Browsing by Author "McKenna, Malcolm C."
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Item Amphicticeps and Amphicynodon (Arctoidea, Carnivora) from Hsanda Gol Formation, central Mongolia, and phylogeny of basal arctoids with comments on zoogeography. American Museum novitates ; no. 3483(New York, NY : American Museum of Natural History, 2005) Wang, Xiaoming, 1957-; McKenna, Malcolm C.; DashzÄ—vÄ—g, DÄ—mbÄ—rÄ—liÄn.; Mongolian-American Museum Paleontological Project.; Mongolyn Shinzhlekh Ukhaany Akademi.; Central Asiatic Expeditions (1921-1930)Amphicticeps shackelfordi and Amphicynodon teilhardi are two small carnivorans from the early Oligocene Hsanda Gol Formation of central Mongolia, and as basal arctoids (infraorder Arctoidea) in Asia, feature unique combinations of morphologies that offer insights into early diversification and zoogeography of the arctoids. Lack of adequate study of Amphicticeps and incomplete knowledge about Amphicynodon, however, prevented them from being figured in the discussions of arctoid relationships. New associated dental and cranial materials collected during recent expeditions in the 1990s substantially enrich our knowledge of the two genera and their stratigraphic positions, and serve as an impetus for a study of their phylogenetic relationships in the broad perspective of basal Arctoidea. Hsanda Gol arctoids are represented by six small- to medium-sized species: Amphicticeps shackelfordi Matthew and Granger 1924, A. dorog, n.sp., A. makhchinus, n.sp., Amphicynodon teilhardi Matthew and Granger 1924,? Cephalogale sp., and Pyctis inamatus Babbitt, 1999. The three species of Amphicticeps apparently form an endemic clade confined to central Asia, whose zoogeographic origin is currently unknown. Amphicynodon has a much higher diversity in Europe than in Asia, and phylogenetically the Asian A. teilhardi seems to be nested within the European congeneric species, indicating an eastward dispersal for this group, linking the European "Grande Coupure" and the Asian "Mongolian Reconstruction" events. To avoid excessive homoplasies in crown groups, we attempted a phylogenetic reconstruction based mostly on stem arctoids. Twenty genera of primitive arctoids occupying basal positions of nearly all major clades are selected for the analysis. The resulting tree, based on 39 characters, approximates the initial divergence of the arctoids. The traditionally dichotomous Arctoidea, formed by sister clades Ursida and Mustelida, is recovered in our analysis. Mustelida is also largely dichotomous with mustelid-like forms on one side and procyonidlike forms on the other. Despite its rather hypercarnivorous dentition, Amphicticeps is found on the Ursida side of the arctoids, although support for such a topology is relatively weak. Amphicynodon is a stem taxon of the Ursida and is a sister to an ursid-pinniped clade.Item Beginning of the age of mammals in Asia : the late Paleocene Gashato fauna, Mongolia. Bulletin of the AMNH ; v. 144, article 4(New York : [American Museum of Natural History], 1971) Szalay, Frederick S.; McKenna, Malcolm C.; Central Asiatic Expeditions (1921-1930)"The earliest Tertiary mammalian fauna known from Asia occurs in southern Mongolia, where it is found in late Paleocene sediments approximately 55 million years old exposed at Gashato and in the Nemegt Basin. Romer (1966) has proposed, but not defined, a 'Gashatan Asiatic Age' for the Gashato fauna and we propose that the term be extended to the occurrence of the same fauna, although to a different faunal facies, in the Nemegt Basin, subsuming Romer's (1966) 'Ulanbulakian Asiatic Age.' We supply a definition of the 'Gashatan Asiatic Age': the joint overlapping time ranges of Palaeostylops, Pseudictops, Prionessus, and Eurymylus. Additional localities in Sinkiang and Kwangtung may also be Gashatan in age. The Gashato fauna is made up of a mixture of endemic genera and a few genera that evidently reached Asia via the Bering route from North America and beyond. There is no special similarity to Paleocene faunas of Europe, but this could be because of a double filtering action. Gashatan mammals have been the notoungulates, but recently Paleocene notoungulates been found in North America and there is no evidence that notoungulates as such originated in Asia. At the beginning of the Eocene (Sparnacian), increased northern dispersal brought about extensive, but still not complete, faunal replacement in eastern Asia. Analysis of geophysical data, as well as the faunal data, suggests that there is strong evidence for a dry-land dispersal route between the North American and European crustal blocks via Greenland and the Barents shelf as late as Sparnacian time in the Eocene, but not thereafter. During Paleocene time, climate and other factors had a filtering effect on dispersal via both the Bering and Greenland-Barents shelf routes, but the former was closer to the rotational pole position in the Paleocene and was a more effective filter. During Sparnacian time, the Bering area still acted as a filter, but the Greenland-Barents shelf route now showed little filter action. Presumably this was the result of a more equable climate. There is no evidence for a Greenland-Iceland-Faeroes dispersal route and some evidence against it. No attempt is made in the present paper to reevaluate, except insofar as they bear on correlation, the Gashatan multituberculates, pseudictopids, eurymylids, Phenacolophus, or pantodonts, but the following taxonomic adjustments are made: 1. Opisthopsalis is synonymized with Sarcodon, and Sarcodon and Hyracolestes are added to the insectivoran family Deltatheridiidae. 2. A new order, Anagalida, is proposed. The Anagalida includes the families Zalambdalestidae, Pseudictopidae, Anagalidae, and Eurymylidae. The Anagalidae are somewhat lagomorph-like and are believed to be related to lagomorphs. 3. Praolestes is referred to the Zalambdalestidae. 4. The Cretaceous genus Zalambdalestes is known from a single species, Z. lechei. The type specimen of Z. lechei is an extremely aged individual with cheek-tooth crowns nearly worn away. P[superscript]1 and P[superscript]2 have dropped out and the alveoli have closed. The type specimen of 'Z. grangeri' is a somewhat younger individual of the same species and the referred specimens in the Polish collections are younger still. New illustrations of American Museum specimens of Zalambdalestes are provided. 5. The Anagalidae are reported from the Paleocene for the first time and a new genus and species, Khashanagale zofiae, is named. A second species of Khashanagale or of a closely related form is present at Gashato, but is not named. 6. A small Dissacus-like mesonychid is present in the Gashato fauna at Gashato. 7. In the classification of uintatheres, utilization of Flerov's subfamily Prodinoceratinae is advocated in preference to Wheeler's subfamily Bathyopsinae"--P. 313.Item A continental Paleocene vertebrate fauna from California. American Museum novitates ; no. 2024(New York, N.Y. : American Museum of Natural History, 1960) McKenna, Malcolm C.Item Cranial anatomy and phylogenetic position of Tsaganomys altaicus (Mammalia, Rodentia) from the Hsanda Gol Formation (Oligocene), Mongolia. American Museum novitates ; no.3156(New York, N.Y. : American Museum of Natural History, 1995) Bryant, J. Daniel (James Daniel), 1966-; McKenna, Malcolm C.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.Item Earliest eutherian ear region : a petrosal referred to Prokennalestes from the early Cretaceous of Mongolia. American Museum novitates ; no. 3322(New York, NY : American Museum of Natural History, 2001) Wible, John R.; Rougier, Guillermo W.; Novacek, Michael J.; McKenna, Malcolm C.; Mongolian-American Museum Paleontological Project.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.A right petrosal from the ?Aptian or Albian Khoobur locality is referred on the basis of size and morphology to Prokennalestes trofimovi, the earliest eutherian previously known only from dentigerous elements. The petrosal shows a mosaic of primitive and derived features, bearing on the purported therian and eutherian morphotypes. Among the primitive features shared with the early Cretaceous prototribosphenidan Vincelestes and other more basal taxa that are modified in later eutherians and metatherians are the pattern of basicranial arterial and venous circulation, including a prootic canal and an intrapetrosal inferior petrosal sinus; a vertical paroccipital process; and a fenestra semilunaris, an incomplete wall between the cavum epiptericum and cavum supracochleare. Among the derived features shared with therians is a cochlea coiled through a