Bulletin of the Museum of Natural History, University of Oregon

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WAVP Abstracts 2019
(2019-03) Davis, Edward B.
Annual compilation of abstracts for the Bulletin of the Museum of Natural History.
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New mammutids (Proboscidea) from the Clarendonian and Hemphillian of Oregon - a survey of Mio-Pliocene mammutids from North America
(2023-05) Koenigswald, W. von; Widga, C.; Gohlich, U.B.
A survey of Miocene-Pliocene Mammutidae from North America is provided. Two important but undescribed specimens from Unity (Clarendonian) and Hermiston (Hemphillian) are reported, and a previously described mandible from Black Butte (Clarendonian) is revisited. The Unity specimen, a maxilla with a tusked longirostrine mandible, represents Zygolophodon proavus. Upper and lower tusks are well developed. Mammutid species are best characterized by traits of the mandible, the upper tusks and lower and upper dentitions. However, they are rarely preserved in a single individual, as in the Unity specimen. A second mammutid mandible from the nearby, stratigraphically similar Black Butte locality has a short, tuskless symphysis and was described as “Mammut (Pliomastodon) furlongi”. We question the independence of this species, because both types of mandibles are coeval in several Eurasian localities. The widespread geographic and stratigraphic co-occurrence of different mandible types cannot be explained through a phylogenetic model alone. Therefore, we discuss whether these parallel mammutid occurrences can be interpreted as resulting from species diversity, intraspecific variability, pathological abnormities, or as a sex-linked morphological difference. The Hermiston maxilla from the upper Hemphillian represents Mammut matthewi. The large upper tusk differs from Z. proavus. The morphology of the mandible, however, remains unknown, thus its precise evolutionary stage is uncertain. The maxillary molars of the Hermiston specimen are larger than in Z. proavus however, we observe a high degree of variability in the size of mammutid molars so this character alone is not indicative of a specific evolutionary stage. The relatively small number of localities with informative specimens and the conservative dental morphology of mammutids throughout the Miocene and Pliocene obscures the potential occurrence of synchronous North American taxa. Our results favor the interpretation of a continuous and endemic evolution from Zygolophodon to Mammut and make an independent immigration of the genus Mammut from Eurasia less probable. Therefore, the genus name Mammut should be avoided for Eurasian mammutids.
Open Access
Early Miocene Cape Blanco Flora of Oregon
(2022-08) Emerson, L.F.; Retallack, G.J.; Hughes, B.G.
Deposition of the shallow marine sandstone of Floras Lake was interrupted by a transient del-taic progradation of redeposited volcanic tuff, which contains the Cape Blanco flora. Dating by 40Ar/39Ar on fresh plagioclase constrains the age of the plant-bearing tuff to 18.24 ± 0.86 Ma, because we interpret this age of eruption and landscape loading with ash, as within only a few years of redeposition. Several plausible sources of the tuff can be identified from caldera eruptions in the Cascade Volcanic Arc. The relation between the early Miocene Cascade volcanic arc and the Klamath Terrane has been fixed since the early Miocene, and the high Cr2O3 in the sandstones is an indication that the source area for the sandstone of Floras Lake was the Klamath Terrane. Fossil leaves and other plant organs of 33 species of the Cape Blanco flora represent floral diversity and paleoclimate of coastal Oregon during the early Miocene. The flora includes a variety of thermo-philic elements from California, including coast redwood (Sequoia affinis), and avocado (Persea pseudocarolinensis), and is numerically dominated by live oak (Quercus hannibalii), and chinqua-pin (Chrysolepis sonomensis). The size and proportion of serrate margins of the fossil leaves are evidence of mean annual temperature of ~14 º C and a mean annual precipitation of ~223 cm/yr for the Cape Blanco flora. Comparison of the Cape Blanco flora with the Temblor flora of Cali-fornia and the Seldovia flora of Alaska reveals a latitudinal gradient of ~ 0.6 º C/degree latitude, compared with a gradient of ~0.3 º C/degree latitude from isotopic composition of marine foramin-ifera of the northeast Pacific Ocean. Both results confirm that the late early Miocene mean annual temperature at 45º north latitude was 4-5 º C warmer than today.
Open Access
Two Pictorial Documents from the Colonial Period in Mexico
(2018-10) Dumond, Don E.
