand archipelago have been devastated by over-exploitation, introduced mammals and habitat destruction. More recently, marine ecosystems have been depleted by over-harvesting. To mitigate against these losses, conservation in terrestrial environments has focused on protection of species and habitats. A similar approach is now under way in marine environments with the establishment of ‘no-take’ marine reserves. On land, conservation is now reaching beyond protection t o the eradication of pests from islands and restoration of their terrestrial ecosystems. Restoration on islands not only reduces threats to rare species; it also raises opportunities to investigate how species interact. In the sea, marine reserves not only enhance the diversity of depleted marine communities; they may also augment stocks of commercially harvested species. These initiatives provide many lessons that could be applied to degraded habitats elsewhere.     

A new species of fossil Scutus Montfort, 1810 from New Zealand (Mollusca: Gastropoda: Fissurellidae)

ABSTRACT

A new fossil species of the genus Scutus (Scutus mirus n. sp.) is described from five Late Oligocene to Early Miocene (Waitakian to Altonian; 25.2–15.9?Ma) localities in the South Island, New Zealand. It is one of the oldest fossil species of Scutus known and probably inhabited very shallow, sub-tropical waters surrounding Zealandia during this time. The holotype of Scutus petrafixus Finlay, 1930 is re-examined; it is possibly from All Day Bay, Kakanui (Waitakian 25.2–21.7?Ma). The New Zealand species documented herein significantly expand our understanding of the fossil record of this shallow-marine molluscan lineage, and by proxy, also indicate the presence of very shallow coastal marine environments around the late Oligocene and early Miocene in southern Zealandia.     

First record of the Australian guava moth Coscinoptycha improbana Meyrick (Lepidoptera: Carposinidae) in New Caledonia: Implication for quarantine and biosecurity surveys in insular territories

We recorded the Australian guava moth for the first time in New Caledonia. Given its biology and recent spread into New Zealand, this moth may be a pest risk for many fruit crops and native plant species if it is proved to have been introduced in New Caledonia. Indeed, this record challenges our capabilities to identify insect interceptions in the context of a high gap of taxonomic knowledge in New Caledonia. It also urges high endemism islands to implement early detection protocols to prevent establishment and spread of new invasive species.     

Good morning Gondwana

Summary

Vicariance and dispersion both must be considered as possibilities for the fauna and flora of New Zealand and New Caledonia. Oligocene submersion, promoted by the geologists and several biologists, does not seem to have been total. Refuge stations must have existed in mountains and even in plains in some surrounding areas. From there the relicts must have radiated after the partial submersion. Certain “primitive” Chrysomelidae Eumolpinae (Bohumiljania spp.) are closely related to Patagonian genera. Their case is not unique among the terrestrial organisms of New Caledonia. How to explain the occurrence of Amborella in New Caledonia and of the tuataras in New Zealand, already very probably extinct elsewhere during the Paleogene?     

Modelling the distribution and interaction of introduced rodents on New Zealand offshore islands

Aim To establish the factors that correlate with the distribution of the four most commonly introduced rodent species on New Zealand offshore islands — ship rat (Rattus rattus), Norway rat (R. norvegicus), Pacific rat or kiore (R. exulans) and house mouse (Mus musculus) — and examine if these distributions are interactive at the archipelago scale. Location The 297 offshore islands of the New Zealand archipelago (latitude: 34° S to 47° S; longitude: 166° E to 179° E). Methods Data on the distribution of all four introduced rodent species and the characteristics of New Zealand offshore islands were collated from published surveys and maps. The distribution of individual rodent species was regressed on island characteristics using a logistic generalized linear model. Interactions were examined by including the distributions of other rodent species as predictors in models. Results All four rodent species appear to be limited by a variety of factors, which differ between species in both number and type. The distribution of ship rats is limited by the most factors, reflecting the extent of its distribution across the archipelago. The distribution of mice is the least explicative. Only the three rat species interacted in their distribution. The distribution of kiore on offshore islands is significantly negatively related to that of ship rats and to a lesser extent Norway rats. The distribution of mice did not appear affected in any way by the number of other rodent species on an island. Main conclusions Differences in competitive ability and dispersal allow all four species to inhabit the New Zealand archipelago. Kiore distribution appears to be most limited by ship rat (and to a lesser extent Norway rat) distribution. The distribution of kiore was not found to interact with the distribution of mice on offshore islands, as has been suggested by others. The distribution of mice on offshore islands was difficult to model, which highlights the difficulties in managing this species. Overall the results offer valuable insights for management methods to assist preventing the invasion of offshore islands.     

Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K–T boundary Takatika Grit

Cretaceous–Tertiary (K–T) boundary (ca. 65 Ma) sections on a Southwest Pacific island containing dinosaurs were unknown until March 2003 when theropod bones were recovered from the Takatika Grit on the remote Chatham Islands (latitude 44° S, longitude 176° W), along the Chatham Rise. Tectonic and palaeontologic evidence support the eastward extension of a ca. 900 km land bridge that connected the islands to what is now New Zealand prior to the K–T boundary. The Chathams terrestrial fauna inhabited coastal, temperate environments along a low-lying, narrow, crustal extension of the New Zealand subcontinent, characterised by a tectonically dynamic, volcanic landscape with eroding hills (horsts) adjacent to flood plains and deltas, all sediments accumulating in grabens. This finger-like tract was blanketed with a conifer and clubmoss (Lycopodiopsida) dominated forest. The Chatham Islands region would have, along with New Zealand, provided a dinosaur island sanctuary after separating from the Gondwana margin ca. 80 Ma.     

Island biogeography and the species richness of introduced mammals on New Zealand offshore islands

Aim To investigate and establish the significance of various island biogeographic relationships (geographical, ecological and anthropological) with the species richness of introduced mammals on offshore islands. Location The 297 offshore islands of the New Zealand archipelago (latitude: 34–47°S; longitude: 166–179°E). Methods Data on New Zealand offshore islands and the introduced mammals on them were collated from published surveys and maps. The species richness of small and large introduced mammals were calculated for islands with complete censuses and regressed on island characteristics using a Poisson distributed error generalized linear model. To estimate the ‘z‐value’ for introduced mammals on New Zealand islands, least‐squares regression was used [log₁₀ S vs. log₁₀ A]. Results High collinearity was found between the area, habitat diversity and elevation of islands. The island characteristics related to the species richness of introduced mammals differed predictably between large and small mammals. The species richness of introduced large mammals was mostly related to human activities on islands, whereas species richness of introduced small mammals was mostly related to island biogeographical parameters. The ‘z‐value’ for total species richness is found to be expectedly low for introduced mammals. Main conclusions Distance appears to have become ecologically trivial as a filter for introduced mammal presence on New Zealand offshore islands. There is strong evidence of a ‘small island’ effect on New Zealand offshore islands. The species richness of both small and large introduced mammals on these islands appears to be most predominantly related to human use, although there is some evidence of natural dispersal for smaller species. The ecological complexity of some islands appears to make them less invasible to introduced mammals. Some human activities have an interactive effect on species richness. A small number of islands have outlying species richness values above what the models predict, suggesting that the presence of some species may be related to events not accounted for in the models.     

Frugivore gape size and the evolution of fruit size and shape in southern hemisphere floras

Abstract The present study uses differences among frugivore faunas of the southern hemisphere landmasses to test whether frugivore characteristics have influenced the evolution of fruit traits. Strong floristic similarities exist among southern landmasses; for example, 75% of New Zealand vascular plant genera also have species in Australia. However, plants in Australia and South America have evolved in the presence of a range of mammalian frugivores, whereas those in New Zealand, New Caledonia and the Pacific Islands have not. In addition, the avian frugivores in New Zealand and New Caledonia are generally smaller than those of Australia. If frugivore characteristics have influenced the evolution of fruit traits, predictable differences should exist between southern hemisphere fruits, particularly fruit size and shape. Fruit dimensions were measured for 77 New Zealand species and 31 Australian species in trans‐Tasman genera. New Zealand fruits became significantly more ellipsoid in shape with increasing size. This is consistent with frugivore gape size imposing a selective pressure on fruit ingestability. This result is not a product of phylogenetic correlates, as fruit length and width scaled isometrically for Australian species in genera shared with New Zealand. Within‐genus contrasts between New Zealand and Australian species in 20 trans‐Tasman genera showed that New Zealand species have significantly smaller fruits than their Australian counterparts. Within‐genus contrasts between New Zealand and South American species in nine genera gave the same result; New Zealand species had significantly smaller fruits than their South American counterparts. No difference was found in fruit size or shape between New Zealand and New Caledonia congeneric species from 12 genera. These results are consistent with the broad characteristics of the frugivore assemblage influencing the evolution of fruit size and shape in related species. The smaller‐sized New Zealand frugivore assemblage has apparently influenced the evolution of fruit size of colonizing taxa sometimes within a relatively short evolutionary timeframe.     

