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Desmostylians from the Pacific coasts of Japan and North America are compared and taxonomy and adaptations in the mammalian order Desmostylia discussed. The taxonomy is based mainly on teeth and skulls. Feeding adaptations and habitat are discussed using teeth and restored skeletons, respectively. In the extinct order two families, six genera and 10 species can now be recognized. Each genus is distinguished by a set of tooth characters. The three species of the genus Paleoparadoxia have different body sizes. Two species of the genus Desmostylus can be distinguished on morphological differences in the cranium. As a result it is clear that both species, D. hesperus, which had long been recognized only in North America, and D. japonicus, which has hitherto been recognized only in Japan, inhabited both coasts of the Pacific. All genera of the Order Desmostylia share a common and distinctive body form, interpreted by Inuzuka as having a laterally placed limb posture. Based on this body form, the optimum habitat is thought to have been an intertidal sandy beach. The dental morphology is variable, and derived species show an adaptation for wear by an abrasive diet. In conclusion, we theorize that the Order Desmostylia was adapted for a coastal habitat from its inception, with each genus adapting to a different sort of herbivorous diet.

Histological study of the ribs in two archaeocetes, Basilosaurus cetoides and Zygorhiza kochii, reveals conspicuous pachyostosis, with hyperostosis of periosteal cortices and absence of a free medu...

A virtually complete skeleton of the pinniped Enaliarctos mealsi is described from the Pyramid Hill Sandstone Member of the Jewett Sand (late Oligocene or early Miocene) in central California. Skel...

A 30-year renaissance in research on fossil marine mammals has brought advances on several fronts and suggests potential directions for future study. Gingerich and Russell have described Pakicetus, the most primitive archaeocete cetacean. Mchedlidze has described a diverse assemblage of late Oligocene/early Miocene cetaceans from the Caucasus and Georgia, S.S.R. Barnes and Fordyce, respectively, have outlined sequences of fossil cetacean assemblages in the northeast and southwest Pacific. Much remains to be done on origin and definition of cetacean suborders, diversification and systematics of families, and relationships among infra-familial taxa. New material has been recovered of the most primitive desmostylians, and other new specimens, especially ones from Japan studied by Inuzuka and others, give a relatively complete picture of their anatomy. Material now exists for phylogenetic analysis. Domning has proposed a phyletic lineage of the sirenian subfamily Hydro-damalinae and has outlined patterns of Late Cenozoic manatee evolution. With Morgan and Ray he reviewed Eocene sirenians in the northwest Atlantic. Numerous new specimens are being actively studied in attempts to reassess relationships within the Sirenia. Mitchell and Tedford described the most primitive otariid, Enaliarctos. Repenning and Tedford reviewed the otarioids. The primitive taxa and their origin near or in the amphicynodontine ursids have been identified. The zoogeography of true seals, the phocids, has been analyzed recently by Repenning, Ray and Grigorescu, and by de Muizon. Most taxa are based on a few fragmentary specimens, and much work needs to be done on basic descriptions, interspecific comparisons and phyletic analysis. However, major progress has been made in the southern hemisphere through description of extensive new materials from Peru and South Africa. Many important phylogenetic gaps in the fossil record of marine mammals have been filled recently, and further advances continue at a rapid rate. Studies of zoogeography, functional anatomy and paleoecology, in addition to phylogeny, are coming into their own and promise an exciting series of discoveries in the coming years.

The partial skull and mandible of an unidentified halitheriine dugongid, collected from the Early Miocene Nye Mudstone in Lincoln County, Oregon, USA, is the earliest record of the Sirenia in the eastern Pacific Ocean. It is probably earlier than Early or Middle Miocene sirenians recently found in Peru, and is definitely earlier than any known from California or Baja California. However, it appears to be slightly younger than fossil sirenian remains recently reported from Late Oligocene rocks in Japan. The Oregon specimen is also the most northern record of the Sirenia on the west coast of North America prior to the Pleistocene although other sirenians did evidently reach and surpass such latitudes by the Late Miocene when a dispersal took place from America to the North Pacific coasts of the Old World. The Oregon specimen probably represents sirenians that spread to the North Pacific from the Caribbean, quite possibly prior to the Miocene. The Nye Mudstone was deposited during the warmest period of the Neogene on the coast of Oregon, and it does not seem necessary to postulate a greater degree of cold-tolerance for the Oregon sirenian than is exhibited by living sea cows.

