Ranch Locality Research Articles

An exquisitely preserved skeleton of Eoarctos vorax (nov. gen. et sp.) from Fitterer Ranch, North Dakota (early Oligocene) and systematics and phylogeny of North American early arctoids (Carnivora, Caniformia)

ABSTRACT An exquisitely preserved male skeleton of an early arctoid, Eoarctos vorax new genus and species, provides a unique window into the origin and early divergence of Carnivora. Recovered from the Fitterer Ranch locality in the early Oligocene (Orellan to Whitneyan North American Land Mammal ages) Brule Formation of southwestern North Dakota (∼32 Ma), the new arctoid offers an opportunity to evaluate the fundamental relationships of the caniform (dog-like) carnivorans. Eoarctos vorax possesses a suite of plesiomorphic characters inherited from its miacid ancestors, making it an ideal model for ancestral arctoids. We present a comprehensive treatment of E. vorax, combining traditional description with photographic documentation, microCT, laser scans, and photogrammetry. Showing its plesiomorphic morphology, Eoarctos vorax is scansorial, somewhat like a modern raccoon, retaining the ability to climb trees and lacking cursorial adaptations present in the early canid Hesperocyon. However, E. vorax shows clear signs of durophagous cranio-dental morphology, presumably for an obligatory diet of mollusks, with frequent damage to shell-crushing premolars, plus associated dental infections. We review several other key North American early arctoids and present total-evidence (nuclear DNA and discrete morphological characters) Bayesian and parsimony analyses of Caniformia phylogeny, including extinct stem taxa plus a living member of all modern families. We recognize an endemic North American ursoid clade, Subparictidae, which includes Eoarctos vorax. We demonstrate the importance of North America as an early cradle of evolution for caniform carnivorans, including early precursors of Canidae, Amphicyonidae, Ursidae, and Pinnipedia.

Paleontology and Geology of the Badwater Creek Area, Central Wyoming. Part 21. Natrona, a New Genus of Rodent, Family Sciuravidae (Mammalia)

A new small sciuravid rodent, Natrona natronensis, new genus and species, from Uintan and Duchesnean deposits in the Wagon Bed Formation at the Hendry Ranch locality in central Wyoming exhibits some morphological parallelism in the structure of its P4 to the M1 of the more derived cricetid rodents. Other occurrences of this new lineage may be from the Eocene of Trans-Pecos Texas and Lac Pelletier, Saskatchewan, Canada.

An avian eggshell from the Brule Formation (Oligocene) of North Dakota

Avian remains are rare from Paleogene sediments in the Great Plains region of North America, especially those that can be identified taxonomically. Here, we describe avian eggshell fragments from the Fitterer Ranch locality within the Oligocene Brule Formation of North Dakota and assign them to ootaxonomy. The specimen examined (NDGS 1934) exhibits low tubercles that form undulating surface ornamentation; 650–900-µm-thick eggshell composed of three structural layers of calcite; abrupt transition between mammillary and continuous layers; prisms visible in continuous layer; squamatic texture primarily visible in lower half of continuous layer; and mammillary-to-total shell thickness ratio of 1:2.70–2.75. Due to this unique combination of characters, we establish the new oospecies Metoolithus jacksonae, oosp. nov. This new oospecies extends both the geographic and temporal ranges of the oogenus Metoolithus and demonstrates the importance of oological research in revealing the diversity of Oligocene avifauna in this region.http//zoobank.org/urn:lsid:zoobank.org:pub:96D66B54-9FBC-4373-B66B-C2CD8C627CCSUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Lawver, D. R., and C. A. Boyd. 2018. An avian eggshell from the Brule Formation (Oligocene) of North Dakota. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1486848.