This brief report concerns two colonial-period picture documents from Mexico that are now in the pos-session of the Museum of Natural and Cultural History at the University of Oregon. Both concern historical matters of geographical import, both are termed mapas (“maps” in Spanish) but most strongly represent political statements. The first of these treated, identified as the Mapa de Cuauhtlantzinco, is apparently one of at least a half-dozen known copies, or partial copies, of an older document now unknown, and concerns especially people said to represent the town of Cuauhtlantzinco, which is located on the central Mexican highlands somewhat more than one hundred kilometers (62 miles) southeast of the heart of modern Mexico City. The second, now designated the Mapa de San Andrés Mixtepec is evidently a single, original document that directs itself to the history of a small settlement in the state of Oaxaca, and at a point located well over four hundred kilometers (249 miles) southeast of Mexico City, and more than three hundred fifty kilometers (217 miles) from Cuauhtlantzinco. Both of these mapas are of evident interest to local inhabitants of the two areas, which led the museum some years ago to gift photographic copies to people of these areas, which were delivered in Mexico through the good offices of a museum colleague, Dr. Stephanie Wood, of the University of Oregon. The first of these towns was Cuauhtlantzinco (on modern maps spelled Cuautlancingo) which led a local resident and student, Alberto Sarmiento Tepoztecatl (his surnames repeating two of those connected histor-ically to the Mapa de Cuauhtlantzinco, as will be seen in Chapter 2) to visit the University of Oregon in the fall of 2002 and present a talk about the local mapa to an audience in the museum. The second (largely a matter of bad roads) was delivered not to the very rural town of San Andrés Mixtepec but to a regional alternative, the Francis-co de Burgoa Library in Oaxaca City (capital of the state of Oaxaca), a library with affiliations to the Museum of Oaxacan Cultures as well as to the Universidad Autónoma Benito Juarez, both located in the state capital. As a pair, the documents—clearly of import for local aspects of Mexican post-colonial history—represent relatively untypical properties for holdings of this Oregon museum, so it seems well to begin with a brief history of how they came to be in the museum collection, and to summarize efforts made to determine precisely both what it is they represent—in a historical sense—and also the ways they can be seen to relate to the time and condi-tions of their Mexican places of named relationship. To approach this, Chapter 1 unwinds to provide information regarding the comparatively recent discovery of the docu-ments within the museum and then summarizes research that revealed how they came to the institution. It goes on to discuss the specific geographical areas and ethnic regions of Mexico to which the documents each relate and adds basic information regarding the substantial differ-ences between the mapas in construction and physical appearances and then of their apparently much smaller differences in probable dates of actual creation. Following this, Chapters 2 and 3—each of them devoted to a separate document—will delve at least super-ficially into the specific historical and ethnic backgrounds against which the documents themselves should be viewed, considering their differing geographical sources within Mexico. Each of these documents also focuses especially on matters of concern to aboriginal people of Mexico, rather than on those of overriding concern to their new colonial Spanish masters. As historical details emerge regarding each document and its milieu, questions can be raised as to why they were composed and completed at the dates that seem indicated by the evidence—dates that in both cases are more than a century after the actual Spanish conquest of Mexico was brought to completion. Chapter 4, then, provides further examinations of historical details that bear strongly on these questions—especially on just why the documents were created at the time or times in which they evidently emerged. Finally, although there will be no attempt in this brief guide to present complete and fully satisfactory color reproduc-tions of either of the documents, portions of them will be presented in hopes of stimulating interest in obtaining more direct views of the documents themselves. In later pages, additional information pertinent to each of the doc-uments will also include relevant addresses of materials on the University website.
Open Access
Oregon 2100: Projected Climatic and Ecological Changes
(2016-03) Retallack, G.J.; Gavin, D.G.; Davis, E.B.; Sheldon, N.D.; Erlandson, J.M.; Reed, M.H.; Bestland, E.A.; Roering, J.J.; Carson, R.J.; Mitchell, R.B.