Mammalia, description of skeletal remains, tabulated measurements, carbon-14 date of 11,900

A nearly complete skeleton of the archaic pinniped Enaliarctos, found in late Oligocene or early Miocene rocks (approximately 23 million years old) of California, provides new evidence on the origin of pinnipeds. Enaliarctos retains many primitive features expected in the hypothesized common ancestor of pinnipeds. Skeletal modifications seen in Enaliarctos document swimming adaptations and indicate that pinnipeds primitively used the axial skeleton and both fore and hindflippers as sources of propulsion. Elongate hindlimbs with prominent bony processes (reflecting powerful musculature) suggest that Enaliarctos was more active on land than modern pinnipeds.

Museum specimens of polar bear from the Pribilof Islands include the skull of an individual shot on St. Paul, and fragmentary remains of uncertain geologic age from a lava cave in Bogoslof Hill, St. Paul, once thought to represent a distinct species. Mammoth remains have been discovered from time to time beginning in 1836, and are here regarded as in part valid evidence that the mammoth actually lived in the area. The literature pertaining to these species on the Pribilof Islands is reviewed.

Ray, C. E. (Department of Paleobiology, Smithsonian Institution, Washington, D. C. 20560) 1976. Fossil Marine Mammals of Oregon. Syst. Zool. 25:420-436.-Although fossil remains of marine mammals were reported from western Oregon as early as 1849, collections and knowledge of them have grown slowly and haltingly until recently. Milestones have been discovery and description of the specimens on which are based the pinnipeds Pontolis magnus (True) 1905 and Desmatophoca oregonensis Condon 1906, the desmostylian Desmostylus cymatius Hannibal 1922, and the cetaceans Cophocetus oregonensis Packard and Kellogg 1934 and Aetiocetus cotylalveus Emlong 1966. Beginning in 1956 and continuing to the present Douglas Emlong of Lincoln City, Oregon, has amassed an unparalleled collection of fossil marine mammals, including approximately 1000 specimens from coastal Oregon, of which some 85 are desmostylians, 360 are pinnipeds, 3 are fissipeds, and the remainder cetaceans. Specimens are known from the Oligocene to the lower Pleistocene; from the Alsea, Yaquina, Nye, Astoria, Empire, Port Orford, and Elk River Formations. As specimens continue to be prepared and studied the Emlong Collection will yield many of the answers to problems of origin, evolution, and interrelationships of many lineages of marine mammals, and will contribute significantly toward establishment of fossil marine mammals as a powerful tool in geologic correlation over long distances. When asked by the organizer of this symposium on "Advances in Systematics of Marine Mammals" to present a summary of the symposium, my first response was one of panic, for I could not presume to restate what each of eleven speakers on diverse topics had said very well for himself. Further, this symposium in particular seemed to defy summarization as our coverage was necessarily anecdotal rather than comprehensive because of the large amount of research in progress by participants in this meeting and by many others. It is no accident that the content of the symposium is overwhelmingly paleontological, in part reflecting the profession of our organizer, Malcolm C. McKenna, but also in no small way due to the unprecedented quantity and diversity of work on fossil marine mammals today. Thus it occurred to me that this occasion might be appropriate for review of one of the more spectacularly burgeoning theaters of fossil marine mammal activities, appropriate particularly in that the theater of choice is western Oregon, and Oregon State University, Corvallis, the site of this symposium, is, with the University of Oregon, Eugene, one of the centers of the pioneering epoch in opening up what we now know to be a fabulously rich archive of marine mammal evolution. It is fair to state of course that this knowledge was a primary stimulus toward organizing this particular symposium at this particular meeting place. Much of this "summary" is adapted from an informal guidebook prepared for a small field conference held 18-20 August 1975 in the marine mammal bearing beds of coastal Oregon. A historical review of the modest record of Oregon's fossil marine mammals as revealed to date will demonstrate how slow and sporadic has been the rate of progress from the beginning until now; then, a preview of things to come will indicate the striking contrast to be expected in the near future. The paleontology of marine mammals is in such a rudimentary stage that a region can go in the span of a few years from virtually unknown to become a major source of information through the field work of one or a few collectors. Although Oregon may offer an especially striking example in view of the geologic span, taxonomic variety, and quantity of good quality specimens, it is by no means unique in the World today, and provides just one spectacular illustration of the information explosion in progress for fossil marine

