Browsing by Author "Tedford, Richard H."
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Item Basicranial anatomy and phylogeny of primitive canids and closely related miacids (Carnivora, Mammalia). American Museum novitates ; no. 3092(New York, N.Y. : American Museum of Natural History, 1994) Wang, Xiaoming, 1957-; Tedford, Richard H.Item The Enaliarctinae : a new group of extinct aquatic Carnivora and a consideration of the origin of the Otariidae. Bulletin of the AMNH ; v. 151, article 3(New York : [American Museum of Natural History], 1973) Mitchell, Edward, 1939-; Tedford, Richard H."The new genus and species Enaliarctos mealsi is based on two partial skulls and two natural endocranial casts discovered in the early Miocene Pyramid Hill Sand Member of the Jewett Sand at Pyramid Hill, Kern County, south-central California. The new mammalian subfamily Enaliarctinae is based on Enaliarctos mealsi. Enaliarctos mealsi was a medium-sized arctoid carnivore, a transitional species that departed in structure from terrestrial ursids (Hemicyoninae) and evolved in the direction of aquatic pinnipeds (Otariinae). Ursid features include presence and structure of upper and lower fourth premolars and of two molariform, quadrate-shaped upper molars; the development of sulcus cruciatus and the presence of an 'ursid lozenge'; and the morphology of the basicranium and middle ear. Features associated with aquatic adaptation include an enlarged narial chamber, reduced olfactory bulbs, wide snout, long and transversely arched palate, tendencies toward premolarization of the molars, narrow interorbital region, and enhanced brain circulation. A family Ursidae is recognized that includes primitive terrestrial ursids such as Cephalogale, Hemicyon, and Dinocyon in the subfamily Hemicyoninae. The Enaliarctinae is placed in Carnivora among the Otariidae near the Desmatophocinae. The Otariinae, specifically the Arctocephalini, might be descended from the Enaliarctinae. The phyletic lineage Hemicyoninae - Enaliarctinae - Otariinae emphasizes that the pinniped diphyly problem should be redefined to focus on the relationship of the Phocidae to even earlier Arctoidea. The Desmatophocinae might represent a third group independently derived from the middle-Tertiary adaptive radiation of Arctoidea. A lectotype for Neotherium mirum Kellogg, 1931 is chosen, and the species is included in the Enaliarctinae. The Pyramid Hill local fauna is named and characterized. The fauna comprises invertebrates and more than 39 species of Elasmobranchii, Teleostei, Chelonia, Aves, Squalodontidae (with a summary of northeast Pacific records), Delphinoidea, Mysticeti, Carnivora, Equidae (Anchitherium cf. A. agatensis), and Tayassuidae (Desmathyus sp.). The composition of the fauna indicates a warm-water, near-shore environment at the site of deposition. The Woody local fauna is named, characterized, and discussed. It is slightly higher stratigraphically in the same rock unit, 14 miles north of Pyramid Hill. We question Wilson's (1935) identifications of otariid pinnipeds from these rocks and doubt the validity of the 'phocid' record. The Pyramid Hill Sand can be assigned to the later Arikareean Land Mammal Age and to the Vaqueros Molluscan Stage, and it lies close to or includes the boundary between the Zemorrian and Saucesian Foraminiferal stages"--P. 205.Item The first Tertiary monotreme from Australia. American Museum novitates ; no. 2588(New York, N.Y. : American Museum of Natural History, 1975) Woodburne, Michael O.; Tedford, Richard H."Remains of a new genus and species of fossil, ornithorhynchid monotreme are described. The specimens were recovered from Miocene deposits in South Australia and are part of the Ngapakaldi and equivalent aged faunas in this region. The fossil genus represents the oldest record of the group in Australia and begins to fill a large gap in our understanding of the evolution of the Monotremata"--P. [1].Item Oligocene marsupials of the Geilston Bay local fauna, Tasmania. American Museum novitates ; no. 3244(New York, NY : American Museum of Natural History, 1998) Tedford, Richard H.; Kemp, Noel R."Fragmentary remains of marsupials from the later Oligocene travertine deposits of Geilston Bay, River Derwent estuary, near Hobart, Tasmania, appear to represent elements of a temperate rainforest fauna then at about 50S latitude. These deposits are capped by alkali basalt that yielded a whole-rock age of 23.0 0.5 Ma, a minimum age for the Geilston Travertine. Identified taxa include a dasyurid, two petauroids, and a burramyid, all belonging to scansorial