Older than New Caledonia emergence? A molecular phylogenetic study of the eneopterine crickets (Orthoptera: Grylloidea)

Aim A New Caledonian insect group was studied in a world‐wide phylogenetic context to test: (1) whether local or regional island clades are older than 37 Ma, the postulated re‐emergence time of New Caledonia; (2) whether these clades show evidence for local radiations or multiple colonizations; and (3) whether there is evidence for relict taxa with long branches in phylogenetic trees that relate New Caledonian species to geographically distant taxa. Location New Caledonia, south‐west Pacific. Methods We sampled 43 cricket species representing all tribes of the subfamily Eneopterinae and 15 of the 17 described genera, focusing on taxa distributed in the South Pacific and around New Caledonia. One nuclear and three mitochondrial genes were analysed using Bayesian and parsimony methods. Phylogenetic divergence times were estimated using a relaxed clock method and several calibration criteria. Results The analyses indicate that, under the most conservative dating scenario, New Caledonian eneopterines are 5–16 million years old. The largest group in the Pacific region dates to 18–29 Ma. New Caledonia has been colonized in two phases: the first around 10.6 Ma, with the subsequent diversification of the endemic genus Agnotecous, and the second with more recent events around 1–4 Ma. The distribution of the sister group of Agnotecous and the lack of phylogenetic long branches in the genus refute an assumption of major extinction events in this clade and the hypothesis of local relicts. Main conclusions Our phylogenetic studies invalidate a simple scenario of local persistence of this group in New Caledonia since 80 Ma, either by survival on the New Caledonian island since its rift from Australia, or, if one accepts the submergence of New Caledonia, by local island‐hopping among other subaerial islands, now drowned, in the region during periods of New Caledonian submergence.     

Phylogeny and historical biogeography of Gondwanan moss-bugs (Insecta: Hemiptera: Coleorrhyncha: Peloridiidae)

The moss bugs of the Peloridiidae, a small group of cryptic and mostly flightless insects, is the only living family in Coleorrhyncha (Insecta: Hemiptera). Today 37 species in 17 genera are known from eastern Australia, New Zealand, New Caledonia and Patagonia, and the peloridiids are thereby a group with a classical southern Gondwanan distribution. To explicitly test whether the present-day distribution of the Peloridiidae actually results from the sequential breakup of southern Gondwana, we provide the first total-evidence phylogenetic study based on morphological and molecular characters sampled from about 75% of recognized species representing 13 genera. The results largely confirm the established morphological phylogenetic context except that South American Peloridium hammoniorum constitutes the sister group to the remaining peloridiids. A timescale analysis indicates that the Peloridiidae began to diversify in the land mass that is today's Patagonia in the late Jurassic (153 Ma, 95% highest posterior density: 78–231 Ma), and that splitting into the three extant well-supported biogeographical clades (i.e. Australia, Patagonia and New Zealand/New Caledonia) is consistent with the sequential breakup of southern Gondwana in the late Cretaceous, indicating that the current transoceanic disjunct distributions of the Peloridiidae are best explained by a Gondwanan vicariance hypothesis.     

Panbiogeography of New Caledonia,south‐west Pacific: basal angiosperms on basement terranes,ultramafic endemics inherited from volcanic island arcs and old taxa endemic to young islands

Aim To investigate areas of endemism in New Caledonia and their relationship with tectonic history. Location New Caledonia, south‐west Pacific. Methods Panbiogeographical analysis. Results Biogeographical patterns within New Caledonia are described and illustrated with reference to eight terranes and ten centres of endemism. The basement terranes make up a centre of endemism for taxa including Amborella, the basal angiosperm. Three of the terranes that accreted to the basement in the Eocene (high‐pressure metamorphic terrane, ultramafic nappe and Loyalty Ridge) have their own endemics. Main conclusions New Caledonia is not simply a fragment of Gondwana but, like New Zealand and New Guinea, is a complex mosaic of allochthonous terranes. The four New Caledonian basement terranes were all formed from island arc‐derived and arc‐associated material (including ophiolites) which accumulated in the pre‐Pacific Ocean, not in Gondwana. They amalgamated and were accreted to Gondwana (eastern Australia) in the Late Jurassic/Early Cretaceous, but in the Late Cretaceous they separated from Australia with the opening of the Tasman Sea and break‐up of Gondwana. An Eocene collision of the basement terranes with an island arc to the north‐east – possibly the Loyalty Ridge – is of special biogeographical interest in connection with New Caledonia–central Pacific affinities. The Loyalty–Three Kings Ridge has had a separate history from that of the Norfolk Ridge/New Caledonia, although both now run in parallel between Vanuatu and New Zealand. The South Loyalty Basin opened between Grande Terre and the Loyalty Ridge in the Cretaceous and attained a width of 750 km. However, it was almost completely destroyed by subduction in the Eocene which brought the Loyalty Ridge and Grande Terre together again, after 30 Myr of separation. The tectonic history is reflected in the strong biogeographical differences between Grande Terre and the Loyalty Islands. Many Loyalty Islands taxa are widespread in the Pacific but do not occur on Grande Terre, and many Grande Terre/Australian groups are not on the Loyalty Islands. The Loyalty Islands are young (2 Myr old) but they are merely the currently emergent parts of the Loyalty Ridge whose ancestor arcs have a history of volcanism dating back to the Cretaceous. Old taxa endemic to the young Loyalty Ridge islands persist over geological time as a dynamic metapopulation surviving in situ on the individually ephemeral islands and atolls found around subduction zones. The current Loyalty Islands, like the Grande Terre terranes, have inherited their biota from previous islands. On Grande Terre, the ultramafic terrane was emplaced on Grande Terre in the Eocene (about the same time as the collision with the island arc). The very diverse endemic flora on the ultramafics may have been inherited by the obducting nappe from prior base‐rich habitat in the region, including the mafic Poya terrane and the limestones typical of arc and intraplate volcanic islands.     