Early Pleistocene leporids (Mammalia, Lagomorpha) of Roland Springs Ranch Locality 1 and the rise of North American Quaternary leporines

Roland Springs Ranch Locality 1 (RSR-1) is an early Pleistocene vertebrate faunal locality on the Rolling Plains of Scurry County, Texas. Leporid remains are common among material recovered from ongoing, systematic excavations at RSR-1. The size and morphology of collected lower third premolars were utilized to identify the leporid taxa present at RSR-1. The resulting sample assemblage is unique in composition, including: Hypolagus gidleyi, Hypolagus spp. (small form), Notolagus lepusculus, Nekrolagus progressus (including forms with the Lepus pattern), and Aztlanolagus agilis. The biochronology of such a combination of taxa indicates placement near the boundary between the early and late subdivisions of the Blancan Land Mammal Age, generally consistent with the current interpretation of RSR-1.The RSR-1 sample is considered against the backdrop of Neogene-Quaternary faunal turnover that included the extinction of the Archaeolaginae and radiation within the extant subfamily, Leporinae. Leporid abundance during the late Pliocene-early Pleistocene (Blancan Land Mammal Age) of North America marks peak species richness for the rabbit family. Late Miocene-early Pleistocene changes in climate and grassland composition and structure in North America coincide with this pivotal period of leporid natural history. Environmental shifts potentially created a period of expanded physical heterogeneity and niche diversification that provided the ecological conditions for archaeolagines, Blancan leporines, and emerging derived, modern type (Lepus pattern) leporines to widely coexist. The Lepus pattern of extant cottontails and jackrabbits, is hypothesized as a competitive advantage initiated by grassland change and particularly suited for the arid and open Quaternary Great Plains.

Sedimentology, stratigraphy, and paleoclimate at the late Miocene Coffee Ranch fossil site in the Texas Panhandle

The late Miocene Coffee Ranch fossil assemblage contains some of the earliest evidence of C4 herbivory in North America. However, little is known regarding the environmental setting associated with the fauna, and a general lack of detailed paleoclimate data exists for the late Miocene from the North American continental interior. In this study, the sedimentary environments, stratigraphy, geochronology, and paleoclimate are interpreted for a series of outcrops of the late Miocene Ogallala Formation in the Texas Panhandle that includes the Coffee Ranch locality. Updated magnetostratigraphy coupled with previously published geochronology indicates that all exposed strata were deposited over a ~277kyr interval within chron C3An.2n from ~6.42–6.70Ma. Depositional environments include fluvial channels, floodplain ponds, floodplain paleosols, eolian paleosols, riverine tufa, and reworked volcanic ash. Trunk and tributary fluvial channels are differentiated using channel dimensions, sedimentary structures, and bounding surface architecture, and indicate seasonally-variable discharge. Paleosols from nine pedofacies are described and preserve a spectrum of weakly developed Entisols and weakly to moderately mature Inceptisols and Vertisols. Constitutive mass-balance calculations reveal that mature paleosols formed along distinct pedogenic pathways. Calcic Vertisols accumulated pedogenic carbonate and exhibited either net volumetric dilation or collapse as a result of mineral weathering. In contrast, non-calcic Vertisols show patterns of decalcification and variable degrees of volumetric dilation and collapse. The presence of the paleosols described in this study requires paleoprecipitation between of 900–1150mm/yr—approximately double modern values—and a westward shift of the continental udic-ustic soil moisture boundary by ~400km during the late Miocene. This finding suggests that climates in the southern midcontinent were not sufficiently arid to select for C4 photosynthetic pathways over C3 photosynthesis in the late Miocene.

Effects of Habitat Alteration on the Epizootiology ofMyxobolus cerebralis, the Causative Agent of Salmonid Whirling Disease