and arboreal groups having important representation in present-day forested environments. Only the petauroids are complete enough for phylogenetic analysis and both are more primitive than other known members of that superfamily. Their presence indicates a pre-Oligocene time of differentiation of the Diprotodontia in accordance with molecular and paleontological interpretations"--P. [1].Item Phylogenetic systematics of the Borophaginae (Carnivora, Canidae). Bulletin of the AMNH ; no. 243([New York] : American Museum of Natural History, 1999) Wang, Xiaoming, 1957-; Tedford, Richard H.; Taylor, Beryl E."The subfamily Borophaginae (Canidae, Carnivora, Mammalia) was erected by G.G. Simpson in 1945 to include seven genera of large, bone-crushing "dogs" in the late Tertiary of the northern continents. As a monophyletic group of canids, the Borophaginae is now known to be much more diverse than was originally envisioned but is confined within the middle to late Tertiary of North America. Fossil records of the borophagines are well represented and members of this prolific clade are often the most common predators in the late Tertiary deposits. Largely due to the Childs Frick Collection at the American Museum of Natural History, borophagines are represented by some of the best materials among fossil carnivorans in anatomical representation, sample size, and stratigraphic density. As a result of this explosive growth of new information, borophagine systematics is now in need of a complete rethinking at a level that could not have been attempted by previous studies. A detailed study of borophagine phylogenetic systematics is presented here, publishing for the first time the entire Frick Collection. A total of 66 species of borophagines, including 18 new species, ranging from Orellan through Blancan ages, are presently recognized. A phylogenetic analysis of these species is performed using cladistic methods, with Hesperocyoninae, an archaic group of canids, as an outgroup. At its base, the Borophaginae has a sister relationship with the subfamily Caninae, which includes all living canids and their most recent fossil relatives. The Borophaginae-Caninae clade is in turn derived from the subfamily Hesperocyoninae. Apart from some transitional forms, most of the Borophaginae can be organized in four major clades (all erected as new tribes or subtribes): Phlaocyonini, Cynarctina, Aelurodontina, and Borophagina. The Borophaginae begins with a group of small fox-sized genera, such as Archaeocyon, Oxetocyon, Otarocyon, and Rhizocyon, in the Orellan through early Arikareean. Relationships among these genera are difficult to resolve due to their primitiveness. Slightly more derived, but still near the base of the Borophaginae, is the Phlaocyonini, a hypocarnivorous clade of the Arikareean and Hemingfordian that includes Cynarctoides and Phlaocyon. These two genera represent divergent approaches toward hypocarnivory. Species of Cynarctoides trend toward selenodonty and remain small in size, whereas species of Phlaocyon specialize toward bunodont dentitions but of increasing size, with an unusual trend toward hypercarnivory by two terminal species in the clade. Four transitional taxa (species of Cormocyon and Desmocyon) occupy intermediate positions between the Phlaocyonini and Cynarctina, and represent a gradual size increase toward medium-size individuals. The subtribe Cynarctina, the second hypocarnivorous clade, includes Paracynarctus and Cynarctus in the Hemingfordian through Clarendonian, and represents a larger size group than the Phlaocyonini, although there is a tendency toward size reduction among advanced species of Cynarctus. The cynarctines feature the most bunodont dentition known among canids. The next series of transitional taxa (Metatomarctus, Euoplocyon, Psalidocyon, Microtomarctus, Protomarctus, and Tephrocyon) are of medium size and occupy a pectinated sequence that contains a rather diverse set of dental morphology. These include the most hypercarnivorous borophagine Euoplocyon, the peculiarly trenchant Psalidocyon, and the dwarf lineage Microtomarctus. The next clade, Aelurodontina, is the first major hypercarnivorous group and is represented by Tomarctus and Aelurodon in the Barstovian and Clarendonian. The aelurodontines evolve around a more consistent theme of increasingly more hypercarnivorous dentitions with strong premolars, forming a rather linear series from Tomarctus to various species of Aelurodon. The terminal clade Borophagina, sister to the Aelurodontina, begins with the mostly mesocarnivorous Paratomarctus and