minimum of 360°, with Prokennalestes extending the range of the oldest occurrence of such a coiled cochlea by at least 10 million years. Shared with late Cretaceous eutherians is a shallow internal acoustic meatus with a thin prefacial commissure. The petrosal referred to Prokennalestes is intermediate in having a reduced anterior lamina and lateral flange, both of which are well developed in Vincelestes and essentially lacking in later eutherians and metatherians. Features previously held to be part of the therian and eutherian morphotypes, such as the absence of the anterior lamina and lateral flange, may have been lost independently in metatherians and in post-Prokennalestes eutherians.Item Estesia mongoliensis : a new fossil varanoid from the late Cretaceous Barun Goyot Formation of Mongolia. American Museum novitates ; no.3045(New York, N.Y. : American Museum of Natural History, 1992) Norell, Mark.; McKenna, Malcolm C.; Novacek, Michael J.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.Item Eupetaurus and the living petauristine sciurids. American Museum novitates ; no. 2104(New York, N.Y. : American Museum of Natural History, 1962) McKenna, Malcolm C.Item Fossil mammals from the "Mesaverde" Formation (late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming : with definitions of late Cretaceous North American land-mammal "ages". American Museum novitates ; no. 2840(New York, N.Y. : American Museum of Natural History, 1986) Lillegraven, Jason A., 1938-; McKenna, Malcolm C."Mammalian faunas are documented for the first time from the 'Mesaverde' Formation (Late Cretaceous) of Wyoming. Nonmarine fossils from the Bighorn and Wind River basins indicate a Judithian (revised definition) 'age' for the assemblages through comparisons with approximately contemporaneous faunas of the Judith River (Montana) and Oldman (Alberta) formations. Three previously unknown genera are recognized, although not named herein, from the 'Mesaverde' Formation (Multituberculata, new genus and species, unidentified; Dryolestidae, new genus and species, unidentified; and Falepetrus barwini). Three new species of previously described genera (Alphadon sahnii, A. attaragos, and Paranyctoides megakeros) are named. All species-level taxa (16 total) except Alphadon lulli are reported from Wyoming for the first time, and new records involve both geographic and geologic range extensions. The temporal record of the dryolestid appears relictual, being previously unknown from post-Jurassic strata in North America. Taxonomic comparisons suggest that the Judithian mammalian fauna of what was then coastal parts of the western interior was essentially homogeneous geographically, at least from southern Alberta to central Wyoming. Nonmarine mammalian assemblages from the Oldman, Judith River, and 'Mesaverde' formations correlate temporally with more easterly marine rock units that lie within (or within four zones above) the Baculites gregoryensis (cephalopod) Zone, part of the standard zonation of Upper Cretaceous rocks of the North American western interior. The upper part of the Red Bird Silty Member of the Pierre Shale at Redbird, Wyoming, holds the largely endemic invertebrate macrofaunal assemblage characteristic of the B. gregoryensis Zone as well as a newly described planktonic foraminiferal assemblage. The microfossils allow correlation to the upper Taylorian and/or lower Navarroan foraminiferal stages of the Gulf Coast. This, in turn, correlates approximately to the Campanian-Maastrichtian stage boundary at Gubbio, Italy, and European stratotypic sections. Judithian mammal faunas of the Rocky Mountains, therefore, must be younger in age (i.e., late Campanian and/or early Maastrichtian) in terms of the European stages than usually is considered on the basis of molluscan zonations within the North American western interior (e.g., well within the Campanian). Judithian mammals from the Rockies probably lived about 74-76 million years ago during the late part of geomagnetic Polarity Chron 33 or the early part of Polarity Chron 32, during the regressive phases of the Claggett cyclothem as recognized for the western shoreline of the Western Interior Seaway. They correlate stratigraphically with the lower part of the Aquilapollenites quadrilobus palynomorph Interval Zone of the northern Rockies. Aquilan (oldest), Judithian, and Lancian (youngest) provincial North American land-mammal 'ages' are redefined for the Late Cretaceous nonmarine sequence of the western interior from an older stage concept; the 'ages,' based upon species-level mammalian assemblages, are modeled after the system used successfully for nonmarine Cenozoic faunas of North America. An Edmontonian 'age' (previously used as a stage term, chronologically intermediate between the Judithian and Lancian) is probably identifiable as a discrete interval of geologic time, but is not yet defensible on the basis of mammalian assemblages. Therefore, it is not redefined as a land-mammal 'age.' We concur with the interpretation that the Djadokhta Formation of southern Mongolia and the Judith River and Oldman faunas of North America are essentially of the same age. This compresses the faunas of the Barun Goyot and Nemegt formations of southern Mongolia, plus that of the poorly known, nearby Bugeen Tsav locality, into an interval of time equivalent to the Judithian and/or Lancian North American land mammal 'ages' and, most probably, to the Maastrichtian stage as typified in western Europe"--P. [1]-2.Item Gobiconodonts from the early Cretaceous of Oshih (Ashile), Mongolia. American Museum novitates ; no. 3348(New York, NY : American Museum of Natural History, 2001) Rougier, Guillermo W.; Novacek, Michael J.; McKenna, Malcolm C.; Wible, John R.; Mongolian-American Museum Paleontological Project.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.We describe here the first discovered mammalian remains from the Mongolian early Cretaceous locality Oshih (Ashile). Four fragmentary, tooth-bearing specimens, probably corresponding to three individuals, have been recovered. All the fossils can be assigned to the family Gobiconodontidae (Chow and Rich, 1984). The specimens include three lower jaw fragments and one upper jaw fragment, and represent at least two different taxa. Gobiconodon hopsoni, n. sp., is described and diagnosed here. This new species is larger than G. ostromi (early Cretaceous Cloverly Formation, USA); thus, it is the largest triconodont and one of the largest Mesozoic mammals known. Gobiconodon sp., found also at Oshih, is slightly larger than G. borissiaki, from the early Cretaceous of Khoobur, Mongolia, but smaller than G. ostromi. The specimens of this second species are poorly preserved and provide insufficient data for a diagnosis. The status of the different species of Gobiconodon and the new gobiconodontid Hangjinia is reviewed. In gobiconodontids and Triconodontidae, the maxillae appear to make a significant contribution to the orbital rim, a condition unusual among basal mammals, in which the lacrimal and jugal are the main components. Other triconodonts such as Jeholodens, likely an "amphilestid", appear to show the primitive mammalian condition for this feature. We present a brief consideration of triconodont relationships and discuss alternative placements of Gobiconodon among Mammaliaformes.Item High-level strata containing early Miocene mammals on the Bighorn Mountains, Wyoming. American Museum novitates ; no. 2490(New York, N.Y. : American Museum of Natural History, 1972) McKenna, Malcolm C.; Love, J. D. (John David), 1913-; Darton, Nelson Horatio, 1865-1948."Fossil mammals of early Miocene age have been found in strata composing Darton's Bluff on the crest of the Bighorn Mountains in the Hazelton Peak Quadrangle, Johnson County, Wyoming. Dating the host strata provides a reference datum for the reconstruction of regional sedimentation during early Miocene time and for determination of the maximum age of epeirogenic uplift. As a result of regional aggradation, the Bighorn Basin was filled with sediments. These buried the rugged peaks and canyons of the Bighorn Mountains up to a level corresponding to the present 9000-foot altitude during early Miocene time. The lower Miocene and older rocks are beveled by the subsummit surface, a remarkably flat and even surface of Miocene or Pliocene age. Excavation of the Bighorn and Powder River basins and exhumation of the Bighorn Mountains must have been accomplished during the relatively short interval of late Cenozoic time after the subsummit surface was cut"--P. [1].Item A late Permian captorhinid from Rhodesia. American Museum novitates ; no. 2688(New York, N.Y. : American