Whirling disease, caused by the myxozoan parasite Myxobolus cerebralis , is a serious health threat to salmonid fish and its control remains problematic. The parasite has a 2-host life cycle involving a salmonid and the aquatic oligochaete Tubifex tubifex . A commonly used strategy to control parasites that requires an obligatory invertebrate host is to eliminate or reduce the host population size to a point where parasite transmission can no longer occur. Large numbers of T. tubifex are frequently found in degraded habitats that are characterized by an abundance of fine sediments, organic matter, and a lack of aquatic invertebrate diversity. If such environments are rehabilitated, then the normal flora and fauna should re-establish and the numbers of T. tubifex should decline due to their inability to compete with the re-established invertebrates. During an epizootiological study on Rock Creek, located in west-central Montana, 2 opportunities were available to examine the effects of habitat restoration on the transmission of M. cerebralis . The Puyear Ranch re-establishment project was a major endeavor conducted on the main channel of Rock Creek, a little more than midway upstream. Another significant restoration was conducted on Upper Willow Creek, a tributary of Rock Creek, located closer to the headwaters. Sentinel trout studies, along with examining T. tubifex for the parasite and measuring various water-quality parameters, revealed that the restoration of the Puyear Ranch locality had no significant effect on reducing the intensity of M. cerebralis in trout. This was likely due to the restored area being located mid-river, just downstream from a "hot spot" of infected T. tubifex . In comparison, there was a significant reduction in the intensity of M. cerebralis in sentinel fish after the Upper Willow Creek restoration project was completed. Unlike the Puyear Ranch locality, there was no hot spot of infected T. tubifex above the area rehabilitated on Upper Willow Creek. Further, the relative abundance of T. tubifex and M. cerebralis -infected worms was reduced. Although further study is needed, it appears that habitat rehabilitation can reduce the transmission of M. cerebralis . Since the triactinomyxon stage of the parasite released from T. tubifex (which infects trout) can float for many kilometers, the rehabilitation of a hot spot may reduce the infection of trout downstream where they inhabit a healthy environment with no M. cerebralis -infected T. tubifex in the vicinity. Thus, rehabilitation of a relatively small area could significantly affect the drainage for many kilometers beyond the improved habitat.

A new neosuchian crocodyliform from the Lower Cretaceous (late Aptian) Twin Mountains Formation of North-Central Texas

ABSTRACT A new fossil crocodyliform, Paluxysuchus newmani, gen. et sp. nov., is established on the basis of a nearly complete skull from the Lower Cretaceous (late Aptian) Twin Mountains Formation of north-central Texas. Partially articulated and disarticulated cranial material representing two individuals was recovered from the Jones Ranch locality in close association with the sauropod Paluxysaurus jonesi. The holotype skull is nearly complete, missing the premaxillae, left palatine, and pterygoids, and does not preserve the choanal region. This taxon is notable for having its frontal separated medially from the orbital margin, an extremely elongate anterolateral process of the postorbital, large and rounded supratemporal fenestrae, and a narrow, rod-like posterior ramus of the jugal. These features indicate affinities with goniopholidids, pholidosaurids, and thalattosuchians. A phylogenetic analysis places Paluxysuchus newmani deep within Neosuchia as the sister taxon to the clade that includes Goniopholididae and Eusuchia. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Vegetative and Reproductive Morphology of an Extinct Early Cretaceous Member of Platanaceae from the Braun’s Ranch Locality, Kansas, U.S.A.

Abstract Early Cretaceous platanoid species are presented, based on observations of isolated organs from the Braun Ranch locality, Kansas, and the Yankee Hill I locality, Nebraska. Approximately 500 leaf specimens and 238 infructescence specimens have been studied in detail. The reproductive axis may contain up to 37 sessile, globose infructescences. Fruits are small achenes and lack dispersal hairs. The leaves are typically three-lobed, with basal or suprabasal actinodromous or palinactinodromous venation. Secondary venation is dominantly craspedodromous. Typically, one secondary vein extends into each tooth and is accompanied by tertiary or higher-order veins, which form a series of ascending loops. Tertiary veins are percurrent, with those in the axils of primary-primary and primary-secondary veins forming a V-shaped pattern. Conically inflated petiole bases are hollow and enclose axillary buds. Stipules are triangular and small and are observed only on immature leaves. The repeated and common co-occur...