Carpocyon in the late Barstovian through late Hemphillian. The terminal species of Carpocyon, C. limosus, shows some hypocarnivorous adaptations. Protepicyon in the Barstovian initiates the hypercarnivorous trend in the terminal clade. Epicyon, the largest known canid, is the dominant predator in the Clarendonian and Hemphillian. Finally, an enlarged concept of Borophagus consists of a series of pectinated species terminated by B. diversidens in the late Blancan. Epicyon and Borophagus are the most highly evolved in their capacity to crush bones. Phylogenetic reconstruction was greatly aided by the high quality of fossil records and the large number of transitional forms. The latter ensures a morphological continuity that facilitates the identification of homoplasies that otherwise could easily be mistaken as synapomorphies. Confidence in the phylogeny is further enhanced by a high congruence between the cladistic rank and the stratigraphic sequence. The temporal and morphological continuity in many borophagine lineages also permits further postulation about their evolutionary processes, such as cladogenetic and anagenetic events. Our considerably enlarged concept of the Borophaginae indicates a much broader trophic diversity than has previously been envisioned. In addition to the commonly recognized hyenalike forms, members of the Borophaginae acquired a wider spectrum of morphologies that surpassed either the hesperocyonine or canine canids. The Borophaginae played broad ecological roles that are performed by at least three living carnivoran families, Canidae, Hyaenidae, and Procyonidae"--P. 9-10.Item Phylogenetic systematics of the North American fossil Caninae (Carnivora, Canidae). (Bulletin of the American Museum of Natural History, no. 325)([New York] : American Museum of Natural History., 2009) Tedford, Richard H.; Wang, Xiaoming, 1957-; Taylor, Beryl E.The canid subfamily Caninae includes all the living canids and their most recent fossil relatives. Their sister taxon is the Borophaginae with which they share an important modification of the lower carnassial, namely the presence of a bicuspid talonid, which gives this tooth an additional function in mastication. Contributing to this function is the enlargement of the posterolingual cingulum of M1 and development of a hypocone. The Caninae diverged from the Borophaginae in the narrowing and elongation of the premolars separated by diastemata and placed in a shallow ramus and narrow muzzle. These latter features allow the Caninae to be recognized in the fossil record as early as the beginning of the Oligocene (34 Ma) and constitute evidence that they represent a monophyletic group. In striking contrast to the history of the Borophaginae, the Caninae remain confined to a closely similar group of fox-sized species (Leptocyon spp.) throughout the Oligocene and showing very limited cladogenesis into the end of the medial Miocene (12 Ma), a span that saw marked adaptive divergence in the Borophaginae and the origin of all its major clades. By 12 Ma (beginning of the Clarendonian Land Mammal age) few fox-sized borophagines remained and most of those held hypocarnivorus adaptations. At that point the Vulpini appear both as mesocarnivores (Vulpes spp.) and hypocarnivores (Metalopex spp.) reproducing, on a much smaller scale, the range of adaptations shown in the initial radiation of the Borophaginae. By the end of the Clarendonian (9 Ma) the first members of the tribe Canini appear. Initially this group was represented by the genus Eucyon, largely by a single widespread North American species E. davisi. Our cladistic analysis predicts that the roots of the South American clade subtribe Cerdocyonina, sister taxon to E. davisi and Canis species (together, subtribe Canina), must also have been present, but taxa representing this group do not appear in the North America record until the earliest Pliocene (latest Hemphillian, 5 Ma). Species of three genera (Cerdocyon, Chrysocyon, and possibly Theriodictis), now confined to South America, appear in the fossil record of the southern United States and northern Mexico prior to and just after the opening of the Panamanian Isthmus (ca. 3 Ma), indicating that important cladogenesis within the South American clade took place in North America. Species of Eucyon make their appearance in the Old World in the late Miocene, and E. davisi has a Pliocene record in Asia. Species of this genus undergo a modest adaptive radiation in Eurasia during the Pliocene. In the late Miocene and early Pliocene two species of Canis appear in North America (C. ferox