Museum of Natural History, 1979) Gaffney, Eugene S.; McKenna, Malcolm C."Two partial skulls from the late Permian Madumabisa Mudstone in the Middle Zambezi Basin of Rhodesia belong to the captorhinid genus Protocaptorhinus. Heretofore, Protocaptorhinus has been known only from the early Permian of Texas, whereas Africa has yielded only one other captorhinid, Moradisaurus, from Niger. The Captorhinidae is a monophyletic group (possibly including turtles) with these derived characters: downturned premaxilla, ectopterygoid and tabular absent, medial process of jugal. Protocaptorhinus differs from Romeria in having a shallow median parietal embayment and differs from remaining captorhinids in lacking a retroarticular process"--P. [1].Item Leptacodon, an American Paleocene nyctithere (Mammalia, Insectivora). American Museum novitates ; no. 2317(New York, N.Y. : American Museum of Natural History, 1968) McKenna, Malcolm C.Item A leptictid mammal from the Hsanda Gol Formation (Oligocene), Central Mongolia, with comments on some Palaeoryctidae. American Museum novitates ; no.3168(New York, N.Y. : American Museum of Natural History, 1996) Kellner, Alexander Wilhelm Armin.; McKenna, Malcolm C.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.Item A mammalian petrosal from the early Cretaceous of Mongolia : implications for the evolution of the ear region and mammaliamorph interrelationships. American Museum novitates ; no.3149(New York, N.Y. : American Museum of Natural History, 1995) Wible, John R.; Rougier, Guillermo W.; Novacek, Michael J.; McKenna, Malcolm C.; DashzÄ—vÄ—g, DÄ—mbÄ—rÄ—liÄn.; Mongolyn ShinzhlÄ—kh Ukhaany Akademi.Item Morphology and relationships of Apternodus and other extinct, zalambdodont, placental mammals. Bulletin of the AMNH ; no. 273(New York, NY : American Museum of Natural History, 2002) Asher, Robert J.; McKenna, Malcolm C.; Emry, Robert J.; Tabrum, Alan R.; Kron, Donald G.We describe and illustrate new, middle Cenozoic fossils of dentally zalambdodont, North American placentals, including six relatively complete crania of Apternodus and two of Oligoryctes, as well as many partial skulls, mandibles, and teeth of these and other taxa. Several of the new Apternodus specimens are also associated with postcrania. We recognize seven species of Apternodus, three of which are new, formally propose the combination Oligoryctes altitalonidus, and recognize two other genera of small, North American, anatomically zalambdodont placentals, Parapternodus and Koniaryctes. We regard two other taxa previously associated with North American fossil zalambdodonts, one Bridgerian and the other Tiffanian, as valid but do not name them in this paper. In addition, we argue that dental zalambdodonty entails a primary occlusal relationship between the paracone and the ectoflexid, and the reduction or absence of the metacone and talonid basin. A phylogenetic analysis of cranial, dental, and postcranial characters of 30 fossil and Recent taxa leads us to conclude that (1) the Apternodontidae as defined in previous literature is not monophyletic and should be restricted to seven species of Apternodus, (2) the genus Oligoryctes contains at least two species and has a considerably longer geologic record than Apternodus, (3) neither Micropternodus nor currently known Paleocene taxa are closely related to Apternodus or Oligoryctes, and (4) a case can be made for a close relationship among modern soricids, Parapternodus, Koniaryctes, Oligoryctes and Apternodus to the exclusion of other insectivoran-grade taxa. With the use of ordered, multistate character transformations, Solenodon comprises the sister taxon to a soricid-fossil zalambdodont clade.Item New evidence against tupaioid affinities of the mammalian family Anagalidae. American Museum novitates ; no. 2158(New York, N.Y. : American Museum of Natural History, 1963) McKenna, Malcolm C.; Central Asiatic Expeditions (1921-1930)Item A new insectivore from the Middle Eocene of Tabernacle Butte, Wyoming. American Museum novitates ; no. 1952(New York, N.Y. : American Museum of Natural History, 1959) McKenna, Malcolm C.; Simpson, George Gaylord, 1902-"Scenopagus is regarded as a very primitive erinaceid differing significantly from advanced members of the family, yet possessing a morphology that is in genral structurally ancestral to advanced