Rhynchotherium falconeri (Proboscidea, Gomphotheriidae) from 111 Ranch, southeastern Arizona with a discussion of the genus

ABSTRACT A mandible and partial skeleton of Rhynchotherium falconeri is described from late Pliocene deposits of the 111 Ranch Locality in southeastern Arizona. The morphology of the mandible and m3 of the 111 Ranch individual is consistent with other specimens of Rhynchotherium and compares closely with previously reported R. falconeri from Arizona, as well as R. simpsoni from Florida. The 111 Ranch specimen is the basis for only the second description of postcranial material for the genus Rhynchotherium, and adds important morphological and ontogenetic attributes to this taxon. A morphometric analysis of specimens including the genotype indicates several junior synonyms are represented and the type specimen for the genus is no longer valid. A suggestion is made to raise F:AM 18225 to type status.

Early Cretaceous angiosperm leaves from the Dakota Formation, Braun Ranch locality, Kansas, USA

Early Cretaceous angiosperm leaves from the Dakota Formation, Braun Ranch locality, Kansas, USA

Ostracodes from the Naco Formation (Upper Carboniferous) at the Kohl Ranch locality, central Arizona

The Kohl Ranch locality in the Naco Formation (Upper Carboniferous, Desmoinesian) of central Arizona contains an ostracode fauna of 13 species of which three are left in open nomenclature because of inadequate materials; all of the others have been previously described. This fauna is strongly dominated by Hollinella (Hollinella) bassleri (Knight, 1928), Cavellina pulchella Coryell, 1928, Bairdia whitesidei Bradfield, 1935, and Bairdiacypris (Fabalicypris) regularis Cooper, 1946. Present in moderate numbers are Amphissites (Amphikegelites) roundyi Knight, 1928, Moorities minutus Warthin, 1930, and Healdia simplex Roundy, 1926. Pseudobythocypris tomlinsonella Cooper, 1946, Bairdia hoxbarensis Harlton, 1927, Sulcella sulcata Coryell and Sample, 1932, and species of Oliganisus, Sansabella and Chamishaella are represented by only small numbers of specimens. The dominant and moderately abundant species indicate a shallow, offshore environment of deposition. The known geographical range of all species present in the fauna is extended into central Arizona.

Nacocrinus elliotti, a new pachylocrinid from the Naco Formation (Pennsylvanian, Desmoinesian) of central Arizona

Nacocrinus elliotti new genus, new species, is reported from the beta member of the Naco Formation (Pennsylvanian, Desmoinesian) at the Kohl Ranch locality in central Arizona. This is the first pachylocrinid reported from the Naco Formation.

Cephalopod predation On a Desmoinesian brachiopod from the Naco Formation, central Arizona

The beta member (Brew, 1970) of the Naco Formation at Kohl Ranch, central Arizona, has yielded an extensive invertebrate fauna and has been a collecting site for amateurs and paleontology classes for many years. Brew and Beus (1976) documented a diverse fauna of brachiopods, bivalves, gastropods, crinoids, and a conularid and dated it as Middle Pennsylvanian (Desmoinesian) in age. In addition, Webster (1981) has described the crinoids, and undescribed bryozoans, nautiloids, edrioasteroids, and sharks have been collected from the locality. Despite the unusual diversity and abundance of the invertebrates at this locality, there is almost no evidence of predation. Many of the biconvex brachiopods show unrepaired crushing similar to that reported by Alexander (1981) in a similar brachiopod fauna from the Upper Mississippian (Chesterian) Chainman Shale of west-central Utah. This damage was attributed to predation by durophagous sharks by Alexander; however, work by Elliott and Bounds (1987) suggests that in the Naco Formation, at least, this damage was more likely to have been caused by lithification of the surrounding sediments. However, one brachiopod from the Kohl Ranch locality does show repaired damage to both valves that was clearly caused by the unsuccessful attack of a predator. This specimen has been deposited at the Museum of Northern Arizona (MNA N8036).