and C. lepophagus), representing the initial cladogenesis within the genus. These animals are all coyote-sized and represent a broadening of body size range within a mesocarnivorous dental adaptation. Toward the end of the Pliocene and into the Pleistocene in North America a curious and rare group of jackal-like species (C. tho¨oides, C. feneus, and C. cedazoensis) seem to form an endemic clade arising near C. lepophagus. These taxa are dentally similar to jackals, especially C. aureus, but share no synapomorphies with them. The early cladogenesis of Canis in the Pliocene of North America produced a somewhat larger form, C. edwardii, that appears in the late Blancan at ca. 3 Ma. It also seems to have a sister relationship with C. lepophagus and with the coyote C. latrans, which appears much later in the record (late Irvingtonian) and quickly becomes distributed across the United States. The golden jackal (C. aureus) shares synapomorphies with the coyote and C. edwardii but does not appear in the fossil record until the early Pleistocene of North Africa. Canis edwardii is extinct by the end of the Irvingtonian. Large wolflike species of Canis seem to be the products of evolution in Eurasia. They appear early in the North American record as immigrants of the crown group of Canis that augment the essentially stem group native species of the New World. The first of these is Canis armbrusteri, which appears early in the Irvingtonian, initially in the Southwest but later in the eastern United States where it survived into the early Rancholabrean of Florida. This is a large wolf, a sister taxon of C. lupus, whose appearance early in the Pleistocene predates the earliest midcontinent occurrence of C. lupus by nearly 1 m.y. In the New World C. armbrusteri gave rise to the native dire-wolf (C. dirus), as evidenced by intergrading morphologies of late Irvingtonian examples that show the transformation to the more hypercarnivorous giant form. The earliest evidence of C. dirus is in the midcontinent and it appears to have displaced C. armbrusteri into the eastern part of the continent while it expanded westward and particularly southward into South America during the late Pleistocene. Canis lupus itself does not appear in midlatitude North America until the late Rancholabrean (0.1 Ma, last glacial cycle), although it was a resident of Arctic North America since the mid-Pleistocene (ca. 0.8 Ma). North America has a limited record of canine diversity during the Pleistocene. Most clades of vulpines and canines that reached the Old World during that span underwent significant cladogenesis so that the canid fauna of Eurasia was always more diverse than that of the New World. From time to time waifs from the Old World centers of origin wandered south into midcontinent North America to briefly enrich the fossil record: Xenocyon spp. in the late Irvingtonian; Cuon alpinus and Canis lupus in the late Rancholabrean, along with the living fox species Vulpes vulpes (late Rancholabrean) and perhaps the swift-fox earlier in the Pleistocene. The center of evolution of the Caninae thus shifted to Eurasia and to South America when avenues of dispersal to those continents were available at the end of the Cenozoic. Because of the diversity of Old World forms that became resident in North America, our analysis of the New World fauna has been expanded to include relevant Old World taxa and to present a broader phylogenetic reconstruction than could be offered only on the basis of strictly New World evidence. This expanded view brings in a greater diversity of morphology, which allows us to better separate homoplasy from true homology. We have considered only Old World taxa that are represented by the most complete material so that missing data are kept to a minimum in our analysis. This still affords sufficient taxa so that the major structure of the phylogeny of Canis can be discerned. Our cladistic analysis found two robustly recognized crown clades within Canis: the mesocarnivorous lupus clade, and the hypercarnivorous Xenocyon clade. The first contains the wolf, C. lupus, and its sister taxon C. armbrusteri + C. dirus, with the latter showing some dental features related to hypercarnivory as an autapomorphy. The Chinese late Pliocene wolf C. chihliensis appears to be a stem group in the Lupus clade and may be closely allied to C. armbrusteri. The Xenocyon clade is also Eurasian in origin and is marked by character reversals to states primitive within Canis. Its earliest record is in the medial Pliocene of eastern Asia (Xenocyon dubius), after which it