Ulmus leaves and fruits from the Early–Middle Eocene of northwestern North America: systematics and implications for character evolution within Ulmaceae

2005 ◽  
Vol 83 (12) ◽  
pp. 1663-1681 ◽  
Author(s):  
Thomas Denk ◽  
Richard M. Dillhoff

Leaves and fruits of Ulmus from the Early–Middle Eocene of British Columbia and Washington are assigned to two species. Ulmus okanaganensis sp.nov. is based on leaves attached to flowering and fruiting twigs and isolated leaves and fruits. Leaves display a polymorphism ranging from large leaves with compound teeth with a blunt apex to small ones with simple teeth resembling those of Zelkova. In extant Ulmus, sucker-shoot leaves, elongation-shoot leaves, and leaves on short annual branches often display a very similar polymorphism. In the fossil, flowers are arranged in fascicles having short pedicels. Fascicles are formed in the axils of leaves of current-year shoots and appear together with the leaves. This is uncommon in modern species of Ulmus, where leaves appear either in spring on previous-year shoots or in autumn in the axils of leaves of current-year shoots. Fruits of U. okanaganensis are samaras with extremely reduced or absent wings. Unwinged fruits of modern Ulmus are typically ciliate along the margin of the endocarp and the persistent styles but only a single fruit of U. okanaganensis has been found preserving hairs. The small, shallowly lobed perianth is situated below the endocarp. A second type of foliage is assigned to Ulmus chuchuanus (Berry) LaMotte. This foliage is wider than that of U. okanaganensis and has more densely spaced secondary veins. It also has characteristic compound teeth with primary and subsidiary teeth displaying conspicuously different orientations. Leaves of U. chuchuanus co-occur with a second type of fruit but have not been found in attachment. These fruits are larger than in U. okanaganensis, with a narrow wing, persistent styles, and a large and wide persistent perianth that tapers abruptly into the perianth tube. A cladistic analysis suggests that U. okanaganensis is nested within the subgenus Ulmus, which is a paraphyletic grade basal to the subgenus Oreoptelea. Ulmus chuchuanus foliage shows affinities to the subgenus Ulmus, while the associated fruits display affinities to the subgenus Oreoptelea.

2004 ◽  
Vol 82 (10) ◽  
pp. 1509-1517 ◽  
Author(s):  
Steven R Manchester ◽  
Richard M Dillhoff

Fruits and leaves from the Middle Eocene of McAbee, British Columbia, and Republic, Washington, provide an earlier record for the genus Fagus than previously accepted for this member of the Fagaceae. The fruits are trigonal nuts borne within spiny four-valved cupules on long peduncles. The leaves are borne alternately on the twigs and are ovate to elliptic with craspedodromous secondary veins and simple teeth distributed one per secondary vein. The shale preserving these megafossils also contains dispersed pollen with morphology and ornamentation diagnostic of Fagus. Previously, the oldest Fagus occurrences confirmed by fruits were early Oligocene (ca. 32 Ma). The recognition of Middle Eocene (ca. 50 Ma) representatives helps to reduce the disparity between molecular evidence favoring Fagus as a primitive genus within Fagaceae, and fossil evidence, which had indicated older occurrences of Castanea and Quercus than Fagus.Key words: Eocene, Fagus, fossil, foliage, fruits, British Columbia.


1990 ◽  
Vol 64 (1) ◽  
pp. 161-164 ◽  
Author(s):  
P. Martin Sander ◽  
Hugo Bucher

The small ichthyosaurMixosaurusis the most widely distributed ichthyosaur. It is known from Lower Triassic rocks of British Columbia, Canada (Callaway and Brinkman, 1989), and Middle Triassic rocks of northwestern North America (Alaska, British Columbia), China, Timor, the western Tethys (Switzerland, Italy, Turkey), the Germanic Triassic, and the high Arctic (Spitsbergen, Exmouth Island) (Mazin, 1986; Callaway and Brinkman, 1989; Callaway and Massare, 1989). The presence ofMixosaurusin one of the richest ichthyosaur provinces, the Middle Triassic of Nevada (Merriam, 1908), has been difficult to establish. The history of this problem is very colorful and is the topic of this note together with the description of a new specimen from the Nevada Middle Triassic.


2016 ◽  
Vol 3 (10) ◽  
pp. 160518 ◽  
Author(s):  
Susumu Tomiya ◽  
Zhijie Jack Tseng

The Middle to Late Eocene sediments of Texas have yielded a wealth of fossil material that offers a rare window on a diverse and highly endemic mammalian fauna from that time in the southern part of North America. These faunal data are particularly significant because the narrative of mammalian evolution in the Paleogene of North America has traditionally been dominated by taxa that are known from higher latitudes, primarily in the Rocky Mountain and northern Great Plains regions. Here we report on the affinities of two peculiar carnivoraforms from the Chambers Tuff of Trans-Pecos, Texas, that were first described 30 years ago as Miacis cognitus and M. australis . Re-examination of previously described specimens and their inclusion in a cladistic analysis revealed the two taxa to be diminutive basal amphicyonids; as such, they are assigned to new genera Gustafsonia and Angelarctocyon , respectively. These two taxa fill in some of the morphological gaps between the earliest-known amphicyonid genus, Daphoenus , and other Middle-Eocene carnivoraforms, and lend additional support for a basal caniform position of the beardogs outside the Canoidea. The amphicyonid lineage had evidently given rise to at least five rather distinct forms by the end of the Middle Eocene. Their precise geographical origin remains uncertain, but it is plausible that southern North America served as an important stage for a very early phase of amphicyonid radiation.