Greenhouse climatic warming is underway and exacerbated by human activities. Future outcomes of these processes can be projected using computer models checked against climatic changes during comparable past atmospheric compositions. This study gives concise quantitative predictions for future climate, landscapes, soils, vegetation, and marine and terrestrial animals of Oregon. Fossil fuel burning and other human activities by the year 2100 are projected to yield atmospheric CO2 levels of about 600-850 ppm (SRES A1B and B1), well above current levels of 400 ppm and preindustrial levels of 280 ppm. Such a greenhouse climate was last recorded in Oregon during the middle Miocene, some 16 million years ago. Oregon’s future may be guided by fossil records of the middle Miocene, as well as ongoing studies on the environmental tolerances of Oregon plants and animals, and experiments on the biological effects of global warming. As carbon dioxide levels increase, Oregon’s climate will move toward warm temperate, humid in the west and semiarid to subhumid to the east, with increased summer and winter drought in the west. Western Oregon lowlands will become less suitable for temperate fruits and nuts and Pinot Noir grapes, but its hills will remain a productive softwood forest resource. Improved pasture and winter wheat crops will become more widespread in eastern Oregon. Tsunamis and stronger storms will exacerbate marine erosion along the Oregon Coast, with significant damage to coastal properties and cultural resources
Open Access
An Early Pliocene North American Deer: Bretzia pseudalces, Its Osteology, Biology, and Place in Cervid History
(2015-05) Gustafson, Eric Paul
The cervid genus Bretzia was fi rst described in 1974 from antler and skull material found in the White Bluffs local fauna of the Pliocene Ringold Formation in south-central Washington. Cervid specimens from the Ringold deposits had been mentioned in published reports in 1917 and 1953, but not until a series of specimens was collected by Willis E. Fry and donated to the Burke Museum in Seattle, about 1970, was the evidence adequate to provide a preliminary diagnosis of Bretzia. The basis of the genus was a series of shed antlers and a portion of the skull of a male individual. Although statements have been made generally characterizing the dentition and postcranial skeleton as similar to Odocoileus, the detailed descriptions of these elements have not previously been published.Bretzia was similar in size to modern O. hemionus (mule deer) but differed in antler morphology and details of the skull, teeth, and postcranial skeleton. The antler pedicles are more widely separated than in most Cer-vidae. The antlers are distinctive, with a single anterior tine and a posterior beam which in adult individuals forms a large palmate structure. Enough antlers are known to present a developmental series including juvenile, adolescent, adult, and senescent forms. Numerous details of the dentition and postcranial skeleton, including the metacarpals show that Bretzia pseudalces was a telemetacarpal deer (subfamily Capreolinae). The relationship of Bretzia to the living tribes (Alcini, Capreolini, and Rangiferini) is uncertain. Bretzia was one of three known genera (Bretzia, Odocoileus, and Eocoileus) in an early Pliocene (ca. 5 Ma) evolutionary radiation of cervids after the initial immigration from Asia into North America around the time of the Miocene-Pliocene boundary. The Ringold Formation deposits in which the cervid sample was found date to the early Blancan (early Pliocene), probably between 5.0 and 4.8 Ma. The White Bluffs cervid sample largely consists of seasonal (winter and spring) accumulations of bones, antlers, and teeth, which were scattered, weathered, and then buried by spring fl oods. The proximal environment was a level fl oodplain with the streams bordered by forest and brush, and surrounded by marsh, small lakes, and grassland. The climate was seasonal but somewhat milder and wetter than at present.
Open Access
Type Specimens at the University of Oregon: Fossil Vertebrates and Plants
(Museum of Natural History, University of Oregon, 1983-03) EATON, JOYCE; GUSTAFSON, ERIC PAUL
A published list of type specimens such as this serves several purposes. First and foremost it is intended to allow quick access to the type holdings of a museum and to the basic information that is present in the museum files. Secondly, it allows some evaluation of the scientific value of a given collection. This latter can be particularly significant in the case of a collection such as that at the University of Oregon, which is of considerable size (13th in the United States in terms of total catalogued specimens of fossil vertebrates as of 1977, according to Langston et al., 1978) but is off the beaten paths which in Vertebrate Paleontology lead back and forth between California and the northeastern states. We hope that this publication will also serve as a biblographic introduction to the widespread literature on fossil vertebrates from Oregon. It certainly will not serve as a complete guide to fossil vertebrate type specimens from the State of Oregon; these are widespread in other collections and only a small fraction of the taxonomic work on the various fossil faunas had been done here.