erinaceids. To a considerable extent Tupaiodon (Oligocene, Mongolia) bridges the gap between advanced forms and Scenopagus, but Tupaiodon occurs too late in time to have been actually intermediate. P[superscript 4] is similar in Scenopagus and Proterixoides, which present the earliest known examples of this characteristic erinaceid tooth. The hypocones of the molars are quite different from those of advanced erinaceids, but intermediate morphology is demonstrated by Proterixoides and Tupaiodon. The transverse nature of the molars is another primitive feature, but again Tupaiodon bridges the gap. The broad cingular shelf, strong parastyle and metastyle, and emarginate buccal edge of the molars are similar to the corresponding structures in Metacodon and may indicate fairly close relationship to the Metacodontidae. The metacodonts probably originated from primitive erinaceids similar to Scenopagus but possessing two lingual uppar molar roots as in the Echinosoricinae"--P. 11.Item A new insectivore from the Oligocene of Mongolia and a new subfamily of hedgehogs. American Museum novitates ; no. 2311(New York, N.Y. : American Museum of Natural History, 1967) McKenna, Malcolm C.; Holton, Charlotte P.; Central Asiatic Expeditions (1921-1930)Item A new Middle Eocene edentate from Wyoming. American Museum novitates ; no. 1950(New York, N.Y. : American Museum of Natural History, 1959) Simpson, George Gaylord, 1902-; McKenna, Malcolm C.Item New records of eutherian mammals from the Goler Formation (Tiffanian, Paleocene) of California and their biostratigraphic and paleobiogeographic implications. (American Museum novitates, no. 3797)(American Museum of Natural History., 2014-02-06) Lofgren, Donald L., 1950-; McKenna, Malcolm C.; Honey, James G.; Nydam, Randall.; Wheaton, Christine.; Yokote, Bryan.; Henn, Lexington.; Hanlon, Whitney.; Manning, Stephen (Stephen Brian), 1990-; McGee, Carter.The Goler Formation is the only rock unit on the West Coast of North America that has yielded a diverse assemblage of Paleocene vertebrates. Intense prospecting of strata representing member 4 of the formation over the past two decades has resulted in recovery of over 70 specimens of eutherian mammals, representing 18 species. All specimens were recovered from member 4a and the lower part of member 4b, except an isolated tooth referred to Phenacodus cf. P. vortmani from member 4d in the uppermost part of the formation. Three taxa are new, the plesiadapid, Nannodectes lynasi, and two hyopsodontid condylarths, Promioclaenus walshi and Protoselene ashtoni. Also present are four species of Phenacodus, two species of Protictis, and single species representing Goleroconus, Mimotricentes, Lambertocyon, Ignacius, Paromomys, Bessoecetor, Thryptacodon, Dissacus, and a taeniodont. The mammalian fauna from member 4a and the lower part of member 4b is collectively referred to as the Goler Assemblage because taxa recovered from sites throughout this 500 m stratigraphic interval are too similar to subdivide into discrete biostratigraphic units. Based on comparison to faunas from well-known Tiffanian sites in the Western Interior, the Goler Assemblage is probably middle Tiffanian (Ti3-Ti4a), although a Ti5a age is also possible. The Goler Assemblage exhibits significant endemism as 40% of its taxa are not reported elsewhere and only four of 18 Goler Assemblage eutherians can be confidently referred to known species. Comparison to seven Ti3-Ti4a aged sites from the Western Interior indicates that the Goler Assemblage has a closer affinity to more southern faunas (southern Wyoming, Colorado, and Texas), than northern faunas (northern Wyoming, North Dakota, and western Canada), and is most similar to the mammalian assemblage from the Ledge Locality in the Bison Basin of southern Wyoming. Presence of late Paleocene-early Eocene marine strata in the uppermost member of the Goler Formation indicates that the Goler Basin was probably adjacent to the Pacific Ocean during most of its existence. Also, significant distances and one or more paleodrainage divides separated the Goler Basin from Western Interior basins, factors that limited the dispersal of mammals between the West Coast and the continental interior and contributed to the formation of a discrete faunal province on the West Coast of North America during the late Paleocene.