Phylogeny recapitulates geography, or why New Zealand has so many species of skinks

The evolutionary history of 25 New Zealand scincid lizards in the endemic genera Oligosoma and Cyclodina was examined using 12S rRNA sequence data. Phylogenetic resolution was poor, despite there being up to 9% sequence divergence between taxa. Lack of resolution was not attributable to biases in the data, such as site saturation or differences in sites free to vary, so we infer that New Zealand skinks underwent two relatively rapid phases of divergence. The rate of substitution for the skink sequences appears to be similar to some bird and mammal groups for which times of divergence have been estimated. Using fhese calibrations diversification of Oligosoma skinks probably began at least 23 million years ago (Mya). The pattern of relationships and the timing of this diversification are interpreted as resulting from rapid allopatric speciation during the Oligocene (25–35 Mya) when New Zealand was fragmented into many low lying islands. A second major phase of speciation involving the Cyclodina seems to have occurred during the Miocene (15–24 Mya), probably as a consequence of increasing land area and habitat diversity. This pattern of skink evolution contrasts with the Oligocene 'environmental crisis' hypodiesis of Cooper & Cooper (Proc. R. Soc. Land. B. 261, 293–302), but can be attributed to differences in the ecology of different taxa. This can be tested by examination of other groups, such as land snails and geckos. The large number of lizard species in New Zealand can be considered a legacy both of past geography as well as the absence of small mammals which would have been both competitors and predators.     

Cancer epidemiology in the small nations of Pacific Islands

BackgroundPacific island countries and territories (PICTs) comprise 20,000–30,000 islands in the Pacific Ocean. PICTs face challenges in relation to small population sizes, geographic dispersion, increasing adoption of unhealthy life-styles and the burden of both communicable and non-communicable diseases, including cancer. This study reviews data on cancer incidence and mortality in the PICTs, with special focus on indigenous populations.MethodsPICTs with populations of <1.5 million (‘small nations’) were included in this study. Information on cancer incidence and mortality was extracted from the GLOBOCAN 2012 database. Scientific and grey literature was narratively reviewed for publications published after 2000.ResultsOf the 21 PICTs, seven countries were included in the GLOBOCAN 2012 (Fiji, French Polynesia, Guam, New Caledonia, Samoa, Solomon Islands, Vanuatu). The highest cancer incidence and mortality rates were reported in New Caledonia (age-standardized incidence and mortality rates 297.9 and 127.3 per 100.000) and French Polynesia (age-standardized incidence and mortality rates 255.0 and 134.4 per 100.000), with relatively low rates in other countries. Literature indicated that cancer was among the leading causes of deaths in most PICTs; thus they now experience a double burden of cancers linked to infections and life-style and reproductive factors. Further, ethnic differences in cancer incidence and mortality have been reported in some PICTs, including Fiji, Guam, New Caledonia and Northern Mariana Islands.ConclusionCancer incidence in the PICTs was recorded to be relatively low, with New Caledonia and French Polynesia being exceptions. Low recorded incidence is likely to be explained by incomplete cancer registration as cancer had an important contribution to mortality. Further endeavors are needed to develop and strengthen cancer registration infrastructure and practices and to improve data quality and registration coverage in the PICTs.     

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.