2012 ◽  
Vol 137 (6) ◽  
pp. 445-451 ◽  
Author(s):  
Michael Dossett ◽  
Chaim Kempler

Resistance to colonization by the raspberry aphid (Amphorophora agathonica Hottes) has been an important objective in North American red raspberry (Rubus idaeus L.) breeding programs since the 1930s because of its effectiveness in controlling the spread of aphid-transmitted viruses in red raspberry. The most widely used source of resistance in North America has been the gene Ag1 from ‘Lloyd George’. The widespread use of Ag1 to control aphids led to the appearance of a resistance-breaking biotype in British Columbia, Canada, in 1990. Our objective was to identify biotypes of A. agathonica present in the commercial red raspberry production region of southwestern British Columbia and northwestern Washington and determine what sources of resistance may still be effective against this pest. We collected 12 aphid isolates and screened them against 15 raspberry cultivars and four selections. Although it has been widely believed that only two biotypes (regular and Ag1-breaking) of A. agathonica were present in the region, we identified six distinct biotypes and characterized them by their ability or inability to colonize a differential set of raspberry cultivars. This has confirmed the loss of previously recognized and unrecognized sources of resistance in some cultivars. The data also support the presence of a seventh biotype that has not yet been observed. In addition, we confirmed resistance from three sources of wild North American red raspberries that hold up to each of these biotypes. Our results will serve as a guide for future efforts to characterize the prevalence of different aphid biotypes in the region and the identification of new sources of resistance for breeding.


2020 ◽  
Vol 78 ◽  
pp. 1-17
Author(s):  
Paul K. Abram ◽  
Audrey E. McPherson ◽  
Robert Kula ◽  
Tracy Hueppelsheuser ◽  
Jason Thiessen ◽  
...  

We report the presence of two Asian species of larval parasitoids of spotted wing Drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), in northwestern North America. Leptopilina japonica Novkovic & Kimura and Ganaspis brasiliensis (Ihering) (Hymenoptera: Figitidae) were found foraging near and emerging from fruits infested by D. suzukii at several locations across coastal British Columbia, Canada in the summer and fall of 2019. While G. brasiliensis was found in British Columbia for the first time in 2019, re-inspection of previously collected specimens suggests that L. japonica has been present since at least 2016. Additionally, we found a species of Asobara associated with D. suzukii in British Columbia that is possibly Asobara rufescens (Förster) (known only from the Palearctic Region) based on COI DNA barcode data. These findings add to the list of cases documenting adventive establishment of candidate classical biological control agents outside of their native ranges. The findings also illustrate the need for revisiting species concepts within Asobara, as well as host and geographic distribution data due to cryptic and/or misidentified species.


1994 ◽  
Vol 72 (3) ◽  
pp. 470-495 ◽  
Author(s):  
Rowland M. Shelley

In northwestern North America, the milliped family Nearctodesmidae is comprised of four genera, Nearctodesmus Silvestri, Kepolydesmus Chamberlin, Ergodesmus Chamberlin, and Bistolodesmus, new genus, and six species, N. insulans (Chamberlin), N. cerasinus (Wood), N. salix Chamberlin, K. anderisus Chamberlin, E. compactus Chamberlin, and B. bonikus (Chamberlin). These species occur along the Pacific coast from San Francisco Bay to Prince Rupert, British Columbia, including all offshore island groups, with an eastward extension into Lewis and Clark County, Montana, east of the Continental Divide. An allopatric population of N. insulanus occurs in the Shuswap Highlands of British Columbia, and an allopatric species, E. remingtoni (Hoffman), inhabits caves in western and southern Illinois. The principal taxonomic characters are the number of secondary projections from the gonopodal telopodite, the configuration of the longer of these, and the length and configuration of the distal zone of the acropodite. Polydesmus bonikus is a nearctodesmid and is assigned to the new genus, Bistolodesmus. The following new synonymies are proposed: Jaliscodesmus Hoffman under Sakophallus Chamberlin; J. alticola Hoffman under S. simplex Chamberlin; N. brunnior, N. campicolens, and N. malkini, all by Chamberlin, under N. cerasinus; N. amissus, N. pseustes, N. renigens, N. carli, and N. boydi, all by Chamberlin, and N. olympus and N. cochlearius, both by Causey, under N. insulanus; K. mimus, K. hesperus, and K. pungo, all by Chamberlin, under K. anderisus; and Ectopodesmus cristatus and E. c. dentatus, both by Loomis and Schmitt, under Ergodesmus compactus. Modern diagnoses and illustrations are presented for the family and all northwestern taxa, along with keys to the genera and species of Nearctodesmus. Accounts and gonopod drawings are also presented of Sakophallus and S. simplex Chamberlin in Michoacan and Jalisco, Mexico.