Causes of damage to brachiopods from the Middle Pennsylvanian Naco Formation, central Arizona

The Kohl Ranch locality in the Naco Formation of central Arizona has yielded an abundant and diverse fauna including eight genera of brachiopods and four of sharks including Cochliodus. The most abundant brachiopod, Composita subtilita, was analyzed for predation damage and of 935 specimens 503 (53.7%) were found to show the type of unrepaired crushing previously attributed to shark predation. Reconstruction of the jaw of Cochliodus, however, suggests that it may have been a selective feeder similar to the modern Heterodontus and unlikely therefore to have left so many damaged but uningested specimens. Evidence from specimens collected in situ suggests that the damage mostly occurred post-mortem due to the compaction of the sediments and was not due to the sharks who would have comminuted any prey items taken.

Biostratigraphy and magnetostratigraphy, late Pliocene rocks, 111 Ranch, Arizona

Fossiliferous strata exposed along the northwestern flank of Dry Mountain on the 111 Ranch, 27 km southeast of Safford, Graham County, Arizona, were dated by means of isotopic methods and the magnetic-reversal time scale. A 100-m fossiliferous interval contains the later part of the Gauss Chron and the early part (pre-Olduvai) of the Matuyama Chron. Zircon fission-track ages on an ash bed just below the Gauss-Matuyama boundary support this identification. Owing to these age constraints, the fossil mammals at the 111 Ranch locality are all constrained within the later part of the Blancan Mammal Age rather than the latest Blancan and early Irvingtonian, as previously stated in the literature. They are, therefore, synchronous with certain localities (Wolf Ranch and California Inst. Technology) in the Saint David Formation of the San Pedro Valley 130 km to the southwest of Dry Mountain. The horse Nannippus persisted in the 111 Ranch locality at least until the end of the Gauss Chron, in confirmation of data from the San Pedro Valley. A diverse group of equine and asinine equids is evident in the 111 Ranch fauna, which argues for an early divergence of these major branches of horse phylogeny. The 111 Ranch fauna records the first appearance of three neotropical immigrants in the southwest, including the sloth Glossotherium , the glyptodont Glyptotherium , and the capybara Neochoerus . A palearctic immigrant, the vole Synaptomys , is also present.

LOWER PALEOZOIC WEDGE EDGES IN SOUTH-CENTRAL NEW MEXICO: NEW CONTROL

A thin sequence of Cambrian and Ordovician beds lying on Precambrian granite and overlain by Pennsylvanian Magdalena beds exists at the Eaton ranch locality along the southeastern edge of the San Mateo Mountains. The section includes representatives that are widespread in southern New Mexico: the Bliss formation, El Paso group, and Montoya group. This is the northernmost known occurrence of these rocks in south-central New Mexico. The occurrence suggests that Cambrian-Ordovician strata originally may have extended more directly northwesterly toward similar rocks in northeastern Arizona and northwestern New Mexico. The position of the Montoya on very low beds of the El Paso emphasizes the mid-Ordovician unconformity in the region.

Jurassic stratigraphy of Central Oregon

Ten formations are recognized in the Jurassic marine sequence of central Oregon. Angular unconformities separate these formations from the Paleozoic and Upper Triassic formations below and the Upper Cretaceous above. No marked diastrophism is indicated within the Jurassic sequence, though long intervals of nondeposition are present. A chronologic arrangement of the formations shows four formations in and near the Middle Lias, four in the early Middle Jurassic, one in the early Upper Jurassic, and one in the Upper Jurassic or Cretaceous. A marked threefold lithologic grouping of the sequence is evident but does not correspond to the chronologic arrangement. The oldest lithologic division consists of late Lower Lias shales and sandstones, over 2000 feet thick, at the isolated Donovan Ranch locality in the Silvies River Canyon near Burns. The second lithologic division contains three Lias formations and two early Middle Jurassic formations at the base of the section in the main Jurassic area. It is characterized by thin calcareous formations abounding in well-preserved fossils. The third division includes the remaining part of the Jurassic sequence consisting of two formations of the early Middle Jurassic and one of the early Upper Jurassic, as well as the uppermost formation of uncertain age. It is characterized by thick, noncalcareous formations of sandstone and shale in which fossils are less abundant and not well preserved.