dispersed to western Eurasia in the early Pleistocene (X. lycaonoides). In the Pleistocene Xenocyon achieved a Holarctic distribution including midlatitide North America (X. texanus and X. lycaonoides). During this episode of expansion the sister taxa Cuon and Lycaon arose in Eurasia and Africa, respectively, most likely from isolated Xenocyon populations. In the latest Pleistocene Cuon alpinus expanded its range into the middle latitudes of the New World. A number of Pliocene and Pleistocene wolf and coyote-sized Eurasian Canis species (C. arnensis, C. etruscus, C. palmidens, C. mosbachensis, and C. variabilis) were included in our cladistic analysis, but the relationships of those forms were difficult to resolve beyond their paraphyletic relationship to the crown clade.Item Phylogeny of the Caninae (Carnivora, Canidae) : the living taxa. American Museum novitates ; no. 3146(New York, N.Y. : American Museum of Natural History, 1995) Tedford, Richard H.; Taylor, Beryl E.; Wang, Xiaoming, 1957-"Fifty-seven characters of the skull, mandible, dentition, and postcranium distributed among 122 character states obtained from specimens representing 15 living genera of the canid subfamily Caninae (67% of which are monotypic) were subjected to cladistic analysis assisted by a maximum-parsimony computer program (HENNIG86). The program found a single tree, 90 steps in length with a consistency index of 65 and retention index of 78. The reconstruction delineates two sister taxa: the foxlike tribe Vulpini, and the wolflike and South American taxa, tribe Canini. This division is also supported by karyological and biomolecular studies although the composition of each group varies with the evidence used. The osteological evidence leads to a more fully resolved relationship than presently available from other systems. Problem taxa include the foxes Urocyon and Otocyon, considered sister taxa, and members of the Vulpini clade osteologically, but either as members of the Canini clade (with Fennecus) on chromosome morphology or in a basal unresolved multichotomy with other canines on allozyme evidence. More contentious is the position of the Asian raccoon-dog Nyctereutes, placed as a sister taxon of the South American crab-eating 'fox' Cerdocyon in our analysis but allied with Vulpes on karyological evidence or a part of the basal canine multichotomy with regard to the allozyme results. The South American bush-dog Speothos, a hypercarnivore, is placed on osteological grounds in a clade with the rest of the South American genera in agreement with chromosome evidence although allozymes relate it to the Canis group. Despite these individual cases there is reasonable concordance in the conclusions drawn from the three lines of phyletic inference. Previous neontological and paleontological studies of canines have not clarified relationships within this group"--P. [1].Item Review of some Carnivora (Mammalia) from the Thomas Farm local fauna (Hemingfordian, Gilchrist County, Florida). American Museum novitates ; no. 2610(New York, N.Y. : American Museum of Natural History, 1976) Tedford, Richard H.; Frailey, David."Species of the carnivore genera Cynelos (Amphicyonidae), Hemicyon (Ursidae), and Euoplocyon (Canidae) are recognized in the medial Hemingfordian Thomas Farm local fauna. In addition early Mustelinae are indicated by the ramus referred to Miomustela(?) by Olsen. The record of the latter and that of Hemicyon and Euoplocyon represent the earliest occurrences of each taxon in North America; all four records constitute the first recognized occurrence of each in eastern North America. The Thomas Farm Cynelos, Hemicyon and musteline are very closely related to European representatives of these taxa from the early Burdigalian, confirming previous correlations of the Burdigalian age with at least part of the Hemingfordian 'age' "--P. [1].Item Sthenurus (Macropodidae, Marsupialia) from the Pleistocene of Lake Callabonna, South Australia. Bulletin of the AMNH ; no. 225([New York] : American Museum of Natural History, 1995) Wells, R. T. (Roderick Tucker), 1941-; Tedford, Richard H."This study of the skeletal remains of three species of the extinct kangaroo Sthenurus (Sthenurinae: Macropodidae) from Lake Callabonna, northern South Australia, details the comparative osteology of these taxa and their functional, anatomical, and phylogenetic implications. Geological study of the locality assigns these fossils to the base of the Quaternary sequence in laminated clay and fine sands that are part of a unit correlated with the Millyera Formation of the Lake Frome