Open Access
The Vertebrate Faunas of the Pliocene Ringold Formation, South-Central Washington
(Museum of Natural History, University of Oregon, 1978-03) GUSTAFSON, ERIC PAUL
The vertebrate fauna of the upper Ringold Formation at the White Bluffs, south-central Washington, has been the subject of several short papers since its discovery in the late 19th century. Additional information from more recent collections, which include remains of many small mammals, expands the knowledge of this White Bluffs local fauna. A rhinoceros mandible from the lowest exposures provides evidence of a second, distinctly earlier fauna, the River Road local fauna. Fossiliferous localities can be correlated by reference to two key beds, the White Bluffs tuff and the Taylor Flat conglomerate, both of which are widely exposed. Vertebrate fossils are most commonly preserved in stream channel conglomerates and less frequently in silt deposits. The White Bluffs local fauna includes three genera of fresh-water snails, two genera of fish (Ictalurus and Archoplites), unidentified anuran amphibians and small reptiles, two or three genera of turtles (Clemmys, Chrysemys?, and possibly Testudo), and 25 genera of mammals. Among the mammalian genera are a mole (Scapanus), two leporids (Hypolagus and Nekrolagus), nine rodents (Paenemarmota or Marmota, Spermophilus?, Ammospermophilus, Thomomys, Castor, Dipoides, Peromyscus, Neotoma, and Ophiomys), an edentate (Megalonyx), six carnivores (Canis, Borophagus, Ursus, Trigonictis, Felis, and a machairodont), a proboscidean (Mammut), an equid (Equus), and four artiodactyls (Platygonus, Megatylopus, Hemiauchenia, and Bretzia). New species are: Hypolagus ringoldensis, a leporid probably derived from H. oregonensis Shotwell; Spermophilus? russelli, a large ground squirrel of uncertain affinities; Ammospermophilus hanfordi, a large antelope ground squirrel; Peromyscus nosher, a deer mouse; Ophiomys mcknighti, a microtine closely related to 0. magilli Hibbard from the Sand Draw local fauna of Nebraska but more primitive than the latter; and Megalonyx rohrmanni, a small ground sloth similar in form to specimens from Hagerman, Idaho. The White Bluffs local fauna is early Blancan (Pliocene) in age. The faunal assemblage is most similar to that of the Hagerman local fauna of Idaho but is probably slightly older. The predominance of browsing forms among the large mammals (particularly Bretzia, Megalonyx, and Platygonus) indicates that the Ringold flood plain supported considerable riparian forest and open woodland, environments extremely restricted in eastern Washington today. Savanna or open grassland, suggested by the presence of Equus and possibly by Megatylopus, may have been important away from the streams, but the absence so far of antilocaprids suggests that these habitats were not important near areas of stream deposition. The River Road local fauna, containing Teleoceras and ?Megatylopus, is probably late Hemphillian in age.
Open Access
GUIDE TO THE GEOLOGY AND LORE OF THE WILD REACH OF THE ROGUE RIVER, OREGON
(Museum of Natural History, University of Oregon, 1977-05) PURDOM, WILLIAM B.
It is the purpose of this Bulletin to provide a general picture of the Rogue River and a more detailed river log of the wild reach of the river. The emphasis of the log is on the geology that the river canyon exposes. The wild reach of the Rogue River is sufficiently remote to have discouraged geologic reconnaissance in past years. Indeed, the same may be said of the Klamath Mountain Province in general. Recent interest in fitting the Klamath Mountains into the new global tectonic framework has brought about fresh interest in the geologic problems in this region, yet the difficulty of working in terrain as rugged and remote as this section of the Rogue River Canyon continues to discourage detailed geologic mapping. Consequently, the user of the River Log included in this Bulletin often will be told what kinds of rock he is seeing at a given point along the river, but may find that the origin of the rock is obscure or its age uncertain. Much more geologic work must be done in this region before these small pieces can be fitted together. The Bulletin attempts also to present the broad geographic and historical setting of the river along its course from the Cascade Mountains to the Pacific Ocean. This is done largely in preliminary sections preceding the River Log proper, though occasional biologic and historical notes punctuate the geologic observations that constitute most of the Log. It is hoped that hikers and boat travelers alike may come to understand the river better. Only in such understanding will its preservation lie.
Open Access
Guide to the Geology of the Owyhee Region of Oregon
(Museum of Natural History, University of Oregon, 1973-09) Kittleman, Laurence R.
The conspicuous plants of the Owyhee region are big sagebrush, cheat grass, and shadscale. Rabbitbrush grows in moist places, and juniper and mountain mahogany grow at higher elevations. The dominant form is sagebrush, the plant by which the habitat is known -- the high sage desert.