Ray, C. E. (Department of Paleobiology, Smithsonian Institution, Washington, D. C. 20560) 1976. Geography of Phocid Evolution. Syst. Zool. 25:391-406.-Phocid distribution suggests origin in and primary radiation from the North Atlantic-Paratethyan region. Phocines and monachines are equally old groups, known first from the lower middle Miocene Calvert Formation. Phocines dominated Paratethys in semi-isolation. Both groups dispersed freely around the margins of the North Atlantic in Miocene and Pliocene time. Phocines entered the North Pacific, probably from the north, in Pliocene time, and have modernized and radiated in latest Cenozoic time, exclusively in the cold waters of the northern hemisphere. Monachine distribution receded southward in the North Atlantic during latest Cenozoic time, and in the Pliocene they spread into both the southern hemisphere, where they radiated in the empty Antarctic, and into the Pacific via the middle American seaway. At least four forces acting independently over the past decade or so combine now to make a fresh look at the geography of marine mammals and its interplay with their systematics rewarding: 1. ITe revitalization of paleogeography resulting from the new dynamism in concepts of crustal evolution. Plate tectonics and sea floor spreading are a general theme in geology today, but most of us in the United States who finished our formal schooling as little as 15 years ago were reared scholastically on the supposedly solid foundation of stable continents, with at most a dutiful if not derisive bow toward continental drift, followed by quick dismissal. The impact of colliding continents is now being felt throughout geology. 2. The development of a cosmopolitan time frame for the Cenozoic Era, through long distance correlation by planktonic foraminifera and nannoplankton, and by magnetic and radiometric techniques. The integration of these lines of evidence, with increasingly rigorous application of stratigraphic principles, has provided a comprehensive working hypothesis against which the fit of patterns of marine mammal relationships may be

The remains of horses have been reported from cave deposits in the state of Yucatan, Mexico, on two previous occasions. Mercer (the hill caves of yucatan, Lippincott, Phila., 1896, p. 172 and map opposite tide page) found horse remains in three caves in the Serrania, a low range of limestone hills lying in southwestern Yucatan and trending roughly parallel to the southwestern border of that state. The horse material was associated with pot sherds and other artifacts and showed no evidence of fossilization. Cope (in Mercer, op. cit. , p. 172, footnote) examined the material and …

Reviewed are records of the sea mink, Mustela macrodon , from Casco Bay to the Bay of Fundy. This species has apparently been extinct for no less than 60 years. Details are presented of a new record from an archaeological site in Middleboro, Massachusetts, 12 miles from the nearest salt water, which extends the known range at least 125 miles southward.

Mormoops megalophylla (Peters), Conepatus leuconotus (Lichtenstein) and Felis pardalis Linn. are reported from Pleistocene deposits in Florida. Molossides floridanus G. M. Allen is transferred to the genus Eumops . The material upon which the reports of Erethizon dorsatum (Linn.), Mammuthus primigenius (Blumenbach) and Cervus canadensis Erxleben are founded is not adequate to justify inclusion of these species in the Pleistocene fauna of Florida. The record of Ovibovinae in the Pleistocene fauna of Florida is spurious.