Nordenskioldia and Trochodendron (Trochodendraceae) from the Miocene of Northwestern North America

Department of Biology, Indiana University Bloomington, Bloomington, Indiana, United States
Botanical Gazette 09/1991; 152(3). DOI: 10.1086/337898


The extinct trochodendraceous genus Nordenskioldia, well represented in the Paleocene of the Northern Hemisphere, is documented for the first time from the Neogene, based upon infructescences, fruits, associated twigs, and foliage from the Miocene of Idaho, Washington, and southern British Columbia. The infructescences and fruits, assigned to Nordenskioldia interglacialis (Hollick) comb. nov., are very similar to Paleocene N. borealis, but differ in ranging to a higher number of carpels per fruit and in being less regularly dehiscent. The leaves, Zizyphoides auriculata (Heer) comb. nov., formerly attributed to Populus and Cocculus, are clearly congeneric with the leaves associated with Nordenskioldia in Paleocene deposits. Zizyphoides auriculata leaves differ from Paleocene Z. flabellum in having generally more prominent dentations along the margin and a broader divergence of the lateral primary veins. Excellent preservation of the Miocene material reveals features not preserved in the Paleocene specimens, and in particular, lignified fruitlets clearly show aborted ovules in addition to the single mature seed. Infructescences of Trochodendron are also documented from the same Miocene localities at which N. interglacialis occurs. The close similarities between Paleocene and Miocene species of Nordenskioldia, and also between the Miocene and extant species of Trochodendron, suggest relative stasis in the morphological evolution of the Trochodendraceae over intervals of up to 45 million years.

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    • "The oldest fossils assigned to Tetracentron date from the Palaeocene to early Eocene (Kamchatka ; Chelebaeva & Shancer, 1988), although more reliable fossil remains have been variously reported from the Miocene to late Pliocene of Japan (Ozaki, 1987; Suzuki et al., 1991), the Miocene and Eocene of western North America (Manchester & Chen, 2006; Pigg et al., 2007) and the Miocene of Iceland (Gr ımsson et al., 2008) (Fig. 1). Trochodendron fossils are also known from the Miocene of Kamchatka (Chelebaeva & Chigayeva, 1988) and Japan (Suzuki et al., 1991) and the Miocene and Eocene of western North America (Manchester et al., 1991; Fields, 1996; Pigg et al., 2001, 2007). The current, relatively narrow distributions of Tetracentron and Trochodendron may in part result from the dramatic global climate changes of the late Neogene and Quaternary periods. "
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    ABSTRACT: AimA phylogeographical study of the widespread but phylogenetically isolated East Asian endemic tree species Tetracentron sinense (Trochodendraceae) was performed to evaluate whether and how Pleistocene and pre-Pleistocene climate changes helped to influence current phylogeographical patterns, and to describe the current patterns of genetic diversity and their implications for conservation.LocationSouthwestern and central subtropical China.Methods Sequences of four chloroplast spacer regions were obtained from 157 individuals of T. sinense. A haplotype network was constructed using tcs. Genetic diversity and differentiation, spatial analysis of molecular variance (SAMOVA) and analysis of molecular variance (AMOVA) were used to test for genetic structure. beast was used to estimate the divergence times between haplotypes. Historical demographic expansion was tested using pairwise mismatch distribution analysis.ResultsOf the 21 recovered haplotypes, three were widely distributed, but most were restricted to particular regions. Populations with high haplotype diversity were located in western Hubei, southern Sichuan and southern Chongqing. The two earliest-diverging haplotypes were found in southwestern China. The haplotype distribution of T. sinense demonstrated significant phylogeographical structure (NST > GST; P < 0.05). The best partitioning of genetic diversity by SAMOVA (K = 5) produced groups that matched the main tcs-derived clades. Two independent range expansions within SAMOVA-derived groups 2 and 3 were dated to approximately 399 and 311 ka, respectively. The time to the most recent common ancestor of all haplotypes was 9.6 (95% highest posterior density: 27.0–2.2) Ma, but most of the haplotype diversity appeared during the Quaternary.Main conclusionsThe extant distribution of T. sinense is likely to have been shaped by both pre-Quaternary and Pleistocene climate changes. Southwestern China may have served as an important refugium for T. sinense throughout the Neogene, while the species also occupied multiple refugia during the late Pleistocene glacial periods. Populations of T. sinense were resolved into five allopatric groups, between which there is apparently no seed movement.
    Full-text · Article · May 2014 · Journal of Biogeography
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    • "Both Tetracentron and Trochodendron had wide distributions in the Northern Hemisphere during the Paleogene and Neogene. Fossil remains of Tetracentron have been found in Japan [60]–[61], Idaho [62], Princeton, British Columbia and Republic, Washington [63], and Iceland [15]; Trochodendron fossil remains have been reported from Kamchatka [64], Japan [11], Idaho and Oregon [11]–[12], Washington [7], and British Columbia [63]. Our estimate of the divergence time between the two genera of Trochodendraceae (44-30 mya) encompasses the recent estimate of 37-31 mya from Bell et al. [65], which was based on analysis of 567 taxa and three genes, as well as the mid-Eocene estimate of ∼45 mya derived from the rbcL analysis of Anderson et al. [66], which employed numerous fossil constraints from the early-diverging eudicots. "
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    ABSTRACT: The early-diverging eudicot order Trochodendrales contains only two monospecific genera, Tetracentron and Trochodendron. Although an extensive fossil record indicates that the clade is perhaps 100 million years old and was widespread throughout the Northern Hemisphere during the Paleogene and Neogene, the two extant genera are both narrowly distributed in eastern Asia. Recent phylogenetic analyses strongly support a clade of Trochodendrales, Buxales, and Gunneridae (core eudicots), but complete plastome analyses do not resolve the relationships among these groups with strong support. However, plastid phylogenomic analyses have not included data for Tetracentron. To better resolve basal eudicot relationships and to clarify when the two extant genera of Trochodendrales diverged, we sequenced the complete plastid genome of Tetracentron sinense using Illumina technology. The Tetracentron and Trochodendron plastomes possess the typical gene content and arrangement that characterize most angiosperm plastid genomes, but both genomes have the same unusual ∼4 kb expansion of the inverted repeat region to include five genes (rpl22, rps3, rpl16, rpl14, and rps8) that are normally found in the large single-copy region. Maximum likelihood analyses of an 83-gene, 88 taxon angiosperm data set yield an identical tree topology as previous plastid-based trees, and moderately support the sister relationship between Buxaceae and Gunneridae. Molecular dating analyses suggest that Tetracentron and Trochodendron diverged between 44-30 million years ago, which is congruent with the fossil record of Trochodendrales and with previous estimates of the divergence time of these two taxa. We also characterize 154 simple sequence repeat loci from the Tetracentron sinense and Trochodendron aralioides plastomes that will be useful in future studies of population genetic structure for these relict species, both of which are of conservation concern.
    Full-text · Article · Apr 2013 · PLoS ONE
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    • "The Latah Formation, widespread in eastern Washington and western Idaho, consists of fluvial and lacustrine deposits interbedded with CRBG flows, and is known for its well-preserved flora [33], [34]. Fallout tuff bearing beds of the Latah Formation at White Bird, Idaho, are contained within ancient and active landslide deposits; their original stratigraphy has been significantly disrupted. "
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    ABSTRACT: Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.
    Full-text · Article · Oct 2012 · PLoS ONE
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