Open Access
JOURNAL OF FIRST TRIP OF UNIVERSITY OF CALIFORNIA TO JOHN DAY BEDS OF EASTERN OREGON
(Museum of Natural History , University of Oregon, 1972-12) Miller, Loye; Shotwell, J. Arnold
The journal is Dr. Miller's account of the University of California field expedition into the John Day Basin of Central Oregon in 1899. This expedition, as well as many that followed from that institution, was led by Dr. John C. Merriam. It began a long association of the University of California with that area of Oregon, an association which still continues. Although the events of this journal occurred over seventy years ago, they by no means represent the first investigation of the area, for these beds were already famous when Miller first saw them. Condon had first seen them forty years previously, and such well known paleontologists as Marsh and Cope among many others had collected there. It was not until the work of Merriam and his students from the University of California began that any real understanding of the geology of the area or the sequence of the faunas present was developed.
Open Access
Smilodonichthys Rastrosus: A New Pliocene Salmonid Fish from Western United States
(Museum of Natural History, University of Oregon, 1972-03) Cavender, Ted M.; Miller, Robert Rush
In western North America, the family Salmonidae is comprised of a diverse number of species (upwards of 30) belonging to seven genera assigned to three subfamilies (Norden, 1961). Though more than half of these species are endemic to the area, an astonishingly few fossil specimens have been discovered which can help document the evolution that has taken place in this group. An exception is the one described in this paper which adds importantly to our understanding of the past life of these fishes. Materials of this fossil salmonid were collected over a period of fifty years from Pliocene, Pacific-slope localities in California and Oregon. As early as 1917, vertebrae, teeth and skull fragments of an extremely large but unfamiliar type of fish were unearthed, along with mammalian remains, at Pinole, Contra Costa County, California. Only within recent years, however, has it been possible to identify these with certainty as being the remains of an extinct form of salmonid that once was distributed in the coastal regions of the Pacific Northwest, probably much the way that Pacific salmon (Oncorhynchus) are today. In 1950 and again in 1964, more complete specimens were discovered of this unusual species from a Pliocene gravel pit in northcentral Oregon. The last find consisted of a large skull which is outstanding for its completeness and detail of preservation. It is a description of this skull that forms the main context of the present paper and which has allowed fruitful comparison to be made with living salmonids. The name Smilodonichthys rastrosus is proposed for this previously undescribed species. Because of its high degree of morphological distinction from other members of the Salmonidae, this species is made the type of a new genus. A number of its osteological features indicate a phyletic relationship closest to Oncorhynchus, yet none of the extant species of that genus approaches the fossil in the specialization of its feeding mechanism.
Open Access
Pliocene Mammals of Southeast Oregon and Adjacent Idaho
(Museum of Natural History, University of Oregon, 1970-08) Shotwell, J. Arnold
The primary purpose of the work described here was to complete the study of a late Tertiary sequence of faunas in the Northern Great Basin. Shotwell (1968) reported on the late Miocene faunas of the region. The subsequent early, middle and late Pliocene faunas are described here. Samples representing a diversity of environmental situations were sought with particular emphasis on the recovery of quantitatively useful data for paleoecological studies. Since many new fossil mammals were encountered in both the Miocene and Pliocene excavations it seemed best to describe the faunas first to provide the new taxonomic information and make it available rather than wait on the more involved paleoecological analysis for which it was originally collected.
Open Access
THE OLIGOCENE MARINE MOLLUSCAN FAUNA OF THE EUGENE FORMATION IN OREGON
(Museum of Natural History, University of Oregon, 1969-08) STENTZ HICKMAN, CAROLE JEAN
Tuffaceous marine sandstone and siltstone of the Oligocene Eugene Formation occur in the southern portion of the Willamette Valley in Oregon from Cottage Grove northward along the margin of the Coburg Hills to Brownsville and Lebanon and into the Salem and Eola Hills west of Salem. The faunal assemblages and associated rocks indicate that the Eugene Formation was deposited in shallow water, 0-40 fathoms. The fauna contains a mixture of subtropical and temperate forms which coexisted in what is interpreted as a gradually cooling environment. Relatively undisturbed assemblages of infaunal pelecypods and scaphopods are common along with concentrated layers of reworked infaunal assemblages containing a variety of epifaunal species. The age of the fauna is believed to span portions of the lower and middle Oligocene. The fauna is partly intermediate between the faunas of the Keasey and Pittsburg Bluff Formations in northwestern Oregon and is considered the partial time equivalent of these formations and the missing interval between them. The author collected several thousand fossil specimens from localities throughout the formation and incorporated them into the collections at the University of Oregon. In addition, previous collections housed at the University of California, California Academy of Sciences, Stanford University, and the U.S. Geological Survey at Menlo Park, California, were examined. Sixty-seven species, representing 48 genera and 31 families, are discussed and figured; and their affinities and stratigraphic ranges are analyzed. Supplementary descriptions are given for previously described species. In addition, nine new taxa are proposed and described: Nemocardium formosum, Tellina aduncanasa, Semele willamettensis, Martesia turnerae, Pandora laevis, Dentalium laneensis, Neverita thomsonae, Bruclarkia vokesi, and Acila nehalemensis subsp. minima.