area immediately south of Lake Callabonna. These deposits accumulated in a lake of variable salinity, several times the size of the present Callabonna playa. The plant remains associated with the Callabonna Fauna suggest a more arborescent flora than that near the present-day salina but one containing taxa that still exist in the surrounding region. These facts indicate a seasonal climate with fluctuating water table but a regionally more effective rainfall than at present. Direct C14 dating of wood from the Sthenurus-bearing deposits establishes an age beyond the limit of the radiocarbon method and regional geological correlations suggest a medial Pleistocene age within the span 0.2-0.7 Ma as most likely for the sthenurine kangaroos and associated large marsupials and ratite birds that constitute the Callabonna Fauna. Like the other large-bodied vertebrates at Lake Callabonna, the Sthenurus species were mired in the clays while attempting to cross the floor of the lake during low-water or dry times. This mode of accumulation has yielded an unprecedented opportunity for comparative study of the remains of individual animals. Three closely allied sthenurine species coexisted at Lake Callabonna: a new giant taxon, Sthenurus stirlingi, a somewhat smaller S. tindalei, and the considerably smaller S. andersoni. Strong sexual dimorphism is shown by the larger taxa, resulting in size overlap between individuals, but morphological criteria identify the sexes and taxa involved. Comparative osteology of these Sthenurus species with Macropus giganteus emphasizes how different they are from the living gray kangaroo, especially in their short, deep skulls, long front feet with very reduced lateral digits, and the virtually monodactyl hind feet. These distinctions, and many others, limit functional analysis for lack of a closely comparable living model. We have nevertheless tried to gather the evidence into a coherent picture of Sthenurus as a living animal. The cheek teeth of these Sthenurus species fit the browsing grade of Sanson's (1978) model. The slender forelimbs are better fitted for feeding than locomotor function. These limbs could be raised above the head, and the hands, with their long phalanges and claws, could have grasped high vegetation. The vertebral column is more rigid than in living kangaroos and flexion is limited, but considerable extension of the anterior pan of the body could have been retained as an important function in reaching for high browse. The pelvis is modified for flexion and adduction of the thigh, which would support a bulky animal while standing or elevating the body. The hind limb is more massive than in Macropus, but the elements are of similar proportion and there appears to be greater emphasis on the elastic properties of the tendons and ligaments to augment muscular action across joints, especially the knee and plantar parts of the pes. We conclude that species of Sthenurus, like other sthenurines, were bulky, browsing kangaroos that sacrificed quadrupedal or pentapedal movement for greater dependence on bipedal saltation and extension of the body and forelimbs for higher browsing. This diverse subfamily was a prominent element in Pleistocene faunas in Australia. Several taxa of comparable size were often found together which suggests partitioning of the browsing feeding mode--a broad niche that seems to contain few adherents among living large kangaroos"--P.3.Item Vertebrate fossils and their context : contributions in honor of Richard H. Tedford. Bulletin of the AMNH ; no. 279(New York, NY : American Museum of Natural History, 2003) Flynn, Lawrence J. (Lawrence John), 1932-; Tedford, Richard H.; Novacek, Michael J.; Woodburne, Michael O.; Hunt, Robert M., Jr., 1941-; Gould, Gina C.; Gaffney, Eugene S.; Qiu, Zhanxiang.; Demere, Thomas A.; Berta, Annalisa.; Adam, Peter J.; Wang, Banyue.; Baskin, Jon A.; Van Valkenburgh, Blaire.; Sacco, Tyson.; Wang, Xiaoming, 1957-; Stevens, Margaret Skeels.; Stevens, James Bowie.; Lindsay, Everett H.; Whistler, David P.; Lander, E. Bruce.; Morgan, Gary S.; Lucas, Spencer G.; Ferrusquia-Villafranca, Ismael.; Webb, S. David (Sawney David), 1936-; Beatty, Brian Lee.; Poinar, George.; MacFadden, Bruce J.; Repenning, Charles A.; Turnbull, William D.; Lundelius, Ernest L.; Archer, Michael, 1945-; Pledge, Neville S.; Rich, Thomas H. V.; Darragh, Thomas A.; Rich, Pat Vickers.; Ye, Jie.; Meng, Jin (Paleontologist); Wu, Wenyu.; Qiu, Zhuding.; Li, Chuan-Kuei.; Winkler, Alisa J.; Downs, Will.; Holec, Peter.; Emry, Robert J.; McKenna, Malcolm C.; Lofgren, Donald L.; Tong, Haiyan.