1973 ◽  
Vol 51 (3) ◽  
pp. 571-580 ◽  
Author(s):  
Dale H. Vitt ◽  
Michael Ostafichuk ◽  
Irwin M. Brodo

Four species of mosses, all in the genus Orthotrichum; 1 species of hepatics; and 16 species of lichens compose the foliicolous bryophyte and lichen flora of Thuja plicata L. leaves in certain areas of western British Columbia. This is the first report of foliicolous mosses and hepatics for North America, north of the tropical and subtropical regions of the southeastern United States. The taxonomy of the four species of Orthotrichum is discussed and a key given differentiating the species.All of the species that have been found on Thuja leaves except perhaps Catillaria bouteillei are facultative foliicolous species and occur on leaves, only in scattered areas of northwestern North America. Two taxa of lichens, Catillaria bouteillei (Desm.) Zahlbr. and Cetrelia cetrarioides (Del. ex Duby) W. Culb. & C. Culb. (perlatolic acid strain) are reported as new to Canada.


2013 ◽  
Vol 91 (8) ◽  
pp. 562-572 ◽  
Author(s):  
Charles J. Krebs ◽  
Knut Kielland ◽  
John Bryant ◽  
Mark O’Donoghue ◽  
Frank Doyle ◽  
...  

Snowshoe hares (Lepus americanus Erxleben, 1777) fluctuate in 9–10 year cycles throughout much of their North American range. Regional synchrony has been assumed to be the rule for these cycles, so that hare populations in virtually all of northwestern North America have been assumed to be in phase. We gathered qualitative and quantitative data on hare numbers and fur returns of Canada lynx (Lynx canadensis Kerr, 1792) in the boreal forest regions of Alaska, Yukon, Northwest Territories, and northern British Columbia to describe synchrony in the time window of 1970–2012. Broad-scale synchrony in lynx fur returns was strong from 1970 to about 1995 but then seemed to break down in different parts of this region. Hare populations at 20 sites in Alaska, the Yukon, and Northwest Territories showed peak populations that lagged by 1–4 years during the 1990s and 2000s cycles. The simplest hypothesis to explain these patterns of asynchrony in hare cycles is the movement of predators from British Columbia north into the Yukon and then east into the Northwest Territories and west into Alaska. A traveling wave of these cycles is clearly seen in the lynx fur returns from western Canada and Alaska from 1970 to 2009. One consequence of a failure of synchrony is that hare predators like Canada lynx and Great-horned Owls (Bubo virginianus (Gmelin, 1788)) can move from one adjacent area to the next within this region and survive long enough to prolong low densities in hare populations that have declined earlier.


2016 ◽  
Vol 56 (2) ◽  
pp. 247-305 ◽  
Author(s):  
Friðgeir Grímsson ◽  
Guido W. Grimm ◽  
Reinhard Zetter ◽  
Thomas Denk

Abstract Modern lineages of the beech family, Fagaceae, one of the most important north-temperate families of woody flowering plants, have been traced back to the early Eocene. In contrast, molecular differentiation patterns indicate that the Fagus lineage, Fagoideae, with a single modern genus, evolved much earlier than the remaining lineages within Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae). The minimum age for this primary split in the Fagaceae has been estimated as 80 ± 20 Ma (i.e. Late Cretaceous) in recently published, time-calibrated phylogenetic trees including all Fagales. Here, we report fagaceous fossils from the Campanian of Wyoming (82-81 Ma; Eagle Formation [Fm]), the Danian of western Greenland (64-62 Ma; Agatdal Fm), and the middle Eocene of British Columbia (ca 48 Ma; Princeton Chert), and compare them to the Fagaceae diversity of the recently studied middle Eocene Hareøen Fm of western Greenland (42-40 Ma). The studied assemblages confirm that the Fagus lineage (= Fagoideae) and the remainder of modern Fagaceae were diverged by the middle Late Cretaceous, together with the extinct Fagaceae lineage(s) of Eotrigonobalanus and the newly recognised genus Paraquercus, a unique pollen morph with similarities to both Eotrigonobalanus and Quercus. The new records push back the origin of (modern) Fagus by 10 Ma and that of the earliest Fagoideae by 30 Ma. The earliest Fagoideae pollen from the Campanian of North America differs from its single modern genus Fagus by its markedly thicker pollen wall, a feature also seen in fossil and extant Castaneoideae. This suggests that a thick type 1 foot layer is also the plesiomorphic feature in Fagoideae although not seen in any of its living representatives. The Danian Fagus pollen of Greenland differs in size from those of modern species but is highly similar to that of the western North American early Eocene F. langevinii, the oldest known beech so far. Together with the Quercus pollen record, absent in the Campanian and Danian formations but represented by several types by the middle Eocene, this confirms recent dating estimates focussing on the genera Fagus and Quercus, while rejecting estimates from all-Fagales-dated trees as too young. The basic Castaneoideae pollen type, still found in species of all five extant genera of this putatively paraphyletic subfamily, represents the ancestral pollen type of most (modern) Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae).


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