Open Access
Item Seriation as an Aid for Elementary Scale and Cluster Analysis
(Musenm of Natural History, University of Oregon, 1968-09) Johnson, LeRoy Jr.
There are two basic needs which this paper may help to meet. First, seriation is a current issue, or at least a current method, particularly in the literature of anthropology and archaeology. The topic has regrettably never been given ample discussion and the need for such is self-evident. Second, seriation is a logical point at which students of biology, natural history, and social science may be introduced to the useful techniques of scale analysis and cluster analysis, to build an understanding of several of the problems involved in such studies before confronting more elegant techniques of analysis. It is hoped that the sophisticate in numerical analysis will not be impatient, then, with the following exposition, since it is addressed to research workers and students having a minimum acquaintance with numerical analysis. The following discussion will treat seriation from several standpoints, notably (1) its basic nature, (2) its history and treatment in the literature, (3) its problems for computer processing, and (4) its proper use, particularly in conjunction with other aids, in generating overviews for bodies of numerical data.
Open Access
Miocene Mammals of Southeast Oregon
(Museum of Natural History, University of Oregon, 1968-08) SHOTWELL, J. ARNOLD
The late Miocene fauna described here represents the earliest step in a sequence of late Tertiary faunas studied as a part of a long range investigation into the interrelationships of the factors of faunal change. The study is deliberately provincial to reduce biogeographic effects and to allow independent time controls to be developed through detailed geologic mapping. The concept of the bulk fauna is used to indicate the entire fauna of the Northern Great Basin at any particular time. The association or community is the basic unit of study, the bulk fauna is the whole of which the associations are the overlapping parts.
Open Access
Historical Background of the Flora of the Pacific Northwest
(Museum of Natural History, University of Oregon, 1968-07) DETLING, LEROY E.
The modern flora of the Pacific Northwest is characterized by associations which show affinities to floras now occupying widely separated areas (Eurasia, South and Central America) and to floras shown by paleobotanical evidence to have occupied all these areas, but particularly the American West. Distinct distribution patterns, both in time and space, manifest themselves. These patterns are and have been influenced by topographic and climatic changes from the Cretaceous to the present. Three principal sources of associations are evident: evolution in situ; northern regions as shown in the Arcto-Tertiary Geoflora; western Mexico and the southwestern United States as shown in the Madro-Tertiary Geoflora.
Open Access
FOSSIL TALPIDAE (lnsectivora, Mammalia) FROM THE LATER TERTIARY OF OREGON
(Museum of Natnral History, University of Oregon, 1968-07) Hutchison, J. Howard
The Talpidae of the late Teritary of Oregon are described and their relationships discussed. Two new genera, Scapanoscapter and Achlyoscapter, a new subgenus, Xeroscapheus, and six new species, Mystipterus pacificus, ?Neurotrichus columbianus, Scalopoides ripafodiator, Scapanoscapter simplicidens, Scapanus (Xeroscapheus) proceridens, and Achlyoscapter longirostris, are recognized.
Open Access
Refinements in Computerized Item Seriation
(Museum of Natural History, University of Oregon, 1968-03) Craytor, William Bert; Johnson, Le Roy Jr
Our purpose in this paper is to refine certain aspects of computerized matrix seriation so as to provide a more precise and efficient automatic technique for determining and displaying interrelationships between compared items. A new program for matrix analysis, called PROGRAM SERIATE, is presented and explained.
Open Access
Late Tertiary Geomyoid Rodents of Oregon
(Museum of Natural History, University of Oregon, 1967-11) Shotwell, J. Arnold
The geomyoid rodents of the late Tertiary of Oregon are described and their relationships discussed. Most of the material involved is new. A new genus, Parapliosaccomys, is recognized and three new species, Parapliosaccomys oregonensis, Adjidaumo quartzi, and Pseudotheridomys pagei.